tarantool / tarantool / 11441338438

87%

push

github

config: expose configured names

Fixes #10308

@TarantoolBot document
Title: Configured names in `config:info()` and `box.info.config`

An instance in the YAML configuration always has a name and always
corresponds to a particular replicaset and a particular group. This is
forced by the hierarchical configuration format.

These names are now reported in `config:info()` and `box.info.config`.

```yaml
# tarantool> config:info()
# or
# tarantool> config:info('v2')
# or
# tarantool> box.info.config
---
- <..status, alerts, meta..>
  hierarchy:
    group: group-001
    replicaset: replicaset-001
    instance: instance-001
...
```

The `hierarchy` field is an empty table if tarantool is started with a
Lua script or in the interactive mode without a script/a config.

Usually `box.info.name` equals to `box.info.config.hierarchy.instance`,
but there are situations, when only one of them is reported.

`box.info.config.hierarchy.instance` corresponds to the *configured*
instance name and it is reported when the YAML configuration is in use.
This instance name is written to the database as well, but the write
operation is postponed if the database schema version is lower then
needed to support the persistent names (see [1] for details).

A user can meet this situation while running tarantool 3.x on data from
tarantool 2.x, before the upgrading procedure is performed.

On the other hand, a user may use the persistent names feature (see [2])
together with the classic approach, when tarantool is run without the
configuration file, using a Lua script. In this case,
`box.info.config.hierarchy` is empty, but `box.info.name` shows the name
passed to `box.cfg({instance_name = <...>})` (and written to the
database).

The same is applicable to `box.info.replicaset.name` and
`box.info.config.hierarchy.replicaset`.

[1]: https://github.com/tarantool/doc/issues/4592
[2]: https://github.com/tarantool/doc/issues/3468

69169 of 122859 branches covered (56.3%)

101970 of 116761 relevant lines covered (87.33%)

2614268.89 hits per line