Yaroslav Dynnikov authored 2 years ago and Yaroslav Dynnikov committed 2 years ago

Do it only when the governor tells to. When `_G.vshard == nil`, it's
more alike `traft::node::global()` which reurns either `Ok` or
`Err(Uninitialized)`.

Yaroslav Dynnikov authored 2 years ago and Yaroslav Dynnikov committed 2 years ago

It produces better error messages.

Before this commit:

```
tarantool> vshard.router.call()
---
- error: '[string "local log = require(''log'')..."]:575: attempt to
    compare number with nil'
...
```

With this commit:

```
- error: 'vshard/router/init.lua:575: attempt to compare number with
    nil'
```

Example:

```console
tarantool> picolib.whoami()
---
- raft_id: 1
  cluster_id: demo
  instance_id: i1
...

tarantool> picolib.peer_info("i1")
---
- raft_id: 1
  instance_id: i1
  instance_uuid: 68d4a766-4144-3248-aeb4-e212356716e4
  replicaset_uuid: e0df68c5-e7f9-395f-86b3-30ad9e1b7b07
  replicaset_id: r1
  advertise_address: localhost:3301
  target_grade: Online
  current_grade: Online
...
```