cmd: add more info to --version

Signed-off-by: Aleksa Sarai <[email protected]>

Author: cyphar

CHANGELOG.md

@@ -41,6 +41,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
   Note that this subcommand is not intended for wider use outside of our tests
   (and it is hidden from the help pages for a reason). Most users are probably
   better off just using `gomtree`.
+* `umoci --version` now provides more information about the specification
+  versions supported by the `umoci` binary as well as the Go version used.
 
 ### Changed ###
 * The output format of `umoci stat` has had some minor changes made to how

cmd/umoci/main.go

@@ -23,10 +23,13 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"runtime"
 	"runtime/pprof"
 
 	"github.com/apex/log"
 	logcli "github.com/apex/log/handlers/cli"
+	imeta "github.com/opencontainers/image-spec/specs-go"
+	rspec "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/urfave/cli"
 
 	"github.com/opencontainers/umoci"
@@ -40,6 +43,15 @@ const (
 	categoryImage  = "image"
 )
 
+func printVersion(c *cli.Context) {
+	w := c.App.Writer
+
+	fmt.Fprintln(w, "umoci version", c.App.Version) //nolint:errcheck // errors not relevant
+	fmt.Fprintln(w, "image spec:", imeta.Version)   //nolint:errcheck // errors not relevant
+	fmt.Fprintln(w, "runtime spec:", rspec.Version) //nolint:errcheck // errors not relevant
+	fmt.Fprintln(w, "go:", runtime.Version())       //nolint:errcheck // errors not relevant
+}
+
 // Main is the underlying main() implementation. You can call this directly as
 // though it were the command-line arguments of the umoci binary (this is
 // needed for umoci's integration test hacks you can find in main_test.go).
@@ -53,7 +65,9 @@ func Main(args []string) error {
 			Email: "[email protected]",
 		},
 	}
+
 	app.Version = umoci.FullVersion()
+	cli.VersionPrinter = printVersion
 
 	app.Flags = []cli.Flag{
 		cli.BoolFlag{

test/help.bats

@@ -22,11 +22,17 @@ load helpers
 
 	umoci --version
 	[ "$status" -eq 0 ]
-	[[ "$output" =~ "umoci version $VERSION"+ ]]
+	[[ "$output" == "umoci version $VERSION"* ]]
+	[[ "$output" == *"image spec: 1."* ]]
+	[[ "$output" == *"runtime spec: 1."* ]]
+	[[ "$output" == *"go: go1."* ]]
 
 	umoci -v
 	[ "$status" -eq 0 ]
-	[[ "$output" =~ "umoci version $VERSION"+ ]]
+	[[ "$output" == "umoci version $VERSION"* ]]
+	[[ "$output" == *"image spec: 1."* ]]
+	[[ "$output" == *"runtime spec: 1."* ]]
+	[[ "$output" == *"go: go1."* ]]
 }
 
 @test "umoci --help" {