Bug #100490 Docker container log doesn't make sense when configuration is mistaken
Submitted: 11 Aug 2020 8:27 Modified: 12 Aug 2020 9:07
Reporter: tsubasa tanaka (OCA) Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Package Repos and Docker Images Severity:S3 (Non-critical)
Version:5.6.49, 5.7.31 OS:Any
Assigned to: CPU Architecture:Any
Tags: Contribution

[11 Aug 2020 8:27] tsubasa tanaka
Description:
docker-entrypoint.sh mistakes to handle wrong configuration in https://github.com/mysql/mysql-docker/blob/mysql-server/5.7/docker-entrypoint.sh#L38 .

$output is only receive "$@ --verbose --help" 's STDOUT, then the container log doesn't print about "what is wrong".

How to repeat:
### 5.6.49 and 5.7.31 miss to print $output and I can't understand "what's wrong".

$ sudo docker run mysql/mysql-server:5.7.31 --invalid-option
[Entrypoint] MySQL Docker Image 5.7.31-1.1.17
[Entrypoint] ERROR: Unable to start MySQL. Please check your configuration.
[Entrypoint]

$ sudo docker run mysql/mysql-server:5.6.49 --invalid-option
[Entrypoint] MySQL Docker Image 5.6.49-1.1.17
[Entrypoint] ERROR: Unable to start MySQL. Please check your configuration.
[Entrypoint]

### 5.5.62 is well

$ sudo docker run mysql/mysql-server:5.5.62 --invalid-option
[Entrypoint] MySQL Docker Image 5.5.62-1.1.10
[Entrypoint] ERROR: Unable to start MySQL. Please check your configuration.
[Entrypoint] 200811  8:18:30 [Note] mysqld (mysqld 5.5.62) starting as process 7 ...
200811  8:18:30 [Note] Plugin 'FEDERATED' is disabled.
mysqld: Table 'mysql.plugin' doesn't exist
200811  8:18:30 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
200811  8:18:30 [ERROR] mysqld: unknown option '--invalid-option'
200811  8:18:30 [ERROR] Aborting

### 8.0.21 misses to receive into $output but MY-000068 covers it.

$ sudo docker run mysql/mysql-server:8.0.21 --invalid-option
[Entrypoint] MySQL Docker Image 8.0.21-1.1.17
2020-08-11T08:18:59.351067Z 0 [ERROR] [MY-000068] [Server] unknown option '--invalid-option'.
2020-08-11T08:18:59.351158Z 0 [ERROR] [MY-010119] [Server] Aborting
[Entrypoint] ERROR: Unable to start MySQL. Please check your configuration.
[Entrypoint]

Suggested fix:
5.5.62 handles STDERR into $output correctly.
Fix the line of docker-entrypoint.sh like 5.5.62's one.

https://github.com/mysql/mysql-docker/blob/mysql-server/5.5/docker-entrypoint.sh#L38
[11 Aug 2020 8:31] tsubasa tanaka
fix as same as 5.5

(*) I confirm the code being submitted is offered under the terms of the OCA, and that I am authorized to contribute it.

Contribution: bug100490.patch (application/octet-stream, text), 1.24 KiB.

[11 Aug 2020 8:32] tsubasa tanaka
The patched container works fine.

$ sudo docker run work --invalid-option
[Entrypoint] MySQL Docker Image 5.7.31-1.1.17
[Entrypoint] ERROR: Unable to start MySQL. Please check your configuration.
[Entrypoint] 2020-08-11T08:32:10.807114Z 0 [ERROR] unknown option '--invalid-option'
2020-08-11T08:32:10.810425Z 0 [ERROR] Aborting
[11 Aug 2020 9:15] MySQL Verification Team
Hello tanaka-San,

Thank you for the report and contribution.

regards,
Umesh
[12 Aug 2020 7:37] Terje Røsten
Hi!

Can you please cut and paste the patch as comment?

Current patch seems to be borken in some way.
[12 Aug 2020 7:39] Lars Tangvald
Posted by developer:
 
Thanks for the report!

When the --validate-config option was added to 8.0 (but not 5.6 and 5.7) we added the method for verifying the config as a variable to the template, but the entry used for the older versions contains an unescaped &, which is sed replaces with the name of the variable, garbling the command. Simply escaping the ampersand should fix this.

Note that the supplied patch seems corrupted
[12 Aug 2020 9:05] tsubasa tanaka
Sorry for broken patch.

diff --git a/5.6/docker-entrypoint.sh b/5.6/docker-entrypoint.sh
index d1b8f30..628f952 100755
--- a/5.6/docker-entrypoint.sh
+++ b/5.6/docker-entrypoint.sh
@@ -35,7 +35,7 @@ if [ "$1" = 'mysqld' ]; then
        # Test that the server can start. We redirect stdout to /dev/null so
        # only the error messages are left.
        result=0
-       output=$("$@" --verbose --help 2>%%VALIDATE_CONFIG%%1 > /dev/null) || result=$?
+       output=$("$@" --verbose --help 2>&1 > /dev/null) || result=$?
        if [ ! "$result" = "0" ]; then
                echo >&2 '[Entrypoint] ERROR: Unable to start MySQL. Please check your configuration.'
                echo >&2 "[Entrypoint] $output"
diff --git a/5.7/docker-entrypoint.sh b/5.7/docker-entrypoint.sh
index 45d13ab..b667658 100755
--- a/5.7/docker-entrypoint.sh
+++ b/5.7/docker-entrypoint.sh
@@ -35,7 +35,7 @@ if [ "$1" = 'mysqld' ]; then
        # Test that the server can start. We redirect stdout to /dev/null so
        # only the error messages are left.
        result=0
-       output=$("$@" --verbose --help 2>%%VALIDATE_CONFIG%%1 > /dev/null) || result=$?
+       output=$("$@" --verbose --help 2>&1 > /dev/null) || result=$?
        if [ ! "$result" = "0" ]; then
                echo >&2 '[Entrypoint] ERROR: Unable to start MySQL. Please check your configuration.'
                echo >&2 "[Entrypoint] $output"
[12 Aug 2020 9:06] tsubasa tanaka
Previous patch is broken

(*) I confirm the code being submitted is offered under the terms of the OCA, and that I am authorized to contribute it.

Contribution: bug100490.patch (application/octet-stream, text), 1.24 KiB.

[12 Aug 2020 9:06] tsubasa tanaka
Sorry, fixed again..

(*) I confirm the code being submitted is offered under the terms of the OCA, and that I am authorized to contribute it.

Contribution: bug100490.patch (application/octet-stream, text), 1.23 KiB.

[12 Aug 2020 9:07] tsubasa tanaka
Sorry for my mistakes..