distribution/cmd/digest/main.go
Sebastiaan van Stijn 1d33874951
go.mod: change imports to github.com/distribution/distribution/v3
Go 1.13 and up enforce import paths to be versioned if a project
contains a go.mod and has released v2 or up.

The current v2.x branches (and releases) do not yet have a go.mod,
and therefore are still allowed to be imported with a non-versioned
import path (go modules add a `+incompatible` annotation in that case).

However, now that this project has a `go.mod` file, incompatible
import paths will not be accepted by go modules, and attempting
to use code from this repository will fail.

This patch uses `v3` for the import-paths (not `v2`), because changing
import paths itself is a breaking change, which means that  the
next release should increment the "major" version to comply with
SemVer (as go modules dictate).

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2021-02-08 18:30:46 +01:00

101 lines
1.7 KiB
Go

package main
import (
"flag"
"fmt"
"io"
"log"
"os"
"github.com/distribution/distribution/v3/version"
"github.com/opencontainers/go-digest"
_ "crypto/sha256"
_ "crypto/sha512"
)
var (
algorithm = digest.Canonical
showVersion bool
)
type job struct {
name string
reader io.Reader
}
func init() {
flag.Var(&algorithm, "a", "select the digest algorithm (shorthand)")
flag.Var(&algorithm, "algorithm", "select the digest algorithm")
flag.BoolVar(&showVersion, "version", false, "show the version and exit")
log.SetFlags(0)
log.SetPrefix(os.Args[0] + ": ")
}
func usage() {
fmt.Fprintf(os.Stderr, "usage: %s [files...]\n", os.Args[0])
fmt.Fprint(os.Stderr, `
Calculate the digest of one or more input files, emitting the result
to standard out. If no files are provided, the digest of stdin will
be calculated.
`)
flag.PrintDefaults()
}
func unsupported() {
log.Fatalf("unsupported digest algorithm: %v", algorithm)
}
func main() {
var jobs []job
flag.Usage = usage
flag.Parse()
if showVersion {
version.PrintVersion()
return
}
var fail bool // if we fail on one item, foul the exit code
if flag.NArg() > 0 {
for _, path := range flag.Args() {
fp, err := os.Open(path)
if err != nil {
log.Printf("%s: %v", path, err)
fail = true
continue
}
defer fp.Close()
jobs = append(jobs, job{name: path, reader: fp})
}
} else {
// just read stdin
jobs = append(jobs, job{name: "-", reader: os.Stdin})
}
digestFn := algorithm.FromReader
if !algorithm.Available() {
unsupported()
}
for _, job := range jobs {
dgst, err := digestFn(job.reader)
if err != nil {
log.Printf("%s: %v", job.name, err)
fail = true
continue
}
fmt.Printf("%v\t%s\n", dgst, job.name)
}
if fail {
os.Exit(1)
}
}