From 0f7253febb1cad14e7fa115799fa170b57731eb8 Mon Sep 17 00:00:00 2001
From: Brad Rydzewski <brad.rydzewski@gmail.com>
Date: Thu, 25 Aug 2016 11:35:28 -0700
Subject: [PATCH] choose ambassador by platform

---
 agent/agent.go        |  2 +-
 yaml/transform/pod.go | 41 +++++++++++++++++++++++++++++++++++++----
 2 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/agent/agent.go b/agent/agent.go
index 9a63fcf4..2a1e343f 100644
--- a/agent/agent.go
+++ b/agent/agent.go
@@ -167,7 +167,7 @@ func (a *Agent) prep(w *queue.Work) (*yaml.Config, error) {
 		transform.ImageVolume(conf, []string{a.Local + ":" + conf.Workspace.Path})
 	}
 
-	transform.Pod(conf)
+	transform.Pod(conf, a.Platform)
 
 	return conf, nil
 }
diff --git a/yaml/transform/pod.go b/yaml/transform/pod.go
index ae734cd6..dd92acbb 100644
--- a/yaml/transform/pod.go
+++ b/yaml/transform/pod.go
@@ -9,21 +9,54 @@ import (
 	"github.com/gorilla/securecookie"
 )
 
+type ambassador struct {
+	image      string
+	entrypoint []string
+	command    []string
+}
+
+// default linux amd64 ambassador
+var defaultAmbassador = ambassador{
+	image:      "busybox:latest",
+	entrypoint: []string{"/bin/sleep"},
+	command:    []string{"86400"},
+}
+
+// lookup ambassador configuration by architecture and os
+var lookupAmbassador = map[string]ambassador{
+	"linux/amd64": {
+		image:      "busybox:latest",
+		entrypoint: []string{"/bin/sleep"},
+		command:    []string{"86400"},
+	},
+	"linux/arm": {
+		image:      "armhf/alpine:latest",
+		entrypoint: []string{"/bin/sleep"},
+		command:    []string{"86400"},
+	},
+}
+
 // Pod transforms the containers in the Yaml to use Pod networking, where every
 // container shares the localhost connection.
-func Pod(c *yaml.Config) error {
+func Pod(c *yaml.Config, platform string) error {
 
 	rand := base64.RawURLEncoding.EncodeToString(
 		securecookie.GenerateRandomKey(8),
 	)
 
+	// choose the ambassador configuration based on os and architecture
+	conf, ok := lookupAmbassador[platform]
+	if !ok {
+		conf = defaultAmbassador
+	}
+
 	ambassador := &yaml.Container{
 		ID:          fmt.Sprintf("drone_ambassador_%s", rand),
 		Name:        "ambassador",
-		Image:       "busybox:latest",
+		Image:       conf.image,
 		Detached:    true,
-		Entrypoint:  []string{"/bin/sleep"},
-		Command:     []string{"86400"},
+		Entrypoint:  conf.entrypoint,
+		Command:     conf.command,
 		Volumes:     []string{c.Workspace.Path, c.Workspace.Base},
 		Environment: map[string]string{},
 	}