Are you tired of cloning, building, testing, and deploying codes time and again? If yes, switch to continuous integration. Continuous Integration aka CI is practice in software engineering of making frequent commits to the code base, building, testing and deploying as we go. CI helps to quickly integrate new codes into the existing code base. If this process is made automated, then this will speed up the development process as it reduces the time taken for the developer to build and test things manually. [Drone][1] is a free and open source project which provides an awesome environment of continuous integration service and is released under Apache License Version 2.0. It integrates with many repository providers like Github, Bitbucket and Google Code and has the ability to pull codes from the repositories enabling us to build the source code written in number of languages including PHP, Node, Ruby, Go, Dart, Python, C/C++, JAVA and more. It is made such a powerful platform cause it uses containers and docker technology for every build making users a complete control over their build environment with guaranteed isolation.
First of all, we'll gonna install Docker as its the most vital element for the complete workflow of Drone. Drone does a proper utilization of docker for the purpose of building and testing application. This container technology speeds up the development of the applications. To install docker, we'll need to run the following commands with respective the distribution of linux. In this tutorial, we'll cover the steps with Ubuntu 14.04 and CentOS 7 linux distributions.
After our docker engine is installed in our centos machine, we'll simply start it by running the following systemd command as systemd is the default init system in centos 7.
It uses SQlite3 database server for storing its data and information by default. It will automatically create a database file named drone.sqlite under /var/lib/drone/ which will handle database schema setup and migration. To setup SQlite3 drivers, we'll need to follow the below steps.
Finally, after we have installed those dependencies successfully, we'll now go further towards the installation of drone in our machine. In this step, we'll simply download the binary package of it from the official download link of the respective binary formats and then install them using the default package manager.
We'll use wget to download the debian package of drone for ubuntu from the [official Debian file download link][2]. Here is the command to download the required debian package of drone.
After the installation is completed, we'll gonna configure drone to make it workable. The configuration of drone is inside **/etc/drone/drone.toml** file. By default, drone web interface is exposed under port 80 which is the default port of http, if we wanna change it, we can change it by replacing the value under server block as shown below.
In order to run Drone we must setup at least one integration points between GitHub, GitHub Enterprise, Gitlab, Gogs, Bitbucket. In this tutorial, we'll only integrate github but if we wanna integrate other we can do that from the configuration file. In order to integrate github, we'll need to create a new application in our [github settings][4].
We should make sure that **Authorization callback URL** looks like http://drone.linoxide.com/api/auth/github.com under the configuration of the application. Then, we'll click on Register application. After done, we'll note the Client ID and Client Secret key as we'll need to configure it in our drone configuration.
If we wanna enable drone to send notifications via emails, then we'll need to specify the SMTP configuration of our SMTP server. If we already have an SMTP server, we can use its configuration but as we don't have an SMTP server, we'll need to install an MTA ie Postfix and then specify the SMTP configuration in the drone configuration.
Note: Here, **user** and **pass** parameters are strongly recommended to be changed according to one's user configuration.
### 7. Configuring Worker ###
As we know that drone utilizes docker for its building and testing task, we'll need to configure docker as the worker for our drone. To do so, we'll need to edit the [worker] section in the drone configuration file.
# nano /etc/drone/drone.toml
Then, we'll uncomment the following lines and append as shown below.
[worker]
nodes=[
"unix:///var/run/docker.sock",
"unix:///var/run/docker.sock"
]
Here, we have set only 2 node which means the above configuration is capable of executing only 2 build at a time. In order to increase concurrency, we can increase the number of nodes.
[worker]
nodes=[
"unix:///var/run/docker.sock",
"unix:///var/run/docker.sock",
"unix:///var/run/docker.sock",
"unix:///var/run/docker.sock"
]
Here, in the above configuration, drone is configured to process four builds at a time, using the local docker daemon.
### 8. Restarting Drone ###
Finally, after everything is done regarding the installation and configuration, we'll now start our drone server in our linux machine.
#### On Ubuntu ####
To start drone in our Ubuntu 14.04 machine, we'll simply run service command as the default init system of Ubuntu 14.04 is SysVinit.
# service drone restart
To make drone start automatically in every boot of the system, we'll run the following command.
# update-rc.d drone defaults
#### On CentOS ####
To start drone in CentOS machine, we'll simply run systemd command as CentOS 7 is shipped with systemd as init system.
# systemctl restart drone
Then, we'll enable drone to start automatically in every system boot.
# systemctl enable drone
### 9. Allowing Firewalls ###
As we know drone utilizes port 80 by default and we haven't changed the port, we'll gonna configure our firewall programs to allow port 80 (http) and be accessible from other machines in the network.
#### On Ubuntu 14.04 ####
Iptables is a popular firewall program which is installed in the ubuntu distributions by default. We'll make iptables to expose port 80 so that we can make our Drone web interface accessible in the network.
As CentOS 7 has systemd installed by default, it contains firewalld running as firewall problem. In order to open the port 80 (http service) on firewalld, we'll need to execute the following commands.
# firewall-cmd --permanent --add-service=http
success
# firewall-cmd --reload
success
### 10. Accessing Web Interface ###
Now, we'll gonna open the web interface of drone using our favourite web browser. To do so, we'll need to point our web browser to our machine running drone in it. As the default port of drone is 80 and we have also set 80 in this tutorial, we'll simply point our browser to http://ip-address/ or http://drone.linoxide.com according to our configuration. After we have done that correctly, we'll see the first page of it having options to login into our dashboard.
As we have configured Github in the above step, we'll simply select github and we'll go through the app authentication process and after its done, we'll be forwarded to our Dashboard.
After its activated, it will ask us to add a new file named .drone.yml in our repository and define the build process and configuration in that file like which image to fetch and which command/script to run while compiling, etc.
We'll need to configure our .drone.yml as shown below.
image: python
script:
- python helloworld.py
- echo "Build has been completed."
After its done, we'll be able to build our application using the configuration YAML file .drone.yml in our drone appliation. All the commits made into the repository is synced in realtime. It automatically syncs the commit and changes made to the repository. Once the commit is made in the repository, build is automatically started in our drone application.
In this article, we learned to completely setup a workable Continuous Intergration platform with Drone. If we want, we can even get started with the services provided by the official Drone.io project. We can start with free service or paid service according to our requirements. It has changed the world of Continuous integration with its beautiful web interface and powerful bunches of features. It has the ability to integrate with many third party applications and deployment platforms. If you have any questions, suggestions, feedback please write them in the comment box below so that we can improve or update our contents. Thank you !
