diff --git a/.github/workflows/update-architectures.yml b/.github/workflows/update-architectures.yml
new file mode 100644
index 000000000..134167362
--- /dev/null
+++ b/.github/workflows/update-architectures.yml
@@ -0,0 +1,47 @@
+name: update-architectures
+
+on:
+  # Convert to schedule when done or whatever is preferred
+  push:
+  pull_request:
+
+jobs:
+  update-architectures:
+    name: update-architectures
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout the docker-node repo
+        uses: actions/checkout@v2
+        with:
+          path: docker-node
+
+      - name: Checkout the official-images repo
+        uses: actions/checkout@v2
+        with:
+          path: official-images
+          repository: docker-library/official-images
+
+      - name: Download bashbrew
+        run: |
+          mkdir -p ${GITHUB_WORKSPACE}/bin
+          wget --no-verbose -O ${GITHUB_WORKSPACE}/bin/bashbrew https://doi-janky.infosiftr.net/job/bashbrew/job/master/lastSuccessfulBuild/artifact/bashbrew-amd64
+          sudo chmod +x ${GITHUB_WORKSPACE}/bin/bashbrew
+          echo "::add-path::${GITHUB_WORKSPACE}/bin"
+
+      - name: Update architectures
+        uses: actions/github-script@v3
+        id: arch-updater
+        env:
+          BASHBREW_LIBRARY: "${{ github.workspace }}/official-images/library"
+        with:
+          script: |
+            const script = require(`${process.env.GITHUB_WORKSPACE}/docker-node/updateArches.js`)
+            return script();
+
+      - name: Open a PR
+        if: steps.arch-updater.outputs.result == 'true'
+        # TODO: open a PR
+        run: |
+          cd docker-node
+          git diff --exit-code
diff --git a/updateArches.js b/updateArches.js
new file mode 100644
index 000000000..9eb30a30e
--- /dev/null
+++ b/updateArches.js
@@ -0,0 +1,146 @@
+const { execFileSync } = require('child_process');
+const { readFileSync, readdirSync, writeFileSync } = require('fs');
+const path = require('path');
+
+const nodeDirRegex = /^\d+$/;
+
+// Given a name and a tag, this returns an array of architectures that it supports
+const fetchImageArches = (repoTag) => execFileSync('bashbrew', [
+  'cat', repoTag,
+], { encoding: 'utf8' }).split('\n')
+  .find((line) => line.startsWith('Architectures:'))
+  .split(':')[1]
+  .trim()
+  .split(/\s*,\s*/);
+
+// Parses an "architectures" file into an object like:
+// {
+//   arch1: ['variant1', 'variant2'],
+//   //...
+// }
+const parseArchitecturesFile = (file) => Object.fromEntries(
+  [...readFileSync(file, 'utf8').matchAll(/^(?<arch>\S+)\s+(?<variants>\S+)$/mg)]
+    .slice(1)
+    .map(({ groups: { arch, variants } }) => [arch, variants.split(',')]),
+);
+
+// Takes in an object like:
+//   {
+//     arch1: ['variant1', 'variant2'],
+//     // ...
+//   }
+// and returns an object like
+//   {
+//     variant1: ['arch1', 'arch2'],
+//     // ...
+//   }
+const invertObject = (obj) => Object.entries(obj)
+  .reduce((acc, [key, vals]) => vals.reduce((valAcc, val) => {
+    const { [val]: keys, ...rest } = valAcc;
+    return {
+      ...rest,
+      [val]: keys
+        ? [...keys, key]
+        : [key],
+    };
+  }, acc), {});
+
+// Returns a list of the child directories in the given path
+const getChildDirectories = (parent) => readdirSync(parent, { withFileTypes: true })
+  .filter((dirent) => dirent.isDirectory())
+  .map(({ name }) => path.resolve(parent, name));
+
+const getNodeVerionDirs = (base) => getChildDirectories(base)
+  .filter((childPath) => nodeDirRegex.test(path.basename(childPath)));
+
+// Assume no duplicates
+const areArraysEquilivant = (arches1, arches2) => arches1.length === arches2.length
+    && arches1.every((arch) => arches2.includes(arch));
+
+// Returns the paths of Dockerfiles that are at: base/*/Dockerfile
+const getDockerfilesInChildDirs = (base) => getChildDirectories(base)
+  .map((childDir) => path.resolve(childDir, 'Dockerfile'));
+
+// Given a path to a Dockerfile like .../14/variant/Dockerfile, this will return "variant"
+const getVariantFromPath = (file) => path.dirname(file).split(path.sep).slice(-1);
+
+const getBaseImageFromDockerfile = (file) => readFileSync(file, 'utf8')
+  .match(/^FROM (\S+)/m)[1];
+
+// Given a dockerfile, this function returns an array like [variant, [arch1, arch2, ...]]
+const getVariantAndArches = (dockerfile) => {
+  const variant = getVariantFromPath(dockerfile);
+  const baseImage = getBaseImageFromDockerfile(dockerfile);
+  const arches = fetchImageArches(baseImage);
+
+  // TODO: filter by arches node supports
+  return [variant, arches];
+};
+
+const getStoredVariantArches = (file) => {
+  const storedArchVariants = parseArchitecturesFile(file);
+  return invertObject(storedArchVariants);
+};
+
+const areVariantArchesEquilivant = (current, stored) => Object.keys(current).length
+  === Object.keys(stored).length
+    && Object.entries(current).every(
+      ([variant, arches]) => stored[variant] && areArraysEquilivant(arches, stored[variant]),
+    );
+
+const formatEntry = ([arch, variants], variantOffset) => `${arch}${' '.repeat(variantOffset - arch.length)}${variants.join(',')}`;
+
+const sortObjectKeys = (obj) => Object.keys(obj)
+  .sort()
+  .reduce((acc, key) => ({
+    ...acc,
+    [key]: obj[key]
+  }), {});
+
+const storeArchitectures = (variantArches, architecturesFile) => {
+  const archVariants = sortObjectKeys(invertObject(variantArches));
+  const data = {
+    'bashbrew-arch': ['variants'],
+    ...archVariants,
+  };
+
+  const maxKeyLength = Math.max(...Object.keys(data).map((key) => key.length));
+  // Variants start 2 spaces after the longest key
+  const variantOffset = maxKeyLength + 2;
+
+  const str = Object.entries(data)
+    .map((entry) => formatEntry(entry, variantOffset))
+    .join('\n') + '\n';
+
+  writeFileSync(architecturesFile, str);
+
+  // Just here for debugging purposes
+  console.log(str);
+  console.log('\n\n');
+};
+
+const updateNodeDirArches = (nodeDir) => {
+  const dockerfiles = getDockerfilesInChildDirs(nodeDir);
+
+  const currentVariantArches = Object.fromEntries(dockerfiles.map(getVariantAndArches));
+  const architecturesFile = path.resolve(nodeDir, 'architectures');
+  const storedVariantArches = getStoredVariantArches(architecturesFile);
+
+  if (areVariantArchesEquilivant(currentVariantArches, storedVariantArches)) {
+    console.log('Architectures up-to-date: ', nodeDir);
+    return false;
+  }
+
+  console.log('Architectures outdated: ', nodeDir);
+  storeArchitectures(currentVariantArches, architecturesFile);
+
+  return true;
+};
+
+const updateArchitectures = () => {
+  const nodeDirs = getNodeVerionDirs(__dirname);
+  const dirsUpdated = nodeDirs.map(updateNodeDirArches);
+  return dirsUpdated.some((updated) => updated);
+};
+
+module.exports = updateArchitectures;