Fleet Unit Templates

This is a collection of Fleet unit files as m4 templates.

Background

Fleet units are a great way to bootstrap a cluster with backing services or more advanced cluster managers like Kubernetes. The problem with units is that they are not very re-usuable if you need to co-deploy N versions for different tennants. Using m4 we can generalize & parameterize fleet units to make them more re-usable.

Sample Usage

/usr/bin/m4 -DDOCKER_VOLUME={{/vol/replicated/assets/:/var/www/html}} \
            -DRSYNC_USERNAME={{nobody}} \
            -DRSYNC_PASSWORD={{super-secret}} \
            -DRSYNC_VOLUME={{/var/www/html/}} \
            -DRSYNC_NAME={{%i}} \
            -DRSYNC_READ_ONLY={{true}} \
            -DRSYNC_TIMEOUT={{60}} \
            -DRSYNC_MAX_CONNECTIONS={{10}} \
            -DFLEET_MACHINE_OF={{durable-storage}} \
            -DDNS_SERVICE_NAME={{rsync/rsyncd}} \
            -DDNS_SERVICE_ID={{assets/%m}} \
            -DDOCKER_NAME={{rsyncd_assets}} \
                /fleet-units/rsyncd.service.m4  > /fleet-units/rsyncd.service

Best Practices

• Use Restart=always in [Service] declarations for services
• Use EnvironmentFile=/etc/environment to access environment including $COREOS_PRIVATE_IPV4