Move namespaces to pkg/namespaces

Signed-off-by: Derek McGowan <derek@mcg.dev>

pkg/namespaces/context.go

@@ -0,0 +1,78 @@
+/*
+   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 namespaces
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/containerd/containerd/v2/pkg/errdefs"
+	"github.com/containerd/containerd/v2/pkg/identifiers"
+)
+
+const (
+	// NamespaceEnvVar is the environment variable key name
+	NamespaceEnvVar = "CONTAINERD_NAMESPACE"
+	// Default is the name of the default namespace
+	Default = "default"
+)
+
+type namespaceKey struct{}
+
+// WithNamespace sets a given namespace on the context
+func WithNamespace(ctx context.Context, namespace string) context.Context {
+	ctx = context.WithValue(ctx, namespaceKey{}, namespace) // set our key for namespace
+	// also store on the grpc and ttrpc headers so it gets picked up by any clients that
+	// are using this.
+	return withTTRPCNamespaceHeader(withGRPCNamespaceHeader(ctx, namespace), namespace)
+}
+
+// NamespaceFromEnv uses the namespace defined in CONTAINERD_NAMESPACE or
+// default
+func NamespaceFromEnv(ctx context.Context) context.Context {
+	namespace := os.Getenv(NamespaceEnvVar)
+	if namespace == "" {
+		namespace = Default
+	}
+	return WithNamespace(ctx, namespace)
+}
+
+// Namespace returns the namespace from the context.
+//
+// The namespace is not guaranteed to be valid.
+func Namespace(ctx context.Context) (string, bool) {
+	namespace, ok := ctx.Value(namespaceKey{}).(string)
+	if !ok {
+		if namespace, ok = fromGRPCHeader(ctx); !ok {
+			return fromTTRPCHeader(ctx)
+		}
+	}
+	return namespace, ok
+}
+
+// NamespaceRequired returns the valid namespace from the context or an error.
+func NamespaceRequired(ctx context.Context) (string, error) {
+	namespace, ok := Namespace(ctx)
+	if !ok || namespace == "" {
+		return "", fmt.Errorf("namespace is required: %w", errdefs.ErrFailedPrecondition)
+	}
+	if err := identifiers.Validate(namespace); err != nil {
+		return "", fmt.Errorf("namespace validation: %w", err)
+	}
+	return namespace, nil
+}

pkg/namespaces/context_test.go

@@ -0,0 +1,71 @@
+/*
+   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 namespaces
+
+import (
+	"context"
+	"testing"
+)
+
+func TestContext(t *testing.T) {
+	ctx := context.Background()
+	namespace, ok := Namespace(ctx)
+	if ok {
+		t.Fatal("namespace should not be present")
+	}
+
+	if namespace != "" {
+		t.Fatalf("namespace should not be defined: got %q", namespace)
+	}
+
+	expected := "test"
+	nctx := WithNamespace(ctx, expected)
+
+	namespace, ok = Namespace(nctx)
+	if !ok {
+		t.Fatal("expected to find a namespace")
+	}
+
+	if namespace != expected {
+		t.Fatalf("unexpected namespace: %q != %q", namespace, expected)
+	}
+}
+
+func TestNamespaceFromEnv(t *testing.T) {
+	ctx := context.Background()
+	namespace, ok := Namespace(ctx)
+	if ok {
+		t.Fatal("namespace should not be present")
+	}
+
+	if namespace != "" {
+		t.Fatalf("namespace should not be defined: got %q", namespace)
+	}
+
+	expected := "test-namespace"
+	t.Setenv(NamespaceEnvVar, expected)
+	nctx := NamespaceFromEnv(ctx)
+
+	namespace, ok = Namespace(nctx)
+	if !ok {
+		t.Fatal("expected to find a namespace")
+	}
+
+	if namespace != expected {
+		t.Fatalf("unexpected namespace: %q != %q", namespace, expected)
+	}
+}

pkg/namespaces/grpc.go

@@ -0,0 +1,61 @@
+/*
+   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 namespaces
+
+import (
+	"context"
+
+	"google.golang.org/grpc/metadata"
+)
+
+const (
+	// GRPCHeader defines the header name for specifying a containerd namespace.
+	GRPCHeader = "containerd-namespace"
+)
+
+// NOTE(stevvooe): We can stub this file out if we don't want a grpc dependency here.
+
+func withGRPCNamespaceHeader(ctx context.Context, namespace string) context.Context {
+	// also store on the grpc headers so it gets picked up by any clients that
+	// are using this.
+	nsheader := metadata.Pairs(GRPCHeader, namespace)
+	md, ok := metadata.FromOutgoingContext(ctx) // merge with outgoing context.
+	if !ok {
+		md = nsheader
+	} else {
+		// order ensures the latest is first in this list.
+		md = metadata.Join(nsheader, md)
+	}
+
+	return metadata.NewOutgoingContext(ctx, md)
+}
+
+func fromGRPCHeader(ctx context.Context) (string, bool) {
+	// try to extract for use in grpc servers.
+	md, ok := metadata.FromIncomingContext(ctx)
+	if !ok {
+		// TODO(stevvooe): Check outgoing context?
+		return "", false
+	}
+
+	values := md[GRPCHeader]
+	if len(values) == 0 {
+		return "", false
+	}
+
+	return values[0], true
+}

pkg/namespaces/store.go

@@ -0,0 +1,44 @@
+/*
+   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 namespaces
+
+import "context"
+
+// Store provides introspection about namespaces.
+//
+// Note that these are slightly different than other objects, which are record
+// oriented. A namespace is really just a name and a set of labels. Objects
+// that belong to a namespace are returned when the namespace is assigned to a
+// given context.
+type Store interface {
+	Create(ctx context.Context, namespace string, labels map[string]string) error
+	Labels(ctx context.Context, namespace string) (map[string]string, error)
+	SetLabel(ctx context.Context, namespace, key, value string) error
+	List(ctx context.Context) ([]string, error)
+
+	// Delete removes the namespace. The namespace must be empty to be deleted.
+	Delete(ctx context.Context, namespace string, opts ...DeleteOpts) error
+}
+
+// DeleteInfo specifies information for the deletion of a namespace
+type DeleteInfo struct {
+	// Name of the namespace
+	Name string
+}
+
+// DeleteOpts allows the caller to set options for namespace deletion
+type DeleteOpts func(context.Context, *DeleteInfo) error

pkg/namespaces/ttrpc.go

@@ -0,0 +1,51 @@
+/*
+   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 namespaces
+
+import (
+	"context"
+
+	"github.com/containerd/ttrpc"
+)
+
+const (
+	// TTRPCHeader defines the header name for specifying a containerd namespace
+	TTRPCHeader = "containerd-namespace-ttrpc"
+)
+
+func copyMetadata(src ttrpc.MD) ttrpc.MD {
+	md := ttrpc.MD{}
+	for k, v := range src {
+		md[k] = append(md[k], v...)
+	}
+	return md
+}
+
+func withTTRPCNamespaceHeader(ctx context.Context, namespace string) context.Context {
+	md, ok := ttrpc.GetMetadata(ctx)
+	if !ok {
+		md = ttrpc.MD{}
+	} else {
+		md = copyMetadata(md)
+	}
+	md.Set(TTRPCHeader, namespace)
+	return ttrpc.WithMetadata(ctx, md)
+}
+
+func fromTTRPCHeader(ctx context.Context) (string, bool) {
+	return ttrpc.GetMetadataValue(ctx, TTRPCHeader)
+}

pkg/namespaces/ttrpc_test.go

@@ -0,0 +1,52 @@
+/*
+   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 namespaces
+
+import (
+	"context"
+	"reflect"
+	"testing"
+
+	"github.com/containerd/ttrpc"
+)
+
+func TestCopyTTRPCMetadata(t *testing.T) {
+	src := ttrpc.MD{}
+	src.Set("key", "a", "b", "c", "d")
+	md := copyMetadata(src)
+
+	if !reflect.DeepEqual(src, md) {
+		t.Fatalf("metadata is copied incorrectly")
+	}
+
+	slice, _ := src.Get("key")
+	slice[0] = "z"
+	if reflect.DeepEqual(src, md) {
+		t.Fatalf("metadata is copied incorrectly")
+	}
+}
+
+func TestTTRPCNamespaceHeader(t *testing.T) {
+	ctx := context.Background()
+	namespace := "test-namespace"
+	ctx = withTTRPCNamespaceHeader(ctx, namespace)
+
+	header, ok := fromTTRPCHeader(ctx)
+	if !ok || header != namespace {
+		t.Fatalf("ttrp namespace header is set incorrectly")
+	}
+}