podmanV2: implement logs

Implement the `podman {container} logs` for the v2 client. The remote
client does not yet support it.  There's some more work needed for the
rest api; some options are missing (e.g., printing names) while others
are broken (e.g., the until http parameter).

The remote parts will be tackled in a future change.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

4 files changed, 74 insertions, 0 deletions

diff --git a/pkg/domain/entities/containers.go b/pkg/domain/entities/containers.go
index 5d302058b..98f9f9471 100644
--- a/pkg/domain/entities/containers.go
+++ b/pkg/domain/entities/containers.go
@@ -172,6 +172,26 @@ type AttachOptions struct {
 	Stderr     *os.File
 }
 
+// ContainerLogsOptions describes the options to extract container logs.
+type ContainerLogsOptions struct {
+	// Show extra details provided to the logs.
+	Details bool
+	// Follow the log output.
+	Follow bool
+	// Display logs for the latest container only. Ignored on the remote client.
+	Latest bool
+	// Show container names in the output.
+	Names bool
+	// Show logs since this timestamp.
+	Since time.Time
+	// Number of lines to display at the end of the output.
+	Tail int64
+	// Show timestamps in the logs.
+	Timestamps bool
+	// Write the logs to Writer.
+	Writer io.Writer
+}
+
 // ExecOptions describes the cli values to exec into
 // a container
 type ExecOptions struct {
diff --git a/pkg/domain/entities/engine_container.go b/pkg/domain/entities/engine_container.go
index 24b7a9acc..fec288eb8 100644
--- a/pkg/domain/entities/engine_container.go
+++ b/pkg/domain/entities/engine_container.go
@@ -20,6 +20,7 @@ type ContainerEngine interface {
 	ContainerKill(ctx context.Context, namesOrIds []string, options KillOptions) ([]*KillReport, error)
 	ContainerList(ctx context.Context, options ContainerListOptions) ([]ListContainer, error)
 	ContainerPause(ctx context.Context, namesOrIds []string, options PauseUnPauseOptions) ([]*PauseUnpauseReport, error)
+	ContainerLogs(ctx context.Context, containers []string, options ContainerLogsOptions) error
 	ContainerRestart(ctx context.Context, namesOrIds []string, options RestartOptions) ([]*RestartReport, error)
 	ContainerRestore(ctx context.Context, namesOrIds []string, options RestoreOptions) ([]*RestoreReport, error)
 	ContainerRm(ctx context.Context, namesOrIds []string, options RmOptions) ([]*RmReport, error)
diff --git a/pkg/domain/infra/abi/containers.go b/pkg/domain/infra/abi/containers.go
index ccbe6d4fd..1aabb2a6b 100644
--- a/pkg/domain/infra/abi/containers.go
+++ b/pkg/domain/infra/abi/containers.go
@@ -4,9 +4,11 @@ package abi
 
 import (
 	"context"
+	"fmt"
 	"io/ioutil"
 	"strconv"
 	"strings"
+	"sync"
 
 	"github.com/containers/buildah"
 	"github.com/containers/image/v5/manifest"
@@ -14,6 +16,7 @@ import (
 	"github.com/containers/libpod/libpod/define"
 	"github.com/containers/libpod/libpod/events"
 	"github.com/containers/libpod/libpod/image"
+	"github.com/containers/libpod/libpod/logs"
 	"github.com/containers/libpod/pkg/checkpoint"
 	"github.com/containers/libpod/pkg/domain/entities"
 	"github.com/containers/libpod/pkg/domain/infra/abi/terminal"
@@ -709,3 +712,48 @@ func (ic *ContainerEngine) ContainerRun(ctx context.Context, opts entities.Conta
 	}
 	return &report, nil
 }
+
+func (ic *ContainerEngine) ContainerLogs(ctx context.Context, containers []string, options entities.ContainerLogsOptions) error {
+	if options.Writer == nil {
+		return errors.New("no io.Writer set for container logs")
+	}
+
+	var wg sync.WaitGroup
+
+	ctrs, err := getContainersByContext(false, options.Latest, containers, ic.Libpod)
+	if err != nil {
+		return err
+	}
+
+	logOpts := &logs.LogOptions{
+		Multi:      len(ctrs) > 1,
+		Details:    options.Details,
+		Follow:     options.Follow,
+		Since:      options.Since,
+		Tail:       options.Tail,
+		Timestamps: options.Timestamps,
+		UseName:    options.Names,
+		WaitGroup:  &wg,
+	}
+
+	chSize := len(ctrs) * int(options.Tail)
+	if chSize <= 0 {
+		chSize = 1
+	}
+	logChannel := make(chan *logs.LogLine, chSize)
+
+	if err := ic.Libpod.Log(ctrs, logOpts, logChannel); err != nil {
+		return err
+	}
+
+	go func() {
+		wg.Wait()
+		close(logChannel)
+	}()
+
+	for line := range logChannel {
+		fmt.Fprintln(options.Writer, line.String(logOpts))
+	}
+
+	return nil
+}
diff --git a/pkg/domain/infra/tunnel/containers.go b/pkg/domain/infra/tunnel/containers.go
index b22c6e3ba..d40f0da36 100644
--- a/pkg/domain/infra/tunnel/containers.go
+++ b/pkg/domain/infra/tunnel/containers.go
@@ -305,6 +305,11 @@ func (ic *ContainerEngine) ContainerCreate(ctx context.Context, s *specgen.SpecG
 	return &entities.ContainerCreateReport{Id: response.ID}, nil
 }
 
+func (ic *ContainerEngine) ContainerLogs(ctx context.Context, containers []string, options entities.ContainerLogsOptions) error {
+	// The endpoint is not ready yet and requires some more work.
+	return errors.New("not implemented yet")
+}
+
 func (ic *ContainerEngine) ContainerAttach(ctx context.Context, nameOrId string, options entities.AttachOptions) error {
 	return errors.New("not implemented")
 }