How to revert changes to a service s configuration

Question

I have created a service as shown: 

$ docker service create --name my-service -p 8080:80 nginx:alpine

This service was running with 1 replica as observed by executing 

$ docker service ls

ID                  NAME                MODE                REPLICAS            IMAGE               PORTS
xbw728mf6q0d        my-service          replicated          1/1                 nginx:alpine        *:8080->80/tcp

Next I updated my service to use 3 replicas:

$ docker service update --replicas=3 my-service

$ docker service ls

ID                  NAME                MODE                REPLICAS            IMAGE               PORTS
xbw728mf6q0d        my-service          replicated          3/3                 nginx:alpine        *:8080->80/tcp

But I want to rollback  to my single replica service. How can i revert back the changes to my service?

Answer 1

In order to roll back the service to its previous version, and confirm it is running a single replica again, run the following command.

$ docker service rollback my-service

$ docker service ls

ID                  NAME                MODE                REPLICAS            IMAGE               PORTS
xbw728mf6q0d        my-service          replicated          1/1                 nginx:alpine        *:8080->80/tcp

This will Revert back the changes made to the service's configuration.