DogStatsD v1.2 Container ID support #640
Description
It appears that statsd_exporter may not support DogStatsD v1.2 https://docs.datadoghq.com/developers/dogstatsd/datagram_shell/?tab=metrics#dogstatsd-protocol-v12
Specifically, the container ID prefix |c:<CONTAINER_ID>. Here's example from debug logging:
level=debug ts=2025-07-08T18:34:11.692Z caller=listener.go:73 msg="Incoming line" proto=udp line=datadog.dogstatsd.client.metrics_by_type:0|c|#service:abc,client:go,client_version:5.4.0,client_transport:udp,metrics_type:count|c:3a88c225dbeb98f20bbb40cbd39ef90b094ce74291ae66fbd98b7f06f2a15b86
level=debug ts=2025-07-08T18:34:11.692Z caller=line.go:295 msg="Invalid sampling factor or tag section" component=#service:abc,client:go,client_version:5.4.0,client_transport:udp,metrics_type:count line=datadog.dogstatsd.client.metrics_by_type:0|c|#service:abc,client:go,client_version:5.4.0,client_transport:udp,metrics_type:count|c:3a88c225dbeb98f20bbb40cbd39ef90b094ce74291ae66fbd98b7f06f2a15b86
Happy to take a crack at this if needed. It looks like adding a switch to https://github.com/prometheus/statsd_exporter/blob/master/pkg/line/line.go#L321 might be the way to handle this.