Script fetchs releases of supported distributions

tools/get_releases.sh

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+#!/usr/bin/env bash
+
+# When something returns an error code, abort the script
+set -e
+
+##################
+# Get Script Dir #
+##################
+
+# Here we are going to get the directory this script lives in, allowing us to
+# find other scripts in this directory that we depend on. This method is
+# resiliant to softlinking.
+
+SOURCE="${BASH_SOURCE[0]}"
+while [ -h "$SOURCE" ]; do # resolve $SOURCE until the file is no longer a symlink
+  DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
+  SOURCE="$(readlink "$SOURCE")"
+  [[ $SOURCE != /* ]] && SOURCE="$DIR/$SOURCE"
+done
+DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
+
+# $DIR now contains the directory this script lives in
+
+######################
+# Define Global Vars #
+######################
+
+get_docker_tags="$DIR/get_releases/get_docker_releases.js"
+
+###########################
+# Define Helper Functions #
+###########################
+
+# error is used to print a message to stderr followed by instructions on how
+# to use this script. It then exits the application with an error code
+error () {
+  echo "$1" 1>&2
+  help
+  exit 1
+}
+
+# help simply prints the instructions for using this script
+help () {
+  echo "USAGE: ./get_releases.sh DIST" 1>&2
+  echo "" 1>&2
+  echo "  This script gathers supported releases from the NodeSource" 1>&2
+  echo "  Node.js binary distributions and cross references them against" 1>&2
+  echo "  the image tags supported by Docker Hub." 1>&2
+  echo "" 1>&2
+  echo "  DIST determines which Linux OS Distribution we are gathering" 1>&2
+  echo "  supported releases of, and can be one of the following:" 1>&2
+  echo "    - fedora" 1>&2
+  echo "    - centos" 1>&2
+  echo "    - debian" 1>&2
+  echo "    - ubuntu" 1>&2
+  echo "" 1>&2
+}
+
+#########################################
+# Define Logic Functions For NodeSource #
+#########################################
+
+# Note: for all of the following distributions, we leave out checking iojs.
+# This is for two reasons:
+#   1) It simplifies logic
+#   2) The iojs repos didn't introduce any new releases
+
+# NodeSource Debian Based Distributions
+# Note: this lumps Ubuntu and Debian into the same group. This is safe because
+# none of the release names overlap
+get_ns_deb () {
+  URLS=(
+    "https://deb.nodesource.com/node/pool/main/n/nodejs/"
+    "https://deb.nodesource.com/node_0.12/pool/main/n/nodejs/"
+    "https://deb.nodesource.com/node_4.x/pool/main/n/nodejs/"
+    "https://deb.nodesource.com/node_5.x/pool/main/n/nodejs/"
+    "https://deb.nodesource.com/node_6.x/pool/main/n/nodejs/"
+  )
+
+  DISTS=$(
+  for url in ${URLS[@]}; do
+    curl ${url} 2>/dev/null \
+      | grep -o ">nodejs_.*1nodesource1~.*\.deb" \
+      | sed 's/>nodejs_.*-1nodesource1~//' \
+      | sed 's/1.*deb//'
+  done
+  )
+
+  echo "$DISTS" | sort | uniq
+}
+
+# NodeSource Fedora Based Distributions
+get_ns_fedora () {
+  URLS=(
+    "https://rpm.nodesource.com/pub/fc/"
+    "https://rpm.nodesource.com/pub_0.12/fc/"
+    "https://rpm.nodesource.com/pub_4.x/fc/"
+    "https://rpm.nodesource.com/pub_5.x/fc/"
+    "https://rpm.nodesource.com/pub_6.x/fc/"
+  )
+
+  DISTS=$(
+  for url in "${URLS[@]}"; do
+    curl ${url} 2>/dev/null \
+      | grep -o '>[0-9][0-9]' \
+      | sed 's/>//'
+  done
+  )
+
+  echo "$DISTS" | sort | uniq
+}
+
+# NodeSource Centos Based Distributions
+get_ns_centos () {
+  URLS=(
+    "https://rpm.nodesource.com/pub/el/"
+    "https://rpm.nodesource.com/pub_0.12/el/"
+    "https://rpm.nodesource.com/pub_4.x/el/"
+    "https://rpm.nodesource.com/pub_5.x/el/"
+    "https://rpm.nodesource.com/pub_6.x/el/"
+  )
+
+  DISTS=$(
+  for url in "${URLS[@]}"; do
+    curl ${url} 2>/dev/null \
+      | grep -o '>[0-9]' \
+      | sed 's/>//'
+  done
+  )
+
+  echo "$DISTS" | sort | uniq
+}
+
+# Compare two lists to find common strings
+comp () {
+  COMMON=""
+  for ns in $1; do
+    for docker in $2; do
+      if [ "$ns" == "$docker" ]; then
+        COMMON="$COMMON $ns"
+      fi
+    done
+  done
+
+  # Remove the first space of the string and return the list
+  echo "$COMMON" | sed 's/^ //'
+}
+
+############################
+# Begin Main Program Logic #
+############################
+
+# Ensure we were passed 1 arguments
+if [ "$#" -ne 1 ]; then
+  error "Invalid number of arguments"
+fi
+
+# Determine which distribution we are being asked about
+case "$1" in
+  fedora)
+    NS=$(get_ns_fedora)
+    DOCKER=$($get_docker_tags fedora)
+    TAGS=$(comp "$NS" "$DOCKER")
+    echo $TAGS
+    ;;
+  centos)
+    NS=$(get_ns_centos)
+    DOCKER=$($get_docker_tags centos)
+    TAGS=$(comp "$NS" "$DOCKER")
+    echo $TAGS
+    ;;
+  debian)
+    NS=$(get_ns_deb)
+    DOCKER=$($get_docker_tags debian)
+    TAGS=$(comp "$NS" "$DOCKER")
+    echo $TAGS
+    ;;
+  ubuntu)
+    NS=$(get_ns_deb)
+    DOCKER=$($get_docker_tags ubuntu)
+    TAGS=$(comp "$NS" "$DOCKER")
+    echo $TAGS
+    ;;
+  *)
+    error "Invalid distribution name"
+esac
+
+# Return success if we didn't encounter an error
+exit 0
+

tools/get_releases/README.md

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+get_releases
+============
+
+Scripts supporting get_releases.sh

tools/get_releases/get_docker_releases.js

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+#!/usr/bin/env nodejs
+
+/*****************
+ * Bring in deps *
+ *****************/
+
+var request = require('request')
+var async = require('async')
+
+/***************************
+ * Define Helper Functions *
+ ***************************/
+
+function error(msg) {
+  console.error(msg)
+  help()
+  process.exit(1)
+}
+
+function help() {
+  var msg = `USAGE: ./get_docker_releases.js DIST
+
+  This script gathers supported tags from the Docker image specified by DIST.
+
+  DIST corresponds to a valid, NodeSource supported, Linux Distribution and
+  can be one of the following:
+    - fedora
+    - centos
+    - debian
+    - ubuntu
+  `
+  console.error(msg)
+}
+
+/**********************
+ * Main Program Logic *
+ **********************/
+
+if(process.argv.length !== 3) {
+  error("Incorrect number of arguments")
+}
+
+// Cache arg to avoid array lookup everywhere
+var dist = process.argv[2]
+
+// Ensure dist is a valid string
+switch(dist) {
+  case 'fedora':
+  case 'centos':
+  case 'debian':
+  case 'ubuntu':
+    break
+  default:
+    // Everything that wasn't defined in the cases above is invalid. The switch
+    // may seem unnatural here, but it was a lot cleaner than an if statement
+    error('Invalid distribution')
+    break
+}
+
+
+// Continue asking for more tags until the Docker Hub tells us we have them all
+// next acts as our async do-while termination condition, when there are no
+// more tags, next will be set to null and the loop will terminate.
+var next = `https://registry.hub.docker.com/v2/repositories/library/${dist}/tags`
+var tags = []
+
+async.whilst(
+  function check () {
+    return next != null
+  },
+  function getTags (cb) {
+    request(next, function fetchedTags (e, resp, body) {
+      // If the request failed, we have nothing left to do. Eventually this
+      // could be made to be more resiliant to network hiccups
+      if(e) {
+        exit(e.message)
+      }
+
+      // Attempt to make sense of the response, if we can't convert it to JSON
+      // or the response doesn't include the values we were expecting, then
+      // we will exit the application
+      try {
+        body = JSON.parse(body)
+      }  catch(e) {
+        exit(e.message)
+      }
+      // The next URL we need to grab will be given to us by Docker Hub
+      next = body.next
+      // Append the names of the images that were returned by Docker Hub to the
+      // tags array. This may be confusing without understanding how the Docker
+      // Hub returns information. Try taking the URL above and plugging it into
+      // a webbrowser to explore the format
+      tags = tags.concat(body.results.map( (v) => v.name))
+      cb()
+    })
+  },
+  function gotTags () {
+    // Once we reache here, we have finished compiling our list of tags.
+    // Note: there is no chance of encountering an error since we never call
+    // the callback with an error condition. When an error was encountered
+    // above, the application would log it and exit.
+    console.log(tags.join('\n'))
+  }
+)

tools/get_releases/package.json

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+{
+  "dependencies": {
+    "async": "1.5.2",
+    "request": "2.72.0"
+  }
+}