Figure out the Witness node UX

[davissp14]

The witness node is now functionally available, but there are a few things that need to be addressed before exposing it.

1. A 2+1 provision option needs to be added to flyctl along with the ability to provision a witness machine.
2. We should consider adding a one-off flyctl command that allows users to add a witness node to their existing setup.
3. We need formal documentation going over the witness node and when/how it should be used.

Witness machine spec

• Same image as a normal member.
• WITNESS environment variable needs to be set.
• Minimal resource allocations. 1GB volume, 256mb memory, 1 cpu, etc.

[guillaumervls]

Can we set the machine resources (disk, cpu, memory...) with fly machine clone? If so we can do 2. with it, right?

[davissp14]

Can we set the machine resources (disk, cpu, memory...) with fly machine clone?

We cannot. The fly machine clone will duplicate the spec of the target machine. This is great for horizontally scaling members, but we wouldn't be able to use it to spin up a witness. You could in theory spin-up two witnesses, but it wouldn't provide any real value. That being said, it would probably make sense to restrict apps to a single witness.

[guillaumervls]

This can help superfly/flyctl#1938

[Ederene20]

Hi @davissp14! Can I work on this?