Add service registration w/ etcd example

Author: jwilder

README.md

@@ -19,7 +19,7 @@ This is can be used to generate config files for:
 docker-gen
 Usage: docker-gen [-config file] [-watch=false] [-notify="restart xyz"] <template> [<dest>]
 ```
-  
+
 *Options:*
 * `-watch` - runs continuously and monitors docker container events.  When containers are started
 or stopped, the template is regenerated.
@@ -29,14 +29,23 @@ haproxy, etc..
 
 If no `<dest>` file is specified, the output is send to stdout.  Mainly useful for debugging.
 
-### Examples
+#### NGINX Reverse Proxy Config
 
-[Docker Log Management With Fluentd](http://jasonwilder.com/blog/2014/03/17/docker-log-management-using-fluentd/)
+`docker-gen -only-exposed -watch -notify "/etc/init.d/nginx reload" templates/nginx.tmpl /etc/nginx/sites-enabled/default`
 
 [Automated Nginx Reverse Proxy for Docker](http://jasonwilder.com/blog/2014/03/25/automated-nginx-reverse-proxy-for-docker/)
 
+#### Fluentd Log Management
+
+`docker-gen -watch -notify "restart fluentd" templates/fluentd.tmpl /etc/fluent/fluent.conf`
+
+[Docker Log Management With Fluentd](http://jasonwilder.com/blog/2014/03/17/docker-log-management-using-fluentd/)
+
+#### Register Containers in Etcd
+
+`docker-gen -notify "/bin/bash /tmp/etcd.sh" -interval 10 templates/etcd.tmpl /tmp/etcd.sh`
+
 
 ### TODO
 
  * Add a way to filter out containers in templates
- * Add a notify interval option

docker-gen.go

@@ -42,10 +42,49 @@ type Address struct {
 type RuntimeContainer struct {
 	ID        string
 	Addresses []Address
-	Image     string
+	Image     DockerImage
 	Env       map[string]string
 }
 
+type DockerImage struct {
+	Registry   string
+	Repository string
+	Tag        string
+}
+
+func (i *DockerImage) String() string {
+	ret := i.Repository
+	if i.Registry != "" {
+		ret = i.Registry + "/" + i.Repository
+	}
+	if i.Tag != "" {
+		ret = ret + ":" + i.Tag
+	}
+	return ret
+}
+
+func splitDockerImage(img string) (string, string, string) {
+
+	index := 0
+	repository := img
+	var registry, tag string
+	if strings.Contains(img, "/") {
+		separator := strings.Index(img, "/")
+		registry = img[index:separator]
+		index = separator + 1
+		repository = img[index:]
+	}
+
+	if strings.Contains(img, ":") {
+		separator := strings.Index(img, ":")
+		repository = img[index:separator]
+		index = separator + 1
+		tag = img[index:]
+	}
+
+	return registry, repository, tag
+}
+
 type Config struct {
 	Template    string
 	Dest        string
@@ -161,9 +200,14 @@ func getContainers(client *docker.Client) ([]*RuntimeContainer, error) {
 			continue
 		}
 
+		registry, repository, tag := splitDockerImage(container.Config.Image)
 		runtimeContainer := &RuntimeContainer{
-			ID:        container.ID,
-			Image:     container.Config.Image,
+			ID: container.ID,
+			Image: DockerImage{
+				Registry:   registry,
+				Repository: repository,
+				Tag:        tag,
+			},
 			Addresses: []Address{},
 			Env:       make(map[string]string),
 		}

docker-gen_test.go

@@ -0,0 +1,99 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestSplitDockerImageRepository(t *testing.T) {
+	registry, repository, tag := splitDockerImage("ubuntu")
+
+	if registry != "" {
+		t.Fail()
+	}
+	if repository != "ubuntu" {
+		t.Fail()
+	}
+	if tag != "" {
+		t.Fail()
+	}
+
+	dockerImage := DockerImage{
+		Registry:   registry,
+		Repository: repository,
+		Tag:        tag,
+	}
+	if "ubuntu" != dockerImage.String() {
+		t.Fail()
+	}
+}
+
+func TestSplitDockerImageWithRegistry(t *testing.T) {
+	registry, repository, tag := splitDockerImage("custom.registry/ubuntu")
+
+	if registry != "custom.registry" {
+		t.Fail()
+	}
+	if repository != "ubuntu" {
+		t.Fail()
+	}
+	if tag != "" {
+		t.Fail()
+	}
+	dockerImage := DockerImage{
+		Registry:   registry,
+		Repository: repository,
+		Tag:        tag,
+	}
+	if "custom.registry/ubuntu" != dockerImage.String() {
+		t.Fail()
+	}
+
+}
+
+func TestSplitDockerImageWithRegistryAndTag(t *testing.T) {
+	registry, repository, tag := splitDockerImage("custom.registry/ubuntu:12.04")
+
+	if registry != "custom.registry" {
+		t.Fail()
+	}
+	if repository != "ubuntu" {
+		t.Fail()
+	}
+	if tag != "12.04" {
+		t.Fail()
+	}
+	dockerImage := DockerImage{
+		Registry:   registry,
+		Repository: repository,
+		Tag:        tag,
+	}
+	if "custom.registry/ubuntu:12.04" != dockerImage.String() {
+		t.Fail()
+	}
+
+}
+
+func TestSplitDockerImageWithRepositoryAndTag(t *testing.T) {
+	registry, repository, tag := splitDockerImage("ubuntu:12.04")
+
+	if registry != "" {
+		t.Fail()
+	}
+
+	if repository != "ubuntu" {
+		t.Fail()
+	}
+
+	if tag != "12.04" {
+		t.Fail()
+	}
+	dockerImage := DockerImage{
+		Registry:   registry,
+		Repository: repository,
+		Tag:        tag,
+	}
+	if "ubuntu:12.04" != dockerImage.String() {
+		t.Fail()
+	}
+
+}

example.conf

@@ -8,4 +8,11 @@ notifycmd = "/etc/init.d/nginx reload"
 template = "templates/fluentd.conf.tmpl"
 dest = "/tmp/fluentd.conf"
 watch = true
-notifycmd = "echo test"
+notifycmd = "echo test"
+
+[[config]]
+template = "templates/etcd.tmpl"
+dest = "/tmp/etcd.sh"
+watch = true
+notifycmd = "/bin/bash /tmp/etcd.sh"
+interval = 10

templates/etcd.tmpl

@@ -0,0 +1,9 @@
+
+#!/bin/bash
+
+
+{{range $key, $value := .}}
+{{ with $address := index $value.Addresses 0 }}
+curl -L http://127.0.0.1:4001/v2/keys/backends/{{ $value.Image.Repository}}/{{printf "%.*s" 12 $value.ID}} -XPUT -d value="{{ $address.IP }}:{{ $address.Port }}" -d ttl=15
+{{ end }}
+{{end}}