container-manager

container-manager is a daemon that watches your containers. It reads container definitions from a config file and creates/removes containers, similar to docker swarm deploy command but does not require Docker daemon to be in swarm mode.

Installing

Install latest released binary from releases page or install development version with:

go get github.com/cenkalti/container-manager

If you're using Arch, you can install container-manager-bin package from AUR.

Usage

Put your container definitions in a config file.
Run contianer-manager -config <path> with systemd, supervisor or etc.
Update configuration when you are about to deploy/update containers. (Do not forget to change the version field.)
Reload configuration with SIGHUP. container-manager will update running containers.

Example config

checkinterval: 60s
listenaddr: 0.0.0.0:26662
containers:
  nginx:
    version: 1
    image: nginx
    portbindings:
      "80/tcp":
        - hostip: "0.0.0.0"
          hostport: 8080
  sleep:
    version: 1
    count: 4
    stoptimeout: 5
    image: ubuntu:16.04
    cmd:
      - bash
      - "-c"
      - sleep 999999999

Notes

Private repositories

If you are using a private Docker repository, you will need credentials to pull new images. container-manager uses the same config file (~/.docker/config) as the docker CLI tool.

Container logs

Because running containers are removed and new containers are created when they get redeployed, log messages will also be deleted if you use json-file log driver (default). It is recommended to use another log-driver to keep your log messages after containers are deleted.

Example:

containers:
  ticker:
    image: ubuntu:16.04
    cmd:
      - bash
      - "-c"
      - while true; do date; sleep 1; done
    logconfig:
      type: journald

If you use journald log driver, you can access logs with following command:

journalctl CONTAINER_NAME=ticker