Fix NoClassDefFoundError when opening notifications

[HoussemNasri]

What does this PR change?

The problem is that Class#forName can throw a LinkageError or ExceptionInInitializerError which wouldn't be caught by the current catch statement. Eventually, since configureMailer() is called during class initialization, the exception will be caught by the classloader and translated into NoClassDefFoundError. However, I still don't know why exactly an Error was thrown in the first place nor I can reproduce the other behaviors reported like the WebUI not responding.

To reproduce, replace the content of configureMailer() with throw new LinkageError();, and then try to visit the notifications page. In the logs, you'll get a similar exception to what was reported in the linked issue. One difference is that the exception starts from prepareUserNotifications not dataUnread.

GUI diff

No difference.

• DONE

Documentation

• No documentation needed.

• DONE

Test coverage

• No tests.

• DONE

Links

Fixes #6918

• DONE

Changelogs

Make sure the changelogs entries you are adding are compliant with https://github.com/uyuni-project/uyuni/wiki/Contributing#changelogs and https://github.com/uyuni-project/uyuni/wiki/Contributing#uyuni-projectuyuni-repository

If you don't need a changelog check, please mark this checkbox:

• No changelog needed

If you uncheck the checkbox after the PR is created, you will need to re-run changelog_test (see below)

Re-run a test

If you need to re-run a test, please mark the related checkbox, it will be unchecked automatically once it has re-run:

• Re-run test "changelog_test"
• Re-run test "backend_unittests_pgsql"
• Re-run test "java_pgsql_tests"
• Re-run test "schema_migration_test_pgsql"
• Re-run test "susemanager_unittests"
• Re-run test "javascript_lint"
• Re-run test "spacecmd_unittests"

[github-actions]

Suggested tests to cover this Pull Request

• minssh_salt_install_package
• min_deblike_monitoring
• srv_power_management
• min_salt_mgrcompat_state
• srv_sync_channels
• proxy_cobbler_pxeboot
• allcli_software_channels_dependencies
• srv_content_lifecycle
• minkvm_guests
• srv_task_status_engine
• srv_patches_page
• srv_logfile
• srv_rename_hostname
• srv_docker_cve_audit
• srv_enable_sync_products
• srv_create_repository
• srv_cobbler_profile
• min_empty_system_profiles
• min_ansible_control_node
• srv_reportdb
• min_retracted_patches
• srv_add_rocky8_repositories
• srv_organization_credentials
• allcli_reboot
• min_bootstrap_ssh_key
• srv_manage_activationkey
• srv_security
• min_deblike_salt_install_package
• buildhost_docker_build_image
• srv_custom_system_info
• minssh_bootstrap_api
• srv_advanced_search
• srv_cobbler_distro
• srv_scc_user_credentials
• min_rhlike_ssh
• allcli_update_activationkeys
• srv_datepicker
• min_salt_openscap_audit
• srv_change_password
• srv_user_preferences
• srv_cobbler_sync
• min_salt_install_with_staging
• allcli_config_channel
• min_salt_software_states
• srv_channels_add
• min_bootstrap_api
• min_bootstrap_reactivation
• min_rhlike_monitoring
• srv_distro_cobbler
• min_rhlike_salt_install_package_and_patch
• min_config_state_channel_api
• buildhost_osimage_build_image
• srv_group_union_intersection
• allcli_action_chain
• min_salt_pkgset_beacon
• buildhost_bootstrap
• proxy_branch_network
• srv_virtual_host_manager
• min_cve_id_new_syntax
• min_deblike_ssh
• srv_check_channels_page
• srv_dist_channel_mapping
• min_config_state_channel
• srv_change_task_schedule
• min_salt_minions_page
• srv_delete_channel_with_tool
• srv_notifications
• min_deblike_remote_command
• sle_ssh_minion
• srv_wait_for_reposync
• srv_salt
• min_custom_pkg_download_endpoint
• allcli_software_channels
• srv_maintenance_windows
• sle_minion
• srv_cobbler_buildiso
• minssh_move_from_and_to_proxy
• srv_users
• srv_user_api
• srv_push_package
• min_docker_api
• srv_check_sync_source_packages
• srv_sync_products
• allcli_system_group
• srv_handle_config_channels_with_ISS_v2
• srv_delete_channel_from_ui
• srv_restart
• srv_power_management_redfish
• srv_user_configuration_salt_states
• min_bootstrap_negative
• min_activationkey
• srv_clone_channel_npn
• min_rhlike_salt
• min_salt_formulas_advanced
• srv_handle_software_channels_with_ISS_v2
• srv_manage_channels_page
• srv_mainpage
• min_salt_migration
• min_recurring_action
• proxy_as_pod_basic_tests
• min_salt_minion_details
• min_salt_lock_packages
• min_deblike_openscap_audit
• srv_menu_filter
• srv_check_reposync
• min_check_patches_install
• min_virthost
• srv_power_management_api
• min_move_from_and_to_proxy
• min_project_lotus
• min_config_state_channel_subscriptions
• srv_payg_ssh_connection
• min_timezone
• min_salt_user_states
• srv_activationkey_api
• minssh_ansible_control_node
• min_deblike_salt
• srv_docker
• buildhost_docker_auth_registry
• srv_monitoring
• min_deblike_salt_install_with_staging
• min_cve_audit
• min_rhlike_remote_command
• srv_channel_api
• proxy_retail_pxeboot_and_mass_import
• min_bootstrap_script
• min_rhlike_openscap_audit
• srv_docker_advanced_content_management
• srv_salt_download_endpoint
• proxy_register_as_minion_with_script
• min_salt_install_package
• srv_menu
• min_monitoring
• min_change_software_channel
• min_action_chain
• srv_osimage
• srv_first_settings
• minssh_action_chain
• srv_create_activationkey
• min_salt_formulas
• allcli_overview_systems_details
• srv_disable_local_repos_off
• min_ssh_tunnel
• allcli_sanity

[mcalmer]

@HoussemNasri can you rebase this branch on top of current master. I think some of the SonarCloud errors will go away.

[HoussemNasri]

SonarCloud is not complaining anymore, but one cucumber test failed.

[mcalmer]

SonarCloud is not complaining anymore, but one cucumber test failed.

That is a known race condition. I rerun the test. Likely it will succeed this time.

[HoussemNasri]

@mcalmer Rerunning did the job, all checks have passed now. Any other changes to add to the PR?

[mcalmer]

master branch is currently "blocked" as we try to release uyuni 2023.09. As soon as it is opened again, I can merge this.
I have also some PRs open which wait for this :-)