feat(pprof): add pprof HTTP server (#807)

- `PPROF_ENABLED=no`
- `PPROF_BLOCK_PROFILE_RATE=0`
- `PPROF_MUTEX_PROFILE_RATE=0`
- `PPROF_HTTP_SERVER_ADDRESS=":6060"`

internal/httpserver/run_test.go

@@ -0,0 +1,75 @@
+package httpserver
+
+import (
+	"context"
+	"regexp"
+	"testing"
+	"time"
+
+	gomock "github.com/golang/mock/gomock"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_Server_Run_success(t *testing.T) {
+	t.Parallel()
+
+	ctrl := gomock.NewController(t)
+
+	logger := NewMockLogger(ctrl)
+	logger.EXPECT().Info(newRegexMatcher("^test http server listening on 127.0.0.1:[1-9][0-9]{0,4}$"))
+	logger.EXPECT().Warn("test http server shutting down: context canceled")
+	const shutdownTimeout = 10 * time.Second
+
+	server := &Server{
+		name:            "test",
+		address:         "127.0.0.1:0",
+		addressSet:      make(chan struct{}),
+		logger:          logger,
+		shutdownTimeout: shutdownTimeout,
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	ready := make(chan struct{})
+	done := make(chan struct{})
+
+	go server.Run(ctx, ready, done)
+
+	addressRegex := regexp.MustCompile(`^127.0.0.1:[1-9][0-9]{0,4}$`)
+	address := server.GetAddress()
+	assert.Regexp(t, addressRegex, address)
+	address = server.GetAddress()
+	assert.Regexp(t, addressRegex, address)
+
+	<-ready
+
+	cancel()
+	_, ok := <-done
+	assert.False(t, ok)
+}
+
+func Test_Server_Run_failure(t *testing.T) {
+	t.Parallel()
+	ctrl := gomock.NewController(t)
+
+	logger := NewMockLogger(ctrl)
+	logger.EXPECT().Error("listen tcp: address -1: invalid port")
+
+	server := &Server{
+		name:       "test",
+		address:    "127.0.0.1:-1",
+		addressSet: make(chan struct{}),
+		logger:     logger,
+	}
+
+	ready := make(chan struct{})
+	done := make(chan struct{})
+
+	go server.Run(context.Background(), ready, done)
+
+	select {
+	case <-ready:
+		t.Fatal("server should not be ready")
+	case _, ok := <-done:
+		assert.False(t, ok)
+	}
+}