Add new "generate-tag-details" helper that creates detailed files with tag data

.template-helpers/generate-tag-details.sh

@@ -0,0 +1,166 @@
+#!/bin/bash
+set -eo pipefail
+
+repo="$1"
+if [ -z "$repo" ]; then
+	echo >&2 "usage: $0 repo"
+	echo >&2 "   ie: $0 hylang"
+	exit 1
+fi
+
+lines="$(curl -fsSL 'https://raw.githubusercontent.com/docker-library/official-images/master/library/'"$repo" | grep -vE '^$|^#')"
+if [ -z "$lines" ]; then
+	echo >&2 "Failed to read manifest file for $repo"
+	exit 1
+fi
+
+IFS=$'\n'
+tags=( $(echo "$lines" | awk -F ': +' '{ print $1 }') )
+unset IFS
+
+tokenUrl="$(curl -sSLD- "https://registry-1.docker.io/v2/library/$repo/tags/list" -o /dev/null | tr -d '\r' | awk -F ': +' 'tolower($1) == "www-authenticate" && gsub(/^Bearer\s+realm="/, "", $2) { sub(/",/, "?", $2); gsub(/"/, "", $2); gsub(/,/, "\\&", $2); print $2 }')"
+token="$(curl -fsSL "$tokenUrl" | tr -d '\r' | sed -r 's/^[{]|[}]$//g' | awk -v RS=',' -F '"' '$2 == "token" { print $4 }')"
+authHeader="Authorization: Bearer $token"
+
+get_digest() {
+	local tag="$1"
+	curl -sSLD- "https://registry-1.docker.io/v2/library/$repo/manifests/$tag" --header "$authHeader" -o /dev/null | tr -d '\r' | awk -F ': +' 'tolower($1) == "docker-content-digest" { print $2 }'
+}
+
+get_manifest() {
+	local tag="$1"
+	curl -sSL "https://registry-1.docker.io/v2/library/$repo/manifests/$tag" --header "$authHeader" | tr -d '\r'
+}
+
+get_blob_headers() {
+	local blob="$1"
+	curl -sSL "https://registry-1.docker.io/v2/library/$repo/blobs/$blob" --header "$authHeader" --head | tr -d '\r'
+}
+
+json_get_data() {
+	local json="$1"; shift
+	local data="$1"; shift
+	local strip="$1"; shift || strip='^"|"$'
+	echo "$json" | awk -F '\t' '$1 ~ /^'"$data"'$/ { gsub(/'"$strip"'/, "", $2); print $2 }'
+}
+
+humanSizeUnits=( B KB MB GB TB )
+humanSizeScale=1
+human_size() {
+	local bytes="$1"
+	local unit=0
+	local unitBytes="$1"
+	while unitBytes="$(echo "scale=0; $bytes / (1000 ^ $unit)" | bc -l)" && [ "$unitBytes" -gt 1000 ]; do
+		if [ ! "${humanSizeUnits[$(( unit + 1 ))]}" ]; then
+			break
+		fi
+		unit="$(( unit + 1 ))"
+	done
+	echo "$(echo "scale=$humanSizeScale; $bytes / (1000 ^ $unit)" | bc -l) ${humanSizeUnits[$unit]}"
+}
+
+size() {
+	text="$(human_size "$1")"
+	if [[ "$text" != *' B' ]]; then
+		text+=" ($1 bytes)"
+	fi
+	echo "$text"
+}
+
+pdate() {
+	TZ=America/Los_Angeles date --date="$1" --rfc-2822
+}
+
+jsonSh="$(curl -fsSL 'https://raw.githubusercontent.com/dominictarr/JSON.sh/ed3f9dd285ebd4183934adb54ea5a2fda6b25a98/JSON.sh')"
+
+echo "# Tags of \`$repo\`"
+
+# add a simple ToC
+echo
+for tag in "${tags[@]}"; do
+	# GitHub heading anchors are strange
+	href="${repo}:${tag}"
+	href="${href//./}"
+	href="${href//:/}"
+	href="${href,,}"
+	echo "- [\`$repo:$tag\`](#${href})"
+done
+
+declare -A layerData=()
+
+for tag in "${tags[@]}"; do
+	echo
+	echo "## \`$repo:$tag\`"
+	digest="$(get_digest "$tag")"
+	if [ "$digest" ]; then
+		echo
+		echo '```console'
+		echo "$ docker pull $repo@$digest"
+		echo '```'
+	fi
+	manifest="$(get_manifest "$tag")"
+	if [ "$manifest" ]; then
+		parsedManifest="$(echo "$manifest" | bash <(echo "$jsonSh") -l)"
+		eval "declare -A layerBlobs=( $(echo "$parsedManifest" | awk -F '\t' 'gsub(/^\["fsLayers",/, "", $1) && gsub(/,"blobSum"\]$/, "", $1) { print "[" $1 "]=" $2 }') )"
+		eval "declare -A layerV1s=( $(echo "$parsedManifest" | awk -F '\t' 'gsub(/^\["history",/, "", $1) && gsub(/,"v1Compatibility"\]$/, "", $1) { print "[" $1 "]=" $2 }') )"
+		declare -A parentChild=()
+		declare -A totals=(
+			[Size]=0
+			[content-length]=0
+		)
+		for i in "${!layerV1s[@]}"; do
+			layerV1="${layerV1s[$i]%'\n'}" # lol \n
+			parsedLayerV1="$(echo "$layerV1" | bash <(echo "$jsonSh"))"
+			layerId="$(json_get_data "$parsedLayerV1" '\["id"\]')"
+			if [ -z "${layerData[$layerId]}" ]; then
+				layerData["$layerId"]=1
+				for field in created parent docker_version Size; do
+					layerData["${layerId}_${field}"]="$(json_get_data "$parsedLayerV1" '\["'"$field"'"\]')"
+				done
+				layerData["${layerId}_container_cmd"]="$(json_get_data "$parsedLayerV1" '\["container_config","Cmd"\]' '')"
+				layerData["${layerId}_blob"]="${layerBlobs[$i]}"
+				blobHeaders="$(get_blob_headers "${layerData["${layerId}_blob"]}")"
+				for header in content-length last-modified; do
+					layerData["${layerId}_${header}"]="$(echo "$blobHeaders" | awk -F ': +' 'tolower($1) == "'"$header"'" { print $2 }')"
+				done
+			fi
+			parentChild["${layerData[${layerId}_parent]:-none}"]="$layerId"
+			for field in Size content-length; do
+				totals["$field"]="$(echo "${totals[$field]} + ${layerData[${layerId}_${field}]}" | bc)"
+			done
+		done
+		echo
+		echo "- Total Virtual Size: $(size "${totals[Size]}")"
+		echo "- Total v2 Content-Length: $(size "${totals[content-length]}"); compressed"
+		if [ "${#parentChild[@]}" -gt 0 ]; then
+			echo
+			echo "### Layers (${#parentChild[@]})"
+			cur="${parentChild[none]}"
+			while [ "$cur" ]; do
+				echo
+				echo "#### \`$cur\`"
+				cmd="${layerData[${cur}_container_cmd]}"
+				if [ "$cmd" ]; then
+					cmd="${cmd//'\u0026'/'&'}"
+					cmd="${cmd//'\u003c'/'<'}"
+					cmd="${cmd//'\u003e'/'>'}"
+					echo
+					echo '```json'
+					echo "$cmd"
+					echo '```'
+				fi
+				echo
+				echo "- Created: $(pdate "${layerData[${cur}_created]}")"
+				if [ "${layerData[${cur}_parent]}" ]; then
+					echo "- Parent Layer: \`${layerData[${cur}_parent]}\`"
+				fi
+				echo "- Docker Version: ${layerData[${cur}_docker_version]}"
+				echo "- Virtual Size: $(size "${layerData[${cur}_Size]}")"
+				echo "- v2 Blob: \`${layerData[${cur}_blob]}\`"
+				echo "- v2 Content-Length: $(size "${layerData[${cur}_content-length]}"); compressed"
+				echo "- v2 Last-Modified: $(pdate "${layerData[${cur}_last-modified]}")"
+				cur="${parentChild[$cur]}"
+			done
+		fi
+	fi
+done

.template-helpers/template.md

@@ -2,7 +2,9 @@
 
 %%TAGS%%
 
-For more information about this image and its history, please see the [relevant manifest file (`library/%%REPO%%`)](https://github.com/docker-library/official-images/blob/master/library/%%REPO%%). This image is updated via pull requests to [the `docker-library/official-images` GitHub repo](https://github.com/docker-library/official-images).
+For more information about this image and its history, please see [the relevant manifest file (`library/%%REPO%%`)](https://github.com/docker-library/official-images/blob/master/library/%%REPO%%). This image is updated via pull requests to [the `docker-library/official-images` GitHub repo](https://github.com/docker-library/official-images).
+
+For detailed information about the virtual/transfer sizes and individual layers of each of the above supported tags, please see [the `%%REPO%%/tag-details.md` file](https://github.com/docker-library/docs/blob/master/%%REPO%%/tag-details.md) in [the `docker-library/docs` GitHub repo](https://github.com/docker-library/docs).
 
 %%CONTENT%%%%VARIANT%%%%LICENSE%%
 

update-tag-details.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+set -eo pipefail
+
+cd "$(dirname "$(readlink -f "$BASH_SOURCE")")"
+helperDir='.template-helpers'
+
+repos=( "$@" )
+if [ ${#repos[@]} -eq 0 ]; then
+	repos=( */ )
+fi
+repos=( "${repos[@]%/}" )
+
+for repo in "${repos[@]}"; do
+	echo -n "$repo ... "
+	{
+		echo "<!-- THIS FILE IS GENERATED BY '$helperDir/generate-tag-details.sh' -->"
+		echo
+		"$helperDir/generate-tag-details.sh" "$repo"
+	} > "$repo/tag-details.md"
+	echo 'done'
+done