Add healthcheck_mode to service config

[fede1024]

The healthcheck_mode option was added to nerve-tools, but it is not actually loaded from the config file since the 'healthcheck_mode' key is not in the whitelist.

[solarkennedy]

I'm surprised this is it? Don't we need something like line 522?

[mjksmith]

It doesn't took like that's necessary because line 515 adds everything in the whitelist to the configuration.

[fede1024]

configure_nerve in nerve tools will use this config, and it will default to the mode if it's not present.

[solarkennedy]

@fede1024 I'm ok with the small change, but in paasta if a service specifies this mode, seems like we should take advantage of it and adjust our healthchecks accordingly?

[Rob-Johnson]

I think this is ok to ship.

@solarkennedy here is the corresponding commit for nerve-tools.

This is a consequence of configure_nerve using paasta as a library, particularly marathon_tools.get_services_runnning_here_for_nerve. That in turn uses this key_whitelist to filter the list of keys returned from the s_c_l, so @fede1024 needed to add healthcheck_mode to that whitelist so nerve can start using it.

in paasta if a service specifies this mode, seems like we should take advantage of it and adjust our
healthchecks accordingly?

I think we're actually okay here. We already use the healthcheck_mode param used, it was nerve that didn't have that capability. This actually brings nerve healthchecking and marathon healthchecking in line with eachother.

[solarkennedy]

@fede1024 can you merge/rebase master and we can see how the tests look?

[fede1024]

It's now rebased on master. Unit tests and integration tests look fine on my box.

[solarkennedy]

Merged.