NETOBSERV-101 R&D: Kube enricher write path for downstream operator

[jpinsonneau]

This PR adds Authorization header to loki client

This header can contains service account token to authenticate in loki operator gateway

[OlivierCazade]

The HTTP client used by the loki client already has a Bearer token feature:
https://github.com/prometheus/common/blob/main/config/http_config.go

I think it would be better to use it so we do not diverge too much from the original loki-client.

[jpinsonneau]

The HTTP client used by the loki client already has a Bearer token feature: https://github.com/prometheus/common/blob/main/config/http_config.go

I think it would be better to use it so we do not diverge too much from the original loki-client.

Very good catch @OlivierCazade, thanks a lot !
We can directly send the following config to flowlogs-pipeline

"clientConfig":{
   "authorization":{
      "type":"Bearer",
      "credentials_file":"/var/run/secrets/tokens/flowlogs-pipeline"
   },
   ...
},

and avoid this PR and netobserv/flowlogs-pipeline#260