Execute java version check in check mode

[katsukamaru]

This PR is related to this issue.
#525

This problem is happened in --check mode, because in check mode ignored test for java_full_path and does not register it.
So this PR changed to execute in check mode and register java_full_path.

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[Crazybus]

So this PR changed to execute in check mode and register java_full_path.

Does this change allow you to run check-mode successfully? Your comment sounds like you meant to set check_mode: yes but the changes have it set to no.

[Crazybus]

jenkins test this please

[katsukamaru]

@Crazybus thank you for your message and added the results in my local environment.

check_mode: yes means that ansible does not execute with --check.
My change check_mode: no means actually execute in --check.

And below are results in my environment.

elastic/master branch
ansible-playbook -i hosts playbook/es-c1.yml --check -v -l 172.20.0.54

TASK [elastic.elasticsearch : Get the installed java path] ************************************************************************************************************************************************
skipping: [172.20.0.54] => {"changed": false, "msg": "skipped, running in check mode"}

TASK [elastic.elasticsearch : correct java version selected] **********************************************************************************************************************************************
fatal: [172.20.0.54]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'dict object' has no attribute 'stdout'\n\nThe error appears to have been in '/home/admin/.ansible/roles/elastic.elasticsearch/tasks/java.yml': line 24, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n- name: correct java version selected\n  ^ here\n"}

...

katsukamaru:java-version-check-in-check-mode branch

ansible-playbook -i hosts playbook/es-c1.yml --check -v -l 172.20.0.54

TASK [elastic.elasticsearch : Get the installed java path] ************************************************************************************************************************************************
ok: [172.20.0.54] => {"changed": false, "cmd": "update-alternatives --display java | grep '^/' | awk '{print $1}' | grep 1.8.0 | head -1", "delta": "0:00:00.021355", "end": "2019-01-15 17:57:41.289218", "failed_when_result": false, "rc": 0, "start": "2019-01-15 17:57:41.267863", "stderr": "", "stderr_lines": [], "stdout": "/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.191.b12-0.amzn2.x86_64/jre/bin/java", "stdout_lines": ["/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.191.b12-0.amzn2.x86_64/jre/bin/java"]}

TASK [elastic.elasticsearch : correct java version selected] **********************************************************************************************************************************************
ok: [172.20.0.54] => {"changed": false}

...

In katsukamaru:java-version-check-in-check-mode branch actually executes the command and returns ok.
Please let me know if there are any problems.

[Crazybus]

check_mode: yes means that ansible does not execute with --check.
My change check_mode: yes means actually execute in --check.

I think you meant check_mode: no here right?

I just had a look at the ansible check mode docs and it looks like I got it around backwards.

Force a task to run in check mode, even when the playbook is called without --check. This is called check_mode: yes.
Force a task to run in normal mode and make changes to the system, even when the playbook is called with --check. This is called check_mode: no.

Pretty confusing actually, but it means that your change does look good then! :)

[Crazybus]

LGTM!

Only thing still needed is to sign the CLA agreement and then this is ready to be merged.

[katsukamaru]

@Crazybus

I think you meant check_mode: no here right?

You are right. I fixed my comment check_mode: yes to check_mode: no. Thank you for pointing it out.

I signed the CLA and seem to be passed all checks.

[Crazybus]

Thanks for your contribution @katsukamaru and teaching me how the check_mode actually works :D