GitHub Action to cache a directory via rsync

.envrc.example

@@ -0,0 +1 @@
+use flake

.github/workflows/test.yml

@@ -10,3 +10,18 @@ jobs:
       - uses: actions/checkout@v6
       - uses: luizm/action-sh-checker@883217215b11c1fabbf00eb1a9a041f62d74c744
         env: { SHFMT_OPTS: -i 2 -d }
+
+  check-actions:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - run: |
+          set -eu
+          npm ci
+
+          # Run all of the tests.
+          npm run test
+
+          # Ensure the dist directories are up-to-date:
+          npm run build
+          git diff --exit-code

.gitignore

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+/.envrc
+/node_modules/

README.md

@@ -1 +1,33 @@
+# OpenMS CI Tools
+
 Scripts used in the OpenMS CI/CD system.
+
+## Actions
+
+To build the actions:
+
+```sh
+npm ci
+npm run build
+```
+
+### Cache via rsync
+
+Push/pull a directory via rsync.
+
+To use, put something like this in your workflow YAML:
+
+```yml
+- uses: OpenMS/ci-tools/actions/rsync-cache@XXXX
+  with:
+    name: vcpkg-cache
+    path: ${{ github.workspace }}/.vcpkg-cache
+    key: ${{ runner.os }}-${{ runner.arch }}-${{ matrix.compiler }}
+    ssh_key: ${{ secrets.ARCHIVE_RRSYNC_SSH }}
+    ssh_host: ${{ secrets.ARCHIVE_RRSYNC_HOST }}
+    ssh_port: ${{ secrets.ARCHIVE_RRSYNC_PORT }}
+    ssh_user: ${{ secrets.ARCHIVE_RRSYNC_USER }}
+```
+
+NOTE: If the `ssh_key` is not available the action will automatically
+disable itself and print a notice to the workflow output.

actions/rsync-cache/action.yml

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+name: "Cache via rsync"
+description: "Cache a directory to a private server using rsync"
+inputs:
+  name:
+    description: "A name to use for the sub-directory on the remote server"
+    required: true
+  path:
+    description: "An absolute path to a directory that should be cached"
+    required: true
+  key:
+    description: "A cache key, which is essentially a sub-directory name on the remote server"
+    required: true
+  ssh_key:
+    description: "The contents of an SSH private key"
+    required: false
+  ssh_host:
+    description: "The host name of the remote server"
+    required: true
+  ssh_port:
+    description: "The port to use for SSH"
+    required: false
+  ssh_user:
+    description: "The remote SSH user"
+    required: true
+runs:
+  using: 'node24'
+  main: dist/restore.js
+  post: dist/commit.js
+  post-if: "success()"