Add v1 to metrics API endpoint

crosbymichael · crosbymichael · commit f23edd3cc0bf · 2017-09-20T16:24:30.000-04:00
Fixes containerd#1399 This versions the prometheus metrics API so we can manage backwards incompatible changes in the future more easily. Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
diff --git a/RELEASES.md b/RELEASES.md
@@ -189,6 +189,15 @@ enumerating the support services and messages. See [api/](api) for details.
 Note that new services may be added in _minor_ releases. New service methods
 and new fields on messages may be added if they are optional.
 
+### Metrics API
+
+The metrics API that outputs prometheus style metrics will be versioned independently,
+prefixed with the API version. i.e. `/v1/metrics`, `/v2/metrics`.
+
+The metrics API version will be incremented when breaking changes are made to the prometheus
+output. New metrics can be added to the output in a backwards compatible manner without
+bumping the API version.
+
 #### Error Codes
 
 Error codes will not change in a patch release, unless a missing error code
diff --git a/docs/getting-started.md b/docs/getting-started.md
@@ -257,7 +257,7 @@ Waiting on things like the container's exit status and cgroup metrics are setup
 If you are familiar with prometheus you can curl the containerd metrics endpoint (in the `config.toml` that we created) to see your container's metrics:
 
 ```bash
-> curl 127.0.0.1:1338/metrics
+> curl 127.0.0.1:1338/v1/metrics
 ```
 
 Pretty cool right?
diff --git a/server/server.go b/server/server.go
@@ -136,7 +136,7 @@ func (s *Server) ServeGRPC(l net.Listener) error {
 // ServeMetrics provides a prometheus endpoint for exposing metrics
 func (s *Server) ServeMetrics(l net.Listener) error {
 	m := http.NewServeMux()
-	m.Handle("/metrics", metrics.Handler())
+	m.Handle("/v1/metrics", metrics.Handler())
 	return trapClosedConnErr(http.Serve(l, m))
 }
 

Original file line number	Diff line number	Diff line change
`@@ -136,7 +136,7 @@ func (s *Server) ServeGRPC(l net.Listener) error {`
`136`	`136`	`// ServeMetrics provides a prometheus endpoint for exposing metrics`
`137`	`137`	`func (s *Server) ServeMetrics(l net.Listener) error {`
`138`	`138`	`m := http.NewServeMux()`
`139`		`- m.Handle("/metrics", metrics.Handler())`
	`139`	`+ m.Handle("/v1/metrics", metrics.Handler())`
`140`	`140`	`return trapClosedConnErr(http.Serve(l, m))`
`141`	`141`	`}`
`142`	`142`