A script to wait for a service running in docker swarm

For docker stack deploy there is no option to wait while all services are in running state. With docker service ps it’s possible to find desired state and current state for one service for each node.

$ docker service ps redis

ID            NAME         IMAGE        NODE      DESIRED STATE  CURRENT STATE                   ERROR  PORTS
50qe8lfnxaxk  redis.1      redis:3.0.6  manager1  Running        Running 6 seconds ago
ky2re9oz86r9   \_ redis.1  redis:3.0.5  manager1  Shutdown       Shutdown 8 seconds ago
3s46te2nzl4i  redis.2      redis:3.0.6  worker2   Running        Running less than a second ago
nvjljf7rmor4   \_ redis.2  redis:3.0.6  worker2   Shutdown       Rejected 23 seconds ago

To check if service is running on all nodes, it’s necessary to filter all tasks by desired state in ready or running and then check that they all have current state in running.

docker service ps -f desired-state=running -f desired-state=ready --format "{{ .DesiredState }} {{.CurrentState }}" my_service | grep -v "Running Running"

To run this in a loop.

check_running() {
   docker service ps -f desired-state=running -f desired-state=ready --format "{{ .DesiredState }} {{.CurrentState }}" my_service | grep -v "Running Running"
}
ATTEMPTS=0
RESULT=0
until [ $RESULT -eq 1 ] || [ $ATTEMPTS -eq 3 ]; do
  sleep 30
  check_running
  RESULT=$?
  ATTEMPTS=$((ATTEMPTS + 1))
done

set -e
test $RESULT -eq 1