add bootstrap feature to AMP cluster CLI (#306)

cmd/amp-cluster/bootstrap-docker.go

@@ -0,0 +1,318 @@
+package main
+
+import (
+	"bytes"
+	"errors"
+	"github.com/blang/semver"
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/swarm"
+	dockerclient "github.com/docker/docker/client"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"os"
+	"os/exec"
+	"regexp"
+	"strings"
+	"syscall"
+)
+
+var DockerChannels = [...]string{"main"}
+
+//var DockerChannels = [...]string{"main", "testing"}
+
+const (
+	minimumDockerEngineVersion = "1.12.3"
+	dockerAPIMinVersion        = "1.24"
+	dockerUrl                  = "unix:///var/run/docker.sock"
+	dockerGetUrl               = "http://get.docker.com"
+	dockerRemoteAPIPort        = "2375"
+)
+
+var startCommands = [...]string{"systemctl start docker.service", "service docker start", "start docker"}
+var enableCommands = [...]string{"systemctl enable docker.service", "chkconfig docker on", "update-rc.d docker defaults"}
+
+func (c *clusterClient) getDockerServerVersion() (string, error) {
+	// first try the Docker api
+	if c.dockerClient == nil {
+		defaultHeaders := map[string]string{"User-Agent": "amp-bootstrap"}
+		c.dockerClient, _ = dockerclient.NewClient(dockerUrl, dockerAPIMinVersion, nil, defaultHeaders)
+	}
+	if c.dockerClient != nil {
+		version, err := c.dockerClient.ServerVersion(c.ctx)
+		if err == nil {
+			return version.Version, nil
+		}
+	}
+	c.printfc(colInfo, "Unable to contact the Docker server through the API, switch to the Docker cli\n")
+	var out bytes.Buffer
+	var stderr bytes.Buffer
+	versionCmd := [...]string{"docker", "version", "-f", "{{ .Server.Version }}"}
+	cmd := exec.Command(versionCmd[0], versionCmd[1:]...)
+	cmd.Stdout = &out
+	cmd.Stderr = &stderr
+	err := cmd.Run()
+	if err != nil {
+		c.printfc(colInfo, "%s failed: %s\n", versionCmd, stderr.String())
+		return "0.0.0", err
+	}
+	c.printfc(colInfo, "Installed Docker engine version: %s\n", out.String())
+	return strings.TrimRight(out.String(), "\n"), nil
+}
+
+func (c *clusterClient) enableDockerEngine() error {
+	var out bytes.Buffer
+	var stderr bytes.Buffer
+	enabled := false
+	c.printfc(colInfo, "Enabling Docker engine... \n")
+	for _, enableCmd := range enableCommands {
+		enableCmdSplitted := strings.Split(enableCmd, " ")
+		cmd := exec.Command(enableCmdSplitted[0], enableCmdSplitted[1:]...)
+		cmd.Stdout = &out
+		cmd.Stderr = &stderr
+		err := cmd.Run()
+		if err != nil {
+			continue
+		}
+		enabled = true
+	}
+	if enabled == false {
+		c.printfc(colInfo, "all methods failed\n")
+		return errors.New("Unable to enable the Docker engine")
+	}
+	c.printfc(colInfo, "done\n")
+	return nil
+}
+
+// update Docker configuration with pre-requisites
+// for now only on systemd compatible systems
+func (c *clusterClient) configureDockerEngine() error {
+	var execstart string
+	var out bytes.Buffer
+	var stderr bytes.Buffer
+	cmd := exec.Command("systemctl", "show", "--property=ExecStart docker")
+	cmd.Stdout = &out
+	cmd.Stderr = &stderr
+	err := cmd.Run()
+	if err != nil {
+		return err
+	}
+	re := regexp.MustCompile(`ExecStart={.*argv\[\]=([^;]*);.*`)
+	match := re.FindStringSubmatch(out.String())
+	if match == nil || len(match) < 2 {
+		// can't find an existing start command, rewrite it
+		execstart = "/usr/bin/dockerd"
+	} else {
+		execstart = match[1]
+	}
+	// add options to the start command
+	execstart = execstart + " -H 0.0.0.0:" + dockerRemoteAPIPort + " -H /var/run/docker.sock"
+
+	_, err = os.Stat("/etc/systemd/system")
+	if err == nil {
+		err := os.MkdirAll("/etc/systemd/system/docker.service.d", 0755)
+		if err != nil {
+			return err
+		}
+		file, err := os.Create("/etc/systemd/system/docker.service.d/override.conf")
+		if err != nil {
+			return err
+		}
+		defer file.Close()
+		content := `[Service]
+ExecStart=-
+ExecStart=` + execstart + `
+LimitNOFILE=-
+LimitNOFILE=infinity`
+		n, err := file.WriteString(content)
+		if err != nil {
+			return err
+		}
+		if n < len(content) {
+			return errors.New("unable to override Docker systemd configuration")
+		}
+	} else {
+		return err
+	}
+	return nil
+}
+
+// Try different methods to start the Docker engine
+func (c *clusterClient) startDockerEngine() error {
+	var out bytes.Buffer
+	var stderr bytes.Buffer
+
+	c.printfc(colInfo, "Starting Docker engine... \n")
+	started := false
+	for _, startCmd := range startCommands {
+		startCmdSplitted := strings.Split(startCmd, " ")
+		cmd := exec.Command(startCmdSplitted[0], startCmdSplitted[1:]...)
+		cmd.Stdout = &out
+		cmd.Stderr = &stderr
+		err := cmd.Run()
+		if err != nil {
+			// try next method
+			continue
+		}
+		started = true
+	}
+	if started == false {
+		c.printfc(colInfo, "all methods failed\n")
+		return errors.New("Unable to start the Docker engine")
+	}
+	c.printfc(colInfo, "done\n")
+	return nil
+}
+
+// Use the official script to install Docker
+func (c *clusterClient) installDockerEngine() error {
+	resp, err := http.Get(dockerGetUrl)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	tmpfile, err := ioutil.TempFile("", "get-docker")
+	if err != nil {
+		c.fatalc("%v\n", err)
+	}
+
+	defer os.Remove(tmpfile.Name())
+	if _, err := tmpfile.Write(body); err != nil {
+		c.fatalc("%v\n", err)
+	}
+	if err := tmpfile.Close(); err != nil {
+		c.fatalc("%v\n", err)
+	}
+
+	var out bytes.Buffer
+	var stderr bytes.Buffer
+
+	cmd := exec.Command("/bin/sh", tmpfile.Name())
+	cmd.Stdout = &out
+	cmd.Stderr = &stderr
+	c.printfc(colInfo, "Installing Docker engine... \n")
+	err = cmd.Run()
+	if err != nil {
+		c.printfc(colInfo, "failed\n")
+		c.printfc(colInfo, out.String())
+		c.printfc(colInfo, stderr.String())
+		return err
+	}
+	c.printfc(colInfo, "done\n")
+	return nil
+}
+
+func (c *clusterClient) validateInstalledDockerEngineVersion(version string) (bool, error) {
+	expected, err := semver.Make(minimumDockerEngineVersion)
+	if err != nil {
+		c.printfc(colInfo, "Minimum version is %s\n", minimumDockerEngineVersion)
+		return false, errors.New("Unable to parse minimum Docker engine version")
+	}
+	observed, err := semver.Make(version)
+	if err != nil {
+		c.printfc(colInfo, "Version is %s\n", version)
+		return false, errors.New("Unable to parse Docker engine version")
+	}
+	return observed.GTE(expected), nil
+}
+
+func (c *clusterClient) isSwarmInit() bool {
+	var out bytes.Buffer
+	var stderr bytes.Buffer
+	var waitStatus syscall.WaitStatus
+	checkCmd := "docker node inspect self"
+	checkCmdSplitted := strings.Split(checkCmd, " ")
+	cmd := exec.Command(checkCmdSplitted[0], checkCmdSplitted[1:]...)
+	cmd.Stdout = &out
+	cmd.Stderr = &stderr
+	err := cmd.Run()
+	if err != nil {
+		if exitError, ok := err.(*exec.ExitError); ok {
+			waitStatus = exitError.Sys().(syscall.WaitStatus)
+			c.printfc(colInfo, "Docker swarm mode is not set\n")
+		} else {
+			c.printfc(colInfo, "Failed to check Swarm status: %s\n", err)
+		}
+		return false
+	}
+	waitStatus = cmd.ProcessState.Sys().(syscall.WaitStatus)
+	if waitStatus != 0 {
+		c.printfc(colInfo, "isSwarmInit: returned %d - %s\n", waitStatus.ExitStatus(), out.String())
+		return false
+	}
+	return true
+}
+
+func (c *clusterClient) joinSwarm() error {
+	if c.dockerClient == nil {
+		defaultHeaders := map[string]string{"User-Agent": "amp-bootstrap"}
+		dclient, err := dockerclient.NewClient(dockerUrl, dockerAPIMinVersion, nil, defaultHeaders)
+		if err != nil {
+			return err
+		}
+		c.dockerClient = dclient
+	}
+	if createSwarm == false {
+		if swarmJoinToken == "" {
+			return errors.New("worker join token not set")
+		}
+		remoteAddresses := []string{swarmManagerHost + swarmManagerPort}
+		req := swarm.JoinRequest{ListenAddr: "0.0.0.0:" + swarmManagerPort, RemoteAddrs: remoteAddresses, JoinToken: swarmJoinToken}
+
+		return c.dockerClient.SwarmJoin(c.ctx, req)
+	}
+	if manager == false {
+		return errors.New("won't initialize the Swarm on a worker node")
+	}
+
+	// if multiple IPs, one should be specified
+	ifaces, err := net.Interfaces()
+	var ip net.IP
+	for _, i := range ifaces {
+		addrs, err := i.Addrs()
+		if err != nil {
+			return err
+		}
+		for _, addr := range addrs {
+			switch v := addr.(type) {
+			case *net.IPNet:
+				ip = v.IP
+			case *net.IPAddr:
+				ip = v.IP
+			}
+			// @todo: decide if the IP can be used for the Swarm network (private or public)
+			break
+		}
+	}
+	if ip == nil {
+		return errors.New("No interface available for Swarm init")
+	}
+	req := swarm.InitRequest{ListenAddr: "0.0.0.0:" + swarmManagerPort, AdvertiseAddr: ip.String()}
+	c.printfc(colInfo, "Swarm init on ip %s\n", ip.String())
+	_, err = c.dockerClient.SwarmInit(c.ctx, req)
+	if err == nil {
+		c.printfc(colInfo, "done\n")
+	}
+	return err
+}
+
+func (c *clusterClient) pullAmpImage(version string) error {
+	image := "appcelerator/amp:" + version
+	reader, err := c.dockerClient.ImagePull(c.ctx, image, types.ImagePullOptions{})
+	if err != nil {
+		return err
+	}
+	data := make([]byte, 1000, 1000)
+	for {
+		_, err := reader.Read(data)
+		if err != nil {
+			if err.Error() == "EOF" {
+				break
+			}
+			return err
+		}
+	}
+	c.printfc(colInfo, "AMP image successfully pulled\n")
+	return err
+}