Pier is an alternative Docker client, which uses the Ruby docker-api gem to access the Docker Remote API. Pier is focused on the use-case of managing one or more clusters of machines which are entirely dedicated to running a Docker swarm.
Pier uses fog for its instance management. For now, only the fog-libvirt backend is supported.
Pier assumes that each cluster has a cluster-manager endpoint, called a "pier." The pier is a running instance that must:
- be accessible via SSH;
- be a manager in your Docker swarm; and
- have
easy-rsainstalled and set up to generate both server and client certificates.
A pier need not be a member of the cluster itself. Pier does not manage the pier, only the cluster visible through the pier.
By default, Pier also assumes that each pier is the libvirt hypervisor for its cluster—i.e. that libvirt's endpoint is accessible as qemu+ssh://[your-pier-endpoint]/system.