Add image for releasing Pony related Emacs modes

.github/workflows/pr.yml

@@ -30,6 +30,14 @@ jobs:
       - name: Docker build
         run: "docker build --pull --file=actionlint/Dockerfile ."
 
+  validate-emacs-mode-release-image-builds:
+    name: Validate release Docker image builds
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Docker build
+        run: "docker build --pull --file=emacs-mode-release/Dockerfile ."
+
   validate-release-a-library-image-builds:
     name: Validate release-a-library Docker image builds
     runs-on: ubuntu-latest

emacs-mode-release/Dockerfile

@@ -0,0 +1,5 @@
+FROM alpine:3.18
+
+RUN apk add --update --no-cache \
+  bash \
+  git

emacs-mode-release/README.md

@@ -0,0 +1,3 @@
+# emacs-mode-release
+
+Simple image with the tools needed to do a release of our Pony related Emacs modes.

emacs-mode-release/build-and-push.bash

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+set -o errexit
+set -o nounset
+
+#
+# *** You should already be logged into GitHub Container Registry
+# when you run this ***
+#
+
+NAME="ponylang/shared-docker-ci-emacs-mode-release"
+TODAY=$(date +%Y%m%d)
+DOCKERFILE_DIR="$(dirname "$0")"
+
+NAME="ghcr.io/${NAME}"
+docker build --pull -t "${NAME}:${TODAY}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TODAY}"