add support for completions

Signed-off-by: Mike Brown <brownwm@us.ibm.com>

Makefile

@@ -1,12 +1,11 @@
-.PHONY: all binary build-container build-local clean install install-binary shell test-integration
+.PHONY: all binary build-container build-local clean install install-binary install-completions shell test-integration
 
 export GO15VENDOREXPERIMENT=1
 
 PREFIX ?= ${DESTDIR}/usr
 INSTALLDIR=${PREFIX}/bin
 MANINSTALLDIR=${PREFIX}/share/man
-# TODO(runcom)
-#BASHINSTALLDIR=${PREFIX}/share/bash-completion/completions
+BASHINSTALLDIR=${PREFIX}/share/bash-completion/completions
 GO_MD2MAN ?= /usr/bin/go-md2man
 
 ifeq ($(DEBUG), 1)
@@ -60,9 +59,7 @@ docs: $(MANPAGES_MD:%.md=%)
 clean:
 	rm -f skopeo docs/*.1
 
-install: install-binary install-docs
-	# TODO(runcom)
-	#install -m 644 completion/bash/skopeo ${BASHINSTALLDIR}/
+install: install-binary install-docs install-completions
 
 install-binary: ./skopeo
 	install -d -m 0755 ${INSTALLDIR}
@@ -72,6 +69,9 @@ install-docs: docs/skopeo.1
 	install -d -m 0755 ${MANINSTALLDIR}/man1
 	install -m 644 docs/skopeo.1 ${MANINSTALLDIR}/man1/
 
+install-completions:
+	install -m 644 -T hack/make/bash_autocomplete ${BASHINSTALLDIR}/skopeo
+
 shell: build-container
 	$(DOCKER_RUN_DOCKER) bash
 

cmd/skopeo/main.go

@@ -16,6 +16,7 @@ var gitCommit = ""
 // createApp returns a cli.App to be run or tested.
 func createApp() *cli.App {
 	app := cli.NewApp()
+	app.EnableBashCompletion = true
 	app.Name = "skopeo"
 	if gitCommit != "" {
 		app.Version = fmt.Sprintf("%s commit: %s", version.Version, gitCommit)

hack/make/bash_autocomplete

@@ -0,0 +1,14 @@
+#! /bin/bash
+
+: ${PROG:=$(basename ${BASH_SOURCE})}
+
+_cli_bash_autocomplete() {
+     local cur opts base
+     COMPREPLY=()
+     cur="${COMP_WORDS[COMP_CWORD]}"
+     opts=$( ${COMP_WORDS[@]:0:$COMP_CWORD} --generate-bash-completion )
+     COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
+     return 0
+ }
+
+ complete -F _cli_bash_autocomplete $PROG