New hologram-boot script that's not adroll-specific

Previous boot script used internal adroll host for checking that network
is up. Replaced it with go binary that gets the hostname for the server
from the config file and doesn't launch "hologram" me until both network
and server are up.

Makefile

@@ -30,7 +30,7 @@ setup: .setup-complete
 
 package: bin/darwin/Hologram-$(GIT_TAG).pkg bin/linux/hologram-$(GIT_TAG).deb bin/linux/hologram-server-$(GIT_TAG).deb
 
-build: bin/darwin/hologram-server bin/linux/hologram-server bin/darwin/hologram-agent bin/linux/hologram-agent bin/darwin/hologram-cli bin/linux/hologram-cli bin/darwin/hologram-authorize bin/linux/hologram-authorize
+build: bin/darwin/hologram-server bin/linux/hologram-server bin/darwin/hologram-agent bin/linux/hologram-agent bin/darwin/hologram-cli bin/linux/hologram-cli bin/darwin/hologram-authorize bin/linux/hologram-authorize bin/darwin/hologram-boot
 
 protocol/hologram.pb.go: protocol/hologram.proto
 	protoc --go_out=. protocol/hologram.proto
@@ -60,6 +60,10 @@ bin/%/hologram-cli: protocol/hologram.pb.go cli/*/*.go log/*.go log/.deps transp
 	@echo "Building CLI version $(GIT_TAG)$(GIT_DIRTY)"
 	@cd cli/bin; gox -osarch="$*/amd64" -output="../../bin/$*/hologram-cli"
 
+bin/darwin/hologram-boot: tools/boot/main.go
+	@cd tools/boot/; go build
+	@mv tools/boot/boot bin/darwin/hologram-boot
+
 bin/ping: tools/ping/main.go log/*.go log/.deps
 	@cd tools/ping; go build
 	@mv tools/ping/ping bin/ping
@@ -72,7 +76,7 @@ bin/darwin/Hologram-%.pkg: bin/darwin/hologram-agent bin/darwin/hologram-cli bin
 	@cp ./bin/darwin/hologram-cli ./pkg/darwin/root/usr/bin/hologram
 	@cp ./bin/darwin/hologram-authorize ./pkg/darwin/root/usr/bin/hologram-authorize
 	@cp ./config/agent.json ./pkg/darwin/root/etc/hologram/agent.json
-	@cp ./agent/support/darwin/hologram-boot.sh ./pkg/darwin/root/usr/bin/hologram-boot
+	@cp ./bin/darwin/hologram-boot ./pkg/darwin/root/usr/bin/hologram-boot
 	@cp ./agent/support/darwin/com.adroll.hologram-ip.plist ./pkg/darwin/root/Library/LaunchDaemons
 	@cp ./agent/support/darwin/com.adroll.hologram.plist ./pkg/darwin/root/Library/LaunchDaemons
 	@cp ./agent/support/darwin/com.adroll.hologram-me.plist ./pkg/darwin/root/Library/LaunchAgents

tools/boot/main.go

@@ -0,0 +1,63 @@
+// Script to launch "hologram me" as soon as the network/server are ready
+//
+// Copyright 2014 AdRoll, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"log"
+	"net"
+	"os/exec"
+	"time"
+)
+
+const configFile = "/etc/hologram/agent.json"
+
+type Config struct {
+	Host string `json:"host"`
+}
+
+func main() {
+	var config Config
+	contents, err := ioutil.ReadFile(configFile)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	err = json.Unmarshal(contents, &config)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for {
+		time.Sleep(1 * time.Second)
+		_, err := net.Dial("tcp", config.Host)
+		if err != nil {
+			// TODO: Better error handling. Exponential backoff if server is truly down
+			log.Println("Error connecting to server", err)
+			continue
+		}
+
+		log.Println("Booting hologram...")
+		cmd := exec.Command("/usr/bin/hologram", "me")
+		err = cmd.Run()
+		if err != nil {
+			log.Fatal("Error when starting up hologram", err)
+		}
+		break
+	}
+}