Request forwarded to wrong container with subdomains

[Twois]

I have two subdomain (dev.domain.com) and (test.domain.com)

Both are placed in different folders
home/

• proxy
• dev.domain.com
• test.domain.com

AS I see, sometimes (~50%) when i surf on dev.domain.com and call an api request that not exist on test.domain.com i got 404.

Because of this i think some times nginx-proxy-automation forward the request to test.domain.com instead of dev.domain.com

The other reason why I think it's a forward problem, because if I stop test.domain.com all request successful.

I have not found any information about there is a problem with subdomains.

Here are some conf:

dev.domain.com

.env

LETSENCRYPT_EMAIL=mail@ofme.com
DOMAINS=dev.domain.com
NETWORK=proxy
NGINX_PORT=3000

docker-compose.yml

version: '3.8'
services:
    #NGINX
    nginx:
        restart: always
        
        image: nginx:1.19.6-alpine

        env_file: 
            - .env

        environment: 
            BACKEND_PORT: ${SERVER_PORT}
            PUBLIC_PORT: ${PUBLIC_PORT}
            VIRTUAL_HOST: ${DOMAINS}
            VIRTUAL_PORT: ${NGINX_PORT}
            LETSENCRYPT_HOST: ${DOMAINS}
            LETSENCRYPT_EMAIL: ${LETSENCRYPT_EMAIL}

        volumes:
            - ./nginx/prod.default.conf.template:/etc/nginx/templates/default.conf.template
            - ./frontend/dist/browser:/usr/share/nginx/html
        
        ports: 
            - '${NGINX_PORT}:80'
        
        logging: 
            driver: none

    #BACKEND
    backend:
        build:
            dockerfile: Dockerfile
            context: ./backend

        env_file: 
            - .env

        environment: 
            MAIL_TO_OAM: ${MAIL_TO_OAM}
            MAIL_TO_WEBSITE: ${MAIL_TO_WEBSITE}
            MAIL_FROM_WEBSITE: ${MAIL_FROM_WEBSITE}

            SMTP_HOST: ${SMTP_HOST}
            SMTP_PORT: ${SMTP_PORT}
            SMTP_USER: ${SMTP_USER}
            SMTP_SECURE: ${SMTP_SECURE}
            SMTP_PASSWORD: ${SMTP_PASSWORD}

            MONGO_DB: ${MONGO_DB}
            MONGO_PORT: ${MONGO_PORT}
            MONGO_HOST: ${MONGO_HOST}
            MONGO_USERNAME: ${MONGO_USERNAME}
            MONGO_PASSWORD: ${MONGO_PASSWORD}
            MONGO_PROTOCOL: ${MONGO_PROTOCOL}
            MONGO_AUTHSOURCE: ${MONGO_AUTHSOURCE}

            SERVER_HOST: ${SERVER_HOST}
            SERVER_PORT: ${SERVER_PORT}
            SERVER_PATH: ${SERVER_PATH}
            SERVER_ENVIRONMENT: ${SERVER_ENVIRONMENT}
            DEBUG_COLORS: "true"
            TERM: xterm-256color
            COLORTERM: truecolor
        
        volumes:
            - ./backend:/app
        
        entrypoint: ["npm", "run", "serve"]

networks:
    default:
        external:
            name: ${NETWORK}

test.domain.com

.env

LETSENCRYPT_EMAIL=mail@ofme.com
DOMAINS=test.domain.com
NETWORK=proxy
NGINX_PORT=3001

docker-compose.yml

version: '3.8'
services:
    #NGINX
    nginx:
        restart: always
        
        image: nginx:1.19.6-alpine

        env_file: 
            - .env

        environment: 
            BACKEND_PORT: ${SERVER_PORT}
            PUBLIC_PORT: ${PUBLIC_PORT}
            VIRTUAL_HOST: ${DOMAINS}
            VIRTUAL_PORT: ${NGINX_PORT}
            LETSENCRYPT_HOST: ${DOMAINS}

        volumes:
            - ./nginx/prod.default.conf.template:/etc/nginx/templates/default.conf.template
            - ./frontend/dist/browser:/usr/share/nginx/html
        
        ports: 
            - '${NGINX_PORT}:80'
        
        logging: 
            driver: none

    #BACKEND
    backend:
        build:
            dockerfile: Dockerfile
            context: ./backend

        env_file: 
            - .env

        environment: 
            MAIL_TO_OAM: ${MAIL_TO_OAM}
            MAIL_TO_WEBSITE: ${MAIL_TO_WEBSITE}
            MAIL_FROM_WEBSITE: ${MAIL_FROM_WEBSITE}

            SMTP_HOST: ${SMTP_HOST}
            SMTP_PORT: ${SMTP_PORT}
            SMTP_USER: ${SMTP_USER}
            SMTP_SECURE: ${SMTP_SECURE}
            SMTP_PASSWORD: ${SMTP_PASSWORD}

            MONGO_DB: ${MONGO_DB}
            MONGO_PORT: ${MONGO_PORT}
            MONGO_HOST: ${MONGO_HOST}
            MONGO_USERNAME: ${MONGO_USERNAME}
            MONGO_PASSWORD: ${MONGO_PASSWORD}
            MONGO_PROTOCOL: ${MONGO_PROTOCOL}
            MONGO_AUTHSOURCE: ${MONGO_AUTHSOURCE}

            SERVER_HOST: ${SERVER_HOST}
            SERVER_PORT: ${SERVER_PORT}
            SERVER_PATH: ${SERVER_PATH}
            SERVER_ENVIRONMENT: ${SERVER_ENVIRONMENT}
            DEBUG_COLORS: "true"
            TERM: xterm-256color
            COLORTERM: truecolor
        
        volumes:
            - ./backend:/app
        
        entrypoint: ["npm", "run", "serve"]

networks:
    default:
        external:
            name: ${NETWORK}

[Twois]

Until now I have made some test and now I see, I was right. So if i have two separated project with subdomains (i have not tested with other domains only with subdomains yet) at VIRTUAL_HOST and LETSENCRYPT_HOST, than the request randomly served between the projects.

[Twois]

I solved it.

The problem was that both subdomain used the same services and the same external network. So the nginx-proxy-automation worked well, that forwarded the request to one of my website (well), but inside it there is an other nginx that also forwarded the request between frontend and backend. And the problem was with this, because the services names where the same, so my internal nginx service sometimes forwarded the request to subdomain1 sometimes subdomain2.

I hope this could help for others.