✅ Add tests and docs for custom prestart script env var (#30)

* ✅ Add tests for custom prestart script

* 📝 Add docs for custom prestart script

* 👷 Trigger Travis after migration

README.md

@@ -286,6 +286,18 @@ You can set it like:
 docker run -d -p 80:8080 -e LOG_LEVEL="warning" myimage
 ```
 
+#### `PRE_START_PATH`
+
+The path where to find the pre-start script.
+
+By default, set to `/app/prestart.sh`.
+
+You can set it like:
+
+```bash
+docker run -d -p 80:8080 -e PRE_START_PATH="/custom/script.sh" myimage
+```
+
 ### Custom Gunicorn configuration file
 
 The image includes a default Gunicorn Python config file at `/gunicorn_conf.py`.
@@ -300,7 +312,7 @@ You can override it by including a file in:
 
 ### 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. 
+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:
 
@@ -324,6 +336,8 @@ If you need to run a Python script before starting the app, you could make the `
 python /app/my_custom_prestart_script.py
 ```
 
+You can customize the location of the prestart script with the environment variable `PRE_START_PATH` described above.
+
 ### Development live reload
 
 The default program that is run is at `/start.sh`. It does everything described above.
@@ -383,6 +397,8 @@ All the image tags, configurations, environment variables and application option
 
 ### Latest Changes
 
+* Add support for custom `PRE_START_PATH` env var. PR [#12](https://github.com/tiangolo/uvicorn-gunicorn-docker/pull/12) by [@mgfinch](https://github.com/mgfinch).
+
 ### 0.5.0
 
 * Refactor tests to use env vars and add image tags for each build date, like `tiangolo/uvicorn-gunicorn:python3.7-2019-10-15`. PR [#15](https://github.com/tiangolo/uvicorn-gunicorn-docker/pull/15).

tests/test_02_app/custom_app/app/custom_app/custom-prestart.sh

@@ -0,0 +1,3 @@
+#! /usr/bin/env sh
+
+echo "Custom prestart script"

tests/test_02_app/test_custom_app.py

@@ -17,7 +17,7 @@
 client = docker.from_env()
 
 
-def verify_container(container, response_text):
+def verify_container(container, response_text, prestart_str):
     config_data = get_config(container)
     assert config_data["workers_per_core"] == 1
     assert config_data["host"] == "0.0.0.0"
@@ -26,23 +26,40 @@ def verify_container(container, response_text):
     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
-    )
+    assert prestart_str in logs
     response = requests.get("http://127.0.0.1:8000")
     assert response.text == response_text
 
 
 @pytest.mark.parametrize(
-    "environment",
+    "environment,prestart_str",
     [
-        {"MODULE_NAME": "custom_app.custom_main", "VARIABLE_NAME": "custom_var"},
-        {"APP_MODULE": "custom_app.custom_main:custom_var"},
+        (
+            {"MODULE_NAME": "custom_app.custom_main", "VARIABLE_NAME": "custom_var"},
+            "Running inside /app/prestart.sh, you could add migrations to this file",
+        ),
+        (
+            {"APP_MODULE": "custom_app.custom_main:custom_var"},
+            "Running inside /app/prestart.sh, you could add migrations to this file",
+        ),
+        (
+            {
+                "MODULE_NAME": "custom_app.custom_main",
+                "VARIABLE_NAME": "custom_var",
+                "PRE_START_PATH": "/app/custom_app/custom-prestart.sh",
+            },
+            "Custom prestart script",
+        ),
+        (
+            {
+                "APP_MODULE": "custom_app.custom_main:custom_var",
+                "PRE_START_PATH": "/app/custom_app/custom-prestart.sh",
+            },
+            "Custom prestart script",
+        ),
     ],
 )
-def test_custom_app(environment):
+def test_custom_app(environment, prestart_str):
     name = os.getenv("NAME")
     dockerfile = f"{name}.dockerfile"
     response_text = os.getenv("TEST_STR2")
@@ -59,11 +76,11 @@ def test_custom_app(environment):
         detach=True,
     )
     time.sleep(sleep_time)
-    verify_container(container, response_text)
+    verify_container(container, response_text, prestart_str)
     container.stop()
     # Test that everything works after restarting too
     container.start()
     time.sleep(sleep_time)
-    verify_container(container, response_text)
+    verify_container(container, response_text, prestart_str)
     container.stop()
     container.remove()