Overview

I installed Docker on EC2 and used nginx-proxy and nginx-proxy-lets-encrypt to set up SSL.

Everything was working fine with the above configuration, but when I created an app that POSTs relatively large files, the following error occurred and the upload failed.

nginx-proxy413(PayloadTooLarge)

I needed to increase Nginx’s client_max_body_size.

Solution

ChatGPT4 taught me the following solution, which resolved the issue.

The 413 Request Entity Too Large error occurs when the payload of a request that the client is trying to send to the server (i.e., the size of the file being uploaded) exceeds the limit set on the server. To resolve this error, you need to increase the maximum request size in the Nginx configuration.

To adjust this setting in the nginx-proxy container, you can increase the upper limit of acceptable request sizes by increasing the value of the client_max_body_size directive. However, when using the jwilder/nginx-proxy image, it is recommended to apply custom configuration rather than directly editing the Nginx configuration file.

Here are the steps needed to increase client_max_body_size:

  1. Create a custom configuration file:

Create a custom Nginx configuration file locally that includes the client_max_body_size directive. For example, if you want to set this to 100M (100 megabytes), create a file with the following content.

my_custom_proxy_settings.conf:

client_max_body_size100M;
  1. Mount the custom configuration file to the Docker container:

Add a configuration to mount this custom configuration file to the /etc/nginx/conf.d directory in the nginx-proxy service definition. This will apply the configuration when Nginx starts.

Example of the modified docker-compose.yml:

sernvgiiicplrcnmoooaeexanr--l---b-ss-gttuet:peas""mhdvc/l"ar:i:84ethhes/scron04smporarm:otxje:3:lastrym:ywr8::rts//_.:i_04/a::rdcgaln"4um//uouilda3s:eencstwem"rtt/kthareeccdeouy/:st//ormbsnhcnnc/_.gna/ggknpjigrniiegrrniegnnriocxn/ixx.nxs-xnn/sxy.p-gxco-_lrpi/hecpseorndorkretxoxhst:tsyx/ptsxteyha.:tyintrdrm-ncmaopwgrlm/isydt.pohctc-o_kennenfgrc:i.r/nsyexopt_ctcpk//r:lnorogxogiy:n_/xcv/oacmrpnalfno.igdo//nnm.gyni_gncixunsxt_opmr_opxryo"xy_settings.conf:ro#Addthisline
  1. Restart the Docker container:

Restart the nginx-proxy container using docker-compose to apply the changes.

ddoocckkeerr--ccoommppoosseeduopwn-d

By following these steps, client_max_body_size will be set to 100M for all requests made through the nginx-proxy container. Adjust the 100M value to an appropriate size as needed.

Summary

I hope this serves as a useful reference for anyone experiencing the same issue.