Documentation
¶
Overview ¶
Package buildinfo wraps runtime/debug.ReadBuildInfo with optional VCS settings injection via -ldflags.
Go's standard `go build` populates VCS settings (vcs.revision, vcs.modified, vcs.time) by inspecting the local Git working tree at build time. In some build environments — sandboxed builders, CI pipelines that ship source as tarballs, vendored snapshots — the working tree is absent and the settings come out empty.
This package lets a build wrapper inject those settings via -ldflags, mirroring what `go build` would have stamped natively:
go build -ldflags "
-X github.com/dagger/dagger/internal/version/buildinfo.InjectedVCS=git
-X github.com/dagger/dagger/internal/version/buildinfo.InjectedVCSRevision=$(git rev-parse HEAD)
-X github.com/dagger/dagger/internal/version/buildinfo.InjectedVCSModified=false
-X github.com/dagger/dagger/internal/version/buildinfo.InjectedVCSTime=$(git log -1 --format=%cI)
" ./...
At runtime, callers use ReadBuildInfo just like they would runtime/debug's. Non-empty Injected* variables override the corresponding settings; empty ones leave whatever the toolchain stamped natively untouched.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var ( InjectedVCS string // VCS system, typically "git" InjectedVCSRevision string // commit hash InjectedVCSModified string // "true" or "false" InjectedVCSTime string // RFC3339 commit time )
Set at link time via `go build -ldflags "-X <pkg>.InjectedXxx=..."`. Empty means "no override; defer to whatever runtime/debug.ReadBuildInfo returns".
Functions ¶
func ReadBuildInfo ¶
ReadBuildInfo returns the build information of the running binary, like runtime/debug.ReadBuildInfo, with VCS settings overridden by any non-empty Injected* package variables.
If runtime/debug.ReadBuildInfo returns ok=false (binary built outside module mode) but any Injected* variable is set, ReadBuildInfo still returns a usable *debug.BuildInfo populated with the injected settings, and ok=true.
Example ¶
ExampleReadBuildInfo shows the typical pattern for reading VCS info from the running binary. Outside any special build environment this returns the same data as runtime/debug.ReadBuildInfo. Under build wrappers that injected values via -ldflags (e.g. -X github.com/dagger/dagger/internal/version/buildinfo.InjectedVCSRevision=…), the injected values appear here too.
package main
import (
"fmt"
"github.com/dagger/dagger/internal/version/buildinfo"
)
func main() {
info, ok := buildinfo.ReadBuildInfo()
if !ok {
return
}
for _, s := range info.Settings {
switch s.Key {
case "vcs.revision":
fmt.Println("commit:", s.Value)
case "vcs.modified":
fmt.Println("dirty: ", s.Value)
case "vcs.time":
fmt.Println("time: ", s.Value)
}
}
}
Output:
Types ¶
This section is empty.
Source Files