[MDEV-31550] "mariadb-admin ping" exits zero when authentication fails Created: 2023-06-26  Updated: 2023-06-26  Resolved: 2023-06-26

Status: Closed
Project: MariaDB Server
Component/s: Scripts & Clients
Fix Version/s: N/A

Type: Task Priority: Minor
Reporter: Brian Kroth Assignee: Sergei Golubchik
Resolution: Not a Bug Votes: 0
Labels: None

Issue Links:
Duplicate
is duplicated by MDEV-31549 "mariadb-admin ping" Closed

 Description   

1. Start a server from the latest docker image using a non-empty password:

docker run --name mariadb -d --rm -e MARIADB_ROOT_PASSWORD=nonempty mariadb:latest

2. Attempt to run a simple health check on it using mariadb-ping:

docker exec -it mariadb mariadb-admin ping ; echo $?
 
mariadb-admin: connect to server at 'localhost' failed
 
error: 'Access denied for user 'root'@'localhost' (using password: NO)'
 
0

Notice that authentication fails, but the exit code is 0 (success).

3. Do the same thing, but with a status check instead:

docker exec -it mariadb mariadb-admin status ; echo $?
 
mariadb-admin: connect to server at 'localhost' failed
 
error: 'Access denied for user 'root'@'localhost' (using password: NO)'
 
1

Notice that the authentication fails, so the exit code is 1 (fail).

I believe both should fail with a non-zero code upon authentication failure. Without this, docker containers, or other setups that rely on "mysqladmin ping" may incorrectly succeed if the server is overwhelmed or otherwise having trouble succeeding with authentication requests.

 Comments   
Comment by Daniel Black [ 2023-06-26 ]

Also see: https://mariadb.org/mariadb-server-docker-official-images-healthcheck-without-mysqladmin/

Why mysqladmin ping/mariadb-admin ping is incorrect as a healthcheck.

With https://github.com/docker-library/official-images/pull/14936 very soon it should be simpiler

 docker run --name mariadb -d --rm -e MARIADB_ROOT_PASSWORD=nonempty --health-cmd="healthcheck.sh --connect --innodb_initialized" --health-interval=5s --health-timeout=5s --health-retries=3 mariadb:latest
 
..
 
 CONTAINER ID  IMAGE                             COMMAND     CREATED         STATUS                   PORTS       NAMES
 
8d2bbb2ae7aa  docker.io/library/mariadb:latest  mariadbd    21 seconds ago  Up 21 seconds (healthy)              mariadb
 
 
 
$ podman exec mariadb  bash -x -v healthcheck.sh --connect --innodb_initialized 
...
 
++ mariadb --defaults-extra-file=/var/lib/mysql/.my-healthcheck.cnf -B --skip-column-names -e 'select 1 from information_schema.ENGINES WHERE engine="innodb" AND support in ("YES", "DEFAULT", "ENABLED")'
 
+ s=1
 
+ '[' 1 == 1 ']'
 
+ test=
 
+ shift
 
+ '[' 0 -gt 0 ']'

Comment by Sergei Golubchik [ 2023-06-26 ]

This is intentional and documented behavior. See https://mariadb.com/kb/en/mariadb-admin/

ping Check if mysqld is alive. Return status is 0 if the server is running (even in the case of an error such as access denied), 1 if it is not.

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