Whenever I run docker-compose up -d --build to start working on my project, it started up my environment just fine up until yesterday.

Upon running docker-compose up -d --build, I get this annoying error that says: ERROR: Service 'app' depends on service 'db' which is undefined.

I'm not sure how this is happening out of no where as I've made absolutely no changes whatsoever to the docker-compose.yml file. I've tried troubleshooting this extensively but to no avail.

What's wrong with my file?

Here's my docker-compose.yml file:

version: "3.7"
services:
    app:
        build:
            args:
                user: sammy
                uid: 1000
            context: ./
            dockerfile: Dockerfile.dev
        working_dir: /var/www/
        environment:
            - COMPOSER_MEMORY_LIMIT=-1
        depends_on:
            - db
        volumes:
            - ./:/var/www
        networks:
            - lahmi

    myApp:
        image: mysql:5.7
        environment:
            MYSQL_DATABASE: ${DB_DATABASE}
            MYSQL_ROOT_PASSWORD: ${DB_PASSWORD}
            MYSQL_PASSWORD: ${DB_PASSWORD}
            MYSQL_USER: ${DB_USERNAME}
            SERVICE_TAGS: dev
            SERVICE_NAME: mysql
        volumes:
            - dbdata:/var/lib/mysql
            - ./docker-compose/mysql/my.cnf:/etc/mysql/my.cnf
            - ./docker-compose/mysql/init:/docker-entrypoint-initdb.d
        ports:
            - 3307:3306
        networks:
            - lahmi

    nginx:
        image: nginx:alpine
        ports:
            - 8005:80
        depends_on:
            - db
            - app
        volumes:
            - ./:/var/www
            - ./docker-compose/nginx:/etc/nginx/conf.d/
        networks:
            - lahmi

networks:
    lahmi:
        driver: bridge

volumes:
    dbdata:
        driver: local

CodePudding user response：

There is no service named db in docker-compose.yml. Changing db to myApp (database service) may work.

If you are referencing the database as db in service app, you must use links configuration to change myApp to db or change service name myApp to db.

https://docs.docker.com/compose/compose-file/compose-file-v3/#links