Merge pull request #3770 from jsternberg/containerd-source-date-epoch

commands: micro optimization for source date epoch

commands/bake.go

@@ -17,6 +17,7 @@ import (
 	"text/tabwriter"
 
 	"github.com/containerd/console"
+	"github.com/containerd/containerd/v2/pkg/epoch"
 	"github.com/containerd/platforms"
 	"github.com/docker/buildx/bake"
 	"github.com/docker/buildx/bake/hclparser"
@@ -241,16 +242,20 @@ func runBake(ctx context.Context, dockerCli command.Cli, targets []string, in ba
 		return err
 	}
 
-	if v := os.Getenv("SOURCE_DATE_EPOCH"); v != "" {
-		// TODO: extract env var parsing to a method easily usable by library consumers
-		for _, t := range tgts {
-			if _, ok := t.Args["SOURCE_DATE_EPOCH"]; ok {
-				continue
-			}
+	var sourceDateEpoch *string
+	for _, t := range tgts {
+		if _, ok := t.Args[epoch.SourceDateEpochEnv]; ok {
+			continue
+		}
+
+		v := os.Getenv(epoch.SourceDateEpochEnv)
+		sourceDateEpoch = &v
+
+		if *sourceDateEpoch != "" {
 			if t.Args == nil {
 				t.Args = map[string]*string{}
 			}
-			t.Args["SOURCE_DATE_EPOCH"] = &v
+			t.Args[epoch.SourceDateEpochEnv] = sourceDateEpoch
 		}
 	}
 

commands/build.go

@@ -18,6 +18,7 @@ import (
 	"time"
 
 	"github.com/containerd/console"
+	"github.com/containerd/containerd/v2/pkg/epoch"
 	"github.com/docker/buildx/build"
 	"github.com/docker/buildx/builder"
 	"github.com/docker/buildx/store"
@@ -139,10 +140,9 @@ func (o *buildOptions) toOptions() (*BuildOptions, error) {
 		ExportLoad:     o.exportLoad,
 	}
 
-	// TODO: extract env var parsing to a method easily usable by library consumers
-	if v := os.Getenv("SOURCE_DATE_EPOCH"); v != "" {
-		if _, ok := opts.BuildArgs["SOURCE_DATE_EPOCH"]; !ok {
-			opts.BuildArgs["SOURCE_DATE_EPOCH"] = v
+	if _, ok := opts.BuildArgs[epoch.SourceDateEpochEnv]; !ok {
+		if v := os.Getenv(epoch.SourceDateEpochEnv); v != "" {
+			opts.BuildArgs[epoch.SourceDateEpochEnv] = v
 		}
 	}
 

commands/history/inspect.go

@@ -19,6 +19,7 @@ import (
 	"github.com/containerd/containerd/v2/core/content"
 	"github.com/containerd/containerd/v2/core/content/proxy"
 	"github.com/containerd/containerd/v2/core/images"
+	"github.com/containerd/containerd/v2/pkg/epoch"
 	"github.com/containerd/platforms"
 	"github.com/docker/buildx/localstate"
 	"github.com/docker/buildx/util/cobrautil/completion"
@@ -392,7 +393,7 @@ workers0:
 	readAttr(attrs, "ulimit", &out.Config.Ulimit, nil)
 	readAttr(attrs, "build-arg:BUILDKIT_CACHE_MOUNT_NS", &out.Config.CacheMountNS, nil)
 	readAttr(attrs, "build-arg:BUILDKIT_DOCKERFILE_CHECK", &out.Config.DockerfileCheckConfig, nil)
-	readAttr(attrs, "build-arg:SOURCE_DATE_EPOCH", &out.Config.SourceDateEpoch, nil)
+	readAttr(attrs, "build-arg:"+epoch.SourceDateEpochEnv, &out.Config.SourceDateEpoch, nil)
 	readAttr(attrs, "build-arg:SANDBOX_HOSTNAME", &out.Config.SandboxHostname, nil)
 
 	var unusedAttrs []keyValueOutput

vendor/github.com/containerd/containerd/v2/pkg/epoch/context.go

@@ -0,0 +1,41 @@
+/*
+   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 epoch
+
+import (
+	"context"
+	"time"
+)
+
+type (
+	epochKey struct{}
+)
+
+// WithSourceDateEpoch associates the context with the epoch.
+func WithSourceDateEpoch(ctx context.Context, tm *time.Time) context.Context {
+	return context.WithValue(ctx, epochKey{}, tm)
+}
+
+// FromContext returns the epoch associated with the context.
+// FromContext does not fall back to read the SOURCE_DATE_EPOCH env var.
+func FromContext(ctx context.Context) *time.Time {
+	v := ctx.Value(epochKey{})
+	if v == nil {
+		return nil
+	}
+	return v.(*time.Time)
+}

vendor/github.com/containerd/containerd/v2/pkg/epoch/epoch.go

@@ -0,0 +1,67 @@
+/*
+   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 epoch provides SOURCE_DATE_EPOCH utilities.
+package epoch
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"time"
+)
+
+// SourceDateEpochEnv is the SOURCE_DATE_EPOCH env var.
+// See https://reproducible-builds.org/docs/source-date-epoch/
+const SourceDateEpochEnv = "SOURCE_DATE_EPOCH"
+
+// SourceDateEpoch returns the SOURCE_DATE_EPOCH env var as *time.Time.
+// If the env var is not set, SourceDateEpoch returns nil without an error.
+func SourceDateEpoch() (*time.Time, error) {
+	v, ok := os.LookupEnv(SourceDateEpochEnv)
+	if !ok || v == "" {
+		return nil, nil // not an error
+	}
+	t, err := ParseSourceDateEpoch(v)
+	if err != nil {
+		return nil, fmt.Errorf("invalid %s value: %w", SourceDateEpochEnv, err)
+	}
+	return t, nil
+}
+
+// ParseSourceDateEpoch parses the given source date epoch, as *time.Time.
+// It returns an error if sourceDateEpoch is empty or not well-formatted.
+func ParseSourceDateEpoch(sourceDateEpoch string) (*time.Time, error) {
+	if sourceDateEpoch == "" {
+		return nil, fmt.Errorf("value is empty")
+	}
+	i64, err := strconv.ParseInt(sourceDateEpoch, 10, 64)
+	if err != nil {
+		return nil, fmt.Errorf("invalid value: %w", err)
+	}
+	unix := time.Unix(i64, 0).UTC()
+	return &unix, nil
+}
+
+// SetSourceDateEpoch sets the SOURCE_DATE_EPOCH env var.
+func SetSourceDateEpoch(tm time.Time) {
+	_ = os.Setenv(SourceDateEpochEnv, fmt.Sprintf("%d", tm.Unix()))
+}
+
+// UnsetSourceDateEpoch unsets the SOURCE_DATE_EPOCH env var.
+func UnsetSourceDateEpoch() {
+	_ = os.Unsetenv(SourceDateEpochEnv)
+}

vendor/modules.txt

@@ -222,6 +222,7 @@ github.com/containerd/containerd/v2/internal/fsverity
 github.com/containerd/containerd/v2/internal/lazyregexp
 github.com/containerd/containerd/v2/internal/randutil
 github.com/containerd/containerd/v2/pkg/archive/compression
+github.com/containerd/containerd/v2/pkg/epoch
 github.com/containerd/containerd/v2/pkg/filters
 github.com/containerd/containerd/v2/pkg/identifiers
 github.com/containerd/containerd/v2/pkg/kernelversion