Allow artifact_file to handle snapshot and latest version correctly

[BarthV]

issue #115

This patch allows artifact_file corectly downloading *-SNAPSHOT and LATEST version :

• It detects artifact version based on existing artifact class method (Thanks to @gregsymons)
• In case of "rolling version", it retrives artifact filename from Nexus metadata and merge it with provided destination folder.
• Cast a log info because provided filename is now ignored when asking for a snapshot version

Anyway, we are now able to download the artifact properly but we still do not know its name. I think it's still very interesting to correct the issue #112

[BarthV]

I did many test (snapshots, static version, latest, etc...), many times. I also tried to make artifact_file resources upgrade/downgrade perfectly (new file is downloaded). Idempotency is still OK.

But it would be nice to all of you to test it again :). Thx

[BarthV]

I got a problem with latest tag (snap is ok), and still have indent issues. Fixing this right now

[BarthV]

Ready to be tested !
Don't forget to merge fix #124 before all ;-)

[BarthV]

OK ... my artifact's version resolution is wrong :
I just read https://github.com/RiotGames/nexus_cli and I realized version is not at a static position but always the last one.
So [...].split(':')[3] is not always correct -> [...].split(':')[-1] should fix this

[bdemers]

We have worked around this issue in the past by creating hard links in the after proc. myartifact-1.2.3-timestamp.jar -> myartifact-1.2.3-SNAPSHOT.jar (also a work around for #112 )

[BarthV]

I'm not sure about it, but hardlink in the after proc suppose that we can guess filename or resolve it from nexus metadata.
Currently if you're using *-snapshot or latest version tag we cannot guess it and make further actions on this file.

That why a providing a built-in procedure to resolve filename or making a symlink would be nice.

Tell me if I'm wrong :/

[bdemers]

Absolutely, a proper solution would be much better. Just doc'ing the work around for anyone googling until this gets a fix.
You can guess the filename by doing something like:

Dir.glob("#{::File.dirname(self.new_resource.name)}/*#{::File.extname(self.new_resource.name)}").last

Granted this is work around is more of a hack then anything...

[BarthV]

rebased

[BarthV]

OK this time I think all cases are covered.
LWRP update should be 100% transparent with previous version and previous syntax (I'm only adding some switching cases)

So ... I have worked and tested a lot to finally bring a very simple modification into load_current_resource to handle snap/latest file from nexus.
I also added a new symlink lwrp attribute which links downloaded file to the specified symlink path.
Idempotency should be ok too.

Symlinking is totally optionnal and you still can download a "latest" artifact without bothering about the filename.

This is a silly example :

artifact_file "/tmp/my-artifact.jar" do
  location "com.test:my-artifact:jar:LATEST"
  owner "me"
  group "mes"
end

We get something like :

• /tmp/my-artifact-1.3.175.jar
• /var/chef/cache/artifact_file/com_test_my-artifact_jar_LATEST-c58fcfa00dc150d5b09e7dd9e113b2a5

if we put a symlink in the resource :

artifact_file "/tmp/my-artifact.jar" do
  location "com.test:my-artifact:jar:LATEST"
  owner "me"
  group "mes"
  symlink "/tmp/my-artifact.jar"
end

We get something like :

• /tmp/my-artifact-1.3.175.jar
• /var/chef/cache/artifact_file/com_test_my-artifact_jar_LATEST-c58fcfa00dc150d5b09e7dd9e113b2a5
• /tmp/my-artifact.jar -> /tmp/my-artifact-1.3.175.jar

Symlink obviously works with non-rolling (ie. static) versions too.

I tried to keep the changes very easy to read and to understand. I think it's ok, but feel free to comment, review or modify this PR.

Thanks !

[KAllan357]

I think we should come up with a way to refactor this so that we don't have to do this splitting logic. I think adding a new snapshot? and latest? to Chef::Artifact::Nexus would do the trick - see https://github.com/RiotGames/artifact-cookbook/blob/master/libraries/chef_artifact_nexus.rb#L30-L31 for reference.

[BarthV]

ok, I'll work on this and think about adding new snapshot/latest method directly at Nexus object level.

[KAllan357]

To piggyback on the discussion in #112, would it make sense that the following example:

artifact_file "/tmp/my-artifact.jar" do
  location "com.test:my-artifact:jar:LATEST"
  owner "me"
  group "mes"
end

Should give you:

• /tmp/my-artifact.jar

I think perhaps that Nexus downloads should again go under your Chef::Config[:file_cache_path] and be copied to your new_resource.path with the appropriate name.

Edit: I'm not sure I fully understand the use case behind the usage of symlink. I think based on the above, the expectation would be that the file's name gets changed and placed in the appropriate directory. Requiring a symlink to get that functionality might be unexpected.

[KAllan357]

Overall this has come along nicely. We certainly appreciate all the effort. Would it be possible to squash this whole pull request into a couple of reasonable-sized commits?

[BarthV]

ok, i'll clean this up a bit

[BarthV]

Closing this PR.
Currently Working on a cleaner version including asked features.