Logging & Metrics for external smeshers

[pigmej]

We had few situations in the past that having the possibility to check logs and therefore evaluate network health and past events would be extremely helpful.

Therefore we need a remote logging (opt-in).

Implementation wise (not limited to)

• logging: support log collection from external smeshers go-spacemesh#3134

Infrastructure wise:

• https://github.com/spacemeshos/Infrastructure/issues/8
• https://github.com/spacemeshos/Infrastructure/issues/9
• https://github.com/spacemeshos/Infrastructure/issues/10

[pigmej]

Metrics done. Logging not. Logging is hard to do correctly in current architecture.