`vrealize:clean` does not work as expected and does not clean well

[Michaelpalacce]

Description

This is the documentation for the command. Read through it to understand what is the purpose of vrealize:clean.

This is how vrealize:clean can be called:

mvn vrealize:clean -DincludeDependencies=true -DcleanUpOldVersions=true -DcleanUpLastVersion=false -PDevLab
mvn vrealize:clean -DincludeDependencies=true -DcleanUpOldVersions=false -DcleanUpLastVersion=true -PDevLab

The problem is that currently it doesn't work as expected. There are actually a few issues here:

1. You can't do cleanupOldVersions and cleanUpLastVersion at the same time due to a bug
   • Take a look at GenericPackageStore.java > deletePackage
   • This section:
   • Reason why it won't work is because pollLast will remove and return the last element (aka latest) from the array and the delete later on in the if statement will delete for (Package p : all) { but latest is actually not there
2. You can't clean up last version in some cases...
   • 
   • if all.size === 0 we are all good, cause it deletes the latest package that was pollLast-ed before...
   • if not, we attempt to delete the previous iteration, not the latest. This is perhaps to safeguard against deleting everything on the environment, but vrealize:clean ought to be used to actually delete the latest when you want to do that.
3. There is a case where the environment does not get fully cleaned up, perhaps a dependency of a dependency or even deeper down. Investigate this

Proposed solutions

Delete old packages

• Fetch package, package dependencies and their dependencies and so on and so forth (up for discussion, could only go one level down?)
• Search for them in vro
• Whatever is found out, should be deleted with deletePackageVersion, aka deleting the package and any obsolete/deprecated/left over code.

Cleanup Environment

This will be essentially delete latest and old at the same time

• Fetch package, package dependencies and their dependencies and so on and so forth (up for discussion, could only go one level down?)
• Search for them in vro
• Delete them with their content and all old versions.

[vasyl-vs]

After internal discussion, we agreed on the following.

1. Flag cleanUpOldVersions will be removed, because in any case old packages must be deleted, so it doesn't make sense to have such flag.
2. If we run clean command without any params by default only the current package will be deleted and all of its versions (old and latest). Dependencies are only if the flag is set to true.
3. When cleanUpLastVersion=false then the old versions of the current package will only be deleted (dependency will not be included unless includeDependencies=true).
4. When cleanUpLastVersion=true and includeDependencies=false then the current package and all it's versions will be deleted.
5. When cleanUpLastVersion=true and includeDependencies=true then the current package and all it's dependencies will be deleted along with all of their old versions.

• We also need to consider the situation when after deleting latest version with dependency, we are installing old version. Because there is possible issue with dependencies. For example if the latest version use dependency with breaking changes. That's why all dependencies (including nested dependencies) must be deleted and older version have to be installed instead.