`tt cluster rs roles add` adds role in config scope provided by flags.

[TarantoolBot]

Product: tt cli
Since: tt 2.5.0
Audience/target: all
Root document: https://www.tarantool.io/en/doc/latest/reference/tooling/tt_cli/cluster/
SME: @ themilchenko @ oleg-jukovec

Details

This patch introduces new command for the cluster replicaset module:

tt cluster replicaset roles add <URI> <ROLE_NAME> [flags]

URI is a target configuration source (etcd/tcs). ROLE_NAME is a role for
adding to a Tarantool config storage. It is necessary to provide flag
with destination in config for role addition. It can be one or more
roles.

Command supports following flags:

• Flags for the destination of role addition:
  • --global (-G) for a global scope to add a role;
  • --instance (-i) string for an application name target to specify
    an instance to add a role;
  • --replicaset (-r) string for an application name target to specify
    a replicaset to add a role;
  • --group (-g) string for an application name target to specify a group.
• Common flag to interact with config storages (etcd / tarantool config
  storage):
  • --force (-f) to skip selecting a key for patching;
  • --username (-u) is a username (used as etcd/tarantool config
    storage credentials);
  • --password (-p) is a password (used as etcd/tarantool config
    storage credentials).

Closes #915
Requested by @themilchenko in tarantool/tt@6574a45.