jaeger-ingester flags for kafka should have kafka prefix

[vprithvi]

Requirement - what kind of business use case are you trying to solve?

Have a consistent format with jaeger-collector, etc

Problem - what in Jaeger blocks you from solving the requirement?

cmd/ingester  go run main.go --help
Jaeger ingester consumes spans from a particular Kafka topic and writes them to all configured storage types.

Usage:
  jaeger-ingester [flags]
  jaeger-ingester [command]

Available Commands:
  env         Help about environment variables
  help        Help about any command
  version     Print the version

Flags:
      --cassandra-archive.connections-per-host int      The number of Cassandra connections from a 
.
.
.

      --ingester.brokers string                         The comma-separated list of kafka brokers. i.e. '127.0.0.1:9092,0.0.0:1234' (default "127.0.0.1:9092")
      --ingester.encoding string                        The encoding of spans ("protobuf" or "json") consumed from kafka (default "protobuf")
      --ingester.group-id string                        The Consumer Group that ingester will be consuming on behalf of (default "jaeger-ingester")
      --ingester.parallelism string                     The number of messages to process in parallel (default "1000")
      --ingester.topic string                           The name of the kafka topic to consume from (default "jaeger-spans")

      --log-level string                                Minimal allowed log Level. For more levels see https://github.com/uber-go/zap (default "info")
      --metrics-backend string                          Defines which metrics backend to use for metrics reporting: expvar, prometheus, none (default "prometheus")
      --metrics-http-route string                       Defines the route of HTTP endpoint for metrics backends that support scraping (default "/metrics")
      --span-storage.type string                        Deprecated; please use SPAN_STORAGE_TYPE environment variable. Run this binary with "env" command for help.

Use "jaeger-ingester [command] --help" for more information about a command.

Proposal - what do you suggest to solve the problem or improve the existing situation?

All kafka related flags should be prefixed with kafka instead of ingester

ingester.topic => kafka.topic
ingester.group-id=> kafka.group-id
ingester.brokers => kafka.brokers

[vprithvi]

FYI @davit-y

[pavolloffay]

@vprithvi @yurishkuro is this still valid?

If so we should do it in the next release along with publishing images and binaries. I think it's ok to do a breaking change. Injester has been released in 1.7 as experimental.

[vprithvi]

@pavolloffay This is still valid, I agree that it's ok to make this breaking change.