Add /health.svg endpoint to serve a small queue status badge.

This is inspired by shields.io, but is served directly.

Future work: show overall health percentage somehow (pie chart? sparklines?).

Author: Ryan Hitchman

hack/verify-flags/exceptions.txt

@@ -1,9 +1,8 @@
-ingress/controllers/nginx/README.md:Enables which HTTP codes should be passed for processing with the [error_page directive](http://nginx.org/en/docs/http/ngx_http_core_module.html#error_page)
-ingress/controllers/nginx/README.md:Setting at least one code this also enables [proxy_intercept_errors](http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_intercept_errors) (required to process error_page)
 ingress/controllers/nginx/nginx.tmpl:        require("error_page")
 ingress/controllers/nginx/nginx.tmpl:    error_page {{ $errCode }} = @custom_{{ $errCode }};{{ end }}
 ingress/controllers/nginx/nginx/config/config.go:	// enables which HTTP codes should be passed for processing with the error_page directive
 mungegithub/mungers/submit-queue.go:		sq.e2e = &fake_e2e.FakeE2ETester{
 mungegithub/mungers/submit-queue.go:	fake_e2e "k8s.io/contrib/mungegithub/mungers/e2e/fake"
+mungegithub/mungers/submit-queue_test.go:	e2e := sq.e2e.(*fake_e2e.FakeE2ETester)
 mungegithub/mungers/submit-queue_test.go:	fake_e2e "k8s.io/contrib/mungegithub/mungers/e2e/fake"
 mungegithub/mungers/submit-queue_test.go:	sq.e2e = &fake_e2e.FakeE2ETester{

mungegithub/mungers/e2e/fake/fake.go

@@ -25,6 +25,7 @@ import (
 type FakeE2ETester struct {
 	JobNames           []string
 	WeakStableJobNames []string
+	NotStableJobNames  []string
 }
 
 // Flakes returns nil.
@@ -47,5 +48,8 @@ func (e *FakeE2ETester) GetBuildStatus() map[string]e2e.BuildInfo {
 	for _, name := range e.WeakStableJobNames {
 		out[name] = e2e.BuildInfo{"Stable", "1"}
 	}
+	for _, name := range e.NotStableJobNames {
+		out[name] = e2e.BuildInfo{"Not Stable", "1"}
+	}
 	return out
 }

mungegithub/mungers/shield/shield.go

@@ -0,0 +1,80 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+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 shield
+
+// shield provides a local version of the shields.io service.
+
+import (
+	"bytes"
+	"html/template"
+)
+
+var svg = `<svg xmlns="http://www.w3.org/2000/svg" width="{{.Width}}" height="20">
+<linearGradient id="a" x2="0" y2="100%">
+  <stop offset="0" stop-color="#bbb" stop-opacity=".1"/>
+  <stop offset="1" stop-opacity=".1"/>
+</linearGradient>
+<rect rx="3" width="100%" height="20" fill="#555"/>
+<g fill="{{.Color}}">
+  <rect rx="3" x="{{.RightStart}}" width="{{.RightWidth}}" height="20"/>
+  <path d="M{{.RightStart}} 0h4v20h-4z"/>
+</g>
+<rect rx="3" width="100%" height="20" fill="url(#a)"/>
+<g fill="#fff" text-anchor="middle" font-family="DejaVu Sans,Verdana,Geneva,sans-serif" font-size="11">
+<g fill="#010101" opacity=".3">
+<text x="{{.XposLeft}}" y="15">{{.Subject}}</text>
+<text x="{{.XposRight}}" y="15">{{.Status}}</text>
+</g>
+<text x="{{.XposLeft}}" y="14">{{.Subject}}</text>
+<text x="{{.XposRight}}" y="14">{{.Status}}</text>
+</g>
+</svg>`
+
+var svgTemplate = template.Must(template.New("svg").Parse(svg))
+
+// Make a small SVG badge that looks like `[subject | status]`, with the status
+// text in the given color.
+func Make(subject, status, color string) []byte {
+	// TODO(rmmh): Use better font-size metrics for prettier badges-- estimating
+	// character widths as 6px isn't very accurate.
+	// See also: https://github.com/badges/shields/blob/master/measure-text.js
+	p := struct {
+		Width, RightStart, RightWidth int
+		XposLeft, XposRight           float64
+		Subject, Status               string
+		Color                         string
+	}{
+		Subject:    subject,
+		Status:     status,
+		RightStart: 13 + 6*len(subject),
+		RightWidth: 13 + 6*len(status),
+	}
+	p.Width = p.RightStart + p.RightWidth
+	p.XposLeft = float64(p.RightStart) * 0.5
+	p.XposRight = float64(p.RightStart) + float64(p.RightWidth-2)*0.5
+	switch color {
+	case "brightgreen":
+		p.Color = "#4c1"
+	case "red":
+		p.Color = "#e05d44"
+	default:
+		panic("Invalid color " + color)
+	}
+	var buf bytes.Buffer
+	svgTemplate.Execute(&buf, p)
+	return buf.Bytes()
+}

mungegithub/mungers/submit-queue.go

@@ -36,6 +36,7 @@ import (
 	"k8s.io/contrib/mungegithub/github"
 	"k8s.io/contrib/mungegithub/mungers/e2e"
 	fake_e2e "k8s.io/contrib/mungegithub/mungers/e2e/fake"
+	"k8s.io/contrib/mungegithub/mungers/shield"
 	"k8s.io/contrib/test-utils/utils"
 
 	"github.com/NYTimes/gziphandler"
@@ -393,6 +394,7 @@ func (sq *SubmitQueue) internalInitialize(config *github.Config, features *featu
 		http.Handle("/merge-info", gziphandler.GzipHandler(http.HandlerFunc(sq.serveMergeInfo)))
 		http.Handle("/priority-info", gziphandler.GzipHandler(http.HandlerFunc(sq.servePriorityInfo)))
 		http.Handle("/health", gziphandler.GzipHandler(http.HandlerFunc(sq.serveHealth)))
+		http.Handle("/health.svg", gziphandler.GzipHandler(http.HandlerFunc(sq.serveHealthSVG)))
 		http.Handle("/sq-stats", gziphandler.GzipHandler(http.HandlerFunc(sq.serveSQStats)))
 		http.Handle("/flakes", gziphandler.GzipHandler(http.HandlerFunc(sq.serveFlakes)))
 		config.ServeDebugStats("/stats")
@@ -1269,6 +1271,40 @@ func (sq *SubmitQueue) servePriorityInfo(res http.ResponseWriter, req *http.Requ
 </ol> `))
 }
 
+func (sq *SubmitQueue) getHealthSVG() []byte {
+	sq.Lock()
+	defer sq.Unlock()
+	blocked := false
+	blockingJobs := make([]string, 0)
+	blocked = !sq.health.MergePossibleNow
+	status := "running"
+	color := "brightgreen"
+	if blocked {
+		status = "blocked"
+		color = "red"
+		for job, status := range sq.e2e.GetBuildStatus() {
+			if status.Status == "Not Stable" {
+				job = strings.Replace(job, "kubernetes-", "", -1)
+				blockingJobs = append(blockingJobs, job)
+			}
+		}
+		sort.Strings(blockingJobs)
+		if len(blockingJobs) > 3 {
+			blockingJobs = append(blockingJobs[:3], "...")
+		}
+		if len(blockingJobs) > 0 {
+			status += " by " + strings.Join(blockingJobs, ", ")
+		}
+	}
+	return shield.Make("queue", status, color)
+}
+
+func (sq *SubmitQueue) serveHealthSVG(res http.ResponseWriter, req *http.Request) {
+	res.Header().Set("Content-type", "image/svg+xml")
+	res.WriteHeader(http.StatusOK)
+	res.Write(sq.getHealthSVG())
+}
+
 func (sq *SubmitQueue) isStaleComment(obj *github.MungeObject, comment githubapi.IssueComment) bool {
 	if !mergeBotComment(comment) {
 		return false

mungegithub/mungers/submit-queue_test.go

@@ -1276,3 +1276,26 @@ func TestHealth(t *testing.T) {
 		t.Errorf("updateHealth didn't truncate old entries: %v", sq.healthHistory)
 	}
 }
+
+func TestHealthSVG(t *testing.T) {
+	sq := getTestSQ(false, nil, nil)
+	e2e := sq.e2e.(*fake_e2e.FakeE2ETester)
+
+	for _, state := range []struct {
+		mergePossible bool
+		expected      string
+		notStable     []string
+	}{
+		{true, "running", nil},
+		{false, "blocked</text>", nil},
+		{false, "blocked by kubemark-500", []string{"kubernetes-kubemark-500"}},
+		{false, "blocked by a, b, c, ...", []string{"a", "b", "c", "d"}},
+	} {
+		sq.health.MergePossibleNow = state.mergePossible
+		e2e.NotStableJobNames = state.notStable
+		res := string(sq.getHealthSVG())
+		if !strings.Contains(res, state.expected) {
+			t.Errorf("SVG doesn't contain `%s`: %v", state.expected, res)
+		}
+	}
+}