tianon/download-frozen-image.sh

## download-frozen-image.sh
#!/bin/bash
set -e

# hello-world                      latest              ef872312fe1b        3 months ago        910 B
# hello-world                      latest              ef872312fe1bbc5e05aae626791a47ee9b032efa8f3bda39cc0be7b56bfe59b9   3 months ago        910 B

# debian                           latest              f6fab3b798be        10 weeks ago        85.1 MB
# debian                           latest              f6fab3b798be3174f45aa1eb731f8182705555f89c9026d8c1ef230cbf8301dd   10 weeks ago        85.1 MB

usage() {
	echo "usage: $0 dir image[:tag][@image-id] ..."
	echo "   ie: $0 /tmp/hello-world hello-world"
	echo "       $0 /tmp/debian-jessie debian:jessie"
	echo "       $0 /tmp/old-hello-world hello-world@ef872312fe1bbc5e05aae626791a47ee9b032efa8f3bda39cc0be7b56bfe59b9"
	echo "       $0 /tmp/old-debian debian:latest@f6fab3b798be3174f45aa1eb731f8182705555f89c9026d8c1ef230cbf8301dd"
	[ -z "$1" ] || exit "$1"
}

dir="$1" # dir for building tar in
shift || usage 1 >&2

[ $# -gt 0 -a "$dir" ] || usage 2 >&2
mkdir -p "$dir"

declare -A repositories=()

while [ $# -gt 0 ]; do
	imageTag="$1"
	shift
	image="${imageTag%%[:@]*}"
	tag="${imageTag#*:}"
	imageId="${tag##*@}"
	[ "$imageId" != "$tag" ] || imageId=
	[ "$tag" != "$imageTag" ] || tag='latest'
	tag="${tag%@*}"

	token="$(curl -sSL -o /dev/null -D- -H 'X-Docker-Token: true' "https://index.docker.io/v1/repositories/$image/images" | awk -F ':[[:space:]]*|\r' '$1 == "X-Docker-Token" { print $2 }')"

	if [ -z "$imageId" ]; then
		imageId="$(curl -sSL -H "Authorization: Token $token" "https://registry-1.docker.io/v1/repositories/$image/tags/$tag")"
		imageId="${imageId//\"/}"
	fi

	ancestryJson="$(curl -sSL -H "Authorization: Token $token" "https://registry-1.docker.io/v1/images/$imageId/ancestry")"
	if [ "${ancestryJson:0:1}" != '[' ]; then
		echo >&2 "error: /v1/images/$imageId/ancestry returned something unexpected:"
		echo >&2 "  $ancestryJson"
		exit 1
	fi

	IFS=','
	ancestry=( ${ancestryJson//[\[\] \"]/} )
	unset IFS

	[ -z "${repositories[$image]}" ] || repositories[$image]+=', '
	repositories[$image]+='"'"$tag"'": "'"$imageId"'"'

	echo "Downloading '$imageTag' (${#ancestry[@]} layers)..."
	for imageId in "${ancestry[@]}"; do
		mkdir -p "$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 -

		# TODO figure out why "-C -" doesn't work here
		# "curl: (33) HTTP server doesn't seem to support byte ranges. Cannot resume."
		# "HTTP/1.1 416 Requested Range Not Satisfiable"
		if [ -f "$dir/$imageId/layer.tar" ]; then
			# TODO hackpatch for no -C support :'(
			echo "skipping existing ${imageId:0:12}"
			continue
		fi
		curl -SL --progress -H "Authorization: Token $token" "https://registry-1.docker.io/v1/images/$imageId/layer" -o "$dir/$imageId/layer.tar" # -C -
	done
	echo
done

echo -n '{' > "$dir/repositories"
firstImage=1
for image in "${!repositories[@]}"; do
	[ "$firstImage" ] || echo -n ',' >> "$dir/repositories"
	firstImage=
	echo -n $'\n\t' >> "$dir/repositories"
	echo -n '"'"$image"'": { '"${repositories[$image]}"' }' >> "$dir/repositories"
done
echo -n $'\n}\n' >> "$dir/repositories"

echo "Download of images into '$dir' complete."
echo "Use something like the following to load the result into a Docker daemon:"
echo "  tar -cC '$dir' . | docker load"

## sample-1.sh-session
$ docker images hello-world
REPOSITORY          TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
$ rm -rf temp && mkdir temp
$ ./download-frozen-image.sh temp/ hello-world
Downloading 'hello-world' (3 layers)...
######################################################################## 100.0%
######################################################################## 100.0%
######################################################################## 100.0%

Download of images into 'temp/' complete.
Use something like the following to load the result into a Docker daemon:
  tar -cC 'temp/' . | docker load
$ tar -cC 'temp/' . | docker load
$ docker images hello-world
REPOSITORY          TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
hello-world         latest              e45a5af57b00        2 weeks ago         910 B
$ docker run --rm hello-world
Hello from Docker.
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (Assuming it was not already locally available.)
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

For more examples and ideas, visit:
 http://docs.docker.com/userguide/
$ docker pull hello-world
hello-world:latest: The image you are pulling has been verified
511136ea3c5a: Already exists
31cbccb51277: Already exists
e45a5af57b00: Already exists
Status: Image is up to date for hello-world:latest

## sample-2.sh-session
$ rm -rf temp && mkdir temp
$ ./download-frozen-image.sh temp $(bashbrew list debian)
Downloading 'debian:8.0' (3 layers)...
######################################################################## 100.0%
######################################################################## 100.0%
######################################################################## 100.0%

Downloading 'debian:8' (3 layers)...
skipping existing 58052b122b60
skipping existing bce696e097dc
skipping existing 511136ea3c5a

Downloading 'debian:jessie' (3 layers)...
skipping existing 58052b122b60
skipping existing bce696e097dc
skipping existing 511136ea3c5a

Downloading 'debian:oldstable' (3 layers)...
######################################################################## 100.0%
######################################################################## 100.0%
skipping existing 511136ea3c5a

Downloading 'debian:sid' (3 layers)...
######################################################################## 100.0%
######################################################################## 100.0%
skipping existing 511136ea3c5a

Downloading 'debian:6.0.10' (3 layers)...
######################################################################## 100.0%
######################################################################## 100.0%
skipping existing 511136ea3c5a

Downloading 'debian:6.0' (3 layers)...
skipping existing 3af93ba75125
skipping existing 0c232c0d0179
skipping existing 511136ea3c5a

Downloading 'debian:6' (3 layers)...
skipping existing 3af93ba75125
skipping existing 0c232c0d0179
skipping existing 511136ea3c5a

Downloading 'debian:squeeze' (3 layers)...
skipping existing 3af93ba75125
skipping existing 0c232c0d0179
skipping existing 511136ea3c5a

Downloading 'debian:stable' (3 layers)...
######################################################################## 100.0%
######################################################################## 100.0%
skipping existing 511136ea3c5a

Downloading 'debian:testing' (3 layers)...
######################################################################## 100.0%
######################################################################## 100.0%
skipping existing 511136ea3c5a

Downloading 'debian:unstable' (3 layers)...
######################################################################## 100.0%
######################################################################## 100.0%
skipping existing 511136ea3c5a

Downloading 'debian:7.8' (3 layers)...
######################################################################## 100.0%
######################################################################## 100.0%
skipping existing 511136ea3c5a

Downloading 'debian:7' (3 layers)...
skipping existing 4d6ce913b130
skipping existing d0a18d3b84de
skipping existing 511136ea3c5a

Downloading 'debian:wheezy' (3 layers)...
skipping existing 4d6ce913b130
skipping existing d0a18d3b84de
skipping existing 511136ea3c5a

Downloading 'debian:latest' (3 layers)...
skipping existing 4d6ce913b130
skipping existing d0a18d3b84de
skipping existing 511136ea3c5a

Downloading 'debian:rc-buggy' (4 layers)...
######################################################################## 100.0%
skipping existing 118c682d4e7e
skipping existing 7cfbedb09b9e
skipping existing 511136ea3c5a

Downloading 'debian:experimental' (4 layers)...
######################################################################## 100.0%
skipping existing 7b55004282c2
skipping existing 9f6f3369c683
skipping existing 511136ea3c5a

Download of images into 'temp' complete.
Use something like the following to load the result into a Docker daemon:
  tar -cC 'temp' . | docker load
$ tar -cC 'temp' . | docker load
$ docker images debian
REPOSITORY          TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
debian              experimental        a29efd117e8b        4 days ago          122.9 MB
debian              rc-buggy            a4868f1cbf49        4 days ago          122.9 MB
debian              7.8                 4d6ce913b130        4 days ago          84.98 MB
debian              wheezy              4d6ce913b130        4 days ago          84.98 MB
debian              7                   4d6ce913b130        4 days ago          84.98 MB
debian              latest              4d6ce913b130        4 days ago          84.98 MB
debian              unstable            7b55004282c2        4 days ago          122.9 MB
debian              testing             357efdf9810d        4 days ago          122.8 MB
debian              stable              2b4d950d5143        4 days ago          84.98 MB
debian              6.0                 3af93ba75125        4 days ago          76.61 MB
debian              6.0.10              3af93ba75125        4 days ago          76.61 MB
debian              6                   3af93ba75125        4 days ago          76.61 MB
debian              squeeze             3af93ba75125        4 days ago          76.61 MB
debian              sid                 118c682d4e7e        4 days ago          122.9 MB
debian              oldstable           06725edcbde9        4 days ago          76.61 MB
debian              jessie              58052b122b60        4 days ago          122.8 MB
debian              8.0                 58052b122b60        4 days ago          122.8 MB
debian              8                   58052b122b60        4 days ago          122.8 MB
$ du -hs temp/
331M	temp/
	#!/bin/bash
	set -e

	# hello-world latest ef872312fe1b 3 months ago 910 B
	# hello-world latest ef872312fe1bbc5e05aae626791a47ee9b032efa8f3bda39cc0be7b56bfe59b9 3 months ago 910 B

	# debian latest f6fab3b798be 10 weeks ago 85.1 MB
	# debian latest f6fab3b798be3174f45aa1eb731f8182705555f89c9026d8c1ef230cbf8301dd 10 weeks ago 85.1 MB

	usage() {
	echo "usage: $0 dir image[:tag][@image-id] ..."
	echo " ie: $0 /tmp/hello-world hello-world"
	echo " $0 /tmp/debian-jessie debian:jessie"
	echo " $0 /tmp/old-hello-world hello-world@ef872312fe1bbc5e05aae626791a47ee9b032efa8f3bda39cc0be7b56bfe59b9"
	echo " $0 /tmp/old-debian debian:latest@f6fab3b798be3174f45aa1eb731f8182705555f89c9026d8c1ef230cbf8301dd"
	[ -z "$1" ] \|\| exit "$1"
	}

	dir="$1" # dir for building tar in
	shift \|\| usage 1 >&2

	[ $# -gt 0 -a "$dir" ] \|\| usage 2 >&2
	mkdir -p "$dir"

	declare -A repositories=()

	while [ $# -gt 0 ]; do
	imageTag="$1"
	shift
	image="${imageTag%%[:@]*}"
	tag="${imageTag#*:}"
	imageId="${tag##*@}"
	[ "$imageId" != "$tag" ] \|\| imageId=
	[ "$tag" != "$imageTag" ] \|\| tag='latest'
	tag="${tag%@*}"

	token="$(curl -sSL -o /dev/null -D- -H 'X-Docker-Token: true' "https://index.docker.io/v1/repositories/$image/images" \| awk -F ':[[:space:]]*\|\r' '$1 == "X-Docker-Token" { print $2 }')"

	if [ -z "$imageId" ]; then
	imageId="$(curl -sSL -H "Authorization: Token $token" "https://registry-1.docker.io/v1/repositories/$image/tags/$tag")"
	imageId="${imageId//\"/}"
	fi

	ancestryJson="$(curl -sSL -H "Authorization: Token $token" "https://registry-1.docker.io/v1/images/$imageId/ancestry")"
	if [ "${ancestryJson:0:1}" != '[' ]; then
	echo >&2 "error: /v1/images/$imageId/ancestry returned something unexpected:"
	echo >&2 " $ancestryJson"
	exit 1
	fi

	IFS=','
	ancestry=( ${ancestryJson//[\[\] \"]/} )
	unset IFS

	[ -z "${repositories[$image]}" ] \|\| repositories[$image]+=', '
	repositories[$image]+='"'"$tag"'": "'"$imageId"'"'

	echo "Downloading '$imageTag' (${#ancestry[@]} layers)..."
	for imageId in "${ancestry[@]}"; do
	mkdir -p "$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 -

	# TODO figure out why "-C -" doesn't work here
	# "curl: (33) HTTP server doesn't seem to support byte ranges. Cannot resume."
	# "HTTP/1.1 416 Requested Range Not Satisfiable"
	if [ -f "$dir/$imageId/layer.tar" ]; then
	# TODO hackpatch for no -C support :'(
	echo "skipping existing ${imageId:0:12}"
	continue
	fi
	curl -SL --progress -H "Authorization: Token $token" "https://registry-1.docker.io/v1/images/$imageId/layer" -o "$dir/$imageId/layer.tar" # -C -
	done
	echo
	done

	echo -n '{' > "$dir/repositories"
	firstImage=1
	for image in "${!repositories[@]}"; do
	[ "$firstImage" ] \|\| echo -n ',' >> "$dir/repositories"
	firstImage=
	echo -n $'\n\t' >> "$dir/repositories"
	echo -n '"'"$image"'": { '"${repositories[$image]}"' }' >> "$dir/repositories"
	done
	echo -n $'\n}\n' >> "$dir/repositories"

	echo "Download of images into '$dir' complete."
	echo "Use something like the following to load the result into a Docker daemon:"
	echo " tar -cC '$dir' . \| docker load"
	$ docker images hello-world
	REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
	$ rm -rf temp && mkdir temp
	$ ./download-frozen-image.sh temp/ hello-world
	Downloading 'hello-world' (3 layers)...
	######################################################################## 100.0%
	######################################################################## 100.0%
	######################################################################## 100.0%

	Download of images into 'temp/' complete.
	Use something like the following to load the result into a Docker daemon:
	tar -cC 'temp/' . \| docker load
	$ tar -cC 'temp/' . \| docker load
	$ docker images hello-world
	REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
	hello-world latest e45a5af57b00 2 weeks ago 910 B
	$ docker run --rm hello-world
	Hello from Docker.
	This message shows that your installation appears to be working correctly.

	To generate this message, Docker took the following steps:
	1. The Docker client contacted the Docker daemon.
	2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
	(Assuming it was not already locally available.)
	3. The Docker daemon created a new container from that image which runs the
	executable that produces the output you are currently reading.
	4. The Docker daemon streamed that output to the Docker client, which sent it
	to your terminal.

	To try something more ambitious, you can run an Ubuntu container with:
	$ docker run -it ubuntu bash

	For more examples and ideas, visit:
	http://docs.docker.com/userguide/
	$ docker pull hello-world
	hello-world:latest: The image you are pulling has been verified
	511136ea3c5a: Already exists
	31cbccb51277: Already exists
	e45a5af57b00: Already exists
	Status: Image is up to date for hello-world:latest
	$ rm -rf temp && mkdir temp
	$ ./download-frozen-image.sh temp $(bashbrew list debian)
	Downloading 'debian:8.0' (3 layers)...
	######################################################################## 100.0%
	######################################################################## 100.0%
	######################################################################## 100.0%

	Downloading 'debian:8' (3 layers)...
	skipping existing 58052b122b60
	skipping existing bce696e097dc
	skipping existing 511136ea3c5a

	Downloading 'debian:jessie' (3 layers)...
	skipping existing 58052b122b60
	skipping existing bce696e097dc
	skipping existing 511136ea3c5a

	Downloading 'debian:oldstable' (3 layers)...
	######################################################################## 100.0%
	######################################################################## 100.0%
	skipping existing 511136ea3c5a

	Downloading 'debian:sid' (3 layers)...
	######################################################################## 100.0%
	######################################################################## 100.0%
	skipping existing 511136ea3c5a

	Downloading 'debian:6.0.10' (3 layers)...
	######################################################################## 100.0%
	######################################################################## 100.0%
	skipping existing 511136ea3c5a

	Downloading 'debian:6.0' (3 layers)...
	skipping existing 3af93ba75125
	skipping existing 0c232c0d0179
	skipping existing 511136ea3c5a

	Downloading 'debian:6' (3 layers)...
	skipping existing 3af93ba75125
	skipping existing 0c232c0d0179
	skipping existing 511136ea3c5a

	Downloading 'debian:squeeze' (3 layers)...
	skipping existing 3af93ba75125
	skipping existing 0c232c0d0179
	skipping existing 511136ea3c5a

	Downloading 'debian:stable' (3 layers)...
	######################################################################## 100.0%
	######################################################################## 100.0%
	skipping existing 511136ea3c5a

	Downloading 'debian:testing' (3 layers)...
	######################################################################## 100.0%
	######################################################################## 100.0%
	skipping existing 511136ea3c5a

	Downloading 'debian:unstable' (3 layers)...
	######################################################################## 100.0%
	######################################################################## 100.0%
	skipping existing 511136ea3c5a

	Downloading 'debian:7.8' (3 layers)...
	######################################################################## 100.0%
	######################################################################## 100.0%
	skipping existing 511136ea3c5a

	Downloading 'debian:7' (3 layers)...
	skipping existing 4d6ce913b130
	skipping existing d0a18d3b84de
	skipping existing 511136ea3c5a

	Downloading 'debian:wheezy' (3 layers)...
	skipping existing 4d6ce913b130
	skipping existing d0a18d3b84de
	skipping existing 511136ea3c5a

	Downloading 'debian:latest' (3 layers)...
	skipping existing 4d6ce913b130
	skipping existing d0a18d3b84de
	skipping existing 511136ea3c5a

	Downloading 'debian:rc-buggy' (4 layers)...
	######################################################################## 100.0%
	skipping existing 118c682d4e7e
	skipping existing 7cfbedb09b9e
	skipping existing 511136ea3c5a

	Downloading 'debian:experimental' (4 layers)...
	######################################################################## 100.0%
	skipping existing 7b55004282c2
	skipping existing 9f6f3369c683
	skipping existing 511136ea3c5a

	Download of images into 'temp' complete.
	Use something like the following to load the result into a Docker daemon:
	tar -cC 'temp' . \| docker load
	$ tar -cC 'temp' . \| docker load
	$ docker images debian
	REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
	debian experimental a29efd117e8b 4 days ago 122.9 MB
	debian rc-buggy a4868f1cbf49 4 days ago 122.9 MB
	debian 7.8 4d6ce913b130 4 days ago 84.98 MB
	debian wheezy 4d6ce913b130 4 days ago 84.98 MB
	debian 7 4d6ce913b130 4 days ago 84.98 MB
	debian latest 4d6ce913b130 4 days ago 84.98 MB
	debian unstable 7b55004282c2 4 days ago 122.9 MB
	debian testing 357efdf9810d 4 days ago 122.8 MB
	debian stable 2b4d950d5143 4 days ago 84.98 MB
	debian 6.0 3af93ba75125 4 days ago 76.61 MB
	debian 6.0.10 3af93ba75125 4 days ago 76.61 MB
	debian 6 3af93ba75125 4 days ago 76.61 MB
	debian squeeze 3af93ba75125 4 days ago 76.61 MB
	debian sid 118c682d4e7e 4 days ago 122.9 MB
	debian oldstable 06725edcbde9 4 days ago 76.61 MB
	debian jessie 58052b122b60 4 days ago 122.8 MB
	debian 8.0 58052b122b60 4 days ago 122.8 MB
	debian 8 58052b122b60 4 days ago 122.8 MB
	$ du -hs temp/
	331M temp/