Remove User CRD

[barkbay]

Fixes:

• Remove the User CRD #727
• Associations: generate unique user names to avoid collisions between different associations. #526
• User secrets (prev. Users) are not watched if there are in another NS
• Secrets are not watched at all by the dynamic handler

Still a WIP:

• Check if it is relevant to add some tests
• Check if we should cache the hashed password as an annotation to save some CPU cycles
• Check/trim usernames

Todo in an other PR:

• Factorize some code between Kibana/APM (lots of TODO in the APM code)

[barkbay]

jenkins test this please

[barkbay]

Todo in some other PRs (I will create them after this one is merged):

• Factorize some code between Kibana/APM (lots of TODO in the APM code)
• Resource name length is only addressed in the context of Elasticsearch (see Trim cluster and pod names up to a limit #318), we should do the same for Kibana/APM and associations as they are used in labels
• They are no (premature) optimization for the password comparison, it has some implications that need to be discussed

[pebrc]

This looks good 👍 For me the only open question before merging is about the ownership of the user secret (see my comments)

[pebrc]

Does this introduce a dependency to testing in production code?

[barkbay]

Good question !
Functions in *_test.go files are not available for import by other tests. Looks like there is no easy way to share some code between tests.

I did some tests and it looks like there is not dependency as long as the function is not explicitly used in some production code.

For example if ChecksUser is explicitly called elsewhere in the production code the binary is 1MB bigger and all the test tooling seems to be embedded in the binary:

$ strings elastic-operator|grep -i 'testing\.'
*testing.T
**testing.T
*[]*testing.T
*testing.common
**testing.common
*testing.matcher
*func(*testing.T)
*testing.indenter
...

If the function ChecksUser is shared by some tests but not in the production code (like in this PR):

$ strings elastic-operator|grep -i 'testing\.'
testing.init
/usr/local/Cellar/go/1.11.4/libexec/src/testing/testing.go
$

it is the same result with the code on the current master branch btw

[pebrc]

👍 Nice analysis!

[barkbay]

jenkins test this please

[sebgl]

LGTM, great work!

[barkbay]

jenkins test this please