Rewrite console.sh and docker-init in Go

cmd/dockerinit/main.go

@@ -0,0 +1,95 @@
+package dockerinit
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path"
+	"strings"
+	"syscall"
+	"time"
+
+	log "github.com/Sirupsen/logrus"
+	"github.com/rancher/os/util"
+)
+
+const (
+	consoleDone = "/run/console-done"
+	dockerConf  = "/var/lib/rancher/conf/docker"
+	dockerLog   = "/var/log/docker.log"
+)
+
+func Main() {
+	if os.Getenv("DOCKER_CONF_SOURCED") == "" {
+		if err := sourceDockerConf(os.Args); err != nil {
+			log.Warnf("Failed to source %s: %v", dockerConf, err)
+		}
+	}
+
+	for {
+		if _, err := os.Stat(consoleDone); err == nil {
+			break
+		}
+		time.Sleep(200 * time.Millisecond)
+	}
+
+	dockerBin := "/usr/bin/docker"
+	for _, binPath := range []string{
+		"/opt/bin",
+		"/usr/local/bin",
+		"/var/lib/rancher/docker",
+	} {
+		if util.ExistsAndExecutable(path.Join(binPath, "dockerd")) {
+			dockerBin = path.Join(binPath, "dockerd")
+			break
+		}
+		if util.ExistsAndExecutable(path.Join(binPath, "docker")) {
+			dockerBin = path.Join(binPath, "docker")
+			break
+		}
+	}
+
+	if err := syscall.Mount("", "/", "", syscall.MS_SHARED|syscall.MS_REC, ""); err != nil {
+		log.Error(err)
+	}
+	if err := syscall.Mount("", "/run", "", syscall.MS_SHARED|syscall.MS_REC, ""); err != nil {
+		log.Error(err)
+	}
+
+	mountInfo, err := ioutil.ReadFile("/proc/self/mountinfo")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for _, mount := range strings.Split(string(mountInfo), "\n") {
+		if strings.Contains(mount, "/var/lib/docker /var/lib/docker") && strings.Contains(mount, "rootfs") {
+			os.Setenv("DOCKER_RAMDISK", "1")
+		}
+	}
+
+	args := []string{
+		"dockerlaunch",
+		dockerBin,
+	}
+
+	if len(os.Args) > 1 {
+		args = append(args, os.Args[1:]...)
+	}
+
+	if os.Getenv("DOCKER_OPTS") != "" {
+		args = append(args, os.Getenv("DOCKER_OPTS"))
+	}
+
+	log.Fatal(syscall.Exec("/usr/bin/dockerlaunch", args, os.Environ()))
+}
+
+func sourceDockerConf(args []string) error {
+	args = append([]string{
+		"bash",
+		"-c",
+		fmt.Sprintf(`[ -e %s ] && source %s; exec docker-init "$@" >> %s 2>&1`, dockerConf, dockerConf, dockerLog),
+	}, args...)
+	env := os.Environ()
+	env = append(env, "DOCKER_CONF_SOURCED=1")
+	return syscall.Exec("/bin/bash", args, env)
+}