Add bash completion to the development container

Adds an environment variable `DOCKER_BASH_COMPLETION_PATH` that allows to
include a bash completion script into the development container.

This is needid for development of bash completion.

Signed-off-by: Harald Albers <github@albersweb.de>

Dockerfile

@@ -217,6 +217,9 @@ COPY hack/dockerfile/install-binaries.sh /tmp/install-binaries.sh
 RUN /tmp/install-binaries.sh tomlv vndr runc containerd tini proxy dockercli
 ENV PATH=/usr/local/cli:$PATH
 
+# Activate bash completion if mounted with DOCKER_BASH_COMPLETION_PATH
+RUN ln -s /usr/local/completion/bash/docker /etc/bash_completion.d/docker
+
 # Wrap all commands in the "docker-in-docker" script to allow nested containers
 ENTRYPOINT ["hack/dind"]
 

Makefile

@@ -24,6 +24,7 @@ DOCKER_ENVS := \
 	-e DOCKER_BUILD_ARGS \
 	-e DOCKER_BUILD_GOGC \
 	-e DOCKER_BUILD_PKGS \
+	-e DOCKER_BASH_COMPLETION_PATH \
 	-e DOCKER_CLI_PATH \
 	-e DOCKER_DEBUG \
 	-e DOCKER_EXPERIMENTAL \
@@ -65,7 +66,8 @@ PKGCACHE_VOLROOT := dockerdev-go-pkg-cache
 PKGCACHE_VOL := $(if $(PKGCACHE_DIR),$(CURDIR)/$(PKGCACHE_DIR)/,$(PKGCACHE_VOLROOT)-)
 DOCKER_MOUNT_PKGCACHE := $(if $(DOCKER_INCREMENTAL_BINARY),$(shell echo $(PKGCACHE_MAP) | sed -E 's@([^ ]*)@-v "$(PKGCACHE_VOL)\1"@g'),)
 DOCKER_MOUNT_CLI := $(if $(DOCKER_CLI_PATH),-v $(shell dirname $(DOCKER_CLI_PATH)):/usr/local/cli,)
-DOCKER_MOUNT := $(DOCKER_MOUNT) $(DOCKER_MOUNT_PKGCACHE) $(DOCKER_MOUNT_CLI)
+DOCKER_MOUNT_BASH_COMPLETION := $(if $(DOCKER_BASH_COMPLETION_PATH),-v $(shell dirname $(DOCKER_BASH_COMPLETION_PATH)):/usr/local/completion/bash,)
+DOCKER_MOUNT := $(DOCKER_MOUNT) $(DOCKER_MOUNT_PKGCACHE) $(DOCKER_MOUNT_CLI) $(DOCKER_MOUNT_BASH_COMPLETION)
 
 GIT_BRANCH := $(shell git rev-parse --abbrev-ref HEAD 2>/dev/null)
 GIT_BRANCH_CLEAN := $(shell echo $(GIT_BRANCH) | sed -e "s/[^[:alnum:]]/-/g")