Refactor busybox downloading as generic "frozen-images"

This makes it much simpler to add new "frozen" images -- simply add them to the `Dockerfile` and in `hack/make/.ensure-frozen-images` and you're off to the races.

Signed-off-by: Andrew "Tianon" Page <admwiggin@gmail.com>

Dockerfile

@@ -142,9 +142,11 @@ ENV DOCKER_BUILDTAGS apparmor selinux btrfs_noversion
 # Let us use a .bashrc file
 RUN ln -sfv $PWD/.bashrc ~/.bashrc
 
-# Get the "busybox" image so we can "docker load" locally instead of pulling
+# Get useful and necessary Hub images so we can "docker load" locally instead of pulling
 COPY contrib/download-frozen-image.sh /go/src/github.com/docker/docker/contrib/
-RUN ./contrib/download-frozen-image.sh /docker-busybox busybox@4986bf8c15363d1c5d15512d5266f8777bfba4974ac56e3270e7760f6f0a8125
+RUN ./contrib/download-frozen-image.sh /docker-frozen-images \
+	busybox:latest@4986bf8c15363d1c5d15512d5266f8777bfba4974ac56e3270e7760f6f0a8125
+# see also "hack/make/.ensure-frozen-images" (which needs to be updated any time this list is)
 
 # Install man page generator
 COPY vendor /go/src/github.com/docker/docker/vendor

contrib/download-frozen-image.sh

@@ -60,7 +60,7 @@ while [ $# -gt 0 ]; do
 		mkdir -p "$dir/$imageId"
 		echo '1.0' > "$dir/$imageId/VERSION"
 		
-		curl -sSL -H "Authorization: Token $token" "https://registry-1.docker.io/v1/images/$imageId/json" -o "$dir/$imageId/json" -C -
+		curl -sSL -H "Authorization: Token $token" "https://registry-1.docker.io/v1/images/$imageId/json" -o "$dir/$imageId/json"
 		
 		# TODO figure out why "-C -" doesn't work here
 		# "curl: (33) HTTP server doesn't seem to support byte ranges. Cannot resume."

project/make/.ensure-busybox

@@ -1,21 +0,0 @@
-#!/bin/bash
-set -e
-
-if ! docker inspect busybox &> /dev/null; then
-	hardCodedDir='/docker-busybox'
-	if [ -d "$hardCodedDir" ]; then
-		( set -x; tar -cC "$hardCodedDir" . | docker load )
-	elif [ -e Dockerfile ] && command -v curl > /dev/null; then
-		# testing for "curl" because "download-frozen-image.sh" is built around curl
-		dir="$DEST/busybox"
-		# extract the exact "download-frozen-image.sh" line from the Dockerfile itself for consistency
-		awk '$1 == "RUN" && $2 == "./contrib/download-frozen-image.sh" && /busybox@/ {
-			for (i = 2; i < NF; i++)
-				printf ( $i == "'"$hardCodedDir"'" ? "'"$dir"'" : $i ) " ";
-			print $NF;
-		}' Dockerfile | sh -x
-		( set -x; tar -cC "$dir" . | docker load )
-	else
-		( set -x; docker pull busybox )
-	fi
-fi

project/make/.ensure-frozen-images

@@ -0,0 +1,42 @@
+#!/bin/bash
+set -e
+
+# this list should match roughly what's in the Dockerfile (minus the explicit image IDs, of course)
+images=(
+	busybox:latest
+)
+
+if ! docker inspect "${images[@]}" &> /dev/null; then
+	hardCodedDir='/docker-frozen-images'
+	if [ -d "$hardCodedDir" ]; then
+		( set -x; tar -cC "$hardCodedDir" . | docker load )
+	elif [ -e Dockerfile ] && command -v curl > /dev/null; then
+		# testing for "curl" because "download-frozen-image.sh" is built around curl
+		dir="$DEST/frozen-images"
+		# extract the exact "RUN download-frozen-image.sh" line from the Dockerfile itself for consistency
+		awk '
+			$1 == "RUN" && $2 == "./contrib/download-frozen-image.sh" {
+				for (i = 2; i < NF; i++)
+					printf ( $i == "'"$hardCodedDir"'" ? "'"$dir"'" : $i ) " ";
+				print $NF;
+				if (/\\$/) {
+					inCont = 1;
+					next;
+				}
+			}
+			inCont {
+				print;
+				if (!/\\$/) {
+					inCont = 0;
+				}
+			}
+		' Dockerfile | sh -x
+		( set -x; tar -cC "$dir" . | docker load )
+	else
+		for image in "${images[@]}"; do
+			if ! docker inspect "$image" &> /dev/null; then
+				( set -x; docker pull "$image" )
+			fi
+		done
+	fi
+fi

project/make/test-integration-cli

@@ -16,7 +16,7 @@ bundle_test_integration_cli() {
 	# even and especially on test failures
 	didFail=
 	if ! {
-		source "$(dirname "$BASH_SOURCE")/.ensure-busybox"
+		source "$(dirname "$BASH_SOURCE")/.ensure-frozen-images"
 		source "$(dirname "$BASH_SOURCE")/.ensure-httpserver"
 		source "$(dirname "$BASH_SOURCE")/.ensure-emptyfs"