Split Proxy from API

[ywwg]

In our other proxies, the API is the object that handles receiving and handling requests. The service that actually spins up a server and listens for connections that get handed to the API is the proxy object. This change splits these pieces apart so they are more clearly separated.

It also implements the proxy as a proper dskit service, which is the standard for Grafana services. It also provides defaults for the logger and registerer so callers don't have to specify obvious defaults.

[grafanabot]

Go coverage report:

Click to expand.

File	%
github.com/grafana/influx2cortex/pkg/errorx/errors.go	67.3%
github.com/grafana/influx2cortex/pkg/errorx/http_translator.go	100.0%
github.com/grafana/influx2cortex/pkg/influx/api.go	100.0%
github.com/grafana/influx2cortex/pkg/influx/errors.go	100.0%
github.com/grafana/influx2cortex/pkg/influx/parser.go	84.1%
github.com/grafana/influx2cortex/pkg/influx/proxy.go	69.2%
github.com/grafana/influx2cortex/pkg/influx/recorder.go	91.7%
github.com/grafana/influx2cortex/pkg/remotewrite/client.go	69.1%
github.com/grafana/influx2cortex/pkg/remotewrite/measured_client.go	88.9%
github.com/grafana/influx2cortex/pkg/remotewrite/recorder.go	100.0%
github.com/grafana/influx2cortex/pkg/route/registerer.go	100.0%
github.com/grafana/influx2cortex/pkg/server/middleware/http_auth.go	0.0%
github.com/grafana/influx2cortex/pkg/server/middleware/http_fake_auth.go	0.0%
github.com/grafana/influx2cortex/pkg/server/middleware/instrument.go	6.7%
github.com/grafana/influx2cortex/pkg/server/middleware/logging.go	69.7%
github.com/grafana/influx2cortex/pkg/server/middleware/middleware.go	0.0%
github.com/grafana/influx2cortex/pkg/server/middleware/request_limits.go	81.8%
github.com/grafana/influx2cortex/pkg/server/middleware/response.go	57.1%
github.com/grafana/influx2cortex/pkg/server/middleware/route_matcher.go	0.0%
github.com/grafana/influx2cortex/pkg/server/middleware/tracer.go	13.0%
github.com/grafana/influx2cortex/pkg/server/server.go	83.3%
github.com/grafana/influx2cortex/pkg/tenant/resolver.go	75.6%
github.com/grafana/influx2cortex/pkg/tenant/tenant.go	91.7%
github.com/grafana/influx2cortex/pkg/util/bytereplacer/byte_replacer.go	100.0%
github.com/grafana/influx2cortex/pkg/util/extract_forwarded.go	66.7%
github.com/grafana/influx2cortex/pkg/util/http.go	68.3%
github.com/grafana/influx2cortex/pkg/util/log/experimental.go	0.0%
github.com/grafana/influx2cortex/pkg/util/log/log.go	0.0%
github.com/grafana/influx2cortex/pkg/util/log/rate_limit.go	90.0%
github.com/grafana/influx2cortex/pkg/util/log/wrappers.go	0.0%
github.com/grafana/influx2cortex/pkg/util/push/push.go	60.0%
total	65.5%

Go lint report:

No issues found. 😎

[leizor]

😎