AWS App Runner not passing health check for a simple python application

Hello.

I was able to confirm that the application works properly by following the AppRunner tutorial and linking with the GitHub repository.
https://docs.aws.amazon.com/apprunner/latest/dg/getting-started.html

I also tried deploying from ECR using the Dockerfile in the GitHub repository you created, and confirmed that it could be deployed successfully.
https://github.com/Sathyvs/apprunner/tree/main

By the way, your Dockerfile installs python3.7, but in the case of Amazon Linux 2023, an error occurs because python3.7 is not included in the default repository.
So I modified it to install python3.11.

FROM public.ecr.aws/amazonlinux/amazonlinux:latest
RUN yum install python3.11 -y && curl -O https://bootstrap.pypa.io/get-pip.py && python3 get-pip.py && yum update -y
COPY . /app
WORKDIR /app
RUN pip3 install -r requirements.txt
CMD python3 server.py
EXPOSE 8080

By the way, where did you execute the "docker build" command?
Please note that using a container image created on M1 Mac as is will result in an error.
https://stackoverflow.com/questions/77822116/exec-sbin-tini-exec-format-error-running-meilisearch-on-aws-app-runner

Also, if you run your "server.py" as is, the following error occurred, so I modified the code.

SyntaxError: f-string: unmatched '('

An f-string error occurred, so I fixed it as follows.
Also, since we did not import "sys", we added an import.

from wsgiref.simple_server import make_server
from pyramid.config import Configurator
from pyramid.response import Response
import os, logging, sys # edit

logging.basicConfig(level=logging.INFO, stream=sys.stdout)
logger = logging.getLogger(__name__)

def hello_world(request):
    name = os.environ.get('NAME')
    if name == None or len(name) == 0:
        name = "world"
    message = "Hello, " + name + "!\n"
    logger.info("api called")
    return Response(message)

if __name__ == '__main__':
    port = int(os.environ.get("PORT"))
    logger.info(f"running main application and listening on port {os.environ.get('PORT')}") # edit
    logger.info(f"value of my port {os.environ.get('MY_PORT')}") # edit
    with Configurator() as config:
        logger.info("configuring apis")
        config.add_route('hello', '/')
        config.add_view(hello_world, route_name='hello')
        app = config.make_wsgi_app()
    server = make_server('0.0.0.0', 8080, app)
    logger.info("starting server")
    server.serve_forever()

Once the application has been successfully deployed, access the AppRunner URL directly and the screen will be displayed.

https://yyyyyyy.ap-northeast-1.awsapprunner.com/

Sorry, I can't post a comment due to an error, so I'm going to separate the thread.

Thats the other thing I have been telling about, I dont see any application logs at all.. I can also try in a different region to see if there is anything wrong with us-east-1
https://jumpshare.com/s/Sk6wo3USjbY20rTn2dpX. ---> this is what I see, the application logs section is just empty

Umm...Please try deploying in the Tokyo region just to be sure.
Please try both GitHub integration and deployment from ECR.
By the way, when trying to deploy from ECR, please use CloudShell to build the container image.
https://docs.aws.amazon.com/cloudshell/latest/userguide/welcome.html

AWS App Runner does indeed support Python applications, but it seems you're encountering some issues with your health check configuration. Let's address your concerns and provide some troubleshooting steps:

1. Python Support: App Runner fully supports Python applications. It offers managed runtimes for building and running web applications based on Python.

2. Application Logs: To view your application logs in App Runner, you can check the Logs tab on your service page in the AWS console. If you're not seeing the startup logs, it might indicate that your application isn't starting correctly.

3. Health Check Issues: The health check is failing, which suggests that App Runner can't reach your application on the specified port and path. Here are some things to check:

   • Ensure your application is listening on 0.0.0.0 (all interfaces) and not just localhost.
   • Verify that the port your application is listening on matches the port specified in your App Runner configuration.
   • Make sure your application is actually starting and not crashing on startup.

4. Troubleshooting Steps:

   • Double-check your App Runner configuration, especially the port and health check settings.
   • Review your Dockerfile to ensure it's correctly set up for App Runner.
   • Try using the TCP protocol for health checks instead of HTTP initially, as it's less likely to fail due to application-specific issues.
   • Examine the full application logs for any error messages or unexpected behavior.

5. Configuration File: Consider using an App Runner configuration file (apprunner.yaml) to specify your build and run commands. For a Python application, it might look like this:

   version: 1.0
   runtime: python3
   build:
     commands:
       build:
         - pip install -r requirements.txt
   run:
     command: python server.py
   

6. Port Configuration: Ensure that the port your application is listening on (in your code) matches the port specified in your App Runner configuration. App Runner typically expects your application to listen on port 8080 by default.

7. Health Check Configuration: You can customize the health check settings in App Runner. Try adjusting the path, interval, or timeout settings to see if it resolves the issue.

If you've tried these steps and are still encountering issues, you may need to review your application code to ensure it's compatible with the App Runner environment. Also, consider starting with a very simple Python application that just returns a basic HTTP response to isolate whether the problem is with your application or the App Runner configuration.
Sources
Troubleshooting - AWS App Runner
Configuring health checks for your service - AWS App Runner
HealthCheckConfiguration - AWS App Runner
AWS App Runner Features – Fully managed container application service – Amazon Web Services
Using the Python platform - AWS App Runner