package daemon // import "github.com/docker/docker/internal/test/daemon"

import (
	"context"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/events"
	"github.com/docker/docker/client"
	"github.com/docker/docker/internal/test"
	"github.com/docker/docker/internal/test/request"
	"github.com/docker/docker/opts"
	"github.com/docker/docker/pkg/ioutils"
	"github.com/docker/docker/pkg/stringid"
	"github.com/docker/go-connections/sockets"
	"github.com/docker/go-connections/tlsconfig"
	"github.com/pkg/errors"
	"gotest.tools/assert"
)

type testingT interface {
	assert.TestingT
	logT
	Fatalf(string, ...interface{})
}

type logT interface {
	Logf(string, ...interface{})
}

const defaultDockerdBinary = "dockerd"
const containerdSocket = "/var/run/docker/containerd/containerd.sock"

var errDaemonNotStarted = errors.New("daemon not started")

// SockRoot holds the path of the default docker integration daemon socket
var SockRoot = filepath.Join(os.TempDir(), "docker-integration")

type clientConfig struct {
	transport *http.Transport
	scheme    string
	addr      string
}

// Daemon represents a Docker daemon for the testing framework
type Daemon struct {
	GlobalFlags       []string
	Root              string
	Folder            string
	Wait              chan error
	UseDefaultHost    bool
	UseDefaultTLSHost bool

	id            string
	logFile       *os.File
	cmd           *exec.Cmd
	storageDriver string
	userlandProxy bool
	execRoot      string
	experimental  bool
	init          bool
	dockerdBinary string
	log           logT

	// swarm related field
	swarmListenAddr string
	SwarmPort       int // FIXME(vdemeester) should probably not be exported
	DefaultAddrPool []string
	SubnetSize      uint32
	DataPathPort    uint32
	// cached information
	CachedInfo types.Info
}

// New returns a Daemon instance to be used for testing.
// This will create a directory such as d123456789 in the folder specified by $DOCKER_INTEGRATION_DAEMON_DEST or $DEST.
// The daemon will not automatically start.
func New(t testingT, ops ...func(*Daemon)) *Daemon {
	if ht, ok := t.(test.HelperT); ok {
		ht.Helper()
	}
	t.Log("Creating a new daemon")
	dest := os.Getenv("DOCKER_INTEGRATION_DAEMON_DEST")
	if dest == "" {
		dest = os.Getenv("DEST")
	}
	assert.Check(t, dest != "", "Please set the DOCKER_INTEGRATION_DAEMON_DEST or the DEST environment variable")

	storageDriver := os.Getenv("DOCKER_GRAPHDRIVER")

	assert.NilError(t, os.MkdirAll(SockRoot, 0700), "could not create daemon socket root")

	id := fmt.Sprintf("d%s", stringid.TruncateID(stringid.GenerateRandomID()))
	dir := filepath.Join(dest, id)
	daemonFolder, err := filepath.Abs(dir)
	assert.NilError(t, err, "Could not make %q an absolute path", dir)
	daemonRoot := filepath.Join(daemonFolder, "root")

	assert.NilError(t, os.MkdirAll(daemonRoot, 0755), "Could not create daemon root %q", dir)

	userlandProxy := true
	if env := os.Getenv("DOCKER_USERLANDPROXY"); env != "" {
		if val, err := strconv.ParseBool(env); err != nil {
			userlandProxy = val
		}
	}
	d := &Daemon{
		id:            id,
		Folder:        daemonFolder,
		Root:          daemonRoot,
		storageDriver: storageDriver,
		userlandProxy: userlandProxy,
		// dxr stands for docker-execroot (shortened for avoiding unix(7) path length limitation)
		execRoot:        filepath.Join(os.TempDir(), "dxr", id),
		dockerdBinary:   defaultDockerdBinary,
		swarmListenAddr: defaultSwarmListenAddr,
		SwarmPort:       DefaultSwarmPort,
		log:             t,
	}

	for _, op := range ops {
		op(d)
	}

	return d
}

// RootDir returns the root directory of the daemon.
func (d *Daemon) RootDir() string {
	return d.Root
}

// ID returns the generated id of the daemon
func (d *Daemon) ID() string {
	return d.id
}

// StorageDriver returns the configured storage driver of the daemon
func (d *Daemon) StorageDriver() string {
	return d.storageDriver
}

// Sock returns the socket path of the daemon
func (d *Daemon) Sock() string {
	return fmt.Sprintf("unix://" + d.sockPath())
}

func (d *Daemon) sockPath() string {
	return filepath.Join(SockRoot, d.id+".sock")
}

// LogFileName returns the path the daemon's log file
func (d *Daemon) LogFileName() string {
	return d.logFile.Name()
}

// ReadLogFile returns the content of the daemon log file
func (d *Daemon) ReadLogFile() ([]byte, error) {
	return ioutil.ReadFile(d.logFile.Name())
}

// NewClientT creates new client based on daemon's socket path
func (d *Daemon) NewClientT(t assert.TestingT) *client.Client {
	if ht, ok := t.(test.HelperT); ok {
		ht.Helper()
	}
	c, err := client.NewClientWithOpts(
		client.FromEnv,
		client.WithHost(d.Sock()))
	assert.NilError(t, err, "cannot create daemon client")
	return c
}

// Cleanup cleans the daemon files : exec root (network namespaces, ...), swarmkit files
func (d *Daemon) Cleanup(t testingT) {
	if ht, ok := t.(test.HelperT); ok {
		ht.Helper()
	}
	// Cleanup swarmkit wal files if present
	cleanupRaftDir(t, d.Root)
	cleanupNetworkNamespace(t, d.execRoot)
}

// Start starts the daemon and return once it is ready to receive requests.
func (d *Daemon) Start(t testingT, args ...string) {
	if ht, ok := t.(test.HelperT); ok {
		ht.Helper()
	}
	if err := d.StartWithError(args...); err != nil {
		t.Fatalf("failed to start daemon with arguments %v : %v", args, err)
	}
}

// StartWithError starts the daemon and return once it is ready to receive requests.
// It returns an error in case it couldn't start.
func (d *Daemon) StartWithError(args ...string) error {
	logFile, err := os.OpenFile(filepath.Join(d.Folder, "docker.log"), os.O_RDWR|os.O_CREATE|os.O_APPEND, 0600)
	if err != nil {
		return errors.Wrapf(err, "[%s] Could not create %s/docker.log", d.id, d.Folder)
	}

	return d.StartWithLogFile(logFile, args...)
}

// StartWithLogFile will start the daemon and attach its streams to a given file.
func (d *Daemon) StartWithLogFile(out *os.File, providedArgs ...string) error {
	d.handleUserns()
	dockerdBinary, err := exec.LookPath(d.dockerdBinary)
	if err != nil {
		return errors.Wrapf(err, "[%s] could not find docker binary in $PATH", d.id)
	}
	args := append(d.GlobalFlags,
		"--containerd", containerdSocket,
		"--data-root", d.Root,
		"--exec-root", d.execRoot,
		"--pidfile", fmt.Sprintf("%s/docker.pid", d.Folder),
		fmt.Sprintf("--userland-proxy=%t", d.userlandProxy),
	)
	if d.experimental {
		args = append(args, "--experimental")
	}
	if d.init {
		args = append(args, "--init")
	}
	if !(d.UseDefaultHost || d.UseDefaultTLSHost) {
		args = append(args, []string{"--host", d.Sock()}...)
	}
	if root := os.Getenv("DOCKER_REMAP_ROOT"); root != "" {
		args = append(args, []string{"--userns-remap", root}...)
	}

	// If we don't explicitly set the log-level or debug flag(-D) then
	// turn on debug mode
	foundLog := false
	foundSd := false
	for _, a := range providedArgs {
		if strings.Contains(a, "--log-level") || strings.Contains(a, "-D") || strings.Contains(a, "--debug") {
			foundLog = true
		}
		if strings.Contains(a, "--storage-driver") {
			foundSd = true
		}
	}
	if !foundLog {
		args = append(args, "--debug")
	}
	if d.storageDriver != "" && !foundSd {
		args = append(args, "--storage-driver", d.storageDriver)
	}

	args = append(args, providedArgs...)
	d.cmd = exec.Command(dockerdBinary, args...)
	d.cmd.Env = append(os.Environ(), "DOCKER_SERVICE_PREFER_OFFLINE_IMAGE=1")
	d.cmd.Stdout = out
	d.cmd.Stderr = out
	d.logFile = out

	if err := d.cmd.Start(); err != nil {
		return errors.Errorf("[%s] could not start daemon container: %v", d.id, err)
	}

	wait := make(chan error)

	go func() {
		ret := d.cmd.Wait()
		d.log.Logf("[%s] exiting daemon", d.id)
		// If we send before logging, we might accidentally log _after_ the test is done.
		// As of Go 1.12, this incurs a panic instead of silently being dropped.
		wait <- ret
		close(wait)
	}()

	d.Wait = wait

	ticker := time.NewTicker(500 * time.Millisecond)
	defer ticker.Stop()
	tick := ticker.C

	// make sure daemon is ready to receive requests
	startTime := time.Now().Unix()
	for {
		d.log.Logf("[%s] waiting for daemon to start", d.id)
		if time.Now().Unix()-startTime > 5 {
			// After 5 seconds, give up
			return errors.Errorf("[%s] Daemon exited and never started", d.id)
		}
		select {
		case <-time.After(2 * time.Second):
			return errors.Errorf("[%s] timeout: daemon does not respond", d.id)
		case <-tick:
			clientConfig, err := d.getClientConfig()
			if err != nil {
				return err
			}

			client := &http.Client{
				Transport: clientConfig.transport,
			}

			req, err := http.NewRequest("GET", "/_ping", nil)
			if err != nil {
				return errors.Wrapf(err, "[%s] could not create new request", d.id)
			}
			req.URL.Host = clientConfig.addr
			req.URL.Scheme = clientConfig.scheme
			resp, err := client.Do(req)
			if err != nil {
				continue
			}
			resp.Body.Close()
			if resp.StatusCode != http.StatusOK {
				d.log.Logf("[%s] received status != 200 OK: %s\n", d.id, resp.Status)
			}
			d.log.Logf("[%s] daemon started\n", d.id)
			d.Root, err = d.queryRootDir()
			if err != nil {
				return errors.Errorf("[%s] error querying daemon for root directory: %v", d.id, err)
			}
			return nil
		case err := <-d.Wait:
			return errors.Errorf("[%s] Daemon exited during startup: %v", d.id, err)
		}
	}
}

// StartWithBusybox will first start the daemon with Daemon.Start()
// then save the busybox image from the main daemon and load it into this Daemon instance.
func (d *Daemon) StartWithBusybox(t testingT, arg ...string) {
	if ht, ok := t.(test.HelperT); ok {
		ht.Helper()
	}
	d.Start(t, arg...)
	d.LoadBusybox(t)
}

// Kill will send a SIGKILL to the daemon
func (d *Daemon) Kill() error {
	if d.cmd == nil || d.Wait == nil {
		return errDaemonNotStarted
	}

	defer func() {
		d.logFile.Close()
		d.cmd = nil
	}()

	if err := d.cmd.Process.Kill(); err != nil {
		return err
	}

	return os.Remove(fmt.Sprintf("%s/docker.pid", d.Folder))
}

// Pid returns the pid of the daemon
func (d *Daemon) Pid() int {
	return d.cmd.Process.Pid
}

// Interrupt stops the daemon by sending it an Interrupt signal
func (d *Daemon) Interrupt() error {
	return d.Signal(os.Interrupt)
}

// Signal sends the specified signal to the daemon if running
func (d *Daemon) Signal(signal os.Signal) error {
	if d.cmd == nil || d.Wait == nil {
		return errDaemonNotStarted
	}
	return d.cmd.Process.Signal(signal)
}

// DumpStackAndQuit sends SIGQUIT to the daemon, which triggers it to dump its
// stack to its log file and exit
// This is used primarily for gathering debug information on test timeout
func (d *Daemon) DumpStackAndQuit() {
	if d.cmd == nil || d.cmd.Process == nil {
		return
	}
	SignalDaemonDump(d.cmd.Process.Pid)
}

// Stop will send a SIGINT every second and wait for the daemon to stop.
// If it times out, a SIGKILL is sent.
// Stop will not delete the daemon directory. If a purged daemon is needed,
// instantiate a new one with NewDaemon.
// If an error occurs while starting the daemon, the test will fail.
func (d *Daemon) Stop(t testingT) {
	if ht, ok := t.(test.HelperT); ok {
		ht.Helper()
	}
	err := d.StopWithError()
	if err != nil {
		if err != errDaemonNotStarted {
			t.Fatalf("Error while stopping the daemon %s : %v", d.id, err)
		} else {
			t.Logf("Daemon %s is not started", d.id)
		}
	}
}

// StopWithError will send a SIGINT every second and wait for the daemon to stop.
// If it timeouts, a SIGKILL is sent.
// Stop will not delete the daemon directory. If a purged daemon is needed,
// instantiate a new one with NewDaemon.
func (d *Daemon) StopWithError() error {
	if d.cmd == nil || d.Wait == nil {
		return errDaemonNotStarted
	}

	defer func() {
		d.logFile.Close()
		d.cmd = nil
	}()

	i := 1
	ticker := time.NewTicker(time.Second)
	defer ticker.Stop()
	tick := ticker.C

	if err := d.cmd.Process.Signal(os.Interrupt); err != nil {
		if strings.Contains(err.Error(), "os: process already finished") {
			return errDaemonNotStarted
		}
		return errors.Errorf("could not send signal: %v", err)
	}
out1:
	for {
		select {
		case err := <-d.Wait:
			return err
		case <-time.After(20 * time.Second):
			// time for stopping jobs and run onShutdown hooks
			d.log.Logf("[%s] daemon stop timeout", d.id)
			break out1
		}
	}

out2:
	for {
		select {
		case err := <-d.Wait:
			return err
		case <-tick:
			i++
			if i > 5 {
				d.log.Logf("tried to interrupt daemon for %d times, now try to kill it", i)
				break out2
			}
			d.log.Logf("Attempt #%d: daemon is still running with pid %d", i, d.cmd.Process.Pid)
			if err := d.cmd.Process.Signal(os.Interrupt); err != nil {
				return errors.Errorf("could not send signal: %v", err)
			}
		}
	}

	if err := d.cmd.Process.Kill(); err != nil {
		d.log.Logf("Could not kill daemon: %v", err)
		return err
	}

	d.cmd.Wait()

	return os.Remove(fmt.Sprintf("%s/docker.pid", d.Folder))
}

// Restart will restart the daemon by first stopping it and the starting it.
// If an error occurs while starting the daemon, the test will fail.
func (d *Daemon) Restart(t testingT, args ...string) {
	if ht, ok := t.(test.HelperT); ok {
		ht.Helper()
	}
	d.Stop(t)
	d.Start(t, args...)
}

// RestartWithError will restart the daemon by first stopping it and then starting it.
func (d *Daemon) RestartWithError(arg ...string) error {
	if err := d.StopWithError(); err != nil {
		return err
	}
	return d.StartWithError(arg...)
}

func (d *Daemon) handleUserns() {
	// in the case of tests running a user namespace-enabled daemon, we have resolved
	// d.Root to be the actual final path of the graph dir after the "uid.gid" of
	// remapped root is added--we need to subtract it from the path before calling
	// start or else we will continue making subdirectories rather than truly restarting
	// with the same location/root:
	if root := os.Getenv("DOCKER_REMAP_ROOT"); root != "" {
		d.Root = filepath.Dir(d.Root)
	}
}

// ReloadConfig asks the daemon to reload its configuration
func (d *Daemon) ReloadConfig() error {
	if d.cmd == nil || d.cmd.Process == nil {
		return errors.New("daemon is not running")
	}

	errCh := make(chan error)
	started := make(chan struct{})
	go func() {
		_, body, err := request.Get("/events", request.Host(d.Sock()))
		close(started)
		if err != nil {
			errCh <- err
		}
		defer body.Close()
		dec := json.NewDecoder(body)
		for {
			var e events.Message
			if err := dec.Decode(&e); err != nil {
				errCh <- err
				return
			}
			if e.Type != events.DaemonEventType {
				continue
			}
			if e.Action != "reload" {
				continue
			}
			close(errCh) // notify that we are done
			return
		}
	}()

	<-started
	if err := signalDaemonReload(d.cmd.Process.Pid); err != nil {
		return errors.Errorf("error signaling daemon reload: %v", err)
	}
	select {
	case err := <-errCh:
		if err != nil {
			return errors.Errorf("error waiting for daemon reload event: %v", err)
		}
	case <-time.After(30 * time.Second):
		return errors.New("timeout waiting for daemon reload event")
	}
	return nil
}

// LoadBusybox image into the daemon
func (d *Daemon) LoadBusybox(t assert.TestingT) {
	if ht, ok := t.(test.HelperT); ok {
		ht.Helper()
	}
	clientHost, err := client.NewClientWithOpts(client.FromEnv)
	assert.NilError(t, err, "failed to create client")
	defer clientHost.Close()

	ctx := context.Background()
	reader, err := clientHost.ImageSave(ctx, []string{"busybox:latest"})
	assert.NilError(t, err, "failed to download busybox")
	defer reader.Close()

	c := d.NewClientT(t)
	defer c.Close()

	resp, err := c.ImageLoad(ctx, reader, true)
	assert.NilError(t, err, "failed to load busybox")
	defer resp.Body.Close()
}

func (d *Daemon) getClientConfig() (*clientConfig, error) {
	var (
		transport *http.Transport
		scheme    string
		addr      string
		proto     string
	)
	if d.UseDefaultTLSHost {
		option := &tlsconfig.Options{
			CAFile:   "fixtures/https/ca.pem",
			CertFile: "fixtures/https/client-cert.pem",
			KeyFile:  "fixtures/https/client-key.pem",
		}
		tlsConfig, err := tlsconfig.Client(*option)
		if err != nil {
			return nil, err
		}
		transport = &http.Transport{
			TLSClientConfig: tlsConfig,
		}
		addr = fmt.Sprintf("%s:%d", opts.DefaultHTTPHost, opts.DefaultTLSHTTPPort)
		scheme = "https"
		proto = "tcp"
	} else if d.UseDefaultHost {
		addr = opts.DefaultUnixSocket
		proto = "unix"
		scheme = "http"
		transport = &http.Transport{}
	} else {
		addr = d.sockPath()
		proto = "unix"
		scheme = "http"
		transport = &http.Transport{}
	}

	if err := sockets.ConfigureTransport(transport, proto, addr); err != nil {
		return nil, err
	}
	transport.DisableKeepAlives = true

	return &clientConfig{
		transport: transport,
		scheme:    scheme,
		addr:      addr,
	}, nil
}

func (d *Daemon) queryRootDir() (string, error) {
	// update daemon root by asking /info endpoint (to support user
	// namespaced daemon with root remapped uid.gid directory)
	clientConfig, err := d.getClientConfig()
	if err != nil {
		return "", err
	}

	c := &http.Client{
		Transport: clientConfig.transport,
	}

	req, err := http.NewRequest("GET", "/info", nil)
	if err != nil {
		return "", err
	}
	req.Header.Set("Content-Type", "application/json")
	req.URL.Host = clientConfig.addr
	req.URL.Scheme = clientConfig.scheme

	resp, err := c.Do(req)
	if err != nil {
		return "", err
	}
	body := ioutils.NewReadCloserWrapper(resp.Body, func() error {
		return resp.Body.Close()
	})

	type Info struct {
		DockerRootDir string
	}
	var b []byte
	var i Info
	b, err = request.ReadBody(body)
	if err == nil && resp.StatusCode == http.StatusOK {
		// read the docker root dir
		if err = json.Unmarshal(b, &i); err == nil {
			return i.DockerRootDir, nil
		}
	}
	return "", err
}

// Info returns the info struct for this daemon
func (d *Daemon) Info(t assert.TestingT) types.Info {
	if ht, ok := t.(test.HelperT); ok {
		ht.Helper()
	}
	c := d.NewClientT(t)
	info, err := c.Info(context.Background())
	assert.NilError(t, err)
	return info
}

func cleanupRaftDir(t testingT, rootPath string) {
	if ht, ok := t.(test.HelperT); ok {
		ht.Helper()
	}
	walDir := filepath.Join(rootPath, "swarm/raft/wal")
	if err := os.RemoveAll(walDir); err != nil {
		t.Logf("error removing %v: %v", walDir, err)
	}
}