sql-exporter issue with .my.cnf file

[Katharina Wolf]

I have an issue with multiple container from sql-exporter.

My docker-compose.yml looks like this:

  db1:
    image: mariadb:10.6
    restart: unless-stopped
    expose:
      - 3306
    ports:
      - 3306:3306
    environment:
      MYSQL_ROOT_PASSWORD: password1
    command: --event_scheduler=ON --log-bin --userstat=ON
    volumes:
      - ./storage/db1:/var/lib/mysql

  db2:
    image: mariadb:10.6
    restart: unless-stopped
    command: --log-bin --userstat=ON    
    ports:
      - 3308:3306
    expose:
      - 3306
    environment:
      MYSQL_ROOT_PASSWORD: password2
      MYSQL_DATABASE: db-schema2
    volumes:
      - ./storage/db2:/var/lib/mysql
 
  sql-exporter-db1:
    image: prom/mysqld-exporter
    expose:
      - 9104
    ports:
      - 9104:9104
    links:
      - db1
    environment:
      - DATA_SOURCE_NAME=root:password1@(db1:3306)/
    command:
      --collect.global_status
      --collect.info_schema.innodb_metrics
      --collect.auto_increment.columns
      --collect.info_schema.processlist
      --collect.binlog_size
      --collect.info_schema.tablestats
      --collect.global_variables
      --collect.info_schema.query_response_time
      --collect.info_schema.userstats
      --collect.info_schema.tables
      --collect.perf_schema.tablelocks
      --collect.perf_schema.file_events
      --collect.perf_schema.eventswaits
      --collect.perf_schema.indexiowaits
      --collect.perf_schema.tableiowaits
      --collect.slave_status
      --collect.info_schema.tables.databases=db-schema1
      --collect.engine_innodb_status
      --web.listen-address=0.0.0.0:9104  
 
  sql-exporter-db2:
    image: prom/mysqld-exporter
    ports:
      - 9105:9104
    links:
      -db2
    volumes:
      - ./mysql-exporter/.my.cnf:/root/.my.cnf
    environment:
      - DATA_SOURCE_NAME:root:password2@(db2:3306)/
    command:
      --collect.global_status
      --collect.info_schema.innodb_metrics
      --collect.auto_increment.columns
      --collect.info_schema.processlist
      --collect.binlog_size
      --collect.info_schema.tablestats
      --collect.global_variables
      --collect.info_schema.query_response_time
      --collect.info_schema.userstats
      --collect.info_schema.tables
      --collect.perf_schema.tablelocks
      --collect.perf_schema.file_events
      --collect.perf_schema.eventswaits
      --collect.perf_schema.indexiowaits
      --collect.perf_schema.tableiowaits
      --collect.slave_status
      --collect.info_schema.tables.databases=db-schema2
      --collect.engine_innodb_status
      --web.listen-address=0.0.0.0:9105  
 
when i am running docker compose up, the sql-exporter for db1 runs without problems and delivers all metrices, i need.
but sql-exporter for db2 just logs these error and quites:

ts=2023-05-26T07:09:18.008Z caller=mysqld_exporter.go:277 level=info msg="Starting mysqld_exporter" version="(version=0.14.0, branch=HEAD, revision=ca1b9af82a471c849c529eb8aadb1aac73e7b68c)"
ts=2023-05-26T07:09:18.008Z caller=mysqld_exporter.go:278 level=info msg="Build context" (gogo1.17.8,userroot@401d370ca42e,date20220304-16:25:15)=(MISSING)
ts=2023-05-26T07:09:18.008Z caller=mysqld_exporter.go:284 level=info msg="Error parsing my.cnf" file=/home/.my.cnf err="failed reading ini file: open /home/.my.cnf: no such file or directory"

i tried different configurations for sql-exporter for db2 like
* mounting a .my.cnf-file
* dont mounting a .my.cnf-file
' DATA_SOURCE_NAME to @(db2:3306)/
' DATA_SOURCE_NAME to @(db2:3308)/

but every time i see only this 3 log lines and then the container exits.

has somebody the same issue and can help me?

[Brian Candler]

This is a docker/docker-compose problem not a prometheus one, but I can see from the error that your container is trying to read

/home/.my.cnf

but you have mounted the file at

/root/.my.cnf

Apart from that, if you have any further problems with the prom/mysqld-exporter image, the best place to raise them would be with the maintainer of that image.