Offline Node Support

[Daniel-VDM]

This feature is needed for a correct deployment of a rosetta 'offline' node. That said, it is a perfectly reasonable feature to have on its own - rosetta notwithstanding. I imagine that it would great for debugging / devs.

One can run a node in offline mode by adding the --run.offline option. This option has been tested to be backwards compatible with older config files. It defaults to an 'online' setting if the option/config is not provided.

An offline node simply means that it does not sync & is not subscribed to any p2p topic or has any p2p peers.
I've had to keep some service instantiations to ensure other services don't crash from a nil pointer.

[JackyWYX]

I would suggest add the following logic:

1. If running in offline mode, force p2p to listen to address 127.0.0.1 (p2p/host.go:68) (It might be better to add a field IP in p2pConfig cmd/harmony/config.go:45).
2. If run in offline mode, instruct node.SyncingPeerProvider to use local network.

This can further prevent node from using network. Else the node is still using libp2p for peer discovery. Do you think this is reasonable?

[LeoHChen]

reasonable request by @JackyWYX , please fix them. thanks.

[Daniel-VDM]

I would suggest add the following logic:

1. If running in offline mode, force p2p to listen to address 127.0.0.1 (p2p/host.go:68) (It might be better to add a field IP in p2pConfig cmd/harmony/config.go:45).
2. If run in offline mode, instruct node.SyncingPeerProvider to use local network.

This can further prevent node from using network. Else the node is still using libp2p for peer discovery. Do you think this is reasonable?

Sure seems fair enough, added this logic and fixed related tests along the way.

[JackyWYX]

I think this is a public variable right? Comments are required for public stuff😂

…

On Fri, Oct 9, 2020 at 2:09 AM Daniel Van Der Maden < ***@***.***> wrote: ***@***.**** commented on this pull request. ------------------------------ In internal/configs/node/network.go <#3383 (comment)>: > @@ -39,6 +39,10 @@ const ( ) const ( + // DefaultLocalListenIP .. Ill remove it then — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#3383 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AJSNLCEZ3T6HV2C55PMA2VTSJ3HLNANCNFSM4SHISFHQ> .

[Daniel-VDM]

I think this is a public variable right? Comments are required for public stuff😂
…
On Fri, Oct 9, 2020 at 2:09 AM Daniel Van Der Maden < @.***> wrote: @Daniel-VDM commented on this pull request. ------------------------------ In internal/configs/node/network.go <#3383 (comment)>: > @@ -39,6 +39,10 @@ const ( ) const ( + // DefaultLocalListenIP .. Ill remove it then — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#3383 (comment)>, or unsubscribe https://github.com/notifications/unsubscribe-auth/AJSNLCEZ3T6HV2C55PMA2VTSJ3HLNANCNFSM4SHISFHQ .

Yea... updated the comment right after

[JackyWYX]

Nice!