display logs for multiple containers at the same time

add the ability for users to specify more than one container at a time
while using podman logs.  If more than one container is being displayed,
podman will also prepend a shortened container id of the container on
the log line.

also, enabled the podman-remote logs command during the refactoring of
the above ability.

fixes issue #2219

Signed-off-by: baude <bbaude@redhat.com>

cmd/podman/commands.go

@@ -21,7 +21,6 @@ func getMainCommands() []*cobra.Command {
 		&_psCommand,
 		_loginCommand,
 		_logoutCommand,
-		_logsCommand,
 		_mountCommand,
 		_pauseCommand,
 		_portCommand,
@@ -63,7 +62,6 @@ func getContainerSubCommands() []*cobra.Command {
 		_execCommand,
 		_exportCommand,
 		_killCommand,
-		_logsCommand,
 		_mountCommand,
 		_pauseCommand,
 		_portCommand,

cmd/podman/container.go

@@ -53,6 +53,7 @@ var (
 		_containerExistsCommand,
 		_contInspectSubCommand,
 		_listSubCommand,
+		_logsCommand,
 	}
 )
 

cmd/podman/logs.go

@@ -1,27 +1,24 @@
 package main
 
 import (
-	"os"
 	"time"
 
 	"github.com/containers/libpod/cmd/podman/cliconfig"
-	"github.com/containers/libpod/cmd/podman/libpodruntime"
 	"github.com/containers/libpod/libpod"
-	"github.com/containers/libpod/pkg/logs"
+	"github.com/containers/libpod/pkg/adapter"
 	"github.com/containers/libpod/pkg/util"
 	"github.com/pkg/errors"
-	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 )
 
 var (
 	logsCommand     cliconfig.LogsValues
-	logsDescription = `Retrieves logs for a container.
+	logsDescription = `Retrieves logs for one or more containers.
 
   This does not guarantee execution order when combined with podman run (i.e. your run may not have generated any logs at the time you execute podman logs.
 `
 	_logsCommand = &cobra.Command{
-		Use:   "logs [flags] CONTAINER",
+		Use:   "logs [flags] CONTAINER [CONTAINER...]",
 		Short: "Fetch the logs of a container",
 		Long:  logsDescription,
 		RunE: func(cmd *cobra.Command, args []string) error {
@@ -29,9 +26,19 @@ var (
 			logsCommand.GlobalFlags = MainGlobalOpts
 			return logsCmd(&logsCommand)
 		},
+		Args: func(cmd *cobra.Command, args []string) error {
+			if len(args) > 0 && logsCommand.Latest {
+				return errors.New("no containers can be specified when using 'latest'")
+			}
+			if !logsCommand.Latest && len(args) < 1 {
+				return errors.New("specify at least one container name or ID to log")
+			}
+			return nil
+		},
 		Example: `podman logs ctrID
   podman logs --tail 2 mywebserver
-  podman logs --follow=true --since 10m ctrID`,
+  podman logs --follow=true --since 10m ctrID
+  podman logs mywebserver mydbserver`,
 	}
 )
 
@@ -54,20 +61,14 @@ func init() {
 }
 
 func logsCmd(c *cliconfig.LogsValues) error {
-	var ctr *libpod.Container
 	var err error
 
-	runtime, err := libpodruntime.GetRuntime(&c.PodmanCommand)
+	runtime, err := adapter.GetRuntime(&c.PodmanCommand)
 	if err != nil {
 		return errors.Wrapf(err, "could not get runtime")
 	}
 	defer runtime.Shutdown(false)
 
-	args := c.InputArgs
-	if len(args) != 1 && !c.Latest {
-		return errors.Errorf("'podman logs' requires exactly one container name/ID")
-	}
-
 	sinceTime := time.Time{}
 	if c.Flag("since").Changed {
 		// parse time, error out if something is wrong
@@ -78,7 +79,7 @@ func logsCmd(c *cliconfig.LogsValues) error {
 		sinceTime = since
 	}
 
-	opts := &logs.LogOptions{
+	opts := &libpod.LogOptions{
 		Details:    c.Details,
 		Follow:     c.Follow,
 		Since:      sinceTime,
@@ -86,30 +87,5 @@ func logsCmd(c *cliconfig.LogsValues) error {
 		Timestamps: c.Timestamps,
 	}
 
-	if c.Latest {
-		ctr, err = runtime.GetLatestContainer()
-	} else {
-		ctr, err = runtime.LookupContainer(args[0])
-	}
-	if err != nil {
-		return err
-	}
-
-	logPath := ctr.LogPath()
-
-	state, err := ctr.State()
-	if err != nil {
-		return err
-	}
-
-	// If the log file does not exist yet and the container is in the
-	// Configured state, it has never been started before and no logs exist
-	// Exit cleanly in this case
-	if _, err := os.Stat(logPath); err != nil {
-		if state == libpod.ContainerStateConfigured {
-			logrus.Debugf("Container has not been started, no logs exist yet")
-			return nil
-		}
-	}
-	return logs.ReadLogs(logPath, ctr, opts)
+	return runtime.Log(c, opts)
 }

cmd/podman/main.go

@@ -45,6 +45,7 @@ var mainCommands = []*cobra.Command{
 	&_inspectCommand,
 	_killCommand,
 	_loadCommand,
+	_logsCommand,
 	podCommand.Command,
 	_pullCommand,
 	_pushCommand,

cmd/podman/search.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"reflect"
 	"strings"
 
 	"github.com/containers/buildah/pkg/formats"
@@ -79,7 +80,10 @@ func searchCmd(c *cliconfig.SearchValues) error {
 		return err
 	}
 	format := genSearchFormat(c.Format)
-	out := formats.StdoutTemplateArray{Output: searchToGeneric(results), Template: format, Fields: results[0].HeaderMap()}
+	if len(results) == 0 {
+		return nil
+	}
+	out := formats.StdoutTemplateArray{Output: searchToGeneric(results), Template: format, Fields: genSearchOutputMap()}
 	formats.Writer(out).Out()
 	return nil
 }
@@ -99,3 +103,16 @@ func searchToGeneric(params []image.SearchResult) (genericParams []interface{})
 	}
 	return genericParams
 }
+
+func genSearchOutputMap() map[string]string {
+	io := image.SearchResult{}
+	v := reflect.Indirect(reflect.ValueOf(io))
+	values := make(map[string]string)
+
+	for i := 0; i < v.NumField(); i++ {
+		key := v.Type().Field(i).Name
+		value := key
+		values[key] = strings.ToUpper(splitCamelCase(value))
+	}
+	return values
+}

cmd/podman/varlink/io.podman.varlink

@@ -19,6 +19,14 @@ type StringResponse (
     message: string
 )
 
+type LogLine (
+    device: string,
+    parseLogType : string,
+    time: string,
+    msg: string,
+    cid: string
+)
+
 # ContainerChanges describes the return struct for ListContainerChanges
 type ContainerChanges (
    changed: []string,
@@ -522,6 +530,8 @@ method ListContainerProcesses(name: string, opts: []string) -> (container: []str
 # capability of varlink if the client invokes it.
 method GetContainerLogs(name: string) -> (container: []string)
 
+method GetContainersLogs(names: []string, follow: bool, latest: bool, since: string, tail: int, timestamps: bool) -> (log: LogLine)
+
 # ListContainerChanges takes a name or ID of a container and returns changes between the container and
 # its base image. It returns a struct of changed, deleted, and added path names.
 method ListContainerChanges(name: string) -> (container: ContainerChanges)

docs/podman-logs.1.md

@@ -1,13 +1,13 @@
 % podman-logs(1)
 
 ## NAME
-podman\-logs - Fetch the logs of a container
+podman\-logs - Fetch the logs of one or more containers
 
 ## SYNOPSIS
-**podman** **logs** [*options*] *container*
+**podman** **logs** [*options*] *container* [*container...*]
 
 ## DESCRIPTION
-The podman logs command batch-retrieves whatever logs are present for a container at the time of execution.
+The podman logs command batch-retrieves whatever logs are present for one or more containers at the time of execution.
 This does not guarantee execution order when combined with podman run (i.e. your run may not have generated
 any logs at the time you execute podman logs
 

libpod/container_log.go

@@ -0,0 +1,208 @@
+package libpod
+
+import (
+	"fmt"
+	"io/ioutil"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/hpcloud/tail"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+const (
+	// logTimeFormat is the time format used in the log.
+	// It is a modified version of RFC3339Nano that guarantees trailing
+	// zeroes are not trimmed, taken from
+	// https://github.com/golang/go/issues/19635
+	logTimeFormat = "2006-01-02T15:04:05.000000000Z07:00"
+)
+
+// LogOptions is the options you can use for logs
+type LogOptions struct {
+	Details    bool
+	Follow     bool
+	Since      time.Time
+	Tail       uint64
+	Timestamps bool
+	Multi      bool
+	WaitGroup  *sync.WaitGroup
+}
+
+// LogLine describes the information for each line of a log
+type LogLine struct {
+	Device       string
+	ParseLogType string
+	Time         time.Time
+	Msg          string
+	CID          string
+}
+
+// Log is a runtime function that can read one or more container logs.
+func (r *Runtime) Log(containers []*Container, options *LogOptions, logChannel chan *LogLine) error {
+	for _, ctr := range containers {
+		if err := ctr.ReadLog(options, logChannel); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// ReadLog reads a containers log based on the input options and returns loglines over a channel
+func (c *Container) ReadLog(options *LogOptions, logChannel chan *LogLine) error {
+	t, tailLog, err := getLogFile(c.LogPath(), options)
+	if err != nil {
+		return errors.Wrapf(err, "unable to read log file %s for %s ", c.ID(), c.LogPath())
+	}
+	options.WaitGroup.Add(1)
+	if len(tailLog) > 0 {
+		for _, nll := range tailLog {
+			nll.CID = c.ID()
+			if nll.Since(options.Since) {
+				logChannel <- nll
+			}
+		}
+	}
+
+	go func() {
+		var partial string
+		for line := range t.Lines {
+			nll, err := newLogLine(line.Text)
+			if err != nil {
+				logrus.Error(err)
+				continue
+			}
+			if nll.Partial() {
+				partial = partial + nll.Msg
+				continue
+			} else if !nll.Partial() && len(partial) > 1 {
+				nll.Msg = partial
+				partial = ""
+			}
+			nll.CID = c.ID()
+			if nll.Since(options.Since) {
+				logChannel <- nll
+			}
+		}
+		options.WaitGroup.Done()
+	}()
+	return nil
+}
+
+// getLogFile returns an hp tail for a container given options
+func getLogFile(path string, options *LogOptions) (*tail.Tail, []*LogLine, error) {
+	var (
+		whence  int
+		err     error
+		logTail []*LogLine
+	)
+	// whence 0=origin, 2=end
+	if options.Tail > 0 {
+		whence = 2
+		logTail, err = getTailLog(path, int(options.Tail))
+		if err != nil {
+			return nil, nil, err
+		}
+	}
+	seek := tail.SeekInfo{
+		Offset: 0,
+		Whence: whence,
+	}
+
+	t, err := tail.TailFile(path, tail.Config{Poll: true, Follow: options.Follow, Location: &seek, Logger: tail.DiscardingLogger})
+	return t, logTail, err
+}
+
+func getTailLog(path string, tail int) ([]*LogLine, error) {
+	var (
+		tailLog     []*LogLine
+		nlls        []*LogLine
+		tailCounter int
+		partial     string
+	)
+	content, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	splitContent := strings.Split(string(content), "\n")
+	// We read the content in reverse and add each nll until we have the same
+	// number of F type messages as the desired tail
+	for i := len(splitContent) - 1; i >= 0; i-- {
+		if len(splitContent[i]) == 0 {
+			continue
+		}
+		nll, err := newLogLine(splitContent[i])
+		if err != nil {
+			return nil, err
+		}
+		nlls = append(nlls, nll)
+		if !nll.Partial() {
+			tailCounter = tailCounter + 1
+		}
+		if tailCounter == tail {
+			break
+		}
+	}
+	// Now we iterate the results and assemble partial messages to become full messages
+	for _, nll := range nlls {
+		if nll.Partial() {
+			partial = partial + nll.Msg
+		} else {
+			nll.Msg = nll.Msg + partial
+			tailLog = append(tailLog, nll)
+			partial = ""
+		}
+	}
+	return tailLog, nil
+}
+
+// String converts a logline to a string for output given whether a detail
+// bool is specified.
+func (l *LogLine) String(options *LogOptions) string {
+	var out string
+	if options.Multi {
+		cid := l.CID
+		if len(cid) > 12 {
+			cid = cid[:12]
+		}
+		out = fmt.Sprintf("%s ", cid)
+	}
+	if options.Timestamps {
+		out = out + fmt.Sprintf("%s ", l.Time.Format(logTimeFormat))
+	}
+	return out + l.Msg
+}
+
+// Since returns a bool as to whether a log line occurred after a given time
+func (l *LogLine) Since(since time.Time) bool {
+	return l.Time.After(since)
+}
+
+// newLogLine creates a logLine struct from a container log string
+func newLogLine(line string) (*LogLine, error) {
+	splitLine := strings.Split(line, " ")
+	if len(splitLine) < 4 {
+		return nil, errors.Errorf("'%s' is not a valid container log line", line)
+	}
+	logTime, err := time.Parse(time.RFC3339Nano, splitLine[0])
+	if err != nil {
+		return nil, errors.Wrapf(err, "unable to convert time %s from container log", splitLine[0])
+	}
+	l := LogLine{
+		Time:         logTime,
+		Device:       splitLine[1],
+		ParseLogType: splitLine[2],
+		Msg:          strings.Join(splitLine[3:], " "),
+	}
+	return &l, nil
+}
+
+// Partial returns a bool if the log line is a partial log type
+func (l *LogLine) Partial() bool {
+	if l.ParseLogType == "P" {
+		return true
+	}
+	return false
+}

libpod/events.go

@@ -92,5 +92,5 @@ func (r *Runtime) getTail(fromStart, stream bool) (*tail.Tail, error) {
 		seek.Whence = 0
 		reopen = false
 	}
-	return tail.TailFile(r.config.EventsLogFilePath, tail.Config{ReOpen: reopen, Follow: stream, Location: &seek})
+	return tail.TailFile(r.config.EventsLogFilePath, tail.Config{ReOpen: reopen, Follow: stream, Location: &seek, Logger: tail.DiscardingLogger})
 }

pkg/adapter/containers.go

@@ -4,7 +4,9 @@ package adapter
 
 import (
 	"context"
+	"fmt"
 	"strconv"
+	"sync"
 	"syscall"
 	"time"
 
@@ -127,3 +129,28 @@ func (r *LocalRuntime) WaitOnContainers(ctx context.Context, cli *cliconfig.Wait
 	}
 	return ok, failures, err
 }
+
+// Log logs one or more containers
+func (r *LocalRuntime) Log(c *cliconfig.LogsValues, options *libpod.LogOptions) error {
+	var wg sync.WaitGroup
+	options.WaitGroup = &wg
+	if len(c.InputArgs) > 1 {
+		options.Multi = true
+	}
+	logChannel := make(chan *libpod.LogLine, int(c.Tail)*len(c.InputArgs)+1)
+	containers, err := shortcuts.GetContainersByContext(false, c.Latest, c.InputArgs, r.Runtime)
+	if err != nil {
+		return err
+	}
+	if err := r.Runtime.Log(containers, options, logChannel); err != nil {
+		return err
+	}
+	go func() {
+		wg.Wait()
+		close(logChannel)
+	}()
+	for line := range logChannel {
+		fmt.Println(line.String(options))
+	}
+	return nil
+}

pkg/adapter/containers_remote.go

@@ -5,18 +5,19 @@ package adapter
 import (
 	"context"
 	"encoding/json"
-	"errors"
+	"fmt"
 	"strconv"
 	"syscall"
 	"time"
 
 	"github.com/containers/libpod/cmd/podman/cliconfig"
 	"github.com/containers/libpod/cmd/podman/shared"
-	"github.com/sirupsen/logrus"
-
-	iopodman "github.com/containers/libpod/cmd/podman/varlink"
+	"github.com/containers/libpod/cmd/podman/varlink"
 	"github.com/containers/libpod/libpod"
 	"github.com/containers/libpod/pkg/inspect"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"github.com/varlink/go/varlink"
 )
 
 // Inspect returns an inspect struct from varlink
@@ -223,3 +224,41 @@ func BatchContainerOp(ctr *Container, opts shared.PsOptions) (shared.BatchContai
 	}
 	return bcs, nil
 }
+
+// Logs one or more containers over a varlink connection
+func (r *LocalRuntime) Log(c *cliconfig.LogsValues, options *libpod.LogOptions) error {
+	//GetContainersLogs
+	reply, err := iopodman.GetContainersLogs().Send(r.Conn, uint64(varlink.More), c.InputArgs, c.Follow, c.Latest, options.Since.Format(time.RFC3339Nano), int64(c.Tail), c.Timestamps)
+	if err != nil {
+		return errors.Wrapf(err, "failed to get container logs")
+	}
+	if len(c.InputArgs) > 1 {
+		options.Multi = true
+	}
+	for {
+		log, flags, err := reply()
+		if err != nil {
+			return err
+		}
+		if log.Time == "" && log.Msg == "" {
+			// We got a blank log line which can signal end of stream
+			break
+		}
+		lTime, err := time.Parse(time.RFC3339Nano, log.Time)
+		if err != nil {
+			return errors.Wrapf(err, "unable to parse time of log %s", log.Time)
+		}
+		logLine := libpod.LogLine{
+			Device:       log.Device,
+			ParseLogType: log.ParseLogType,
+			Time:         lTime,
+			Msg:          log.Msg,
+			CID:          log.Cid,
+		}
+		fmt.Println(logLine.String(options))
+		if flags&varlink.Continues == 0 {
+			break
+		}
+	}
+	return nil
+}

pkg/varlinkapi/containers.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"sync"
 	"syscall"
 	"time"
 
@@ -602,3 +603,56 @@ func ContainerStatsToLibpodContainerStats(stats iopodman.ContainerStats) libpod.
 	}
 	return cstats
 }
+
+// GetContainersLogs is the varlink endpoint to obtain one or more container logs
+func (i *LibpodAPI) GetContainersLogs(call iopodman.VarlinkCall, names []string, follow, latest bool, since string, tail int64, timestamps bool) error {
+	var wg sync.WaitGroup
+	if call.WantsMore() {
+		call.Continues = true
+	}
+	sinceTime, err := time.Parse(time.RFC3339Nano, since)
+	if err != nil {
+		return call.ReplyErrorOccurred(err.Error())
+	}
+	options := libpod.LogOptions{
+		Follow:     follow,
+		Since:      sinceTime,
+		Tail:       uint64(tail),
+		Timestamps: timestamps,
+	}
+
+	options.WaitGroup = &wg
+	if len(names) > 1 {
+		options.Multi = true
+	}
+	logChannel := make(chan *libpod.LogLine, int(tail)*len(names)+1)
+	containers, err := shortcuts.GetContainersByContext(false, latest, names, i.Runtime)
+	if err != nil {
+		return call.ReplyErrorOccurred(err.Error())
+	}
+	if err := i.Runtime.Log(containers, &options, logChannel); err != nil {
+		return err
+	}
+	go func() {
+		wg.Wait()
+		close(logChannel)
+	}()
+	for line := range logChannel {
+		call.ReplyGetContainersLogs(newPodmanLogLine(line))
+		if !call.Continues {
+			break
+		}
+
+	}
+	return call.ReplyGetContainersLogs(iopodman.LogLine{})
+}
+
+func newPodmanLogLine(line *libpod.LogLine) iopodman.LogLine {
+	return iopodman.LogLine{
+		Device:       line.Device,
+		ParseLogType: line.ParseLogType,
+		Time:         line.Time.Format(time.RFC3339Nano),
+		Msg:          line.Msg,
+		Cid:          line.CID,
+	}
+}

test/e2e/logs_test.go

@@ -4,6 +4,7 @@ package integration
 
 import (
 	"os"
+	"strings"
 
 	. "github.com/containers/libpod/test/utils"
 	. "github.com/onsi/ginkgo"
@@ -34,7 +35,6 @@ var _ = Describe("Podman logs", func() {
 
 	})
 
-	//sudo bin/podman run -it --rm fedora-minimal bash -c 'for a in `seq 5`; do echo hello; done'
 	It("podman logs for container", func() {
 		logc := podmanTest.Podman([]string{"run", "-dt", ALPINE, "sh", "-c", "echo podman; echo podman; echo podman"})
 		logc.WaitWithDefaultTimeout()
@@ -106,4 +106,30 @@ var _ = Describe("Podman logs", func() {
 		Expect(results.ExitCode()).To(Equal(0))
 		Expect(len(results.OutputToStringArray())).To(Equal(3))
 	})
+
+	It("podman logs latest and container name should fail", func() {
+		results := podmanTest.Podman([]string{"logs", "-l", "foobar"})
+		results.WaitWithDefaultTimeout()
+		Expect(results.ExitCode()).ToNot(Equal(0))
+	})
+
+	It("podman logs two containers and should display short container IDs", func() {
+		log1 := podmanTest.Podman([]string{"run", "-dt", ALPINE, "sh", "-c", "echo podman; echo podman; echo podman"})
+		log1.WaitWithDefaultTimeout()
+		Expect(log1.ExitCode()).To(Equal(0))
+		cid1 := log1.OutputToString()
+
+		log2 := podmanTest.Podman([]string{"run", "-dt", ALPINE, "sh", "-c", "echo podman; echo podman; echo podman"})
+		log2.WaitWithDefaultTimeout()
+		Expect(log2.ExitCode()).To(Equal(0))
+		cid2 := log2.OutputToString()
+
+		results := podmanTest.Podman([]string{"logs", cid1, cid2})
+		results.WaitWithDefaultTimeout()
+		Expect(results.ExitCode()).To(Equal(0))
+
+		output := results.OutputToStringArray()
+		Expect(len(output)).To(Equal(6))
+		Expect(strings.Contains(output[0], cid1[:12]) || strings.Contains(output[0], cid2[:12])).To(BeTrue())
+	})
 })