php_network_getaddresses: getaddrinfo failed error in Docker's adminer

Question

I have problem with access to adminer in my docker container with laravel 5/mysql app. I got error :

SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo failed: Name does not resolve

My docker-compose.yml :

version: '3'

services:

    votes_app:
        build:
            context: ./web
            dockerfile: Dockerfile.yml

        container_name: votes_app_container
        environment:
            - APACHE_RUN_USER=#1000
        volumes:
            - ${APP_PATH_HOST}:${APP_PTH_CONTAINER}
        ports:
            - 8081:80
        working_dir: ${APP_PTH_CONTAINER}


    votes_db:
        image: mysql:5.6.41
        container_name: votes_db_container

        restart: always
        environment: 
            MYSQL_ROOT_PASSWORD: 1
        volumes:
            - ${DB_PATH_HOST}:/var/lib/mysql


    votes_adminer:
        image: adminer
        container_name: votes_adminer_container
        restart: always
        ports:
            - 8082:8080
        links:
            - votes_db


    votes_composer:
        image: composer:1.6
        container_name: votes_composer_container
        volumes:
            - ${APP_PATH_HOST}:${APP_PTH_CONTAINER}
        working_dir: ${APP_PTH_CONTAINER}
        command: composer install --ignore-platform-reqs

I got different ports for app and db container.

Here https://hub.docker.com/_/adminer/ I found:

Usage with external server You can specify the default host with the ADMINER_DEFAULT_SERVER environment variable. This is useful if you are connecting to an external server or a docker container named something other than the default db.

docker run -p 8080:8080 -e ADMINER_DEFAULT_SERVER=mysql adminer

In console of my app I run command

$ docker run -p 8089:8080 -e ADMINER_DEFAULT_SERVER=votes_db adminer 

with unused in my apps port and this command was not succesfull anyway, as I got the same error trying to log to adminer https://i.sstatic.net/4yPTe.jpg.

Which is the right way ?

MODIFIED BLOCK # 2:

In my docker-compose.yml :

version: '3'

services:

    votes_app:
        build:
            context: ./web
            dockerfile: Dockerfile.yml

        container_name: votes_app_container
        environment:
            - APACHE_RUN_USER=#1000
        volumes:
            - ${APP_PATH_HOST}:${APP_PTH_CONTAINER}
        ports:
            - 8081:80
        working_dir: ${APP_PTH_CONTAINER}


    db:
        image: mysql:5.6.41
        restart: always
        environment: 
            MYSQL_ROOT_PASSWORD: 1
        volumes:
            - ${DB_PATH_HOST}:/var/lib/mysql


    adminer:
        image: adminer
        restart: always
        ports:
            - 8082:8080
        links:
            - db


    votes_composer:
        image: composer:1.6
        container_name: votes_composer_container
        volumes:
            - ${APP_PATH_HOST}:${APP_PTH_CONTAINER}
        working_dir: ${APP_PTH_CONTAINER}
        command: composer install --ignore-platform-reqs

I rebuilded the app but I failed to login into adminer : https://i.sstatic.net/PdQqE.jpg

I run in console of my OS pointing to other unused 8089 port:

$ docker run -p 8089:8080 -e ADMINER_DEFAULT_SERVER=db adminer
PHP 7.2.11 Development Server started at Thu Nov  1 07:00:46 2018
[Thu Nov  1 07:01:11 2018] ::ffff:172.17.0.1:34048 [200]: /
[Thu Nov  1 07:01:20 2018] ::ffff:172.17.0.1:34052 [302]: /
[Thu Nov  1 07:01:21 2018] ::ffff:172.17.0.1:34060 [403]: /?server=db&username=root

But again error logining to adminer to 8089 port, but the error message was different :

https://i.sstatic.net/pEuHx.jpg

What is wrong ?

MODIFIED BLOCK # 3:

I suppose yes, as after I rebuilded the container I entered into the box and see “root” in console output:

$ docker-compose exec votes_app bash
root@a4aa907373f5:/var/www/html# ls -la
total 1063
drwxrwxrwx 1 root root   4096 Oct 27 12:01 .
drwxr-xr-x 1 root root   4096 Oct 16 00:11 ..
-rwxrwxrwx 1 root root    234 Oct 13 07:15 .editorconfig
-rwxrwxrwx 1 root root   1029 Oct 31 06:10 .env
-rwxrwxrwx 1 root root    651 Oct 13 07:15 .env.example
drwxrwxrwx 1 root root   4096 Nov  1 11:10 .git
-rwxrwxrwx 1 root root    111 Oct 13 07:15 .gitattributes
-rwxrwxrwx 1 root root    294 Oct 13 07:15 .gitignore
-rwxrwxrwx 1 root root   4356 Oct 13 07:15 1.txt
drwxrwxrwx 1 root root      0 Oct 13 07:15 __DOCS
drwxrwxrwx 1 root root      0 Oct 13 07:15 __SQL
drwxrwxrwx 1 root root   4096 Oct 13 07:15 app
-rwxrwxrwx 1 root root   1686 Oct 13 07:15 artisan                                                                                                                                                                     
drwxrwxrwx 1 root root      0 Oct 13 07:15 bootstrap                                                                                                                                                                   
-rwxrwxrwx 1 root root   2408 Oct 13 07:15 composer.json                                                                                                                                                               
-rwxrwxrwx 1 root root 200799 Oct 13 07:15 composer.lock                                                                                                                                                               
drwxrwxrwx 1 root root   4096 Oct 13 07:15 config                                                                                                                                                                      
drwxrwxrwx 1 root root   4096 Oct 13 07:15 database                                                                                                                                                                    
-rwxrwxrwx 1 root root  52218 Oct 17 05:25 db_1_err.txt                                                                                                                                                                
-rwxrwxrwx 1 root root 482562 Oct 13 07:15 package-lock.json                                                                                                                                                           
-rwxrwxrwx 1 root root   1168 Oct 13 07:15 package.json                                                                                                                                                                
-rwxrwxrwx 1 root root   1246 Oct 13 07:15 phpunit.xml                                                                                                                                                                 
drwxrwxrwx 1 root root   4096 Oct 13 07:15 public
-rwxrwxrwx 1 root root     66 Oct 13 07:15 readme.txt
drwxrwxrwx 1 root root      0 Oct 13 07:15 resources
drwxrwxrwx 1 root root   4096 Oct 13 07:15 routes
-rwxrwxrwx 1 root root    563 Oct 13 07:15 server.php
drwxrwxrwx 1 root root   4096 Oct 13 07:15 storage
drwxrwxrwx 1 root root      0 Oct 13 07:15 tests
drwxrwxrwx 1 root root   8192 Nov  1 13:05 vendor
-rwxrwxrwx 1 root root   1439 Oct 13 07:15 webpack.mix.js
-rwxrwxrwx 1 root root 261143 Oct 13 07:15 yarn.lock
root@a4aa907373f5:/var/www/html# echo $USER

root@a4aa907373f5:/var/www/html#  uname -a
Linux a4aa907373f5 4.15.0-36-generic #39-Ubuntu SMP Mon Sep 24 16:19:09 UTC 2018 x86_64 GNU/Linux

Can it be issue anyway ?

MODIFIED BLOCK # 4

I remade this docker, I set default names of containers(I suppose that it raise some confusion) and I set image: composer:1.8 latest version So in my docker-compose.yml :

version: '3.1'

services:

    web:

        build:
            context: ./web
            dockerfile: Dockerfile.yml

        environment:
            - APACHE_RUN_USER=#1000
        volumes:
            - ${APP_PATH_HOST}:${APP_PTH_CONTAINER}
        ports:
            - 8081:80
        working_dir: ${APP_PTH_CONTAINER}

    db:
        image: mysql:5.6.41
        restart: always
        environment: 
            MYSQL_ROOT_PASSWORD: 1
        volumes:
            - ${DB_PATH_HOST}:/var/lib/mysql

    adminer:
        image: adminer
        restart: always
        ports:
            - 8082:8080
        links:
            - db

    composer:
        image: composer:1.8
        volumes:
            - ${APP_PATH_HOST}:${APP_PTH_CONTAINER}
        working_dir: ${APP_PTH_CONTAINER}
        command: composer install --ignore-platform-reqs

and in web/Dockerfile.yml :

FROM php:7.2-apache

RUN apt-get update -y && apt-get install -y libpng-dev nano

RUN docker-php-ext-install \
    pdo_mysql \
    && a2enmod \
    rewrite

But anyway after rebuilding of the project and connecting to adminer with http://127.0.0.1:8082 url I got error:

SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo failed: Try again

P.S.: I have other laravel 5.0/php:5.6 / image: composer:1.6 / mcrypt installed docker project on the same local server of my laptop, which works ok for me and I can enter adminer and can login to db from this app. This docker project has files:

docker-compose.yml:

version: '3.1'

services:

    web:
        build:
            context: ./web
            dockerfile: Dockerfile.yml

        environment:
            - APACHE_RUN_USER=#1000
        volumes:
            - ${APP_PATH_HOST}:${APP_PTH_CONTAINER}
        ports:
            - 8085:80
        working_dir: ${APP_PTH_CONTAINER}


    db:
        image: mysql:5.5.62
        restart: always
        environment: 
            MYSQL_ROOT_PASSWORD: 1
        volumes:
            - ${DB_PATH_HOST}:/var/lib/mysql


    adminer:
        image: adminer
        restart: always
        ports:
            - 8086:8080
        links:
            - db


    composer:
        image: composer:1.6
        volumes:
            - ${APP_PATH_HOST}:${APP_PTH_CONTAINER}
        working_dir: ${APP_PTH_CONTAINER}
        command: composer install --ignore-platform-reqs

and Dockerfile.yml :

FROM php:5.6-apache

RUN apt-get update -y && apt-get install -y libpng-dev   nano  libmcrypt-dev

RUN docker-php-ext-install \
    pdo_mysql \
    mcrypt \
    && a2enmod \
    rewrite

Is this issue some php 7.2 specific feature(like some packages missing ?)

MODIFIED BLOCK # 5: with defined :

phpmyadmin:
    depends_on:
      - db
    image: phpmyadmin/phpmyadmin
    restart: always
    ports:
      - 8082:8080
    environment:
      PMA_HOST: db
      MYSQL_ROOT_PASSWORD: 1

Running http://127.0.0.1:8082/ I got error in browser :

This site can’t be reached The webpage at http://127.0.0.1:8082/ might be temporarily down or it may have moved permanently to a new web address.
ERR_SOCKET_NOT_CONNECTED

While trying app url http://127.0.0.1:8081/public/ I got error :

SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo failed: Temporary failure in name resolution 

MODIFIED BLOCK # 6: I remade with phpmyadmin in docker-compose.yml :

version: '3.1'

services:

#  docker run -p 8089:8080 -e ADMINER_DEFAULT_SERVER=db adminer
    web:

        # env_file:
        #     - ./mysql.env

        build:
            context: ./web
            dockerfile: Dockerfile.yml

        environment:
            - APACHE_RUN_USER=#1000
        volumes:
            - ${APP_PATH_HOST}:${APP_PTH_CONTAINER}
        ports:
            - 8081:80
        working_dir: ${APP_PTH_CONTAINER}


    db:
        image: mysql:5.6.41
        restart: always
        environment: 
            MYSQL_ROOT_PASSWORD: 1
        volumes:
            - ${DB_PATH_HOST}:/var/lib/mysql


    phpmyadmin:
        depends_on:
          - db
        image: phpmyadmin/phpmyadmin
        restart: always
        ports:
          - 8082:80
        environment:
          PMA_HOST: db
          MYSQL_ROOT_PASSWORD: 1

    composer:
        image: composer:1.8
        volumes:
            - ${APP_PATH_HOST}:${APP_PTH_CONTAINER}
        working_dir: ${APP_PTH_CONTAINER}
        command: composer install --ignore-platform-reqs

but trying to login into phpMyAdmin at

http://127.0.0.1:8082

I got the same error : https://i.sstatic.net/YCYUt.jpg

Also I have ports :

$ docker ps
CONTAINER ID        IMAGE                    COMMAND                  CREATED             STATUS                          PORTS                            NAMES
471de34926b9        phpmyadmin/phpmyadmin    "/run.sh supervisord…"   41 minutes ago      Up 41 minutes                   9000/tcp, 0.0.0.0:8082->80/tcp   votes_docker_phpmyadmin_1
226fcdbeeb25        mysql:5.6.41             "docker-entrypoint.s…"   41 minutes ago      Restarting (1) 49 seconds ago                                    votes_docker_db_1
1cb1efb10561        votes_docker_web         "docker-php-entrypoi…"   41 minutes ago      Up 41 minutes                   0.0.0.0:8081->80/tcp             votes_docker_web_1
d6718cd16256        adminer                  "entrypoint.sh docke…"   13 hours ago        Up About an hour                0.0.0.0:8088->8080/tcp           ads_docker_adminer_1
1928a54e1d66        mysql:5.5.62             "docker-entrypoint.s…"   13 hours ago        Up About an hour                3306/tcp                         ads_docker_db_1
e43b2a1e9cc7        adminer                  "entrypoint.sh docke…"   6 days ago          Up About an hour                0.0.0.0:8086->8080/tcp           youtubeapi_demo_adminer_1
47a034fca5a2        mysql:5.5.62             "docker-entrypoint.s…"   6 days ago          Up About an hour                3306/tcp                         youtubeapi_demo_db_1
3dcc1a4ce8f0        adminer                  "entrypoint.sh docke…"   6 weeks ago         Up About an hour                0.0.0.0:8083->8080/tcp           lprods_adminer_container
933d9fffaf76        postgres:9.6.10-alpine   "docker-entrypoint.s…"   6 weeks ago         Up About an hour                0.0.0.0:5433->5432/tcp           lprods_db_container

  MODIFIED BLOCK # 7  I am not sure which debugging info can I provide, but seems loging has some warning. Are they critical ? Which additive debugging info can I provide ?

serge@serge:/mnt/_work_sdb8/wwwroot/lar/DockerApps/votes_docker$ docker-compose up -d --build              
Creating network "votes_docker_default" with the default driver 
Building web 
Step 1/3 : FROM php:7.2-apache 
 ---> cf1a377ba77f 
Step 2/3 : RUN apt-get update -y && apt-get install -y libpng-dev nano 
 ---> Using cache 
 ---> 2c4bce73e8cc 
Step 3/3 : RUN docker-php-ext-install     pdo_mysql     && a2enmod     rewrite 
 ---> Using cache 
 ---> 241c9bf59ac0 
Successfully built 241c9bf59ac0 
Successfully tagged votes_docker_web:latest 
Creating votes_docker_composer_1   ... done 
Creating votes_docker_web_1        ... done 
Creating votes_docker_db_1       ... done 
Creating votes_docker_phpmyadmin_1 ... done 
serge@serge:/mnt/_work_sdb8/wwwroot/lar/DockerApps/votes_docker$ clear 
serge@serge:/mnt/_work_sdb8/wwwroot/lar/DockerApps/votes_docker$ docker logs --tail=20  votes_docker_web_1 
AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 172.20.0.4. Set the 'ServerName' directive globally to suppress this message 
AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 172.20.0.4. Set the 'ServerName' directive globally to suppress this message 
[Wed Dec 26 12:26:34.113194 2018] [mpm_prefork:notice] [pid 1] AH00163: Apache/2.4.25 (Debian) PHP/7.2.11 configured -- resuming normal operations 
[Wed Dec 26 12:26:34.113247 2018] [core:notice] [pid 1] AH00094: Command line: 'apache2 -D FOREGROUND' 
serge@serge:/mnt/_work_sdb8/wwwroot/lar/DockerApps/votes_docker$ docker logs --tail=20  votes_docker_db_1 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'INNODB_CMP_PER_INDEX' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'INNODB_CMPMEM_RESET' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'INNODB_CMPMEM' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'INNODB_CMP_RESET' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'INNODB_CMP' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'INNODB_LOCK_WAITS' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'INNODB_LOCKS' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'INNODB_TRX' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'BLACKHOLE' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'ARCHIVE' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'MRG_MYISAM' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'MyISAM' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'MEMORY' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'CSV' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'sha256_password' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'mysql_old_password' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'mysql_native_password' 
2018-12-26 12:26:43 1 [Note] Shutting down plugin 'binlog' 
2018-12-26 12:26:43 1 [Note] mysqld: Shutdown complete 

serge@serge:/mnt/_work_sdb8/wwwroot/lar/DockerApps/votes_docker$ docker logs --tail=20  votes_docker_composer_1    
> @php artisan package:discover 
Discovered Package: aloha/twilio 
Discovered Package: barryvdh/laravel-debugbar 
Discovered Package: beyondcode/laravel-dump-server 
Discovered Package: cviebrock/eloquent-sluggable 
Discovered Package: davejamesmiller/laravel-breadcrumbs 
Discovered Package: fideloper/proxy 
Discovered Package: intervention/image 
Discovered Package: itsgoingd/clockwork 
Discovered Package: jrean/laravel-user-verification 
Discovered Package: laravel/tinker 
Discovered Package: laravelcollective/html 
Discovered Package: mews/captcha 
Discovered Package: nesbot/carbon 
Discovered Package: nunomaduro/collision 
Discovered Package: proengsoft/laravel-jsvalidation 
Discovered Package: rap2hpoutre/laravel-log-viewer 
Discovered Package: themsaid/laravel-mail-preview 
Discovered Package: yajra/laravel-datatables-oracle 
Package manifest generated successfully. 
serge@serge:/mnt/_work_sdb8/wwwroot/lar/DockerApps/votes_docker$ docker logs --tail=20  votes_docker_phpmyadmin_1 
phpMyAdmin not found in /var/www/html - copying now... 
Complete! phpMyAdmin has been successfully copied to /var/www/html 
/usr/lib/python2.7/site-packages/supervisor/options.py:461: UserWarning: Supervisord is running as root and it is searching for its configuration file in default locations (including its current working directory); 
you probably want to specify a "-c" argument specifying an absolute path to a configuration file for improved security. 
  'Supervisord is running as root and it is searching ' 
2018-12-26 12:26:35,973 CRIT Supervisor is running as root.  Privileges were not dropped because no user is specified in the config file.  If you intend to run as root, you can set user=root in the config file to av
oid this message. 
2018-12-26 12:26:35,973 INFO Included extra file "/etc/supervisor.d/nginx.ini" during parsing 
2018-12-26 12:26:35,973 INFO Included extra file "/etc/supervisor.d/php.ini" during parsing 
2018-12-26 12:26:35,984 INFO RPC interface 'supervisor' initialized 
2018-12-26 12:26:35,984 CRIT Server 'unix_http_server' running without any HTTP authentication checking 
2018-12-26 12:26:35,984 INFO supervisord started with pid 1 
2018-12-26 12:26:36,986 INFO spawned: 'php-fpm' with pid 23 
2018-12-26 12:26:36,988 INFO spawned: 'nginx' with pid 24 
[26-Dec-2018 12:26:37] NOTICE: fpm is running, pid 23 
[26-Dec-2018 12:26:37] NOTICE: ready to handle connections 
2018-12-26 12:26:38,094 INFO success: php-fpm entered RUNNING state, process has stayed up for > than 1 seconds (startsecs) 
2018-12-26 12:26:38,095 INFO success: nginx entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)

What is wrong ?

Thanks!

Answer 1

In my case after adding phpmyadmin/adminer to the composer file, I failed to add the "networks" field under the phpmyadmin configurations in the docker-compose file. Looks like By default laravel sail for laravel 10 creates a "network" in the docker-compose.yml so one has to add it if necessary, to all additional services that will be added to the docker-compose file

Answer 2

I was having the same issue, then I find that the default value in Adminer application for server address is 'db', which doesn't match with the service name for my MySQL container.

Answer 3

change the container name to db for mysql image made the difference for me You can see about it in https://hub.docker.com/_/adminer/

services: db: image: mysql:5.6

Answer 4

The question has already been answered, but adding my solution to a similar problem here for reference.

Adding a 'links' parameter to my docker-compose phpmyadmin/adminer service block solved it for me, based on the assumption that the service name of the database block is in fact db as used in examples in answered above too. This link makes it possible to then in the phpmyadmin login interface use 'db' as the host and it will connect.

links:
  - db:db

Answer 5

The problem with your setup is because of the environment variable DB_PATH_HOST. You have setup everything fine in your compose file. but before running docker-compose you are supposed to define the environment variable DB_PATH_HOST. Since the environment variable is not defined it throws an error. See this for more details on Environment variables and it's precedence in Docker.

So what you should have done is, Before starting docker container you should have defined the environment variable either by defining it in compose file or exporting it in shell as shell variable before running docker-compose or should have used env file or by using ENV instrction in dockerfile. (These are all the possible ways of defining environment variables and I've listed all of them the method that comes first takes priority. refer this for more info).

So the proper docker-compose.yml file should be as follows.

version: '3.2'
services:
   db:
        image: mysql:5.6.41
        restart: always
        environment: 
            MYSQL_ROOT_PASSWORD: 1
            DB_PATH_HOST: /tmp/mysql #this is the host location where mysql data will be stored.
        volumes:
            - ${DB_PATH_HOST}:/var/lib/mysql

    phpmyadmin:
        depends_on:
          - db
        image: phpmyadmin/phpmyadmin
        restart: always
        ports:
          - 8082:80
        environment:
          PMA_HOST: db
          MYSQL_ROOT_PASSWORD: 1

Now coming to the next point I see that from your discussions you have concluded that removing volumes from the db container fixed your problem. But actually not. How?

First let me explain why volume is used here. The data generated my mysql should be stored somewhere. Docker by default runs containers in non-persistant mode, which means all the data generated by the running docker conatiner will be erased when that container is brought down/killed. So in order to persist(store/save) data we use volumes. There are different types of volumes used in docker. I encourage you to read Storage documentation of docker for more details. The type of volume used here is a bind mount which is, You bind a host directory to a docker directory and docker stores all the data directly in host machine such that even if docker container is brought down data is still preserved.

Hence if you don't use volumes in mysql all the db changes irrespective of whatever you do, will be lost whenever the container is stopped.

Bonus Poits:

1. By default MySQL container doesn't allow remote connections. So if you want to access mysql from anywhere else apart from phpmyadmin. You have to allow remote connections.
2. Since we are preserving the data here the root password will be set only on the first time whenever you start mysqll container. From next time onwards root password environment variable will be ignored.
3. If you log into docker containers using docker exec mostly you can see that you will be root. That's because whenever you create a docker container with Dockerfile by using either docker build or docker-compose build unless you specify an instruction on Dockerfile to create and use a new user docker will run everything as root user.
4. Now whenever you run the above compose file. You can see that the mysql data location's ownership will be changed. It's because whenever you mount a host directory to docker, Docker changes the file permission according to the user and group as per that container's Dockerile definition. Here mysql has defined a user and group called mysql and the uid and gid is 999. hence /tmp/mysql will be havng 999:999 as ownership. If these id's are mapped with any other user account in your system you will see those names instead of ids whenever you do ls -al in host machine. If id's are not mapped then you will see the id's directly.
5. I've used /tmp/mysql as mysql data directory for an example. Pleae don't use the same as the data in /tmp will be removed whenever there is a system restart.

Answer 6

Try with phpMyAdmin :)

version: '3.2'
services:
    db:
        image: mysql:5.7

        restart: always
        environment:
          MYSQL_ROOT_PASSWORD: myUserPass
          MYSQL_DATABASE: mydb
          MYSQL_USER: myUser
          MYSQL_PASSWORD: myUser

    phpmyadmin:
        depends_on:
          - db
        image: phpmyadmin/phpmyadmin
        restart: always
        ports:
          - 8088:80
        environment:
          PMA_HOST: db
          MYSQL_ROOT_PASSWORD: myUserPass

Answer 7

You can see about it in https://hub.docker.com/_/adminer/

Example

version: '3.1'

services:

  adminer:
    image: adminer
    restart: always
    ports:
      - 8080:8080

  db:
    image: mysql:5.6
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: example