riyasdeen/docker-swarm-redeploy repository overview

⁠docker-swarm-redeploy

Adopted from Shephard⁠ to enabled unsupervised redeploy of services deployed in docker swarm. Similar to how it used to be in Docker Cloud when it was alive.

⁠Usage

⁠1. Setup server

• Deploy a service using riyasdeen/docker-swarm-redeploy:latest.
• Please replace secure-token with a secure token value, can be any string. Request from docker hub webhook will be authenticated with this token

docker service create --name auto-redeploy \
                      --replicas 1 \
                      --constraint "node.role==manager" \
                      --mount type=bind,source=/var/run/docker.sock,target=/var/run/docker.sock \
                      --env TOKEN=secure-token
                      --publish published=5000,target=80
                      riyasdeen/docker-swarm-redeploy

⁠2. Docker Registry Authentication

If you are using private images in docker registry then your registry credentials can be provided via Docker Secrets⁠.

Create a Secret names registry-auth with secret value as { username: your-docker-username, password: your-docker-password }. Please replace your-docker-username and your-docker-password with your docker credentials

$ docker secret create registry-auth -
{ username: your-docker-username, password: your-docker-password }

⁠3. Docker Hub Configuration

Add a webhook in Docker hub for the repository that you would like to be redeployed when a new image is pushed. Please replace your-server-endpoint with public end point of docker-swarm-redeploy, and secure-token with token used in step 1

That's it!!! Every time a new image is pushed to your repository, the services using that image will be redeployed with the new image.

⁠How does it work?

docker-swarm-redeploy just triggers a service update of all services deployed with image name & tag as posted by Docker Hub.

Most of the work is thankfully done by Docker which resolves the image tag, checks the registry for a newer version and updates running container tasks as needed⁠.

Also, Docker handles all the work of applying rolling updates⁠. So at least with replicated services, there should be no noticeable downtime.