Add dry run flag

[mtivi]

Support dry run install. Intended to enable better CI/CD pipelines.

The releaser:next goal does not the release goals.

This PR will require:

• A Test case
• Documentation

Before doing the additional work, I'd like to know if this will be approved / merged.

Open to other options; e.g. branch filter to create tags & deploy.

@danielflower

[danielflower]

Hi, I think "dry run" is a bit misleading because it all this doesn't do is push the tags, right? A user may have a deploy step which would still be called by this, but may expect it not to be called in a "dry run".

There is an option already to not push tags: https://danielflower.github.io/multi-module-maven-release-plugin/release-mojo.html#pushTags

[mtivi]

Hi, I think "dry run" is a bit misleading because it all this doesn't do is push the tags, right? A user may have a deploy step which would still be called by this, but may expect it not to be called in a "dry run".

There is an option already to not push tags: https://danielflower.github.io/multi-module-maven-release-plugin/release-mojo.html#pushTags

The intention was to prevent tags from being created at all. An alternative solution could be running tests, and non deploy goals from the next goal (vs simply printing what would be built).

My team's use of the plugin is creating multiple build profiles for main/ non-main branches. The non main branch doesn't push tags.

By creating, and not pushing tags, there is a risk of developers accidently pushing tags from their local machines later on.

[danielflower]

So it seems like this is another tag option? Maybe pushTags should be deprecated and a new property called tagAction or something with values NoTags, Create and CreateAndPush (the default).

[mtivi]

Yeah that sounds a lot cleaner. When I get an opportunity, I'll give that a go.

It is not the two line change I was hoping for, but it does leave the plugin in a much cleaner state.

Perhaps something along the lines of

public enum TagOption {
  ...,
  NOOP(false,false);

  private final boolean createTags:
  private final boolean pushTags;

  public TagOption(boolean createTags, boolean pushTags){
      this.createTags = createTags;
      This.pushTags = pushTags;
   }
}

?

[paul-hammant]

I would think -Ddryrun would mean make no tags in Git and don't actually push to Nexus (etc). Ideally Nexus would also have a dry-run capability.

Output (ideally) would be "Nexus reports that it would have accepted G:A:V for publication were you to do this same command without -Ddryrun"