Merge pull request #2 from tiangolo/add-prestart-sh

Add support for /app/prestart.sh

README.md

@@ -367,16 +367,50 @@ It uses the environment variables declared above to set all the configurations.
 
 You can override it by including a file in:
 
-* `/app/gunicorn_conf.py`,
-* `/app/app/gunicorn_conf.py` or replacing the one in
-* `/gunicorn_conf.py` or replacing the one in
+* `/app/gunicorn_conf.py`
+* `/app/app/gunicorn_conf.py`
+* `/gunicorn_conf.py`
+
+
+### Custom `/app/prestart.sh`
+
+If you need to run anything before starting the app, you can add a file `prestart.sh` to the directory `/app`. The image will automatically detect and run it before starting everything. 
+
+For example, if you want to add Alembic SQL migrations (with SQLALchemy), you could create a `./app/prestart.sh` file in your code directory (that will be copied by your `Dockerfile`) with:
+
+```bash
+#! /usr/bin/env bash
+
+# Let the DB start
+sleep 10;
+# Run migrations
+alembic upgrade head
+```
+
+and it would wait 10 seconds to give the database some time to start and then run that `alembic` command.
+
+If you need to run a Python script before starting the app, you could make the `/app/prestart.sh` file run your Python script, with something like:
+
+```bash
+#! /usr/bin/env bash
+
+# Run custom Python script before starting
+python /app/my_custom_prestart_script.py
+```
 
 
 ## Tests
 
 All the image tags, configurations, environment variables and application options are tested.
 
 
+## Release Notes
+
+### 0.1.0
+
+* Add support for `/app/prestart.sh`.
+
+
 ## License
 
 This project is licensed under the terms of the MIT license.

tests/test_01_main/test_defaults.py

@@ -4,11 +4,30 @@
 import pytest
 import requests
 
-from ..utils import CONTAINER_NAME, get_config, stop_previous_container
+from ..utils import CONTAINER_NAME, get_config, get_logs, remove_previous_container
 
 client = docker.from_env()
 
 
+def verify_container(container, response_text):
+    config_data = get_config(container)
+    assert config_data["workers_per_core"] == 2
+    assert config_data["host"] == "0.0.0.0"
+    assert config_data["port"] == "80"
+    assert config_data["loglevel"] == "info"
+    assert config_data["workers"] > 2
+    assert config_data["bind"] == "0.0.0.0:80"
+    logs = get_logs(container)
+    assert "Checking for script in /app/prestart.sh" in logs
+    assert "Running script /app/prestart.sh" in logs
+    assert (
+        "Running inside /app/prestart.sh, you could add migrations to this file" in logs
+    )
+    response = requests.get("http://127.0.0.1:8000")
+    data = response.json()
+    assert data["message"] == response_text
+
+
 @pytest.mark.parametrize(
     "image,response_text",
     [
@@ -35,20 +54,16 @@
     ],
 )
 def test_defaults(image, response_text):
-    stop_previous_container(client)
+    remove_previous_container(client)
     container = client.containers.run(
         image, name=CONTAINER_NAME, ports={"80": "8000"}, detach=True
     )
     time.sleep(1)
-    config_data = get_config(container)
-    assert config_data["workers_per_core"] == 2
-    assert config_data["host"] == "0.0.0.0"
-    assert config_data["port"] == "80"
-    assert config_data["loglevel"] == "info"
-    assert config_data["workers"] > 2
-    assert config_data["bind"] == "0.0.0.0:80"
-    response = requests.get("http://127.0.0.1:8000")
-    data = response.json()
-    assert data["message"] == response_text
+    verify_container(container, response_text)
+    container.stop()
+    # Test that everything works after restarting too
+    container.start()
+    time.sleep(1)
+    verify_container(container, response_text)
     container.stop()
     container.remove()

tests/utils.py

@@ -26,10 +26,15 @@ def get_config(container):
     return json.loads(result.output.decode())
 
 
-def stop_previous_container(client):
+def remove_previous_container(client):
     try:
         previous = client.containers.get(CONTAINER_NAME)
         previous.stop()
         previous.remove()
     except NotFound:
         return None
+
+
+def get_logs(container):
+    logs: str = container.logs()
+    return logs.decode("utf-8")