Commit 330a003533
introduced "synchronous" service update and rollback, using progress bars to show
current status for each task.
As part of that change, progress bars were "reversed" when doing a rollback, to
indicate that status was rolled back to a previous state.
Reversing direction is somewhat confusing, as progress bars now return to their
"initial" state to indicate it was "completed"; for an "automatic" rollback, this
may be somewhat clear (progress bars "move to the right", then "roll back" if the
update failed), but when doing a manual rollback, it feels counter-intuitive
(rolling back is the _expected_ outcome).
This patch removes the code to reverse the direction of progress-bars, and makes
progress-bars always move from left ("start") to right ("finished").
Before this patch
----------------------------------------
1. create a service with automatic rollback on failure
$ docker service create --update-failure-action=rollback --name foo --tty --replicas=5 nginx:alpine
9xi1w3mv5sqtyexsuh78qg0cb
overall progress: 5 out of 5 tasks
1/5: running [==================================================>]
2/5: running [==================================================>]
3/5: running [==================================================>]
4/5: running [==================================================>]
5/5: running [==================================================>]
verify: Waiting 2 seconds to verify that tasks are stable...
2. update the service, making it fail after 3 seconds
$ docker service update --entrypoint="/bin/sh -c 'sleep 3; exit 1'" foo
overall progress: rolling back update: 2 out of 5 tasks
1/5: running [==================================================>]
2/5: running [==================================================>]
3/5: starting [============================================> ]
4/5: running [==================================================>]
5/5: running [==================================================>]
3. Once the service starts failing, automatic rollback is started; progress-bars now move in the reverse direction;
overall progress: rolling back update: 3 out of 5 tasks
1/5: ready [===========> ]
2/5: ready [===========> ]
3/5: running [> ]
4/5: running [> ]
5/5: running [> ]
4. When the rollback is completed, the progressbars are at the "start" to indicate they completed;
overall progress: rolling back update: 5 out of 5 tasks
1/5: running [> ]
2/5: running [> ]
3/5: running [> ]
4/5: running [> ]
5/5: running [> ]
rollback: update rolled back due to failure or early termination of task bndiu8a998agr8s6sjlg9tnrw
verify: Service converged
After this patch
----------------------------------------
Progress bars always go from left to right; also in a rollback situation;
After updating to the "faulty" entrypoint, task are deployed:
$ docker service update --entrypoint="/bin/sh -c 'sleep 3; exit 1'" foo
foo
overall progress: 1 out of 5 tasks
1/5:
2/5: running [==================================================>]
3/5: ready [======================================> ]
4/5:
5/5:
Once tasks start failing, rollback is started, and presented the same as a regular
update; progress bars go from left to right;
overall progress: rolling back update: 3 out of 5 tasks
1/5: ready [======================================> ]
2/5: starting [============================================> ]
3/5: running [==================================================>]
4/5: running [==================================================>]
5/5: running [==================================================>]
rollback: update rolled back due to failure or early termination of task c11dxd7ud3d5pq8g45qkb4rjx
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
678c2fde98