fix(build.go,builder_key.go,etcd.go,run.go): add etcd read functionality

to read the builder key

Author: arschles

pkg/gitreceive/build.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"code.google.com/p/go-uuid/uuid"
+	"github.com/coreos/go-etcd/etcd"
 	"github.com/deis/builder/pkg"
 	"github.com/deis/builder/pkg/log"
 	"gopkg.in/yaml.v2"
@@ -28,7 +29,13 @@ func (e errGitShaTooShort) Error() string {
 	return fmt.Sprintf("git sha %s was too short", e.sha)
 }
 
-func build(conf *Config, newRev string) error {
+func build(conf *Config, etcdClient *etcd.Client) error {
+	// TODO: replace etcd usage here with something else. See https://github.com/deis/builder/issues/81
+	builderKey, err := getBuilderKey(etcdClient)
+	if err != nil {
+		return fmt.Errorf("couldn't get builder key %s (%s)", builderKey, err)
+	}
+
 	// HTTP_PREFIX="http"
 	// REMOTE_STORAGE="0"
 	// # if minio is in the cluster, use it. otherwise use fetcher
@@ -431,7 +438,7 @@ func build(conf *Config, newRev string) error {
 
 	cfg, err := getAppConfig(
 		conf,
-		getBuilderKey(),
+		builderKey,
 		conf.Username,
 		conf.App,
 	)
@@ -464,7 +471,7 @@ func build(conf *Config, newRev string) error {
 	}
 	buildHookResp, err := publishRelease(
 		conf,
-		getBuilderKey(),
+		builderKey,
 		buildHook,
 	)
 	if err != nil {

pkg/gitreceive/builder_key.go

@@ -0,0 +1,26 @@
+package gitreceive
+
+import (
+	"errors"
+
+	"github.com/coreos/go-etcd/etcd"
+)
+
+const (
+	builderKey = "/deis/controller/builderKey"
+)
+
+var (
+	errNoNode = errors.New("no etcd node")
+)
+
+func getBuilderKey(etcdClient *etcd.Client) (string, error) {
+	resp, err := etcdClient.Get(builderKey, false, false)
+	if err != nil {
+		return "", err
+	}
+	if resp.Node == nil {
+		return "", errNoNode
+	}
+	return resp.Node.Value, nil
+}

pkg/gitreceive/etcd/etcd.go

@@ -0,0 +1,60 @@
+package etcd
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+	"time"
+
+	"github.com/coreos/go-etcd/etcd"
+)
+
+const (
+	hostEnvVar         = "DEIS_ETCD_1_SERVICE_HOST"
+	portEnvVar         = "DEIS_ETCD_1_SERVICE_PORT_CLIENT"
+	defaultHost        = "localhost"
+	defaultPort        = "4001"
+	defaultRetryCycles = 2
+)
+
+var (
+	defaultRetrySleep = 200 * time.Millisecond
+)
+
+func CreateClientFromEnv() (*etcd.Client, error) {
+	host := os.Getenv(hostEnvVar)
+	port := os.Getenv(portEnvVar)
+	if host == "" {
+		host = defaultHost
+	}
+	if port == "" {
+		port = defaultPort
+	}
+	hosts := []string{
+		fmt.Sprintf("http://%s:%s", host, port),
+	}
+	client := etcd.NewClient(hosts)
+	client.CheckRetry = getCheckRetryFunc(defaultRetryCycles, defaultRetrySleep)
+
+	return client, nil
+}
+
+func getCheckRetryFunc(retryCycles int, retrySleep time.Duration) func(*etcd.Cluster, int, http.Response, error) error {
+	return func(c *etcd.Cluster, numReqs int, last http.Response, err error) error {
+		if numReqs > retryCycles*len(c.Machines) {
+			return fmt.Errorf("Tried and failed %d cluster connections: %s", retryCycles, err)
+		}
+
+		switch last.StatusCode {
+		case 0:
+			return nil
+		case 500:
+			time.Sleep(retrySleep)
+			return nil
+		case 200:
+			return nil
+		default:
+			return fmt.Errorf("Unhandled HTTP Error: %s %d", last.Status, last.StatusCode)
+		}
+	}
+}

pkg/gitreceive/run.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"os"
 	"strings"
+
+	"github.com/deis/builder/pkg/gitreceive/etcd"
 )
 
 // #!/bin/bash
@@ -49,6 +51,10 @@ func readLine(line string) (string, string, string, error) {
 }
 
 func Run(conf *Config) error {
+	etcdClient, err := etcd.CreateClientFromEnv()
+	if err != nil {
+		return err
+	}
 	scanner := bufio.NewScanner(os.Stdin)
 	for scanner.Scan() {
 		line := scanner.Text()
@@ -60,7 +66,7 @@ func Run(conf *Config) error {
 		if err := receive(conf, newRev); err != nil {
 			return err
 		}
-		if err := build(conf, newRev); err != nil {
+		if err := build(conf, etcdClient); err != nil {
 			return err
 		}
 	}