push-gateway does not support passing authentication information

[JasonLi-cn]

metrics/metrics-exporter-prometheus/src/builder.rs

Line 65 in 8e2e39d

PushGateway { endpoint: Uri, interval: Duration },

Currently, pus-gateway only supports passing uri and interval, but not username and password.

[dzmitry-lahoda]

yeah, better have HTTPs support and support for default format for push in grafana cloud

API_KEY="<USER>:<TOKEN>"
URL="https://influx-prod-10-prod-us-central-0.grafana.net/api/v1/push/influx/write"

curl -X  POST -H  "Authorization: Bearer $API_KEY" -H  "Content-Type: text/plain" "$URL" -d "test,bar_label=abc,source=grafana_cloud_docs metric=35.2"

[tobz]

Addressed via #366.