Move global_buildozer_dir to workspace

Dockerfile

@@ -11,5 +11,6 @@ RUN pip3 uninstall -y buildozer
 RUN echo "Set disable_coredump false" | sudo tee -a /etc/sudo.conf > /dev/null
 
 COPY entrypoint.sh /action/entrypoint.sh
+COPY patches.py /action/patches.py
 
 ENTRYPOINT ["/action/entrypoint.sh"]

README.md

@@ -41,6 +41,30 @@ Filename of built package relative to repository root.
 
 - Example: `test_app/bin/testapp-0.1-armeabi-v7a-debug.apk`
 
+## Caching
+
+You can set up cache for Buildozer global and local directories. Global
+directory is in root of repository. Local directory is in workdir.
+
+- Global: `.buildozer-global` (sdk, ndk, platform-tools)
+- Local: `test_app/.buildozer` (dependencies, build temp, _not recommended to cache_)
+
+I don't recommend to cache local buildozer directory because Buildozer doesn't
+automatically update dependencies to latest version.
+
+Use cache only if it speeds up your workflow! Usually this only adds 1-3 minutes
+to job running time, so I don't use it.
+
+Example:
+
+```yaml
+- name: Cache Buildozer global directory
+  uses: actions/cache@v2
+  with:
+    path: .buildozer-global
+    key: buildozer-global-${{ hashFiles('test_app/buildozer.spec') }} # Replace with your path
+```
+
 ## Example usage
 
 ```yaml

entrypoint.sh

@@ -34,6 +34,14 @@ if ! cd "$INPUT_WORKDIR"; then
   exit 1
 fi
 
+# Apply patches
+echo ::group::Applying patches to Buildozer
+if ! python3 /action/patches.py; then
+  echo ::error::Error while running patches.py
+  # exit 1  # Allow to fail
+fi
+echo ::endgroup::
+
 # Run command
 if ! sh -c "$INPUT_COMMAND"; then
   echo ::error::Error while executing command \""$INPUT_COMMAND"\"

patches.py

@@ -0,0 +1,20 @@
+import os
+import buildozer
+
+print("Changing global_buildozer_dir")
+source = open(buildozer.__file__, "r", encoding="utf-8").read()
+new_source = source.replace(
+    """
+    @property
+    def global_buildozer_dir(self):
+        return join(expanduser('~'), '.buildozer')
+""",
+    f"""
+    @property
+    def global_buildozer_dir(self):
+        return '{os.environ["GITHUB_WORKSPACE"]}/.buildozer_global'
+""",
+)
+if new_source == source:
+    print("::warning::Cannot change global buildozer directory. Update buildozer-action to new version or create a Bug Request")
+open(buildozer.__file__, "w", encoding="utf-8").write(new_source)