swarm-service-restart

Some applications require periodic restarts to keep things running smoothly, but

Rather than using set of shell scripts or cron jobs, this tool allows you to attach a label to services (edu.wm.restartService.schedule) that contains a crontab like scheduling syntax.

The cron library used is a modified of robfig's cron.v2 library. The cron syntax is the same.

At this point I'd consider everything not quite alpha stability.

Requirements

The swarm-service-restart tool has to run on a manager node (or at least have access to a manager node's API, possibly using something like mikesir87 describes).

The binary can be run directly on the node, or can be run as its own service (recommended).

Example

A docker compose file might look something like

version: "3.7"

services:
  service-restarter:
    image: pcfens/swarm-service-restart
    deploy:
      placement:
        constraints:
          - node.role == manager
    volumes:
      - type: bind
        source: /var/run/docker.sock
        target: /var/run/docker.sock
        read_only: false

A service that will be restarted at 2am everyday would look something like

version: "3.7"

services:
  nginx:
    image: nginx
    deploy:
      labels:
        edu.wm.restartService.schedule: "0 2 * * *"

The files docker-compose.yaml and test-nginx.yaml are both used during development.

Future Plans

• I'd like to build something like this for Kubernetes, possibly in the same tool.
• As the code shows, I'm not all that familiar with Go, so there are numerous opportunities to clean things up.