Cleanup after package installations (yum clean all)

[TJM]

A few package cleanup improvements...

• ~Do not use rpm directly to add or remove packages. yum install can handle URLs and prevents the STDERR "rpm database has been modified outside of yum"~ (upon further investigation, the URL is not a simple file, and thus yum localinstall ignores it. (further investigation required)

• Any place that yum is used, follow up with && yum clean all (in the same "RUN" command)

  • It might be best to "combine" the two yum RUN layers?

• ~gem probably also has a cache that can be cleaned up~ (this turns out to not be significant)

[TJM]

After adding the && yum clean all ...

$ docker images | grep puppet-dev-tools
tommythekid/puppet-dev-tools                                    latest                        4c270f1497a4        14 minutes ago      1.1GB
puppet/puppet-dev-tools                                         latest                        02287227c5bf        11 days ago         1.42GB

Not huge, but still over 320MB smaller... and there is still room for improvement based on the following:

$ CI=true dive tommythekid/puppet-dev-tools
Fetching image... (this can take a while with large images)
Parsing image...
Analyzing image...
  efficiency: 90.3114 %
  wastedBytes: 160070291 bytes (160 MB)
  userWastedPercent: 14.5564 %
Run CI Validations...
  Using default CI config
  FAIL: highestUserWastedPercent: too many bytes wasted, relative to the user bytes added (%-user-wasted-bytes=0.14556405872910816 > threshold=0.1)
  SKIP: highestWastedBytes: rule disabled
  PASS: lowestEfficiency
Result:FAIL [Total:3] [Passed:1] [Failed:1] [Warn:0] [Skipped:1]