Unexpected error running Liquibase: java.lang.RuntimeException: Cannot find database driver: com.mysql.jdbc.Driver

Question

I installed Liquibase CLI using snap package manager on Kubuntu.

Invoking the following command results in a

liquibase calculateChecksum 2022-01-06-test.sql::1::bobby.tables --changeLogFile 2022-01-06-test.sql 
--url jdbc:mysql://localhost:3306 --username root --password password 
--driver com.mysql.jdbc.Driver --classpath ~/.m2/repository/mysql/mysql-connector-java/8.0.21/mysql-connector-java-8.0.21.jar

Results in a stacktrace (DEBUG)

liquibase.exception.DatabaseException: liquibase.exception.DatabaseException: java.lang.RuntimeException: Cannot find database driver: com.mysql.jdbc.Driver
        at liquibase.integration.commandline.CommandLineUtils.createDatabaseObject(CommandLineUtils.java:131)
        at liquibase.integration.commandline.Main.doMigration(Main.java:1408)
        at liquibase.integration.commandline.Main$1.lambda$run$0(Main.java:361)
        at liquibase.Scope.lambda$child$0(Scope.java:160)
        at liquibase.Scope.child(Scope.java:169)
        at liquibase.Scope.child(Scope.java:159)
        at liquibase.Scope.child(Scope.java:138)
        at liquibase.Scope.child(Scope.java:222)
        at liquibase.Scope.child(Scope.java:226)
        at liquibase.integration.commandline.Main$1.run(Main.java:360)
        at liquibase.integration.commandline.Main$1.run(Main.java:193)
        at liquibase.Scope.child(Scope.java:169)
        at liquibase.Scope.child(Scope.java:145)
        at liquibase.integration.commandline.Main.run(Main.java:193)
        at liquibase.integration.commandline.Main.main(Main.java:156)
Caused by: liquibase.exception.DatabaseException: java.lang.RuntimeException: Cannot find database driver: com.mysql.jdbc.Driver
        at liquibase.database.DatabaseFactory.openConnection(DatabaseFactory.java:250)
        at liquibase.database.DatabaseFactory.openDatabase(DatabaseFactory.java:140)
        at liquibase.integration.commandline.CommandLineUtils.createDatabaseObject(CommandLineUtils.java:96)
        ... 14 more
Caused by: java.lang.RuntimeException: Cannot find database driver: com.mysql.jdbc.Driver
        at liquibase.database.DatabaseFactory.openConnection(DatabaseFactory.java:192)
        ... 16 more

I am not using a liquibase.properties file as I just want to calculate an md5 hash sum, so I can compare it with a different md5 value.

Do I need to put the mysql.jar where the liquibase binary is?

If so, where does it live as a snap package?

Answer 1

It turns out Snap doesn't allow access to .m2 folder in the user's $HOME directory (which is madness/stupidity).

Therefore you need to give the liquibase snap access to the .m2 folder

To see where Liquibase can access:

snap connections liquibase

Which will print out this:

Interface        Plug                         Slot      Notes
home             liquibase:home               :home     -
network          liquibase:network            :network  -
personal-files   liquibase:dot-m2-repository  -         -
removable-media  liquibase:removable-media    -         -

Then run the following command to give Liquibase access to .m2 folder

sudo snap connect liquibase:dot-m2-repository

This should allow Liquibase to function properly.

Why this is not documented anywhere? I do not know...