Wait for fake influxd to have started

Two fake influxd types have been implemented for use in tests. The
funcs which started them would sometimes return before the fake server
was listening, causing test failures. The start funcs now wait for the
listener to have started before returning, eliminating occasional
spurious test failures.

spouttest/influxd.go

@@ -21,6 +21,7 @@ import (
 	"log"
 	"net/http"
 	"sync"
+	"time"
 )
 
 // RunFakeInfluxd starts a fake influxd instance with the HTTP port
@@ -31,12 +32,19 @@ func RunFakeInfluxd(port int) *FakeInfluxDB {
 		server: &http.Server{
 			Addr: fmt.Sprintf(":%d", port),
 		},
+		ready: make(chan struct{}),
 		lines: make(map[string][]string),
 	}
 
 	f.wg.Add(1)
 	go f.run()
 
+	select {
+	case <-f.ready:
+	case <-time.After(LongWait):
+		panic("FakeInfluxDB failed to start")
+	}
+
 	return f
 }
 
@@ -45,6 +53,7 @@ func RunFakeInfluxd(port int) *FakeInfluxDB {
 type FakeInfluxDB struct {
 	server *http.Server
 	wg     sync.WaitGroup
+	ready  chan struct{}
 
 	mu    sync.Mutex
 	lines map[string][]string
@@ -78,6 +87,7 @@ func (f *FakeInfluxDB) run() {
 	f.server.Handler = mux
 
 	log.Printf("fake influxd listening on %s", f.server.Addr)
+	close(f.ready)
 	f.server.ListenAndServe()
 }
 

writer/writer_medium_test.go

@@ -311,6 +311,7 @@ type testInfluxd struct {
 	server *http.Server
 	wg     sync.WaitGroup
 	Writes chan string
+	ready  chan struct{}
 }
 
 func runTestInfluxd() *testInfluxd {
@@ -319,9 +320,17 @@ func runTestInfluxd() *testInfluxd {
 			Addr: fmt.Sprintf(":%d", influxPort),
 		},
 		Writes: make(chan string, 99),
+		ready:  make(chan struct{}),
 	}
+
 	s.wg.Add(1)
 	go s.run()
+	select {
+	case <-s.ready:
+	case <-time.After(spouttest.LongWait):
+		panic("testInfluxd failed to start")
+	}
+
 	return s
 }
 
@@ -353,6 +362,7 @@ func (s *testInfluxd) run() {
 	mux := http.NewServeMux()
 	mux.HandleFunc("/write", s.handleWrite)
 	s.server.Handler = mux
+	close(s.ready)
 	s.server.ListenAndServe()
 }