CI/CD as a service in the VMmanager platform

Ilya Kalinichenko

VMmanager DevOps

With VMmanager, you can provide users with a SaaS service – deploying virtual machines with preinstalled software. Ilya Kalinichenko, VMmanager DevOps, tells how to arrange automatic CI/CD provisioning using the platform.

VMmanager supports shell scripts. You can set variables for them. When creating a virtual machine, VMmanager will automatically request variable values from users or generate them automatically.

Let us configure the service to automatically provide virtual machines with a ready development environment. To do this, we will create a script that will install Gitlab and Mattermost. Gitlab has everything developers need to work together:

Git repository;
a convenient portal with different permission levels;
a built-in system for integration and deployment automation.

Mattermost — is a free equivalent of Slack. Developers love to discuss products, plan, design, and just talk, and Mattermost is great for that.

Preparing a script to install Gitlab and Mattermost


# Install the SSH server
yum install -y curl policycoreutils openssh-server openssh-clients
systemctl enable sshd
systemctl start sshd
 
# Open ports 22, 80 and 443 in the firewall
firewall-cmd --permanent --add-service=http
firewall-cmd --permanent --add-service=https
firewall-cmd --permanent --add-service=ssh
systemctl reload firewalld
 
# Install Postfix
yum install postfix -y
systemctl enable postfix
systemctl start postfix
 
# Install the Gitlab repository
curl -sS https://packages.gitlab.com/install/repositories/gitlab/gitlab-ce/script.rpm.sh |  bash
 
if [ -z "($GITLAB_URL)" ] || [ "($GITLAB_URL)" = "()" ]; then
    GITLAB_URL=gitlab.example.com
else
    GITLAB_URL="($GITLAB_URL)"
fi
 
if [ -z "($MM_URL)" ] || [ "($MM_URL)" = "()" ]; then
    MM_URL=mattermost.example.com
else
    MM_URL="($MM_URL)"
fi
 
# Install Gitlab
EXTERNAL_URL="$GITLAB_URL" yum install -y gitlab-ce
 
# Enable Mattermost and configure it
sed -i "/mattermost_external_url/cmattermost_external_url 'http://$MM_URL'" /etc/gitlab/gitlab.rb
sed -i "/mattermost\['enable'\]/cmattermost['enable'] = true" /etc/gitlab/gitlab.rb
sed -i "/mattermost_nginx\['enable'\]/cmattermost_nginx['enable'] = true" /etc/gitlab/gitlab.rb
sed -i "/letsencrypt\['enable'\]/cletsencrypt['enable'] = false" /etc/gitlab/gitlab.rb
sed -i "/package\['modify_kernel_parameters'\]/cpackage['modify_kernel_parameters'] = false" /etc/gitlab/gitlab.rb
 
# Launch reconfiguration so that Gitlab creates all necessary files and settings
gitlab-ctl reconfigure

Configuring the settings in VMmanager

Creating a script in VMmanager

In the platform, open the script list and create a new script:

Name — name of the script which the clients will see.
Owner — VMmanager user who will be updating the script as required.
Access — to all or the Owner only. Here you can temporarily disable client access to the script to debug something.
Tags are used to designate the OS for which the script will be available. We will enable it here for CentOS 7 and CentOS 8.
A Brief description that the client will see in the list of scripts..
The Script parameters are variables. VMmanager will request them from users when launching the script. We have two such variables:
GITLAB_URL — here you will need to specify the domain on which Gitlab will run.
MM_URL — here you will need to specify the domain on which Mattermost will run.
When the end user orders a service, VMmanager will request this data from him.
Script — here the script itself will be written. An example I tested on CentOS 8.

Let us check if the script works

Run the script on a freshly installed VM. Note that GItlab is a large application that needs at least 4 cores and 4GB RAM.
System requirements for Gitlab

Creating a VM with script execution. Users enter the values of the specified variables in the interface

After the script is completed, go to http://gitlab.example.com or http://mattermost.example.com in your web browser for further configuration.

Check the work of Gitlab: the service has been deployed on the domain created simultaneously with the VM http://gitlab.example.com

Check the work of Mattermost: the service has been deployed on the domain created simultaneously with the VM http://gitlab.example.com

Now your clients can install the CI\CD platform in two clicks for convenient development. Similarly, you can configure other scripts in VMmanager and provide SaaS service.
Scripts in VMmanager. Documentation