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>

3 files changed, 124 insertions, 4 deletions

diff --git a/pkg/adapter/containers.go b/pkg/adapter/containers.go
index 756369196..932d209cd 100644
--- a/pkg/adapter/containers.go
+++ b/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
+}
diff --git a/pkg/adapter/containers_remote.go b/pkg/adapter/containers_remote.go
index 5646d2297..a8146567a 100644
--- a/pkg/adapter/containers_remote.go
+++ b/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
+}
diff --git a/pkg/varlinkapi/containers.go b/pkg/varlinkapi/containers.go
index fe38a7cdc..3185ba0e9 100644
--- a/pkg/varlinkapi/containers.go
+++ b/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,
+	}
+}