Docker provides a convenient way to package entire applications into runnable containers. OTOH in the data center we use RPM packages to deliver software and configuration to our servers.
This wrapper build a bridge between Docker appliances and Linux services by packaging a Docker image as a Linux service into an RPM package.
The resulting Linux service can be simply used like any other Linux service, for example start the service with service schlomo start.
See also this blog article.
Simply clone this git repo.
For demonstration purposes this repo includes an example app schlomo (nginx with a custom HTML page). To build the RPM with the example app simply run
make example
to build an RPM package. To test install the RPM package on a system with docker-engine already installed. Then start the service with
service schlomo start
and validate the running service with
curl http://localhost
After a reboot the schlomo service should come up again.
To build an RPM from your own Docker image or an appliance you find on DockerHub simply run make with a few parameters like this
make rpm IMAGE=nginx:latest NAME=nginx VERSION=74 RELEASE=4.110 REQUIRES=is24-docker RUNARGS="-p 80:80 --env-file=/etc/nginx-environment"
The IMAGE and RUNARGS variables define the Docker image to take and additional arguments to docker run. Use this to pass in environment variables, set Docker volumes etc.
The NAME, VERSION, RELEASE variables define the name, version and release of the RPM.
The REQUIRES variable defines the RPM requires of the RPM, for example at ImmobilienScout24 we ship Docker in the is24-docker RPM. You can also add here another RPM that will provide required components for the service, e.g. a Docker data container or configuration files.