Decouple InfluxDB and Fluentbit, allow configuration of multiple Fluentbit outputs. Rework logger config.

[timopulkkinen]

Description

This pull request decouples InfluxDB from the Logger as the sole persistence layer by adding the possibility to pass a customOutput config in values.xml and making InfluxDB dependency optional. It is possible to pass secrets and public env variables to Fluent Bit by using new attribute extraEnv.

Note: influxdb.enabled has been moved under logger.fluentbit, this will break existing configuration.

Example snippet from values.xml to use PostgreSQL as an log output target:

logger:
    enabled: true
    fluentbit:
      extraEnv:
        sensitive:
           DB_PASSWORD: x
        public:
           DB_TABLE: table   
      influxdb:
        enabled: false
      customOutput: |
        [OUTPUT]
          Name pgsql
          Match log.*
          Host ${DB_HOST}
          Port 5432
          Database ${DB_DATABASE}
          User ${DB_USER}
          Password ${DB_PASSWORD}
          Table ${DB_TABLE}

Which issue(s) this PR fixes:

Fixes no open issues that I know of.

Testing

helm lint
Installed chart with default + custom setup.

Checklist:

• I ran tests as well as code linting locally to verify my changes.
• I have done manual verification of my changes, changes working as expected.
• I have added new tests to cover my changes.
• My changes follow contributing guidelines of Fission.
• I have signed all of my commits.