Documentation: add compatibility doc

Documentation/compatibility.md

@@ -0,0 +1,26 @@
+# Compatibility
+
+The Prometheus Operator supports a number of Kubernetes and Prometheus releases.
+
+## Kubernetes
+
+The Prometheus Operator uses client-go to communicate with Kubernetes clusters. The supported Kubernetes cluster version is determined by client-go. The compatibility matrix for client-go and Kubernetes clusters can be found [here](https://github.com/kubernetes/client-go#compatibility-matrix). All additional compatibility is only best effort, or happens to still/already be supported. The currently used client-go version is "v4.0.0-beta.0".
+
+## Prometheus
+
+The versions of Prometheus compatible to be run with the Prometheus Operator are:
+
+* v1.4.0
+* v1.4.1
+* v1.5.0
+* v1.5.1
+* v1.5.2
+* v1.5.3
+* v1.6.0
+* v1.6.1
+* v1.6.2
+* v1.6.3
+* v1.7.0
+* v1.7.1
+* v2.0.0-alpha.3
+* v2.0.0-beta.0

Makefile

@@ -49,12 +49,13 @@ promu:
 embedmd:
 	@go get github.com/campoy/embedmd
 
-apidocgen:
-	@go install github.com/coreos/prometheus-operator/cmd/apidocgen
+po-docgen:
+	@go install github.com/coreos/prometheus-operator/cmd/po-docgen
 
-docs: embedmd apidocgen
+docs: embedmd po-docgen
 	$(GOPATH)/bin/embedmd -w `find Documentation -name "*.md"`
-	$(GOPATH)/bin/apidocgen pkg/client/monitoring/v1alpha1/types.go > Documentation/api.md
+	$(GOPATH)/bin/po-docgen api pkg/client/monitoring/v1alpha1/types.go > Documentation/api.md
+	$(GOPATH)/bin/po-docgen compatibility > Documentation/compatibility.md
 
 generate: jsonnet-docker
 	docker run --rm -v `pwd`:/go/src/github.com/coreos/prometheus-operator po-jsonnet make jsonnet generate-bundle docs

cmd/po-docgen/api.go

@@ -21,7 +21,6 @@ import (
 	"go/doc"
 	"go/parser"
 	"go/token"
-	"os"
 	"reflect"
 	"strings"
 )
@@ -48,17 +47,17 @@ var (
 	selfLinks = map[string]string{}
 )
 
-func main() {
+func printAPIDocs(path string) {
 	fmt.Println(firstParagraph)
 
-	types := ParseDocumentationFrom(os.Args[1])
+	types := ParseDocumentationFrom(path)
 	for _, t := range types {
 		strukt := t[0]
 		selfLinks[strukt.Name] = "#" + strings.ToLower(strukt.Name)
 	}
 
 	// we need to parse once more to now add the self links
-	types = ParseDocumentationFrom(os.Args[1])
+	types = ParseDocumentationFrom(path)
 
 	for _, t := range types {
 		strukt := t[0]

cmd/po-docgen/compatibility.go

@@ -0,0 +1,39 @@
+// Copyright 2016 The prometheus-operator Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"fmt"
+
+	"github.com/coreos/prometheus-operator/pkg/prometheus"
+)
+
+func printCompatMatrixDocs() {
+	fmt.Println(`# Compatibility
+
+The Prometheus Operator supports a number of Kubernetes and Prometheus releases.
+
+## Kubernetes
+
+The Prometheus Operator uses client-go to communicate with Kubernetes clusters. The supported Kubernetes cluster version is determined by client-go. The compatibility matrix for client-go and Kubernetes clusters can be found [here](https://github.com/kubernetes/client-go#compatibility-matrix). All additional compatibility is only best effort, or happens to still/already be supported. The currently used client-go version is "v4.0.0-beta.0".
+
+## Prometheus
+
+The versions of Prometheus compatible to be run with the Prometheus Operator are:
+`)
+	for _, v := range prometheus.CompatibilityMatrix {
+		fmt.Printf("* %s\n", v)
+	}
+}

cmd/po-docgen/main.go

@@ -0,0 +1,28 @@
+// Copyright 2016 The prometheus-operator Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"os"
+)
+
+func main() {
+	switch os.Args[1] {
+	case "api":
+		printAPIDocs(os.Args[2])
+	case "compatibility":
+		printCompatMatrixDocs()
+	}
+}

pkg/prometheus/statefulset.go

@@ -66,6 +66,7 @@ var (
 		"v1.7.0",
 		"v1.7.1",
 		"v2.0.0-alpha.3",
+		"v2.0.0-beta.0",
 	}
 )