Add relay routing capabilities

[pcarranza]

Not sure how easy this would be, but I would like to be able of having multiple relays with the same bundle, and then at runtime be able of picking which relay I want to execute a given command.

This could be particularly helpful for things like recovering database replication in only one of the secondaries -> I need to pick which host is the one executing the command.

The reason why I would also like to have this is because then I would not need to have any other form of login information to perform this kind of action - no ssh needed to execute a remote script.

[pcarranza]

cc/ @northrup

[davejlong]

I'll add 👍 to this. I would love to see support for routing to relays based on command structure. I have a few instances where I'd like to use Cog to run some commands at remote client sites by installing a Relay at those sites.

[nmohoric]

I've been thinking tonight about what would be needed for this so thought I'd put it in here.

• [ ] ability to assign command to multiple relays
• [ ] ability to set config per relay
• [ ] how to specify this at runtime (maybe bundle:command:relay? or a specific command? (ie !route "staging-relay" | command:bundle))
• [ ] a rule for this? (ie when option['env'] == 'staging' use 'staging-relay')