Add syslog forwarder

[making]

What this PR does / why we need it:

This PR adds ops-file to enable syslog forwarding with syslog-release.

How can this PR be verified?

Configure a syslog endpoint in add-syslog.yml and add-syslog-tls.yml (if TLS is required) and check whether component logs (such as kube-apiserver) are received in the syslog server.

Is there any change in kubo-release?

No

Is there any change in kubo-ci?

No

Does this affect upgrade, or is there any migration required?

No

Which issue(s) this PR fixes:

Forwarding component logs to a syslog endpoint

Release note:

Added ops-files to forward component logs to a syslog endpoint.

[cfdreddbot]

Hey making!

Thanks for submitting this pull request! I'm here to inform the recipients of the pull request that you and the commit authors have already signed the CLA.

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/159586577

The labels on this github issue will be updated when the story is started.

[alex-slynko]

Hi @making

Is there any particular reason you would like it deployed as the manifest addon and not use runtime config?

[making]

@alex-slynko For the user who just wants to manage kubernetes with bosh and foward logs related to only k8s, configuring log forwarding is not a separation of concerns. Runtime config seems too wide. Using include or exclude in a separated file is not comfortable.

I think this is just as same as other deployments suppport syslog forwarding:

• https://github.com/cloudfoundry/cf-deployment/blob/master/operations/addons/enable-component-syslog.yml
• https://github.com/concourse/concourse-bosh-deployment/blob/master/cluster/operations/syslog_forwarder.yml
• https://github.com/cloudfoundry/cf-mysql-deployment/blob/develop/operations/enable-syslog.yml

[alex-slynko]

Hi @making

Could you please fix the unit tests for manifest interpolation? It is ./bin/run_tests. You can add sample variables in https://github.com/cloudfoundry-incubator/kubo-deployment/tree/master/manifests/ops-files/example-vars-files

[making]

@alex-slynko Fixed

[alex-slynko]

@making you can pass multiple ops-files to the test. See for example https://github.com/cloudfoundry-incubator/kubo-deployment/pull/338/files#diff-18093856d0498026e07aa1435ad1eea3L39

[making]

@alex-slynko Put two ops-files to one check_interpolation