package service
import (
"bytes"
"fmt"
"io"
"strconv"
"strings"
"golang.org/x/net/context"
"github.com/docker/docker/api/types"
"github.com/docker/docker/api/types/swarm"
"github.com/docker/docker/cli"
"github.com/docker/docker/cli/command"
"github.com/docker/docker/cli/command/idresolver"
"github.com/docker/docker/client"
"github.com/docker/docker/pkg/stdcopy"
"github.com/docker/docker/pkg/stringid"
"github.com/pkg/errors"
"github.com/spf13/cobra"
)
type logsOptions struct {
noResolve bool
noTrunc bool
noTaskIDs bool
follow bool
since string
timestamps bool
tail string
target string
}
// TODO(dperny) the whole CLI for this is kind of a mess IMHOIRL and it needs
// to be refactored agressively. There may be changes to the implementation of
// details, which will be need to be reflected in this code. The refactoring
// should be put off until we make those changes, tho, because I think the
// decisions made WRT details will impact the design of the CLI.
func newLogsCommand(dockerCli *command.DockerCli) *cobra.Command {
var opts logsOptions
cmd := &cobra.Command{
Use: "logs [OPTIONS] SERVICE|TASK",
Short: "Fetch the logs of a service or task",
Args: cli.ExactArgs(1),
RunE: func(cmd *cobra.Command, args []string) error {
opts.target = args[0]
return runLogs(dockerCli, &opts)
},
Tags: map[string]string{"version": "1.29"},
}
flags := cmd.Flags()
// options specific to service logs
flags.BoolVar(&opts.noResolve, "no-resolve", false, "Do not map IDs to Names in output")
flags.BoolVar(&opts.noTrunc, "no-trunc", false, "Do not truncate output")
flags.BoolVar(&opts.noTaskIDs, "no-task-ids", false, "Do not include task IDs in output")
// options identical to container logs
flags.BoolVarP(&opts.follow, "follow", "f", false, "Follow log output")
flags.StringVar(&opts.since, "since", "", "Show logs since timestamp (e.g. 2013-01-02T13:23:37) or relative (e.g. 42m for 42 minutes)")
flags.BoolVarP(&opts.timestamps, "timestamps", "t", false, "Show timestamps")
flags.StringVar(&opts.tail, "tail", "all", "Number of lines to show from the end of the logs")
return cmd
}
func runLogs(dockerCli *command.DockerCli, opts *logsOptions) error {
ctx := context.Background()
options := types.ContainerLogsOptions{
ShowStdout: true,
ShowStderr: true,
Since: opts.since,
Timestamps: opts.timestamps,
Follow: opts.follow,
Tail: opts.tail,
Details: true,
}
cli := dockerCli.Client()
var (
maxLength = 1
responseBody io.ReadCloser
tty bool
)
service, _, err := cli.ServiceInspectWithRaw(ctx, opts.target, types.ServiceInspectOptions{})
if err != nil {
// if it's any error other than service not found, it's Real
if !client.IsErrServiceNotFound(err) {
return err
}
task, _, err := cli.TaskInspectWithRaw(ctx, opts.target)
tty = task.Spec.ContainerSpec.TTY
// TODO(dperny) hot fix until we get a nice details system squared away,
// ignores details (including task context) if we have a TTY log
// if we don't do this, we'll vomit the huge context verbatim into the
// TTY log lines and that's Undesirable.
if tty {
options.Details = false
}
responseBody, err = cli.TaskLogs(ctx, opts.target, options)
if err != nil {
if client.IsErrTaskNotFound(err) {
// if the task ALSO isn't found, rewrite the error to be clear
// that we looked for services AND tasks
err = fmt.Errorf("No such task or service")
}
return err
}
maxLength = getMaxLength(task.Slot)
responseBody, err = cli.TaskLogs(ctx, opts.target, options)
} else {
tty = service.Spec.TaskTemplate.ContainerSpec.TTY
// TODO(dperny) hot fix until we get a nice details system squared away,
// ignores details (including task context) if we have a TTY log
if tty {
options.Details = false
}
responseBody, err = cli.ServiceLogs(ctx, opts.target, options)
if err != nil {
return err
}
if service.Spec.Mode.Replicated != nil && service.Spec.Mode.Replicated.Replicas != nil {
// if replicas are initialized, figure out if we need to pad them
replicas := *service.Spec.Mode.Replicated.Replicas
maxLength = getMaxLength(int(replicas))
}
}
defer responseBody.Close()
if tty {
_, err = io.Copy(dockerCli.Out(), responseBody)
return err
}
taskFormatter := newTaskFormatter(cli, opts, maxLength)
stdout := &logWriter{ctx: ctx, opts: opts, f: taskFormatter, w: dockerCli.Out()}
stderr := &logWriter{ctx: ctx, opts: opts, f: taskFormatter, w: dockerCli.Err()}
// TODO(aluzzardi): Do an io.Copy for services with TTY enabled.
_, err = stdcopy.StdCopy(stdout, stderr, responseBody)
return err
}
// getMaxLength gets the maximum length of the number in base 10
func getMaxLength(i int) int {
return len(strconv.FormatInt(int64(i), 10))
}
type taskFormatter struct {
client client.APIClient
opts *logsOptions
padding int
r *idresolver.IDResolver
cache map[logContext]string
}
func newTaskFormatter(client client.APIClient, opts *logsOptions, padding int) *taskFormatter {
return &taskFormatter{
client: client,
opts: opts,
padding: padding,
r: idresolver.New(client, opts.noResolve),
cache: make(map[logContext]string),
}
}
func (f *taskFormatter) format(ctx context.Context, logCtx logContext) (string, error) {
if cached, ok := f.cache[logCtx]; ok {
return cached, nil
}
nodeName, err := f.r.Resolve(ctx, swarm.Node{}, logCtx.nodeID)
if err != nil {
return "", err
}
serviceName, err := f.r.Resolve(ctx, swarm.Service{}, logCtx.serviceID)
if err != nil {
return "", err
}
task, _, err := f.client.TaskInspectWithRaw(ctx, logCtx.taskID)
if err != nil {
return "", err
}
taskName := fmt.Sprintf("%s.%d", serviceName, task.Slot)
if !f.opts.noTaskIDs {
if f.opts.noTrunc {
taskName += fmt.Sprintf(".%s", task.ID)
} else {
taskName += fmt.Sprintf(".%s", stringid.TruncateID(task.ID))
}
}
padding := strings.Repeat(" ", f.padding-getMaxLength(task.Slot))
formatted := fmt.Sprintf("%s@%s%s", taskName, nodeName, padding)
f.cache[logCtx] = formatted
return formatted, nil
}
type logWriter struct {
ctx context.Context
opts *logsOptions
f *taskFormatter
w io.Writer
}
func (lw *logWriter) Write(buf []byte) (int, error) {
contextIndex := 0
numParts := 2
if lw.opts.timestamps {
contextIndex++
numParts++
}
parts := bytes.SplitN(buf, []byte(" "), numParts)
if len(parts) != numParts {
return 0, errors.Errorf("invalid context in log message: %v", string(buf))
}
logCtx, err := lw.parseContext(string(parts[contextIndex]))
if err != nil {
return 0, err
}
output := []byte{}
for i, part := range parts {
// First part doesn't get space separation.
if i > 0 {
output = append(output, []byte(" ")...)
}
if i == contextIndex {
formatted, err := lw.f.format(lw.ctx, logCtx)
if err != nil {
return 0, err
}
output = append(output, []byte(fmt.Sprintf("%s |", formatted))...)
} else {
output = append(output, part...)
}
}
_, err = lw.w.Write(output)
if err != nil {
return 0, err
}
return len(buf), nil
}
func (lw *logWriter) parseContext(input string) (logContext, error) {
context := make(map[string]string)
components := strings.Split(input, ",")
for _, component := range components {
parts := strings.SplitN(component, "=", 2)
if len(parts) != 2 {
return logContext{}, errors.Errorf("invalid context: %s", input)
}
context[parts[0]] = parts[1]
}
nodeID, ok := context["com.docker.swarm.node.id"]
if !ok {
return logContext{}, errors.Errorf("missing node id in context: %s", input)
}
serviceID, ok := context["com.docker.swarm.service.id"]
if !ok {
return logContext{}, errors.Errorf("missing service id in context: %s", input)
}
taskID, ok := context["com.docker.swarm.task.id"]
if !ok {
return logContext{}, errors.Errorf("missing task id in context: %s", input)
}
return logContext{
nodeID: nodeID,
serviceID: serviceID,
taskID: taskID,
}, nil
}
type logContext struct {
nodeID string
serviceID string
taskID string
}