Setup validate-golint

- Add a validate-lint target (and script/validate-lint that does the
  job)
- Add the first package that is covered by it : version.

Related to docker#14

Dockerfile

@@ -11,6 +11,7 @@ RUN go get github.com/mitchellh/gox
 RUN go get github.com/aktau/github-release
 RUN go get github.com/tools/godep
 RUN go get golang.org/x/tools/cmd/cover
+RUN go get github.com/golang/lint/golint
 
 # Which docker version to test on
 ENV DOCKER_VERSION 1.7.1

Makefile

@@ -37,7 +37,10 @@ validate-dco: build
 validate-gofmt: build
 	$(DOCKER_RUN_LIBCOMPOSE) ./script/make.sh validate-gofmt
 
-validate: validate-dco validate-gofmt
+validate-lint: build
+	$(DOCKER_RUN_LIBCOMPOSE) ./script/make.sh validate-lint
+
+validate: validate-dco validate-gofmt validate-lint
 
 shell: build
 	$(DOCKER_RUN_LIBCOMPOSE) bash

script/validate-lint

@@ -0,0 +1,35 @@
+#!/bin/bash
+
+# We will eventually get to the point when packages should be the complete list
+# of subpackages, vendoring excluded, as given by:
+#
+# packages=( $(go list ./... 2> /dev/null | grep -vE "^github.com/docker/docker/vendor" || true ) )
+
+packages=(
+    version
+)
+
+errors=()
+for p in "${packages[@]}"; do
+	# Run golint on package/*.go file explicitly to validate all go files
+	# and not just the ones for the current platform.
+	failedLint=$(golint "$p"/*.go)
+	if [ "$failedLint" ]; then
+		errors+=( "$failedLint" )
+	fi
+done
+
+if [ ${#errors[@]} -eq 0 ]; then
+	echo 'Congratulations!  All Go source files have been linted.'
+else
+	{
+		echo "Errors from golint:"
+		for err in "${errors[@]}"; do
+			echo "$err"
+		done
+		echo
+		echo 'Please fix the above errors. You can test via "golint" and commit the result.'
+		echo
+	} >&2
+	false
+fi