From d781c83cec16781f86eb016372d36c83a3c71395 Mon Sep 17 00:00:00 2001 From: "Jonathan A. Sternberg" Date: Fri, 3 Apr 2026 10:02:50 -0500 Subject: [PATCH] commands: micro optimization for source date epoch Avoids the call to `os.Getenv` when it is unnecessary because it would be overwritten anyway. Removes the comments about moving environment variable parsing to a method for use by library consumers. That method exists in containerd and this set of code doesn't actually perform any parsing since the parsing of this time is done within buildkit and not on the client. Signed-off-by: Jonathan A. Sternberg --- commands/bake.go | 19 ++++-- commands/build.go | 8 +-- commands/history/inspect.go | 3 +- .../containerd/v2/pkg/epoch/context.go | 41 ++++++++++++ .../containerd/v2/pkg/epoch/epoch.go | 67 +++++++++++++++++++ vendor/modules.txt | 1 + 6 files changed, 127 insertions(+), 12 deletions(-) create mode 100644 vendor/github.com/containerd/containerd/v2/pkg/epoch/context.go create mode 100644 vendor/github.com/containerd/containerd/v2/pkg/epoch/epoch.go diff --git a/commands/bake.go b/commands/bake.go index 2b23032b6..391db4c92 100644 --- a/commands/bake.go +++ b/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 } } diff --git a/commands/build.go b/commands/build.go index aa58a6e04..455d8143e 100644 --- a/commands/build.go +++ b/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 } } diff --git a/commands/history/inspect.go b/commands/history/inspect.go index a045d1ec7..6930a25da 100644 --- a/commands/history/inspect.go +++ b/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 diff --git a/vendor/github.com/containerd/containerd/v2/pkg/epoch/context.go b/vendor/github.com/containerd/containerd/v2/pkg/epoch/context.go new file mode 100644 index 000000000..fd16f9519 --- /dev/null +++ b/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) +} diff --git a/vendor/github.com/containerd/containerd/v2/pkg/epoch/epoch.go b/vendor/github.com/containerd/containerd/v2/pkg/epoch/epoch.go new file mode 100644 index 000000000..2b6718fa6 --- /dev/null +++ b/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) +} diff --git a/vendor/modules.txt b/vendor/modules.txt index d92877426..2168ef6c0 100644 --- a/vendor/modules.txt +++ b/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