Merge pull request #120 from stevvooe/add-version-reporting

Add version reporting to registry binary

.gitignore

@@ -22,3 +22,6 @@ _testmain.go
 *.exe
 *.test
 *.prof
+
+# never checkin from the bin file (for now)
+bin/*

AUTHORS

@@ -6,3 +6,4 @@ Brian Bland <brian.bland@docker.com>
 Josh Hawn <josh.hawn@docker.com>
 Olivier Gambier <olivier@docker.com>
 Stephen J Day <stephen.day@docker.com>
+Tianon Gravi <admwiggin@gmail.com>

Dockerfile

@@ -1,15 +1,13 @@
 FROM golang:1.4
 
 ENV CONFIG_PATH /etc/docker/registry/config.yml
-RUN mkdir -pv "$(dirname $CONFIG_PATH)"
-
 ENV DISTRIBUTION_DIR /go/src/github.com/docker/distribution
+ENV GOPATH $DISTRIBUTION_DIR/Godeps/_workspace:$GOPATH
+
 WORKDIR $DISTRIBUTION_DIR
 COPY . $DISTRIBUTION_DIR
-ENV GOPATH $GOPATH:$DISTRIBUTION_DIR/Godeps/_workspace
-
-RUN go install -v ./cmd/registry
-
+RUN make PREFIX=/go clean binaries
+RUN mkdir -pv "$(dirname $CONFIG_PATH)"
 RUN cp -lv ./cmd/registry/config.yml $CONFIG_PATH
 
 EXPOSE 5000

Makefile

@@ -1,15 +1,26 @@
-# This project makefile is around for generating peices of documentation and
-# code. For most purposes, running it is not necessary.
+# Set an output prefix, which is the local directory if not specified
+PREFIX?=$(shell pwd)
 
-.PHONY: clean
+# Used to populate version variable in main package.
+GO_LDFLAGS=-ldflags "-X `go list ./version`.Version `git describe --match 'v[0-9]*' --dirty='.m' --always`"
+
+.PHONY: clean binaries
 .DEFAULT: default
 
 default:
-	@echo Please read the make targets before using this Makefile. It is \
-	    currently only used for documentation and autogenerated files.
+	@echo Please read the make targets before using this Makefile.
 
 AUTHORS: .mailmap .git/ORIG_HEAD .git/FETCH_HEAD .git/HEAD
 	 git log --format='%aN <%aE>' | sort -fu >> $@
 
+# This only needs to be generated by hand when cutting full releases.
+version/version.go:
+	./version/version.sh > $@
+
+${PREFIX}/bin/registry: version/version.go $(shell find . -type f -name '*.go')
+	go build -o $@ ${GO_LDFLAGS} ./cmd/registry
+
+binaries: ${PREFIX}/bin/registry
+
 clean:
-	rm -rf AUTHORS
+	rm -rf "${PREFIX}/bin/registry"

cmd/registry/main.go

@@ -19,12 +19,24 @@ import (
 	_ "github.com/docker/distribution/storagedriver/filesystem"
 	_ "github.com/docker/distribution/storagedriver/inmemory"
 	_ "github.com/docker/distribution/storagedriver/s3"
+	"github.com/docker/distribution/version"
 )
 
+var showVersion bool
+
+func init() {
+	flag.BoolVar(&showVersion, "version", false, "show the version and exit")
+}
+
 func main() {
 	flag.Usage = usage
 	flag.Parse()
 
+	if showVersion {
+		version.PrintVersion()
+		return
+	}
+
 	config, err := resolveConfiguration()
 	if err != nil {
 		fatalf("configuration error: %v", err)

version/print.go

@@ -0,0 +1,26 @@
+package version
+
+import (
+	"fmt"
+	"io"
+	"os"
+)
+
+// FprintVersion outputs the version string to the writer, in the following
+// format, followed by a newline:
+//
+// 	<cmd> <project> <version>
+//
+// For example, a binary "registry" built from github.com/docker/distribution
+// with version "v2.0" would print the following:
+//
+// 	registry github.com/docker/distribution v2.0
+//
+func FprintVersion(w io.Writer) {
+	fmt.Fprintln(w, os.Args[0], Package, Version)
+}
+
+// PrintVersion outputs the version information, from Fprint, to stdout.
+func PrintVersion() {
+	FprintVersion(os.Stdout)
+}

version/version.go

@@ -0,0 +1,11 @@
+package version
+
+// Package is the overall, canonical project import path under which the
+// package was built.
+var Package = "github.com/docker/distribution"
+
+// Version indicates which version of the binary is running. This is set to
+// the latest release tag by hand, always suffixed by "+unknown". During
+// build, it will be replaced by the actual version. The value here will be
+// used if the registry is run after a go get based install.
+var Version = "v2.0.0-alpha.1+unknown"

version/version.sh

@@ -0,0 +1,22 @@
+#!/bin/sh
+
+# This bash script outputs the current, desired content of version.go, using
+# git describe. For best effect, pipe this to the target file. Generally, this
+# only needs to updated for releases. The actual value of will be replaced
+# during build time if the makefile is used.
+
+set -e
+
+cat <<EOF
+package version
+
+// Package is the overall, canonical project import path under which the
+// package was built.
+var Package = "$(go list)"
+
+// Version indicates which version of the binary is running. This is set to
+// the latest release tag by hand, always suffixed by "+unknown". During
+// build, it will be replaced by the actual version. The value here will be
+// used if the registry is run after a go get based install.
+var Version = "$(git describe --match 'v[0-9]*' --dirty='.m' --always)+unknown"
+EOF