Draft: Adds possibility to call BBS to retrieve stats for application's processes states.

[gmllt]

The purpose of this PR is to propose the use of BBS to fetch the RUNNING state of the main application process.
This should help to avoid calls to /v2/space/:space_guid/summary endpoints

bbs internal client is configurable with :

      --bbs.api_url=BBS.API_URL  BBS API URL ($CF_EXPORTER_BBS_API_URL)
      --bbs.ca_file=BBS.CA_FILE  BBS CA File ($CF_EXPORTER_BBS_CA_FILE)
      --bbs.cert_file=BBS.CERT_FILE
                                 BBS Cert File ($CF_EXPORTER_BBS_CERT_FILE)
      --bbs.key_file=BBS.KEY_FILE
                                 BBS Key File ($CF_EXPORTER_BBS_KEY_FILE)
      --bbs.skip_ssl_verify      Disable SSL Verify for BBS ($CF_EXPORTER_BBS_SKIP_SSL_VERIFY)
      --bbs.timeout=5            BBS API Timeout ($CF_EXPORTER_BBS_TIMEOUT)

If bbs is not configured or unreachable, the code switch to the old method using /v2/space/:space_guid/summary to retrieve application running instances number.

Buildpacks information are retrieve with the new relationship introduced since CAPI 1.189.0

[gmllt]

Waiting for cloudfoundry/cloud_controller_ng!3863 to be merged and released.
This will only work with capi shipping the correct version of cloud_controller_ng

[gmllt]

Waiting for cloudfoundry/cli!2933 to be merged.

[benjaminguttmann-avtq]

@gmllt the BBS API URL, what would that be ? => https://github.com/cloudfoundry/cf-deployment/blob/a0f8634a507108481c6b08304719ab7babace102/cf-deployment.yml#L151

[benjaminguttmann-avtq]

I receive always

ERRO[0100] unable to initialize bbs client error="failed to ping BBS"
so would be good if you have an example config, so I can find out what I am doing wrong here

[benjaminguttmann-avtq]

got it to work, setting skip-ssl to true made the trick. Unfortunately the logs do not give you any insights why the connection did not work.

I don't think we do a fallback to the old logic, as it gets removed nevertheless. I would remove the fallback and make the BBS config optional, e.g. if the BBS config is not present do not gather the summary metrics as maybe not everyone wants to make BBS available to their monitoring VMs.