[DPE-2763] POC Status reporting shard side

[MiaAltieri]

Issue

Statuses are not properly reported for shards in update status hook

Solution

Report statuses

Testing

# deploy charms 
juju deploy ./*charm --config role="config-server" config-server-one 
juju deploy ./*charm --config role="shard" shard-one 
juju deploy ./*charm --config role="shard" shard-two 

# speed up frequency of status checks
juju model-config update-status-hook-interval=10s

# monitor `juju status --watch 1s`
Unit                  Workload  Agent  Machine  Public address  Ports            Message
config-server-one/0*  active    idle   2        10.61.64.75     27017-27018/tcp  Primary
shard-one/0*          blocked   idle   0        10.61.64.126    27017/tcp        missing relation to config server
shard-two/0*          blocked   idle   1        10.61.64.216    27017/tcp        missing relation to config server

# relate application
juju integrate config-server-one:config-server shard-one:sharding
juju integrate config-server-one:config-server shard-two:sharding

# monitor `juju status --watch 1s`
Unit                  Workload  Agent  Machine  Public address  Ports            Message
config-server-one/0*  active    idle   2        10.61.64.75     27017-27018/tcp  Primary
shard-one/0*          active    idle   0        10.61.64.126    27017/tcp        Shard connected to config-server: config-server-one
shard-two/0*          active    idle   1        10.61.64.216    27017/tcp        Shard connected to config-server: config-server-one

# remove a relation to shard
juju remove-relation config-server-one:config-server shard-two:sharding

# monitor `juju status --watch 1s`
config-server-one/0*  active    idle   0        10.61.64.50     27017-27018/tcp  Primary
shard-one/0*          active    idle   1        10.61.64.235    27017/tcp        Shard connected to config-server: config-server-one
shard-two/0*          active    idle   2        10.61.64.128    27017/tcp        Shard drained from cluster, ready for removal

# add non supported relation
cd mongodb-operator/tests/integration/relation_tests/new_relations/application-charm
charmcraft pack
juju deploy ./*charm
juju integrate shard-one application

# monitor `juju status --watch 1s`
application/0*        active    idle   3        10.61.64.203
config-server-one/0*  active    idle   0        10.61.64.43     27017-27018/tcp
shard-one/0*          blocked   idle   1        10.61.64.31     27017/tcp        Sharding roles do not support mongodb_client interface.
shard-two/0*          active    idle   2        10.61.64.239    27017/tcp

[Mehdi-Bendriss]

Great work Mia! just a few points / questions to clarify