Would be nice to have a `docker stack deploy --dry-run` option

[hairyhenderson]

Because it's not always obvious what state an existing stack is in when a docker stack deploy command is issued, it would be useful to be able to see a plan of action before it's executed to prevent surprises.

I'm proposing --dry-run as the option name.

[hairyhenderson]

Looks like this was already proposed in moby/moby#32365 though I'm not sure where the issue should reside with all the repo-shuffling that's going on 😉

[netflash]

Are there any chances to see this live ?

[immerrr]

FTR, the issue in moby repository is closed in favour of this one.

[00dav00]

Any updates on this one? It would be a very useful option.

That looks like is on a very low priority...
We also need this one as it would help our Saltstack in omitting stack application when it sees no changes.
And then, it's always good to have this option (--dry-run) so one isn't scared applying an updated stack to the production.

[bcsgh]

And now for the roughly annual update where someone says they would also find this useful. :-(

[haraldfw]

I would also find this very helpful

[Re4zOon]

Just to have the annual update: I would also find this helpful.

[josteinaj]

I would also find this very helpful!

The important thing I want to know is which services will be updated. I don't need a detailed diff or anything.

[frizzr]

I will add to the chorus that having a --dry-run option would be incredibly useful.