add 'none' logger

pkg/logging/log_viewer.go

@@ -135,6 +135,10 @@ func InitContainerLogViewer(containerLabels map[string]string, lvopts LogViewOpt
 		return nil, fmt.Errorf("the `cri` log viewer requires nerdctl to be running in experimental mode")
 	}
 
+	if lcfg.Driver == "none" {
+		return nil, fmt.Errorf("log type `none` was selected, nothing to log")
+	}
+
 	lv := &ContainerLogViewer{
 		loggingConfig:     lcfg,
 		logViewingOptions: lvopts,

pkg/logging/logging.go

@@ -90,6 +90,9 @@ func GetDriver(name string, opts map[string]string) (Driver, error) {
 }
 
 func init() {
+	RegisterDriver("none", func(opts map[string]string) (Driver, error) {
+		return &NoneLogger{}, nil
+	}, NoneLogOptsValidate)
 	RegisterDriver("json-file", func(opts map[string]string) (Driver, error) {
 		return &JSONLogger{Opts: opts}, nil
 	}, JSONFileLogOptsValidate)

pkg/logging/none_logger.go

@@ -0,0 +1,45 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package logging
+
+import (
+	"github.com/containerd/containerd/v2/core/runtime/v2/logging"
+)
+
+type NoneLogger struct {
+	Opts map[string]string
+}
+
+func (n *NoneLogger) Init(dataStore, ns, id string) error {
+	return nil
+}
+
+func (n *NoneLogger) PreProcess(dataStore string, config *logging.Config) error {
+	return nil
+}
+
+func (n *NoneLogger) Process(stdout <-chan string, stderr <-chan string) error {
+	return nil
+}
+
+func (n *NoneLogger) PostProcess() error {
+	return nil
+}
+
+func NoneLogOptsValidate(_ map[string]string) error {
+	return nil
+}

pkg/logging/none_logger_test.go

@@ -0,0 +1,72 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package logging
+
+import (
+	"os"
+	"testing"
+	"time"
+
+	"gotest.tools/v3/assert"
+
+	"github.com/containerd/containerd/v2/core/runtime/v2/logging"
+)
+
+func TestNoneLogger(t *testing.T) {
+	// Create a temporary directory for potential log files
+	tmpDir := t.TempDir()
+
+	logger := &NoneLogger{
+		Opts: map[string]string{},
+	}
+
+	t.Run("NoLoggingOccurs", func(t *testing.T) {
+		initialFiles, err := os.ReadDir(tmpDir)
+		assert.NilError(t, err, "Failed to read temp dir")
+
+		// Run all logger methods
+		logger.Init(tmpDir, "namespace", "id")
+		logger.PreProcess(tmpDir, &logging.Config{})
+
+		stdout := make(chan string)
+		stderr := make(chan string)
+
+		go func() {
+			for i := 0; i < 10; i++ {
+				stdout <- "test stdout"
+				stderr <- "test stderr"
+			}
+			close(stdout)
+			close(stderr)
+		}()
+
+		err = logger.Process(stdout, stderr)
+		assert.NilError(t, err, "Process() returned unexpected error")
+
+		logger.PostProcess()
+
+		// Wait a bit to ensure any potential writes would have occurred
+		time.Sleep(100 * time.Millisecond)
+
+		// Check if any new files were created
+		afterFiles, err := os.ReadDir(tmpDir)
+		assert.NilError(t, err, "Failed to read temp dir after operations")
+
+		assert.Equal(t, len(afterFiles), len(initialFiles), "Expected no new files, but directory content changed")
+
+	})
+}