fix: Allow upload limit increase in kubernetes deployment

[Dexter192]

For kubernetes deployments, the maximum filesize for e.g. File Components is capped at 1MB due to the Nginx default limit

Since the Nginx service is started via a start-nginx.sh file, adding annotations to the ingress part of the values.yaml does not work
e.g.

ingress:
  enabled: true
  annotations:
    nginx.ingress.kubernetes.io/client-max-body-size: "200M"

or

frontend:
  nginx:
    client_max_body_size: "200M" 

The workaround described in the helm repo also does not work (for me) since the ingress.yaml template sets the service name and port for every path identically:

service:
  name: {{ $fullName }}
    port: 
      number: {{ $svcPort }}

The proposed change would allow the configuration of the client_max_body_size for the nginx configuration while using the existing environment variable LANGFLOW_MAX_FILE_SIZE_UPLOAD. Reusing this variable makes sense as it's purpose is to configure the maximum upload size.

[jrespeto]

I was looking into this issue today and saw this PR.

The envsubst is not editing the nginx.conf file.

Maybe move the docker/frontend/nginx.conf changes you have to docker/frontend/default.conf.template to inside the http block and change the __LANGFLOW_MAX_FILE_SIZE_UPLOAD__ to ${LANGFLOW_MAX_FILE_SIZE_UPLOAD} to match the other variables.

[Dexter192]

@jrespeto Thanks for the pointer! You're absolutely right. I missed the copy part in the Dockerfile

I'll apply your suggestions when I get some time for it next week!

[ogabrielluiz]

That's nice.

Thank you @Dexter192

Have you tested it thoroughly?

[jrespeto]

I implemented the changes in my environment by patching the container image and confirm it does work.
Thanks @Dexter192

dockerfile

FROM langflowai/langflow-frontend:latest as langflow-frontend

COPY --chown=nginx src/default.conf.template /etc/nginx/conf.d/default.conf.template
COPY --chown=nginx --chmod=755 src/start-nginx.sh /start-nginx.sh

ENTRYPOINT ["/start-nginx.sh"]

default.conf.template

worker_processes auto;
pid /tmp/nginx.pid;
events {}

http {
    client_max_body_size ${LANGFLOW_MAX_FILE_SIZE_UPLOAD}M;
    include /etc/nginx/mime.types;
    default_type text/plain;

    types {
        text/html html;
        text/css css;
        application/javascript js;
    }

    server {
        gzip on;
        gzip_comp_level 2;
        gzip_min_length 1000;
        gzip_types text/xml text/css;
        gzip_http_version 1.1;
        gzip_vary on;
        gzip_disable "MSIE [4-6] \.";

        listen ${FRONTEND_PORT};

        location / {
            root /usr/share/nginx/html;
            index index.html index.htm;
            try_files $uri $uri/ /index.html =404;
            expires 1d;
            add_header Cache-Control "public";
        }
        location = /index.html {
            root /usr/share/nginx/html;
            add_header Cache-Control "no-cache, no-store, must-revalidate";
            etag on;
        }

        location /api {
            proxy_pass ${BACKEND_URL};
        }
        location /health_check {
            proxy_pass ${BACKEND_URL};
        }
        location /health {
            proxy_pass ${BACKEND_URL};
        }

        include /etc/nginx/extra-conf.d/*.conf;
    }
}

start-nginx.sh

#!/bin/sh
set -e

# Define writable directory for the final config
CONFIG_DIR="/tmp/nginx"
mkdir -p $CONFIG_DIR

# Check and set environment variables
if [ -z "$BACKEND_URL" ]; then
  BACKEND_URL="$1"
fi
if [ -z "$FRONTEND_PORT" ]; then
  FRONTEND_PORT="$2"
fi
if [ -z "$FRONTEND_PORT" ]; then
  FRONTEND_PORT="80"
fi
if [ -z "$LANGFLOW_MAX_FILE_SIZE_UPLOAD" ]; then
  LANGFLOW_MAX_FILE_SIZE_UPLOAD="1"
fi
if [ -z "$BACKEND_URL" ]; then
  echo "BACKEND_URL must be set as an environment variable or as first parameter. (e.g. http://localhost:7860)"
  exit 1
fi

# Export variables for envsubst
export BACKEND_URL FRONTEND_PORT LANGFLOW_MAX_FILE_SIZE_UPLOAD

# Use envsubst to substitute environment variables in the template
envsubst '${BACKEND_URL} ${FRONTEND_PORT} ${LANGFLOW_MAX_FILE_SIZE_UPLOAD}' < /etc/nginx/conf.d/default.conf.template > $CONFIG_DIR/default.conf

# Start nginx with the new configuration
exec nginx -c $CONFIG_DIR/default.conf -g 'daemon off;'

[Dexter192]

@ogabrielluiz I have built a docker image with the modification and deployed it on kubernetes cluster to validate that the changes work.

When deploying the image using Helm, some additional changes to the frontend helm template are required.

For testing I simply added this to the env block:

{{with .Values.langflow.frontend.env }}
{{- toYaml . | nindent 12 }}
{{- end }}

It might be better to reference the value from the backend env block since the env variable is used in the Langflow backend as well. However, this would increase the dependency of the frontend and backend part in the chart.