multiple final fixes + better readme

Author: Valian

.dockerignore

@@ -1 +1,3 @@
-test
+example
+.git
+.idea

Dockerfile

@@ -1,23 +1,19 @@
 FROM python:3.6 as builder
 
-
 COPY requirements.txt requirements.txt
 RUN pip install -r requirements.txt
 
-COPY . /srv
-
 
 FROM lambci/lambda:python3.6
-
 WORKDIR /srv
 
 USER root
 
 RUN yum install -y git
 
 COPY --from=builder /usr/local/lib/python3.6/site-packages /var/lang/lib/python3.6/site-packages
-COPY --from=builder /srv /srv
-
+COPY . /srv
 
+# let's clear previous entrypoint
 ENTRYPOINT []
 CMD ["python", "-u", "app.py"]

README.md

@@ -1,2 +1,88 @@
 # python-lambda-local-server
-A thin wrapper around python-lambda-local package to run as a server instead cli. This package is designed to be run by Docker.
+![build](https://img.shields.io/docker/build/valian/python-lambda-local-server.svg)
+A Docker image to help with development of a local AWS lambda Python functions.
+Based on the [lambci/lambda](https://hub.docker.com/r/lambci/lambda/) image.
+Created, because I haven't found an easy way to run lambda function locally.
+
+Features:
+* Automatically installs packages from requirements.txt during startup
+* Mirrored AWS Lambda environment thanks to lambci images
+* Code is reloaded for each submitted event
+* Available simple Web UI for better workflow
+
+# Usage
+
+Go to directory with your lambda Python code. Next, run this command:
+
+```bash
+docker run -it \
+  -p 8080:8080 \
+  -v lambda-packages-cache:/packages/ \
+  -v $PWD:/var/task/ \
+  valian/python-lambda-local-server
+```
+
+It should automatically install packages from your requirements.txt and start web sever written in aiohttp.
+To see web UI, head to http://localhost:8080. You should see a simple web UI for testing your lambda function.
+
+![Event UI](https://raw.githubusercontent.com/valian/python-lambda-local-server/master/pictures/event_ui.png)
+
+Assuming that you have your lambda entrypoint in `lambda.py` and handler is named `handler`, you should
+type it into desired inputs. Next, add JSON body that should be passed to the function as an event, and press 'Submit event'.
+Result and logs should be visible on the right panel after a moment.
+
+
+# Example
+
+First, clone this repository:
+
+```bash
+git clone https://github.com/Valian/python-lambda-local-server
+cd python-lambda-local-server
+```
+
+Next, start server with a proper volume mounted:
+```bash
+docker run -it \
+  -p 8080:8080 \
+  -v $PWD/example:/var/task/ \
+  valian/python-lambda-local-server
+```
+
+## Web UI usage
+
+Go to http://localhost:8080. You should see something like this:
+
+![Event UI](https://raw.githubusercontent.com/valian/python-lambda-local-server/master/pictures/event_ui.png)
+
+Specify file, handler and event and click `Submit event`.
+It invokes handler and prints execution logs and return value.
+
+
+Api gateway tab automatically formats event to an AWS API Gateway format:
+![API UI](https://raw.githubusercontent.com/valian/python-lambda-local-server/master/pictures/api_ui.png)
+
+## Console example
+
+You can of course use `curl` to submit events. Start sever and type:
+
+```bash
+curl -XPOST localhost:8080 -d '{"event": {"url": "https://example.com"}, "file": "handler.handler"}'
+
+{
+  "stdout": {
+    "statusCode": 200,
+    "url": "https://example.com/"
+  },
+  "stderr": "START RequestId: b1891caf-c22b-4ce6-8639-e74862adae30 Version: $LATEST\nINFO:root:Starting request\nINFO:root:Request done, status code: 200\nEND RequestId: b1891caf-c22b-4ce6-8639-e74862adae30\nREPORT RequestId: b1891caf-c22b-4ce6-8639-e74862adae30 Duration: 803 ms Billed Duration: 900 ms Memory Size: 1536 MB Max Memory Used: 23 MB\n"
+}
+```
+
+# TODO
+* [ ] Add support for `Serverless.yml` file
+* [ ] Cleanup code, better error codes
+* [ ] Support for chaining lambda calls either through AWS SDK or API endpoint
+
+# License
+
+MIT

test/event.json renamed to example/event.json

@@ -0,0 +1,44 @@
+import json
+import logging
+import requests
+
+
+def init_logging():
+    # lambci adds root logging handler, we have to remove it first
+    root_logger = logging.getLogger()
+    for h in root_logger.handlers:
+        root_logger.removeHandler(h)
+    logging.basicConfig(level=logging.INFO)
+
+
+def make_request(url: str) -> dict:
+    logging.info("Starting request")
+    response = requests.get(url=url)
+    logging.info(f"Request done, status code: {response.status_code}")
+    return {
+        "statusCode": response.status_code,
+        "url": response.url
+    }
+
+
+def handler(event, context):
+    init_logging()
+    logging.info(f"Event: {event}")
+    return make_request(
+        url=event.get('url', 'http://example.com')
+    )
+
+
+def api_handler(event, context):
+    init_logging()
+    logging.info(f"Event: {event}")
+    body = event.get('body', '')
+    event = json.loads(body)
+    url = event.get('url', 'http://example.com')
+    response_data = make_request(url=url)
+    return {
+        'statusCode': response_data['statusCode'],
+        'isBase64Encoded': False,
+        'headers': {'Content-Type': 'application/json'},
+        'body': json.dumps(response_data)
+    }

example/handler.py

@@ -39,16 +39,21 @@ def get_requirements_directory(self, requirements_path):
             return None
 
     def ensure_installed(self, force_reinstall=False):
-        req_dir = self.directory
-        if not req_dir or not path.exists(req_dir) or force_reinstall:
-            logger.info(f"Updating requirements for tag '{self.tag}'...")
-            # If previous requirements exists, let's remove them
-            shutil.rmtree(req_dir, ignore_errors=True)
-            new_requirements_dir = self.get_requirements_directory(self.requirements_path)
-            subprocess.run([
-                "pip", "install",
-                "-t", new_requirements_dir,
-                "-r", self.requirements_path])
-            shutil.copy(self.requirements_path, self.cached_requirements_path)
+        if not path.exists(self.requirements_path):
+            logger.info(f"No requirements.txt found, skipping package installation")
         else:
-            logger.info(f"Requirements not changed, skipping update for tag '{self.tag}'...")
+            if self.directory and path.exists(self.directory) and not force_reinstall:
+                logger.info(f"Requirements not changed, skipping update for tag '{self.tag}'...")
+            else:
+                self._install_packages()
+
+    def _install_packages(self):
+        logger.info(f"Updating requirements for tag '{self.tag}'...")
+        # If previous requirements exists, let's remove them
+        shutil.rmtree(self.directory, ignore_errors=True)
+        new_requirements_dir = self.get_requirements_directory(self.requirements_path)
+        subprocess.run([
+            "python", "-m", "pip", "install",
+            "-t", new_requirements_dir,
+            "-r", self.requirements_path])
+        shutil.copy(self.requirements_path, self.cached_requirements_path)