How To Install Docker on Ubuntu 16.04

Adding Docker to an Ubuntu server.

Docker is an open-source software tool designed to automate and ease the process of creating, packaging, and deploying applications using an environment called a container. The use of Linux containers to deploy applications is called containerization. A Container allows us to package an application with all of the parts needed to run an application (code, system tools, logs, libraries, configuration settings and other dependencies) and sends it out as a single standalone package deployable via Ubuntu (in this case 16.04 LTS). Docker can be installed on other platforms as well. Currently, the Docker software is maintained by the Docker community and Docker Inc. Check out the official documentation to find more specifics on Docker. Docker Terms and Concepts

Docker is made up of several components:

  • Docker for Linux: Software which runs Docker containers on the Ubuntu Linux OS.
  • Docker Engine: Used for building Docker images and creating Docker containers.
  • Docker Registry: Used to store various Docker images.
  • Docker Compose: Used to define applications using multiple Docker containers.

 

Some of the other essential terms and concepts you will come into contact with are:

  • Containerization: Containerization is a lightweight alternative to full machine virtualization (like VMWare) that involves encapsulating an application within a container with its own operating environment.

Docker also uses images and containers. The two ideas are closely related, but very distinct.

  • Docker Image: A Docker Image is the basic unit for deploying a Docker container. A Docker image is essentially a static snapshot of a container, incorporating all of the objects needed to run a container.  
  • Docker Container: A Docker Container encapsulates a Docker image and when live and running, is considered a container. Each container runs isolated in the host machine.
  • Docker Registry: The Docker Registry is a stateless, highly scalable server-side application that stores and distributes Docker images. This registry holds Docker images, along with their versions and, it can provide both public and private storage location. There is a public Docker registry called Docker Hub which provides a free-to-use, hosted Registry, plus additional features like organization accounts, automated builds, and more. Users interact with a registry by using Docker push or pull commands. Example:

docker pull registry-1.docker.io/distribution/registry:2.1.

  • Docker Engine: The Docker Engine is a layer which exists between containers and the Linux kernel and runs the containers. It is also known as the Docker daemon. Any Docker container can run on any server that has the Docker-daemon enabled, regardless of the underlying operating system.
  • Docker Compose: Docker Compose is a tool that defines, manages and controls multi-container Docker applications. With Compose, a single configuration file is used to set up all of your application’s services. Then, using a single command, you can create and start all the services from that file.
  • Dockerfiles: Dockerfiles are merely text documents (.yaml files) that contains all of the configuration information and commands needed to assemble a container image. With a Dockerfile, the Docker daemon can automatically build the container image.

    Example: The following basic Dockerfile sets up an SSHd service in a container that you can use to connect to and inspect other containers volumes, or to get quick access to a test container.

FROM ubuntu:16.04
RUN apt-get update && apt-get install -y openssh-server
RUN mkdir /var/run/sshd
RUN echo 'root:screencast' | chpasswd
RUN sed -i 's/PermitRootLogin prohibit-password/PermitRootLogin
yes/' /etc/ssh/sshd_config
# SSH login fix. Otherwise user is kicked off after login
RUN sed 's@session\s*required\s*pam_loginuid.so@session optional
pam_loginuid.so@g' -i /etc/pam.d/sshd
ENV NOTVISIBLE "in users profile"
RUN echo "export VISIBLE=now" >> /etc/profile
EXPOSE 22
CMD ["/usr/sbin/sshd", "-D"]

Docker Versions

There are three versions of Docker available, each with its own unique use:

  • Docker CE is the simple, classic Docker Engine.
  • Docker EE is Docker CE with certification on some systems and support by Docker Inc.
  • Docker CS (Commercially Supported) is kind of the old bundle version of Docker EE for versions <= 1.13.

We will be installing Docker CE.

 

Docker logo

Step 1 — Checking Prerequisites

To begin, start with the following server environment: 

  1. 64-bit Ubuntu 16.04 server
  2. Logged in as the root user
Important:
Docker on Ubuntu requires a 64-bit architecture for installation and, the Linux Kernel version must be 3.10 or above.

Before installing Docker, we need to set up the repository which contains the latest version of the software (Docker is unavailable in the standard Ubuntu 16.04 repository). Adding the repository allows us to easily update the software later as well.

Step 2 — Installing Docker

The next step is to remove any default Docker packages from the existing system before installing Docker on a Linux VPS. Execute the following commands to start this process:

root@test:~# apt-get remove docker docker-engine docker.io lxc-docker
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package 'docker-engine' is not installed, so not removed
Package 'docker' is not installed, so not removed
Package 'docker.io' is not installed, so not removed
E: Unable to locate package lxc-docker

Note:
In certain instances, a specific variant of the linux kernel is slimmed down by removing less common modules (or drivers). If this is the case, the “linux-image-extra” package contains all of the “extra” kernel modules which were left out. Use this command to re-add them: root@test:~# sudo apt-get install linux-image-extra-$(uname -r) linux-image-extra-virtual

Step 3 — Add required packages

Now, we need to install some required packages on your system. Run the commands below to accomplish this:

root@test:~# apt-get install curl apt-transport-https ca-certificates software-properties-common

Note:
If you get the error: “E: Unable to locate package curl”, Use the commands “curl -V” to see if curl is already installed; if so, move on to step 4.

Step 4 — Verify, Add and Update Repositories

Add the Docker GPG key to your system:

root@test:~# curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
OK

Next, update the APT sources to add the source:

root@test:~# add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu xenial stable" | tee /etc/apt/sources.list.d/docker.list

Run the update again so the Docker packages are recognized:

root@test:~# apt-get update
Get:1 http://security.ubuntu.com/ubuntu xenial-security InRelease [107 kB]
Hit:2 http://us.archive.ubuntu.com/ubuntu xenial InRelease                              
Get:3 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease [109 kB]             
Get:4 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease [107 kB]                 
Fetched 323 kB in 0s (827 kB/s)                             
Reading package lists... Done
E: The method driver /usr/lib/apt/methods/https could not be found.
N: Is the package apt-transport-https installed?
E: Failed to fetch https://download.docker.com/linux/ubuntu/dists/xenial/InRelease  
E: Some index files failed to download. They have been ignored, or old ones used instead.

Note:
If you get the error seen above: “N: Is the package apt-transport-https installed?”, Use the following command to correct this. root@test:~# sudo apt-get install apt-transport-https

Let’s rerun the update:

root@test:~# apt-get update
Hit:1 http://us.archive.ubuntu.com/ubuntu xenial InRelease
Get:2 http://security.ubuntu.com/ubuntu xenial-security InRelease [107 kB]
Get:3 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease [109 kB]        
Get:4 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease [107 kB]                 
Hit:5 https://download.docker.com/linux/ubuntu xenial InRelease
Fetched 323 kB in 0s (656 kB/s)
Reading package lists... Done

Success! Now, verify we are installing Docker from the correct repo instead of the default Ubuntu 16.04 repo:

root@test:~# apt-cache policy docker-ce
docker-ce:
 Installed: (none)
 Candidate: 18.06.0~ce~3-0~ubuntu
 Version table:
    18.06.0~ce~3-0~ubuntu 500
       500 https://download.docker.com/linux/ubuntu xenial/stable amd64 Packages

Step 5 — Install Docker

Finally, let’s start the Docker install:

root@test:~# apt-get install -y docker-ce
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
 aufs-tools cgroupfs-mount libltdl7 pigz
Suggested packages:
 mountall
The following NEW packages will be installed:
 aufs-tools cgroupfs-mount docker-ce libltdl7 pigz
0 upgraded, 5 newly installed, 0 to remove and 0 not upgraded.
Need to get 40.3 MB of archives.
After this operation, 198 MB of additional disk space will be used.
Get:1 http://us.archive.ubuntu.com/ubuntu xenial/universe amd64 pigz amd64 2.3.1-2 [61.1 kB]
Get:2 http://us.archive.ubuntu.com/ubuntu xenial/universe amd64 aufs-tools amd64 1:3.2+20130722-1.1ubuntu1 [92.9 kB]
Get:3 http://us.archive.ubuntu.com/ubuntu xenial/universe amd64 cgroupfs-mount all 1.2 [4,970 B]
Get:4 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 libltdl7 amd64 2.4.6-0.1 [38.3 kB]
Get:5 https://download.docker.com/linux/ubuntu xenial/stable amd64 docker-ce amd64 18.06.0~ce~3-0~ubuntu [40.1 MB]
Fetched 40.3 MB in 1s (38.4 MB/s)    
...
...

Docker should now be installed, the daemon started, and the process enabled to start on boot. Let’s check to see if it’s running:

root@test:~# systemctl status docker
* docker.service - Docker Application Container Engine
  Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
  Active: active (running) since Wed 2018-08-08 13:51:22 EDT; 2min 13s ago
    Docs: https://docs.docker.com
Main PID: 6519 (dockerd)
  CGroup: /system.slice/docker.service
          |-6519 /usr/bin/dockerd -H fd://
          `-6529 docker-containerd --config /var/run/docker/containerd/containerd.toml

Aug 08 13:51:22 test.docker.com dockerd[6519]: time="2018-08-08T13:51:22.192600502-04:00" level=info msg="ClientConn switching balancer to \"pick_first\"" module=grpc
Aug 08 13:51:22 test.docker.com dockerd[6519]: time="2018-08-08T13:51:22.192630873-04:00" level=info msg="pickfirstBalancer: HandleSubConnStateChange: 0xc42020f6a0, CONNECTING" module=grpc
Aug 08 13:51:22 test.docker.com dockerd[6519]: time="2018-08-08T13:51:22.192854891-04:00" level=info msg="pickfirstBalancer: HandleSubConnStateChange: 0xc42020f6a0, READY" module=grpc
Aug 08 13:51:22 test.docker.com dockerd[6519]: time="2018-08-08T13:51:22.192867421-04:00" level=info msg="Loading containers: start."
Aug 08 13:51:22 test.docker.com dockerd[6519]: time="2018-08-08T13:51:22.340349000-04:00" level=info msg="Default bridge (docker0) is assigned with an IP address 172.17.0.0/16. Daemon option --bip can be used to set a preferred IP address"
Aug 08 13:51:22 test.docker.com dockerd[6519]: time="2018-08-08T13:51:22.397715134-04:00" level=info msg="Loading containers: done."
Aug 08 13:51:22 test.docker.com dockerd[6519]: time="2018-08-08T13:51:22.424005987-04:00" level=info msg="Docker daemon" commit=0ffa825 graphdriver(s)=overlay2 version=18.06.0-ce
Aug 08 13:51:22 test.docker.com dockerd[6519]: time="2018-08-08T13:51:22.424168214-04:00" level=info msg="Daemon has completed initialization"
Aug 08 13:51:22 test.docker.com dockerd[6519]: time="2018-08-08T13:51:22.448805942-04:00" level=info msg="API listen on /var/run/docker.sock"
Aug 08 13:51:22 test.docker.com systemd[1]: Started Docker Application Container Engine.
~
~
~
(press q to quit)

Excellent! Good to go!

If Docker is not started automatically after the installation, run the following commands:

root@test:~# systemctl start docker.service
root@test:~# systemctl enable docker.service

Step 6 — Test Docker

Let’s check the new Docker build by downloading the hello-world test image.
To start testing, issue the following command:

 


root@test:~# docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
9db2ca6ccae0: Pull complete
Digest: sha256:4b8ff392a12ed9ea17784bd3c9a8b1fa3299cac44aca35a85c90c5e3c7afacdc
Status: Downloaded newer image for hello-world:latest

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
1. The Docker client contacted the Docker daemon.
2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
   (amd64)
3. The Docker daemon created a new container from that image which runs the
   executable that produces the output you are currently reading.
4. The Docker daemon streamed that output to the Docker client, which sent it
   to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
$ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
https://hub.docker.com/

For more examples and ideas, visit:
https://docs.docker.com/engine/userguide/

Step 7 — The ‘Docker’ Command

With Docker installed and working, now is the time to become familiar with the command line utility. The ‘Docker’ command consists of using Docker with a chain of options followed by arguments. The syntax takes this form:

root@test:~# docker
Usage: docker [OPTIONS] COMMAND
A self-sufficient runtime for containers
Run 'docker COMMAND --help' for more information on a command.


To view all of the available Options and Management Commands, simply type:

docker

To view the switches available for a specific command, type:

docker docker-subcommand --help

Lastly, To view system-wide information about Docker, use:

docker info

Docker is a dynamic, robust and responsive tool that makes it very simple to run applications within a containerized environment. It is portable, less resource-intensive, and more reliant on the host operating system which allows for multiple uses. Overall, Docker is a ‘must have’ system and should be included in your toolkit for automation, deployment, and scaling of your applications!

Our Support Teams are filled with talented admins with an intimate knowledge of multiple web hosting technologies, especially those discussed in this article. If you are uncomfortable walking through the steps outlined here, we are a phone call, chat or ticket away from assisting you with this process. If you’re running one of our fully Managed Cloud VPS Servers, we can provide more information on directly implementing the software described in this article.

 

SQL Databases Migration with Command Line

What if you have dozens of SQL databases and manually backing up/restoring each database is too time-consuming for your project? No problem! We can script out a method that will export and import all databases at once without needing manual intervention. For help with transferring SQL Logins and Stored Procedures & Views take a look at our MSSQL Migration with SSMS article.

1. Open SSMS (Microsoft SQL Server Management Studio) on the source server, log in to the SQL instance and open a New Query window. Run the following query:

SELECT name FROM master.sys.databases

This command will output a list of all MSSQL databases on your server. To copy this list out, click anywhere in the results and use the keyboard shortcut CTRL+A (Command + A for Mac users) to select all databases. After highlighting all the databases right click and select copy.

2. Open Notepad, paste in your results and delete all databases (in the newly copied notepad text) you do NOT wish to migrate, as well as deleting the following entries:

  • master
  • tempdb
  • model
  • msdb

These entries are the system’s databases, and copying them is not necessary. Make sure to delete everything except explicitly the databases you need to migrate.  You should now have a list of all required databases separated by a line. i.e.

  • AdventureWorks2012
  • AdventureWorks2014
  • AdventureWorks2016

3. Save this result on the computer as C:\databases.txt.

4. Create a new Notepad window, copy/paste the following into the document and save it as C:\db-backup.bat

mkdir %systemdrive%\dbbackups
for /F "tokens=*" %%a in (databases.txt) do ( sqlcmd.exe -Slocalhost -Q"BACKUP DATABASE %%a TO DISK ='%systemdrive%\dbbackups\%%a.bak' WITH STATS" )

5. Now that you’ve saved the file as C:\db-backup.bat, navigate to the Start menu and type cmd and right click on Command Prompt to select Run as Administrator.Type the following command:

cd C:\

And hit enter. Afterward, type db-backup.bat and hit enter once again.

At this point, your databases have begun exporting and you will see the percentage progress of each databases export (pictured below).

Command line shows the process of each database that is exported.

Take note of any failed databases, as you can re-run the batch file when it’s done, using only the databases that may have failed. If the databases are failing to back up, take note of the error message displayed in the command prompt, address the error by modifying the existing C:\databases.txt file to include only the failed databases and re-run db-backup.bat until all databases are successfully exported.

 

By now you have the folder C:\dbbackups\ that contains .bak files for each database you want to migrate. You will need to copy the folder and your C:\databases.txt file to the destination server. There are numerous ways to move your data to the destination server; you can use USB, Robocopy or FTP. The folder on the C drive of the destination server should be called C:\dbbackups . It’s important to accurately name the file as our script will be looking for the .bak files here. Be sure that the destination server has your C:\databases.txt file as well, as our script will be looking for the database names here.

 

1. Open a Notepad and copy/paste the following into the document and save it as C:\db-restore.bat

for /F "tokens=*" %%a in (C:\databases.txt) do (
sqlcmd.exe -E -Slocalhost -Q"RESTORE DATABASE %%a FROM DISK='%systemdrive%\dbbackups\%%a.bak' WITH RECOVERY"
)

2. Save the file as C:\db-restore.bat 

3. Navigate to the Start menu and type cmd.

4. Right click on Command Prompt and select Run as Administrator. Type the following command:

cd C:\

and hit Enter. Now type db-restore.bat and hit Enter.

Your databases have now begun importing. You will see the percentage of each databases restoration and the message “RESTORE DATABASE successfully processed” for each database that has been successfully processed.

Take note of any failed databases, as you can re-run the batch file when it’s done, using only the databases that have failed. If the databases are failing to back up, take note of the error message displayed in the command prompt, address the error (you can change the batch file as necessary), modify C:\databases.txt to include only the failed databases and re-run db-restore.bat until all databases are successfully exported.

Congratulations, you have now backed up and restored all of your databases to the new server. If you have any login issues while testing the SQL connections on the destination server, refer to the Migrating Microsoft SQL Logins (anchor link) section of this article and follow the steps therein. To migrate views or stored procedures please refer to the Migrating Views and Stored Procedures section. Every SQL server will have it’s own configurations and obstacles to face but we hope this article has given you a strong foundation for your Microsoft SQL Server Migration.

 

SQL Database Migration with SSMS

Migrating MSSQL between servers can be challenging without the proper guidelines to keep you on track. In this article, I will be outlining the various ways to migrate Microsoft SQL Server databases between servers or instances. Whether you need to move a single database,  many databases, logins or stored procedures and views we have you covered!

There are many circumstances where you will need to move a database or restore databases. The most common reasons are:

 

  • Moving to an entirely new server.
  • Moving to a different instance of SQL.
  • Creating a development server or going live to a production server.
  • Restoring databases from a backup.

 

There are two main ways to move SQL databases. Manually with Microsoft SQL Server Management Studio (SSMS) or with the command line. The method you choose depends on what you need to accomplish. If you are moving a single database or just a few, manually backing up and restoring the databases with SSMS will be the easiest approach. If you are moving a lot of databases (think more than 10) then using the command line method will speed up the process. The command line method takes more prep work beforehand, but if you are transferring dozens of databases, then it is well worth the time spent configuring the script instead of migrating each database individually. If you aren’t sure which method to use, try the manual approach first while you get comfortable with the process. I recommend reading all the way through for a deeper understanding of the methodology.

 

Useful References for Terminology

SSMS – An acronym for Microsoft SQL Server Management Studio.

Source Server – The server or instance you are moving databases from or off.

Destination Server – The server or instance you are moving databases to.

 

Moving SQL databases with the manual method can be very easy. It is the preferred process for transferring a few or smaller databases. To follow this part of the guide, you must have MSSQL, and Microsoft SQL Server Management Studio (SSMS) installed.

 

1. Begin by logging into the Source server (the server you are moving databases from or off of). You will want to open Microsoft SQL Server Management Studio by selecting Start > Microsoft SQL Server >  Microsoft SQL Server Management Studio.

2.Log into the SQL server using Windows Authentication or SQL Authentication.

3. Expand the server(in our case SQL01), expand Databases, select the first database you want to move (pictured below).

Select your database within Microsoft SQL Server Management Studio.

4. Right click on your database and select Tasks then click Back Up.

Back up button in Microsoft SQL Server Management Studio.

5. From here you are now at the Back Up Database screen. You can choose a Backup Type such as Full or Differential, make sure the correct database is selected, and set the destination for the SQL backup. For our example, we can leave the Backup Type as Full.

6. Under Backup Type, check the box for “Copy-only backup.” If you are running DPM or another form of server backup, backing up without the Copy-Only flag will cause a break in the backup log chain.

7. You will see a location under Destination for the path of the new backup. Typically you will Remove this entry then Add a new one to select a folder that SQL has read/write access. Adding a new Backup Destination shows a path similar to the following:

C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\Backup\

This C:\ path is where your stored database backup is. Note this location for later reference, as this is the default path to stored backups and will have to have proper read/write access for SQL services.

Note:
Advanced users may be comfortable leaving the destination as is, provided the permissions are correct on the output folder.

8. Next, append a filename to the end of this path such as AdventureWorks2012-081418.bak – Be sure to end the filename with the extension .bak and select OKSet the file name with the .bak extension in Microsoft SQL Server Management Studio

10. Once you have pressed OK on the Select Backup Destination prompt, you are ready to back up the database! All you need to do now is hit OK, and the database will begin backing up. You will see a progress bar in the bottom left-hand corner, and when the backup is complete, a window will appear saying ‘The backup of database ‘AdventureWorks2012’ completed successfully.

Navigate to the destination path, noted earlier, (in this case C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\Backup\) you will see your newly created file (in this case AdventureWorks2012-081418.bak) – Congratulations! This file is the full export of your database and is ready to be imported to the new server.  If you have more databases, then repeat the steps above for each database you are moving. After copying all database process to the next step of restoring databases to the destination server.

 

You should now have a .bak file of all your databases on the source server. These database files need to be transferred to the destination server. There are numerous ways to move your data to the destination server; you can use USB, Robocopy or FTP. After copying a database you can store it on your destination server,  for our example, we have stored it on the C drive in a folder named C:\dbbackups .

1. Open Microsoft SQL Server Management Studio.

2. Log in to the SQL server using Windows Authentication or SQL Authentication.

3. Expand the server and right click on Databases and select Restore Database.

4. The Restore Database screen looks very similar to the Back Up Database screen.Under Source, you will want to select Device instead of Database. Selecting Device allows you to restore directly from a file. Once you’ve chosen Device, click the browse icon […]

5. Select Add, then navigate to the folder in which your .bak files lives. (In this case, C:\dbbackups).

6. Select the first database .bak you would like to restore and click OK.

Select the .bak file to import your database into the destination server via SSMS.

7. Click OK and now you are ready to import the database. Before importing, let’s take a look at the Options section on the left-hand side. Under Options, you will see other configurations for restoring databases such as Overwrite the Existing Database, Preserve the Replication Settings and Restrict Access to the Restored DatabaseIn this case, we are not replacing an existing database so I will leave all these options unchecked. If you wanted to replace an existing database (for example, the backed up database has newer data than on the destination server or you are replacing a development or production database) then simply select Overwrite the Existing Database.

Note:
Advanced users may be comfortable leaving the destination as is, provided the permissions are correct on the output folder.

8. Clicking OK  begins the restore process as indicated by the popup window that reads ‘Database ‘AdventureWorks2012′ restored successfully.’ You have migrated your database from the source to the destination server.

Repeat this process for each database that you are migrating. You can then update path references in your scripts/application to point to the new server, verify that the migration was successful.

 

After importing your databases if you are unable to connect using your SQL login, you may receive the error ‘Login failed for user ‘example.’ (Microsoft SQL Server, Error: 18456).‘ Because the database is in the Traditional Login and User Model, logins are stored separately in the source server and credentials are not contained within the database itself. From this point on, the destination server can be configured to use the Contained Database User Model which keeps the logins in your database and out of the source server. (You can read more about this here.)Until then, we will have to move and interact with the users as part of the Traditional model. Continue below to proceed with the migration of your SQL users.

Backing up and restoring the databases did move your SQL logins relation to the databases (your logins are still associated with the correct databases with the correct permissions) but the actual logins itself did not transfer to the new server.  You can verify this by opening SSMS on the destination server and navigating to Server > Security > Logins. You will notice that any custom SQL logins you created on the previous server did not transfer over here, but if you go to Server > Databases > Your Database (AdventureWorks2012 in this case) > Security > Users you’ll see the correct login associated with the database.

If you have one or two SQL users, you can just delete the user’s association to the database in Servers > Databases > AdventureWorks2012 > Security > Users, re-create the user in Server > Security > Logins and map it to the proper database.

If you have a lot of logins, you will have to follow an additional process outlined below. To migrate all SQL users, open a New Query window on the source server and run the following script:

SQL Login Script
USE master
GO
IF OBJECT_ID ('sp_hexadecimal') IS NOT NULL
DROP PROCEDURE sp_hexadecimal
GO
CREATE PROCEDURE sp_hexadecimal
@binvalue varbinary(256),
@hexvalue varchar (514) OUTPUT
AS
DECLARE @charvalue varchar (514)
DECLARE @i int
DECLARE @length int
DECLARE @hexstring char(16)
SELECT @charvalue = '0x'
SELECT @i = 1
SELECT @length = DATALENGTH (@binvalue)
SELECT @hexstring = '0123456789ABCDEF'
WHILE (@i <= @length)
BEGIN
DECLARE @tempint int
DECLARE @firstint int
DECLARE @secondint int
SELECT @tempint = CONVERT(int, SUBSTRING(@binvalue,@i,1))
SELECT @firstint = FLOOR(@tempint/16)
SELECT @secondint = @tempint - (@firstint*16)
SELECT @charvalue = @charvalue +
SUBSTRING(@hexstring, @firstint+1, 1) +
SUBSTRING(@hexstring, @secondint+1, 1)
SELECT @i = @i + 1
END
SELECT @hexvalue = @charvalue
GO
IF OBJECT_ID ('sp_help_revlogin') IS NOT NULL
DROP PROCEDURE sp_help_revlogin
GO
CREATE PROCEDURE sp_help_revlogin @login_name sysname = NULL AS
DECLARE @name sysname
DECLARE @type varchar (1)
DECLARE @hasaccess int
DECLARE @denylogin int
DECLARE @is_disabled int
DECLARE @PWD_varbinary varbinary (256)
DECLARE @PWD_string varchar (514)
DECLARE @SID_varbinary varbinary (85)
DECLARE @SID_string varchar (514)
DECLARE @tmpstr varchar (1024)
DECLARE @is_policy_checked varchar (3)
DECLARE @is_expiration_checked varchar (3)
DECLARE @defaultdb sysname
IF (@login_name IS NULL)
DECLARE login_curs CURSOR FOR
SELECT p.sid, p.name, p.type, p.is_disabled, p.default_database_name, l.hasaccess, l.denylogin FROM
sys.server_principals p LEFT JOIN sys.syslogins l
ON ( l.name = p.name ) WHERE p.type IN ( 'S', 'G', 'U' ) AND p.name <> 'sa'
ELSE
DECLARE login_curs CURSOR FOR
SELECT p.sid, p.name, p.type, p.is_disabled, p.default_database_name, l.hasaccess, l.denylogin FROM
sys.server_principals p LEFT JOIN sys.syslogins l
ON ( l.name = p.name ) WHERE p.type IN ( 'S', 'G', 'U' ) AND p.name = @login_name
OPEN login_curs
FETCH NEXT FROM login_curs INTO @SID_varbinary, @name, @type, @is_disabled, @defaultdb, @hasaccess, @denylogin
IF (@@fetch_status = -1)
BEGIN
PRINT 'No login(s) found.'
CLOSE login_curs
DEALLOCATE login_curs
RETURN -1
END
SET @tmpstr = '/* sp_help_revlogin script '
PRINT @tmpstr
SET @tmpstr = '** Generated ' + CONVERT (varchar, GETDATE()) + ' on ' + @@SERVERNAME + ' */'
PRINT @tmpstr
PRINT ''
WHILE (@@fetch_status <> -1)
BEGIN
IF (@@fetch_status <> -2)
BEGIN
PRINT ''
SET @tmpstr = '-- Login: ' + @name
PRINT @tmpstr
IF (@type IN ( 'G', 'U'))
BEGIN -- NT authenticated account/group
SET @tmpstr = 'CREATE LOGIN ' + QUOTENAME( @name ) + ' FROM WINDOWS WITH DEFAULT_DATABASE = [' + @defaultdb + ']'
END
ELSE BEGIN -- SQL Server authentication
-- obtain password and sid
SET @PWD_varbinary = CAST( LOGINPROPERTY( @name, 'PasswordHash' ) AS varbinary (256) )
EXEC sp_hexadecimal @PWD_varbinary, @PWD_string OUT
EXEC sp_hexadecimal @SID_varbinary,@SID_string OUT
-- obtain password policy state
SELECT @is_policy_checked = CASE is_policy_checked WHEN 1 THEN 'ON' WHEN 0 THEN 'OFF' ELSE NULL END FROM sys.sql_logins WHERE name = @name
SELECT @is_expiration_checked = CASE is_expiration_checked WHEN 1 THEN 'ON' WHEN 0 THEN 'OFF' ELSE NULL END FROM sys.sql_logins WHERE name = @name
SET @tmpstr = 'CREATE LOGIN ' + QUOTENAME( @name ) + ' WITH PASSWORD = ' + @PWD_string + ' HASHED, SID = ' + @SID_string + ', DEFAULT_DATABASE = [' + @defaultdb + ']'
IF ( @is_policy_checked IS NOT NULL )
BEGIN
SET @tmpstr = @tmpstr + ', CHECK_POLICY = ' + @is_policy_checked
END
IF ( @is_expiration_checked IS NOT NULL )
BEGIN
SET @tmpstr = @tmpstr + ', CHECK_EXPIRATION = ' + @is_expiration_checked
END
END
IF (@denylogin = 1)
BEGIN -- login is denied access
SET @tmpstr = @tmpstr + '; DENY CONNECT SQL TO ' + QUOTENAME( @name )
END
ELSE IF (@hasaccess = 0)
BEGIN -- login exists but does not have access
SET @tmpstr = @tmpstr + '; REVOKE CONNECT SQL TO ' + QUOTENAME( @name )
END
IF (@is_disabled = 1)
BEGIN -- login is disabled
SET @tmpstr = @tmpstr + '; ALTER LOGIN ' + QUOTENAME( @name ) + ' DISABLE'
END
PRINT @tmpstr
END
FETCH NEXT FROM login_curs INTO @SID_varbinary, @name, @type, @is_disabled, @defaultdb, @hasaccess, @denylogin
END
CLOSE login_curs
DEALLOCATE login_curs
RETURN 0
GO

This script creates two stored procedures in the source database which helps with migrating these logins. Open a New Query window and run the following:
EXEC sp_help_revlogin

This query outputs a script that creates new logins for the destination server. Copy the output of this query and save it for later. You will need to run this on the destination server.

Once you’ve copied the output of this query, login to SSMS on the destination server and open a New Query window. Paste the contents from the previous script (it should have a series of lines that look similar to — Login: BUILTIN\Administrators
CREATE LOGIN [BUILTIN\Administrators] FROM WINDOWS WITH DEFAULT_DATABASE = [master]) and hit Execute.

You have now successfully imported all SQL logins and can now verify that the databases have been migrated to the destination server by using your previous credentials.

Views and stored procedures will migrate with the database if you are using the typical SQL Tape backups. Follow the instructions below if you need to migrate views and stored procedures independently.

  1. Open Microsoft SQL Management Studio on the Source server.
  2. Log in to your SQL server.
  3. Expand the server and as well as Databases.
  4. Right click on the name of your database and go to Tasks > Generate Scripts.
  5. Click Next.
  6. We will change Script entire database and all database objects to Select specific database objects and only check Views and Stored Procedures.Transfer Stored Procedures and Views within Microsoft SQL Server Management Studio
  7. Click Next, notice the Save to File option. Take note of the file path listed. In my case, it is C:\Users\Administrator\Documents\script.sql – The path of saved views and stored procedures.
  8. Click Next >> Next >>Finish, and select C:\Users\Administrator\Documents\script.sql and copy it to the destination server.
  9. Go to the destination server, open SSMS and log in to the SQL server.
  10. Go to File > Open > File or use the keyboard shortcut CTRL+O to open the SQL script. Select the file C:\Users\Administrator\Documents\script.sql to open it.
  11. You will see the script generated from the source server containing all views and stored procedures. Click Execute or use the keyboard shortcut F5 and run the script.
Note:
Unfortunately, there is no built-in way to do this with the command line. There are 3rd party tools and even a tool by Microsoft called mssql-scripter for more advanced scripting.

You have now migrated the views and stored procedures to your destination server! Repeat this process for each database you are migrating. A little guidance goes a long way in database administration. Every SQL server will have it’s own configurations and obstacles to face but we hope this article has given you a strong foundation for your Microsoft SQL Server Migration.

Looking for a High Availability, platform-independent SQL service that is easily scalable and can grow with your business? Check out our SQL as a Service product offered at Liquid Web. Speak with one of our amazing Hosting Advisers to find the perfect solution for you!

 

Improving Security for your Remote Desktop Connection

Remote Desktop Protocol (RDP) is the easiest and most common method for managing a Windows server. Included in all versions of Windows server and has a built-in client on all Windows desktops. There are also free applications available for Macintosh and Linux based desktops. Unfortunately, because it is so widely used, RDP is also the target of a large number of brute force attacks on the server. Malicious users will use compromised computers to attempt to connect to your server using RDP. Even if the attack is unsuccessful in guessing your administrator password, just the flood of attempted connections can cause instability and other performance issues on your server. Fortunately, there are some approaches you can use to minimize your exposure to these types of attacks.

Using a Virtual Private Network (or VPN) is one of the best ways to protect your server from malicious attacks over RDP. Using a VPN connection means that before attempting to reach your server, a connection must first be made to the secure private network. This private network is encrypted and hosted outside of your server, so the secure connection itself does not require any of your server’s resources. Once connected to the private network, your workstation is assigned a private IP address that is then used to open the RDP connection to the server. When using a VPN, the server is configured only to allow connections from the VPN address, rejecting any attempts from outside IP addresses (see Scoping Ports in Windows Firewall). The VPN not only protects the server from malicious connections, but it also protects the data transmitted between your local workstation and the server over the VPN connection. For more information, see our article What is a VPN Tunnel?

Note
All Liquid Web accounts come with one free Cloud VPN user. For a small monthly fee, you can add additional users. See our Hosting Advisors if you have any questions about our Cloud VPN service.

Like using a VPN, adding a hardware firewall to your server infrastructure further protects your server from malicious attacks. You can add a Liquid Web firewall to your account to allow only RDP connection from a trusted location. Our firewalls operate in much the same way that the software Windows firewall operates, but the functions are handled on the hardware itself, keeping your server resources free to handle legitimate requests. To learn more about adding a hardware firewall to your account, contact our Solutions team. If you already have a Liquid Web firewall in place, our Support team can verify that it is correctly configured to protect RDP connections.

Similar to using a VPN, you can use your Windows firewall to limit access to your RDP port (by default, port 3389). The process of restricting access to a port to a single IP address or group of IP addresses is known as “scoping” the port. When you scope the RDP port, your server will no longer accept connection attempts from any IP address not included in the scope. Scoping frees up server resources because the server doesn’t need to process malicious connection attempts, the rejected unauthorized user is denied at the firewall before ever reaching the RDP system. Here are the steps necessary to scope your RDP port:

  1. Log in to the server, click on the Windows icon, and type Windows Firewall into the search bar.
    Windows Firewall Search
  2. Click on Windows Firewall with Advanced Security.
  3. Click on Inbound Rules
    Inbound Firewall Rules section
  4. Scroll down to find a rule labeled RDP (or using port 3389).
  5. Double-click on the rule, then click the Scope tab.
    RDP Scope
  6. Make sure to include your current IP address in the list of allowed Remote IPs (you can find your current public IP address by going to http://ip.liquidweb.com.
  7. Click on the radio button for These IP Addresses: under Remote IP addresses.
  8. Click OK to save the changes.

While scoping the RDP port is a great way to protect your server from malicious attempts using the Remote Desktop Protocol, sometimes it is not possible to scope the port. For instance, if you or your developer must use a dynamic IP address connection, it may not be practical to limit access based on IP address. However, there are still steps you can take to improve performance and security for RDP connections.

Most brute force attacks on RDP use the default port of 3389. If there are numerous failed attempts to log in via RDP, you can change the port that RDP uses for connections.

  1. Before changing the RDP port, make sure the new port you want to use is open in the firewall to prevent being locked out of your server. The best way to do this is duplicate the current firewall rule for RDP, then update the new rule with the new port number you want to use.
  2. Login to your server and open the Registry editor by entering regedit.exe in the search bar.
  3. Once in the registry navigate to the following: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp
  4. Once there scroll down the list till you find “PortNumber”
  5. Double-clicking on this will bring up the editor box.
  6. Change it from HEX to DEC so it’s in numbers.
  7. Set the port number here and hit OK (you can use whatever port number you wish, but you should pick a port that already isn’t in use for another service. A list of commonly used port numbers can be found on MIT’s website.)
  8. Close the registry editor and reboot the server.
  9. Be sure to reconnect to the server with the new RDP port number.

 

What is Power DNS?

PowerDNS (pdns) is an open source authoritative DNS server that works as an alternative to traditional BIND (named) DNS. PowerDNS offers better performance and has minimal memory requirements. PowerDNS also works with many supporting backends ranging from simple zone files to complex database setups as well as various SQL platforms (Mysql, MariaDB, Oracle, PostgreSQL).

Note
PowerDNS uses a separate program called PowerDNS Recursor (pdns_recursor) as the “resolving DNS server” as a standalone software package.

Authoritative and Recursor DNS Servers

Authoritative Nameservers are DNS Servers that contain the DNS records for your domains. The authoritative nameserver will answer queries with information directly from its records.

Recursor DNS servers (commonly referred to as Recursive or Resolving) function between the end user and the authoritative DNS server. Queries that are submitted by the end user arrive at the recursive DNS server first, which then searches for the records in its cache. If the queried record cannot be found in the cache, the Recursive server then sends the query to the authoritative nameserver to resolve the requested record details.
For a deeper understanding of the DNS process visit our helpful Knowledge Base article.

PowerDNS Caching

By default, PowerDNS uses ‘Packet Cache’ to identify similar queries and the provides related answers respectively. It does this without any further processing of the request. The default cache interval is based on the TTL (time to live) setting for PowerDNS, which is 20 seconds.
In addition to caching entire packets, PowerDNS can also cache individual queries. Most DNS queries typically involve additional backend queries. An excellent example of a backend queries would be the lookup for a CNAME record.

When an end-user queries the ‘A’ record for ‘www.example.com,’ PowerDNS must first run a background query to check for the ‘www’ CNAME record. The PowerDNS Query Cache will cache these types queries for quicker recall in the event of similar future requests.

PowerDNS Advantages

While BIND is perfectly fine for the average host or user, PowerDNS provides a robust set of features and added performance suited for larger server environments with load-balancer configurations, such as reseller. One of the critical elements of PowerDNS is that it supports DNSSEC (DNS Security Extensions) creating an extra layer of security for your domains DNS. Also, PowerDNS has a convenient web-based user interface called Poweradmin that has a variety of helpful management tools.

For a full list of notable features pertaining to the PowerDNS Authoritative Server and PowerDNS Recursor, visit the links below:

https://www.powerdns.com/auth.html
https://www.powerdns.com/recursor.html

Poweradmin

Poweradmin is a browser-based administration tool for PowerDNS. It supports master, native and slave zones types. It can also be used for automatic provisioning and supports multiple coding languages. Below are a few examples of what the Poweradmin interface looks like and the tools and features it posses. For a full list of Poweradmin features visit https://www.poweradmin.org/features.html.

Main Page –  Available tools and features can be seen on the main page of Poweradmin when you first log in.

Available tools and features with Poweradmin

 

Search Tool – Utilizing the search tool allows you to query all of the DNZ zone setups with your PowerDNS for a specific string of text (name, IP address, etc.)

Search for tools in Poweradmin

Add a Master Zone – The Master Zone is used as the primary point of a query for all DNS requests made to the PowerDNS.

Adding a Master Zone in Poweradmin

Secondary Zone – As a failsafe, the secondary zone handles DNS queries should the Master Zone experience issues or go unresponsive.

adding a secondary zone in poweradmin

Install Multiple PHP Versions on Ubuntu 16.04

As a default, Ubuntu 16.04 LTS servers assign the PHP 7.0 version. Though PHP 5.6 is coming to the end of life in December of 2018, some applications may not be compatible with PHP 7.0. For this tutorial, we instruct on how to switch between PHP 7.0 and PHP 5.6 for Apache and the overall default PHP version for Ubuntu.

Step 1: Update Apt-Get

As always, we update and upgrade our package manager before beginning an installation. If you are currently running PHP 7.X, after updating apt-get, continue to step 2 to downgrade to PHP 5.6.

apt-get update && apt-get upgrade

Step 2: Install PHP 5.6
Install the PHP5.6 repository with these two commands.

apt-get install -y software-properties-common
add-apt-repository ppa:ondrej/php
apt-get update
apt-get install -y php5.6

Step 3: Switch PHP 7.0 to PHP 5.6
Switch from PHP 7.0 to PHP 5.6 while restarting Apache to recognize the change:

a2dismod php7.0 ; a2enmod php5.6 ; service apache2 restart

Note
Optionally you can switch back to PHP 7.0 with the following command: a2dismod php5.6 ; a2enmod php7.0 ; service apache2 restart

Verify that PHP 5.6 is running on Apache by putting up a PHP info page. To do so, use the code below in a file named as infopage.php and upload it to the /var/www/html directory.

<? phpinfo(); ?>

By visiting http://xxx.xxx.xxx.xxx/infopage.php (replacing the x’s with your server’s IP address), you’ll see a PHP info banner similar to this one, confirming the PHP Version for Apache:

Example of PHP Info page

Continue onto the section PHP Version for Ubuntu to edit the PHP binary from the command line.

Step 4: Edit PHP Binary

Maintenance of symbolic links or the /etc/alternatives path through the update-alternatives command.

update-alternatives --config php

Output:
There are 2 choices for the alternative php (providing /usr/bin/php).
Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/bin/php7.0 70 auto mode
1 /usr/bin/php5.6 56 manual mode
2 /usr/bin/php7.0 70 manual mode
Press to keep the current choice[*], or type selection number:

Select php5.6 version to be set as default, in this case, its the number one option.

You can now verify that PHP 5.6 is the default by running:
php -v

Output:
PHP 5.6.37-1+ubuntu16.04.1+deb.sury.org+1 (cli)
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies
with Zend OPcache v7.0.6-dev, Copyright (c) 1999-2016, by Zend Technologies

Install Nginx on Ubuntu 16.04

Nginx is an open source Linux web server that accelerates content while utilizing low resources. Known for its performance and stability Nginx has many other uses such as load balancing, reverse proxy, mail proxy and HTTP cache. With all these qualities it makes a definite competitor for Apache. To install Nginx follow our straightforward tutorial.

Pre-Flight Check

  • Logged into an as root and are working on an Ubuntu 16.04 LTS server powered by Liquid Web! If using a different user with admin privileges use sudo before each command.

Step 1: Update Apt-Get

As always, we update and upgrade our package manager.

apt-get update && apt-get upgrade

Step 2: Install Nginx

One simple command to install Nginx is all that is needed:

apt-get -y install nginx

Step 3: Verify Nginx Installation

When correctly installed Nginx’s default file will appear in /var/www/html as index.nginx-debian.html . If you see the Apache default page rename index.html file. Much like Apache, by default, the port for Nginx is port 80, which means that if you already have your A record set for your server’s hostname you can visit the IP to verify the installation of Nginx. Run the following command to get the IP of your server if you don’t have it at hand.

ip addr show eth0 | grep inet | awk '{ print $2; }' | sed 's/\/.*$//'

Take the IP given by the previous command and visit via HTTP. (http://xxx.xxx.xxx.xxx) You will be greeted with a similar screen, verifying the installation of Nginx!

Nginx Default Page

Note
Nginx, by default, does not execute PHP scripts and must be configured to do so.

If you already have Apache established to port 80, you may find the Apache default page when visiting your host IP, but you can change this port to make way for Nginx to take over port 80. Change Apache’s port by visiting the Apache port configuration file:

vim /etc/apache2/ports.conf

Change “Listen 80” to any other open port number, for our example we will use port 8090.

Listen 8090

Restart Apache for the changes to be recognized:

service apache2 restart

All things Apache can now be seen using your IP in the replacement of the x’s. For example http://xxx.xxx.xxx.xxx:8090

Install XFCE Desktop Environment on Ubuntu 16.04

Since 1996, XFCE Desktop gives users the ability to have a graphical user interface (GUI) environment, visually turning your Linux server into an environment more like your desktop computer. With its no-frills look, XFCE does not weigh heavy on the server’s hardware and is faster than GNOME and KDE to boot. Once completed with this small tutorial, you’ll be able to share and connect to the XFCE GUI by continuing to the next tutorial on How To Install VNC.

Pre-flight

  • These instructions are intended for installing Xfce Desktop Environment on an Ubuntu 16.04 LTS server.
  • Logged in as a root user, but for non-root users precede all commands with the word sudo.

Step 1: Update apt-get
With best practices in mind, we will update before proceeding to install XFCE 4

apt-get update

Step 2: Install XFCE4 Desktop Environment
With one command we can install Xfce itself and some useful utilities that come with Xfce:
apt-get install -y xfce4 xfce4-goodies
 

Step 1:
Run each of these commands so that apt-get can utilize them during the purge of Xfce.
apt-get -f install
apt-get clean
apt-get autoclean
apt-get update

Step 2:
Purge Xfce from your Ubuntu server:
apt-get purge xfce4

As mentioned in our opening paragraph the next step is to configure VNC (virtual network computing) Installing VNC is necessary to open the recently installed Xfce interface. It’s optional but advisable to set up an SSH tunnel that connects to VNC for a secure connection.  Check out our Knowledge Base on the subject of VNC to find your choice of articles.

 

Install Memcached on Ubuntu 16.04

Memcached works to enhance performance by keeping a copy of commonly used script elements within the server’s memory in a form that is more easily read by the server thus reducing time. A bonus feature of this object cacher is its ability to decrease the number of connections to your database. In this tutorial, we instruct how to install Memcached, but it’s important to note that when using Memcache in an application, the application must be specially coded or configured to store and retrieve data this cached data.

Learn more about caching from our dedicated article or visit our series for database optimization.

Pre-flight

  • We are logged in as root on an Ubuntu 16.04 VPS powered by Liquid Web!
  • Installed and running Apache and PHP 7.

Installation of Memcached

Step 1:
Following best practices, we will do a quick package update by using the following command:
apt-get update
Step 2:
Install the Memcached daemon using
apt-get install memcached -y
Step 3:
Install the Memcache module for PHP fuctionality:
apt-get install php-memcached -y

Verify installation of Memcached

Use the php -m flag to show compiled modules while sorting through specifically looking for memcached.

php -m | grep memcached
memcached

Optional Configurations

At some point, you may find that you need to change the default settings of Memcached. These include adjusting the port number, memory for your cache, and the listening IP address.
vim /etc/memcached.conf

Adjust these configurations by keeping the same flags (-m, -p, -u, -l), adjusting the letter or number after the flag and save the file by typing :wq .
# Start with a cap of 64 megs of memory. It's reasonable, and the daemon default
# Note that the daemon will grow to this size, but does not start out holding this much
# memory
-m 64
 
# Default connection port is 11211
-p 11211
 
# Run the daemon as root. The start-memcached will default to running as root if no
# -u command is present in this config file
-u memcache
 
# Specify which IP address to listen on. The default is to listen on all IP addresses
# This parameter is one of the only security measures that memcached has, so make sure
# it's listening on a firewalled interface.
-l 127.0.0.1

 

Restart your Memcached service to recognize the changes to this file:
systemctl restart memcached

How to Install Cassandra on Ubuntu 16.04 LTS

Apache Cassandra is a free open-source database system that is NoSQL based. Meaning Cassandra does not use the table model seen in MySQL, MSSQL or PostgreSQL, but instead uses a cluster model. It’s designed to handle large amounts of data and is highly scalable. We will be installing Cassandra and its pre-requisites, Oracle Java, and if necessary the Cassandra drivers.

Pre-Flight Check

  • We are logged in as root on an Ubuntu 16.04 VPS powered by Liquid Web!
  • Apache Cassandra and this article expect that you are using Oracle Java Standard Edition 8, as opposed to OpenJDk . Verify your Java version by typing the command below into your terminal:

java --version

  • At the time of this article, Python 2.7.11 and later versions will need to install updated Cassandra drivers to fix a known bug with the cqlsh command. You can check your Python version similar to checking your Java version:

python --version

  • If you have Python 2.7.11+ or later, download the required driver by running the pip command. You will need pip installed. Within this tutorial, we will show you how to install pip. However, pip is usually pre-installed with Python by default.

Step 1: Install Oracle Java (JRE)

Cassandra requires your using Oracle Java SE (JRE) installed on your server. First, you will have to add Personal Package Archives to make the (JRE) package available.

sudo add-apt-repository ppa:webupd8team/java

After entering this command, it may prompt you to hit enter to continue.
Once it completes update the package database using the following:

sudo apt-get update

You can now install Oracle JRE with the following:
sudo apt-get install oracle-java8-set-default

A pink screen prompts you to agree to the terms and conditions of JRE. Hit enter to continue from this screen and accept the terms and conditions in the next screen.

Java Installer Screen

 

Once successfully installed verify the default version of Java by typing:

java -version

You’ll receive the following or something very similar :

Java Version Output

 

Step 2: Installing Apache Cassandra

First, we have to install the Cassandra repository to /etc/apt/sources.list.d/cassandra.sources.list directory by running following command (When we made this article Cassandra 3.6 was the current version. You may need to edit this line to reflect the latest release by updating the 36x value. For example, use 37x if Cassandra 3.7 is the newest version.):
echo "deb http://www.apache.org/dist/cassandra/debian 36x main" | sudo tee -a /etc/apt/sources.list.d/cassandra.sources.list

Next, run the cURL command to add the repository keys :

curl https://www.apache.org/dist/cassandra/KEYS | sudo apt-key add -

We can now update the repositories:

sudo apt-get update

 

Note
If you get the following error: GPG error: http://www.apache.org 36x InRelease: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY A278B781FE4B2BDA
Add the public key by running the following command:
sudo apt-key adv --keyserver pool.sks-keyservers.net --recv-key A278B781FE4B2BDARepeat the update to the repositories:
sudo apt-get update

Finally, finish installing by entering the following:
sudo apt-get install cassandra

Verify the installation of Cassandra by running:
nodetool status

The desired output will show UN meaning everything is up and running normally.

Verifying Cassandra is Installed

 

Step 3: Connect with cqlsh

If you have an older version of Python before 2.7.11, you’ll skip this step and start using Cassandra with the cqlsh command. Good for you! You have successfully installed Cassandra!
cqlsh

You should see something similar to this:
Connected to Test Cluster at 127.0.0.1:9042.
[cqlsh 5.0.1 | Cassandra 3.6 | CQL spec 3.4.2 | Native protocol v4] Use HELP for help.

Note
For future reference, Cassandra’s configuration file, data directory and logs can be found in:

  • /etc/cassandra is the default file configuration location.
  • /var/log cassandra and /var/lib cassandra are the default log and data directories location.

However, if you get the following error,

Connection error: (‘Unable to connect to any servers’, {‘127.0.0.1’: TypeError(‘ref() does not take keyword arguments’,)}),

you’ll update the Cassandra drivers. These drivers have a known bug with Cassandra and later versions of Python. Check your Python version by typing:
python --version

Luckily, I am going to show you how you can fix this error in 3 easy steps by downloading the drivers.

 

Step 3a: First we will need pip installed. If you don’t have it already, you can get it with the following command.

sudo apt-get install python-pip

 

Step 3b: Once pip is installed, run the following to install the new Cassandra driver. Please note this command may take a while to execute. Grab a snack and wait for it to complete. It can take 5-10 minutes to install fully.

pip install cassandra-driver

 

Step 3c: Finally disable the embedded driver by entering :

export CQLSH_NO_BUNDLED=true

You should now be able to run the cqlsh command.

cqlsh

You should see this if successful :

Connected to Test Cluster at 127.0.0.1:9042.
[cqlsh 5.0.1 | Cassandra 3.6 | CQL spec 3.4.2 | Native protocol v4] Use HELP for help.

To exit cqlsh type exit:
cqlsh> exit

Congrats! You have successfully installed Cassandra!

Note

Cassandra should start automatically, but you’ll want to stop Cassandra to make any additional configuration changes. Start and stop it with the following:

sudo service cassandra start
sudo service cassandra stop