Issue #1185 Prevent docker:save failing when no images are defined.

[wrosenuance]

Address issue #1185 by having docker:save handle POMs with no images with a build configuration.

Signed-off-by: William Rose william.rose@nuance.com

BEFORE

$ mvn io.fabric8:docker-maven-plugin:0.28.0:save
[INFO] Scanning for projects...
[INFO]
[INFO] -------------------< io.fabric8:docker-maven-plugin >-------------------
[INFO] Building docker-maven-plugin 0.28-SNAPSHOT
[INFO] ----------------------------[ maven-plugin ]----------------------------
[INFO]
[INFO] --- docker-maven-plugin:0.28.0:save (default-cli) @ docker-maven-plugin ---
[ERROR] DOCKER> More than one image with build configuration is defined. Please specify the image with 'docker.name' or 'docker.alias'.
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.227 s
[INFO] Finished at: 2019-04-09T00:07:12-04:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal io.fabric8:docker-maven-plugin:0.28.0:save (default-cli) on project docker-maven-plugin: More than one image with build configuration is defined. Please specify the image with 'docker.name' or 'docker.alias'. -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

AFTER

$ mvn io.fabric8:docker-maven-plugin:0.28-SNAPSHOT:save
[INFO] Scanning for projects...
[INFO]
[INFO] -------------------< io.fabric8:docker-maven-plugin >-------------------
[INFO] Building docker-maven-plugin 0.28-SNAPSHOT
[INFO] ----------------------------[ maven-plugin ]----------------------------
[INFO]
[INFO] --- docker-maven-plugin:0.28-SNAPSHOT:save (default-cli) @ docker-maven-plugin ---
[INFO] DOCKER> No images have a build configuration defined: save skipped
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.978 s
[INFO] Finished at: 2019-04-09T00:07:24-04:00
[INFO] ------------------------------------------------------------------------

[codecov]

Codecov Report

Merging #1194 into master will decrease coverage by 0.03%.
The diff coverage is 0%.

@@             Coverage Diff              @@
##             master    #1194      +/-   ##
============================================
- Coverage     52.82%   52.78%   -0.04%     
  Complexity     1511     1511              
============================================
  Files           150      150              
  Lines          7974     7979       +5     
  Branches       1200     1202       +2     
============================================
  Hits           4212     4212              
- Misses         3348     3353       +5     
  Partials        414      414

Impacted Files	Coverage Δ	Complexity Δ
...rc/main/java/io/fabric8/maven/docker/SaveMojo.java	0% <0%> (ø)	0 <0> (ø)	⬇️

[codecov]

Codecov Report

Merging #1194 into master will decrease coverage by 0.03%.
The diff coverage is 0%.

@@             Coverage Diff              @@
##             master    #1194      +/-   ##
============================================
- Coverage     52.82%   52.78%   -0.04%     
  Complexity     1511     1511              
============================================
  Files           150      150              
  Lines          7974     7979       +5     
  Branches       1200     1202       +2     
============================================
  Hits           4212     4212              
- Misses         3348     3353       +5     
  Partials        414      414

Impacted Files	Coverage Δ	Complexity Δ
...rc/main/java/io/fabric8/maven/docker/SaveMojo.java	0% <0%> (ø)	0 <0> (ø)	⬇️

[codecov]

Codecov Report

Merging #1194 into master will decrease coverage by 0.03%.
The diff coverage is 0%.

@@             Coverage Diff              @@
##             master    #1194      +/-   ##
============================================
- Coverage     52.82%   52.78%   -0.04%     
  Complexity     1511     1511              
============================================
  Files           150      150              
  Lines          7974     7979       +5     
  Branches       1200     1202       +2     
============================================
  Hits           4212     4212              
- Misses         3348     3353       +5     
  Partials        414      414

Impacted Files	Coverage Δ	Complexity Δ
...rc/main/java/io/fabric8/maven/docker/SaveMojo.java	0% <0%> (ø)	0 <0> (ø)	⬇️

[rhuss]

Can we move that check up to the start of executeInternal() ? E.g. we can obtain the configuration there and add it as an argument to this method.

Its much clearer to skip execution early if needed.

[rhuss]

Looks good to me except that I would move the check to a poistion as early as the check for skipSave. (see comment below).

Please add an entry to changelog.md, too.

[wrosenuance]

I made this change, but I am not sure it's clearer -- is this what you meant?

[rhuss]

Thanks ! No, not fully what I meant. Is ok when I push to your branch with the changes I thought about ? (it's easier to explain in code ;-). It's only a small change.

Thanks for the test btw !

[wrosenuance]

Please do! I agree it will be faster 😁

[rhuss]

Coolio. However, you would need to give me access to this as your master branch seems to be protected.
See https://help.github.com/en/articles/committing-changes-to-a-pull-request-branch-created-from-a-fork for more info, but in essence, the easiest way is to create a PR on a separate branch as this is by default allowed to push it.

If this is too much of a hassle for you, I can create a new pull request (and we could close this one).

[rhuss]

I created a new PR #1196 with my suggestion.