e2e: add readiness check in tests

Fixes #224

Author: mmatczuk

cmd/forwarder/httpbin/httpbin.go

@@ -46,7 +46,7 @@ func Command() (cmd *cobra.Command) {
 		apiServerConfig:  forwarder.DefaultHTTPServerConfig(),
 		logConfig:        log.DefaultConfig(),
 	}
-	c.apiServerConfig.Addr = ":10000"
+	c.apiServerConfig.Addr = "localhost:10000"
 
 	defer func() {
 		fs := cmd.Flags()

e2e/docker-compose.yaml

@@ -3,6 +3,8 @@ version: "3.8"
 services:
   proxy:
     image: saucelabs/forwarder:${FORWARDER_VERSION}
+    environment:
+      FORWARDER_API_ADDRESS: ":10000"
 
   upstream-proxy:
     extends: proxy

e2e/e2e_test.go

@@ -4,6 +4,7 @@ package e2e
 
 import (
 	"context"
+	"flag"
 	"fmt"
 	"math/rand"
 	"net"
@@ -15,8 +16,29 @@ import (
 	"testing"
 
 	"github.com/gavv/httpexpect/v2"
+	"golang.org/x/sync/errgroup"
 )
 
+func TestMain(m *testing.M) {
+	if !flag.Parsed() {
+		flag.Parse()
+	}
+
+	var eg errgroup.Group
+	eg.Go(func() error {
+		return waitForServerReady(*proxy)
+	})
+	eg.Go(func() error {
+		return waitForServerReady(*httpbin)
+	})
+	if err := eg.Wait(); err != nil {
+		fmt.Fprintf(os.Stderr, err.Error()+"\n")
+		os.Exit(1)
+	}
+
+	os.Exit(m.Run())
+}
+
 func TestStatusCodes(t *testing.T) {
 	// List of all valid status codes plus some non-standard ones.
 	// See https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml

e2e/framework.go

@@ -1,13 +1,16 @@
 package e2e
 
 import (
+	"context"
 	"crypto/tls"
 	"flag"
+	"fmt"
 	"net/http"
 	"net/url"
 	"os"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/gavv/httpexpect/v2"
 	"github.com/gorilla/websocket"
@@ -16,6 +19,7 @@ import (
 var (
 	proxy              = flag.String("proxy", "", "URL of the proxy to test against")
 	httpbin            = flag.String("httpbin", "", "URL of the httpbin server to test against")
+	maxWait            = flag.Duration("max-wait", 5*time.Second, "Maximum time to wait for the containers to become ready")
 	insecureSkipVerify = flag.Bool("insecure-skip-verify", false, "Skip TLS certificate verification")
 )
 
@@ -27,6 +31,44 @@ func init() {
 	}
 }
 
+// waitForServerReady checks the API server /readyz endpoint until it returns 200.
+// It assumes that the server is running on port 10000.
+func waitForServerReady(baseURL string) error {
+	var client http.Client
+
+	u, err := url.Parse(baseURL)
+	if err != nil {
+		return err
+	}
+	readyz := fmt.Sprintf("http://%s:10000/readyz", u.Hostname())
+
+	req, err := http.NewRequest(http.MethodGet, readyz, http.NoBody)
+	if err != nil {
+		return err
+	}
+
+	const backoff = 200 * time.Millisecond
+
+	var (
+		resp *http.Response
+		rerr error
+	)
+	for i := 0; i < int(*maxWait/backoff); i++ {
+		resp, rerr = client.Do(req.Clone(context.Background()))
+
+		if resp != nil && resp.StatusCode == http.StatusOK {
+			return nil
+		}
+
+		time.Sleep(backoff)
+	}
+	if rerr != nil {
+		return fmt.Errorf("%s not ready: %w", u.Hostname(), rerr)
+	}
+
+	return fmt.Errorf("%s not ready", u.Hostname())
+}
+
 func newTransport(t testing.TB) *http.Transport {
 	t.Helper()
 

e2e/go.mod

@@ -5,6 +5,7 @@ go 1.20
 require (
 	github.com/gavv/httpexpect/v2 v2.6.1
 	github.com/gorilla/websocket v1.4.2
+	golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9
 )
 
 require (

e2e/go.sum

@@ -117,6 +117,7 @@ golang.org/x/net v0.0.0-20220225172249-27dd8689420f h1:oA4XRj0qtSt8Yo1Zms0CUlsT3
 golang.org/x/net v0.0.0-20220225172249-27dd8689420f/go.mod h1:CfG3xpIq0wQ8r1q4Su4UZFWDARRcnwPjda9FqA0JpMk=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9 h1:SQFwaSi55rU7vdNs9Yr0Z324VNlrF+0wMqRXT4St8ck=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=