Ensure Migration APIs are up to date for 7.0

[gwbrown]

Context: We have the Migration Assistance API and the Migration Upgrade API to handle updating system indices as needed to make sure they are ready for a major version upgrade.

This issue is to track the process of ensuring that these APIs are up to date for any changes needed for upgrading from 6.x to 7.0. This may or may not actually involve any changes to those APIs. Could someone who is familiar with each of these features could verify whether or not there are any special upgrades needed, and if so, whether the upgrade procedure has been updated?

Security

• The upgrade procedure for .security is ready for the 6.x to 7.0 upgrade

Watcher

• The upgrade procedure for .watches and .triggered_watches is ready for the 6.x to 7.0 upgrade

[elasticmachine]

Pinging @elastic/es-security

[elasticmachine]

Pinging @elastic/es-core-features

[gwbrown]

@spinscale confirmed that no upgrades are needed for Watcher, and @tvernum confirmed that no upgrades are needed for Security. The only thing left to do on this is remove any upgrade code that may still be hanging around to make sure it won't break anything if the Upgrade API is used.

[gwbrown]

These APIs are good for 7.0, so I'm closing this issue. While they still run a script to ensure the documents are in the correct format, the scripts will not modify documents that are already in the correct shape. Therefore, I'm going to leave them in place to keep the infrastructure in place for when they need to be used in the future.