Add fetch script and github workflow.

.github/workflows/build.yml

@@ -0,0 +1,21 @@
+name: Build app root
+
+on: [push, pull_request]
+
+jobs:
+  build_app_root:
+    name: Build app root
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Build AppImage
+        run: |
+          make
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: app_root
+          path: *.AppImage

Makefile

@@ -5,10 +5,10 @@ all: Setup SnapPyApp
 .PHONY: Setup SnapPyApp
 
 Setup:
-	echo fetch app_root tarball
+	bash bin/fetch_app_root.sh
 	bash bin/install_snappy.sh
 	rm -rf app_root
-	tar xvfz app_root_final.tgz
+	tar xfz app_root_final.tgz
 
 SnapPyApp:
 	cp app_files/* app_root

bin/fetch_app_root.sh

@@ -0,0 +1,20 @@
+PYTHON_VERSION=3.13
+RELEASE_TAG=v1.0
+ARCHIVE=app_root-${PYTHON_VERSION}.tgz
+HASH_FILE=app_root-${PYTHON_VERSION}.sha256
+DOWNLOAD=https://github.com/3-manifolds/py_appimage/releases/download
+ARCHIVE_URL=${DOWNLOAD}/${RELEASE_TAG}/${ARCHIVE}
+HASH_URL=${DOWNLOAD}/${RELEASE_TAG}/${HASH_FILE}
+if ! [ -e ${ARCHIVE} ]; then
+    curl -L -O ${ARCHIVE_URL}
+fi
+if ! [ -e ${HASH_FILE} ]; then
+    curl -L -O ${HASH_URL}
+fi
+ACTUAL_HASH=`sha256sum ${ARCHIVE}`
+HASH=`cat ${HASH_FILE}`
+if [ "${HASH}" != "${ACTUAL_HASH}" ]; then
+    echo Invalid sha256 hash
+    exit 1
+fi
+