+++ This bug was initially created as a clone of Bug #1861868 +++

I would like to be able to detect if there are pending Candlepin database migrations to allow only running the migration task if there are. This helps the Satellite installer be idempotent.

[root@pipeline-upgrade-luna-nightly-centos7 candlepin]# ./cpdb --status --user=candlepin --password W7EkKTcVvT6W654kexPLFCQRNhDeoMxt
Configuring PostgreSQL with JDBC URL: jdbc:postgresql:candlepin
--driver=org.postgresql.Driver --classpath=/var/lib/tomcat/webapps/candlepin/WEB-INF/lib/postgresql-42.2.2.jar:/var/lib/tomcat/webapps/candlepin/WEB-INF/classes/ --url=jdbc:postgresql:candlepin --username=$DBUSERNAME --changeLogFile=db/changelog/changelog-update.xml --password=$DBPASSWORD --logLevel=severe
4 change sets have not been applied to candlepin@jdbc:postgresql:candlepin
     db/changelog/20140408160212-add-pool-source-sub-table.xml::20140408160212-4::ckozak
     db/changelog/20140408160212-add-pool-source-sub-table.xml::20140408160212-5::ckozak
     db/changelog/20150401140006-add-pool-type-to-db.xml::20150401140006-3::crog
     db/changelog/20170718095058-purge-orphaned-pools.xml::20170718095058-0::crog
Liquibase 'status' Successful

This would imply there are 4 changesets that need migrated and applied. If I then run 'migrate' I see it try to apply these changesets, mention "skip on failure" in the logs. This implies that this check will never return 0 as there are changsets that attempt to get applied, are skipped and the migration is OK with that.