Support for multiple Prefix values in RPM spec.

[justinnichols]

Added support for multiple Prefix values in the RPM spec. This is not backward compatible, the interface has changed. Also fixed it so when the RPM spec is written, "prefix:" is now "Prefix:".

[muuki88]

cc @fsat @huntc

[muuki88]

I would like to merge this, but I have no experience with rpmPrefix after all. This feature has caused some confusions in the passed, so I would like to be extra carefully here.

@justinnichols also could you add some notes to the docs ( RpmPlugin ) on how to use this

[justinnichols]

@muuki88 I altered/added documentation to the rpm.rst. I hope it is clear and concise.

[justinnichols]

I'm not sure what the commit quality needs to be (aside from squashing the commits into one). Please advise if I'm needed to do anything here. Thanks!

[fsat]

Hi @muuki88 and @justinnichols - apologies for not looking at this earlier.

I've looked the PR, and changing rpmPrefix from Option[String] to Seq[String] is only the first step to enable support for multiple RPM prefix.

I believe there are further changes which are required to make this work. Unfortunately the changes are going to be quite involved due to:

• Code on master making the assumption that there's only 1 rpmPrefix
• RPM scriptlets and startup script are bundled during package build time
• Relocation path(s) is only known during package install time
• But the RPM scriptlets and startup script need to take into account these relocated paths

These are the changes required.

1. RPM pre-inst scriptlet

https://github.com/justinnichols/sbt-native-packager/blob/c957fdfcf2fc6f05cc2234eef0552f79fa7b3ab7/src/main/resources/com/typesafe/sbt/packager/archetypes/java_server/rpm/preinst-template#L13

Modification required:

• Store the mapping of the original directory and its relocated path as opposed to storing a single value

Why is this required:

• The mapping will be used by the start script to cd into the relocated install directory
• The mapping will also be used by the RPM post content scriptlet to ensure the symlinks within the original paths are relocated correctly

2. Start script

https://github.com/justinnichols/sbt-native-packager/blob/c957fdfcf2fc6f05cc2234eef0552f79fa7b3ab7/src/main/resources/com/typesafe/sbt/packager/archetypes/java_server/systemloader/systemv/start-rpm-template#L40

Modification required:

• Load the relocated path mapping from Step 1
• Check if default install path is amongst the relocated paths
• If the default install path is relocated, use the relocated path
• Otherwise, use default install path

Why is this required:

• This will ensure the application is started with current working directory pointing to the correct install directory.

3. Relocate symlink

https://github.com/justinnichols/sbt-native-packager/blob/c957fdfcf2fc6f05cc2234eef0552f79fa7b3ab7/src/main/scala/com/typesafe/sbt/packager/rpm/RpmMetadata.scala#L260
https://github.com/justinnichols/sbt-native-packager/blob/c957fdfcf2fc6f05cc2234eef0552f79fa7b3ab7/src/main/scala/com/typesafe/sbt/packager/rpm/RpmMetadata.scala#L287

Modification required:

• Load the relocated path mapping from Step 1
• Ensure each the symlinks within relocated path are updated, (i.e. not pointing to the original default location)

Why this is required:

• If the symlinks are not moved to the relocated path, it will be broken and application may not function correctly.

4. SystemD service file

45bc15f#diff-4cd37cfbb35d81cf7067b4496c0c6a9cR15

Modification required:

• Load the relocated path mapping from Step 1
• Ensure each the path within the service file which are relocated path are updated with the correct location, (i.e. not pointing to the original default location)

[muuki88]

@justinnichols Would you be able to make these changes to complete this PR?
Regarding the quality of the code this one looks fine.

My wish would be that we have integration tests (#545) with ansible for testing these stuff. However we don't have any infrastructure for this yet :(
So the only kind of tests you can write are that the scripts are generated properly (see sbt-test folder)

[justinnichols]

I will do everything I can to help make this more complete. Given the holidays and normal work schedule, it may be some time before I would have something for this. Do you want to leave this PR open until then or would you like to close this and then I can submit a new one once I feel I have completed everything @fsat laid out? Also, thank you, @fsat, for your wonderful descriptions of what would need to be done and the pointers to where things are.

[fsat]

@justinnichols - you're most welcome :-)

Hi @muuki88 & @justinnichols - I updated the description to add Step 4 which is to include systemd's user service file since #711 has been merged into master.

If you decide to keep this PR going, I'd recommend rebase against master.

[muuki88]

@justinnichols I will close this PR for a now and we can link it with your new one.
Thanks from my side as well @fsat :)