lambda-adapter State: Ready Events: []

[hopewise]

hello

I am trying to use nginx on lambda, I am getting this error:

2023-01-21T17:08:42.824+03:00 | * Starting nginx nginx
2023-01-21T17:08:42.844+03:00 | ...fail!
2023-01-21T17:08:42.845+03:00 | EXTENSION Name: lambda-adapter State: Ready Events: []

but I don't have any further details, how can I fix this ?

[bnusunny]

@hopewise have you checkout the Nginx example? It should give you a good starting point.

To debug Lambda Web Adapter, just update the RUST_LOG environment variable to debug.

[hopewise]

Yes, I have used the example with most of settings, however, I did not start from:

public.ecr.aws/docker/library/nginx:1.21.6

I have changed it to my image that have Nginx installed and other dependencies ( Ruby 3) as well for my app.
Are there any restrictions for the required Nginx version? or I must use the exact image public.ecr.aws/docker/library/nginx:1.21.6 to use Nginx with Lambda ??

[bnusunny]

No, you could use any base images with Nginx installed.

Did you replace the default Nginx config files with the ones from Nginx example? Lambda's filesystem is read-only, except /tmp. We need to change a few configurations to make Nginx write logs, and temp files into /tmp.

Next thing to check is the readiness check. By default, Lambda Web Adapter will send http GETs to http://127.0.0.1:8080/ to determine if the web app is ready. If the adapter receives any http response, the check passes. Otherwise, the adapter will retry this request every 10ms. More detail in the project README. You can turn on DEBUG log for the adapter and see those readiness check requests in CloudWatch Logs.

[hopewise]

Ah! thanks for the valuable info, yes I used the default Nginx files, but I found this in my settings:

access_log /var/log/nginx/access.log;
error_log /var/log/nginx/error.log;

would that prevent nginx from starting? I will point them to /tmp and check again.

[bnusunny]

A few more config options should be updated as well. Please look at this file.

[hopewise]

Yes I tried it, I am stuck here if you can provide help 🙏 https://stackoverflow.com/questions/75284241/bin-bash-1-entrypoint-sh-not-found?noredirect=1#comment132846695_75284241

[bnusunny]

'/tmp' is special in Lambda. It is cleaned for each new sandbox. Please store your files in another directory.

[hopewise]

each new sandbox? can you please explain more with response to this issue context

[bnusunny]

Oh, officially it is called the Lambda execution environment. Technically, it is a Firecracker MicroVM. Each invocation to Lambda is served by one Firecracker MicroVM. Your code (Zip or Docker Image) runs inside a MicroVM. The /tmp directory is always empty for a new MicroVM, even if you store code in that directory in the docker image.

[hopewise]

Ah I see, and when deploying a new deployment, would previous files from the previous deployment exist? ex: say my app files were at /home/app when I built the docker image.

[bnusunny]

No, new deployment will run in new MicroVMs.

[hopewise]

Thanks, problem solved for entrypoint, but when I added my site config in sites-enabled to nginx, I started getting this error:

nginx: [alert] could not open error log file: open() "/var/log/nginx/error.log" failed (30: Read-only file system)
--
2023/01/30 16:36:58 [warn] 14#14: the "user" directive makes sense only if the master process runs with super-user privileges, ignored in /etc/nginx/nginx.conf:1
2023/01/30 16:36:58 [emerg] 14#14: bind() to 0.0.0.0:80 failed (13: Permission denied)
nginx: [emerg] bind() to 0.0.0.0:80 failed (13: Permission denied)

Shouldn't nginx use the tmp folder to write errors?
Also, isn't the example provided already working on port 80, why would a permission issue occur with my setup?
Can you have a look here please https://gist.github.com/hopewise/3685fc10c15483f79cede02550f4f7a6

[bnusunny]

The function/processes run inside Lambda MicroVM without root privilege. So Nginx can't listen on port 80. You should change the port to something higher than 1024. I suggest listening on port 8080. It is the default port Lambda Web Adapter uses.

[hopewise]

I am using lambda function behind a target group, I notice that I can't specify the port on the target group when target type is lambda, so how would I actually use the lambda function on port 8080 when using an ELB?

[bnusunny]

You need to configure Nginx to listen on port 8080. This is configured in Nginx config files.

Here is an example: https://github.com/awslabs/aws-lambda-web-adapter/blob/main/examples/nginx/app/config/conf.d/default.conf