diff --git a/installers/charm/ro/src/charm.py b/installers/charm/ro/src/charm.py
index 8e6d576..ae92d98 100755
--- a/installers/charm/ro/src/charm.py
+++ b/installers/charm/ro/src/charm.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# Copyright 2020 Canonical Ltd.
+# Copyright 2021 Canonical Ltd.
 #
 # Licensed under the Apache License, Version 2.0 (the "License"); you may
 # not use this file except in compliance with the License. You may obtain
@@ -20,116 +20,73 @@
 # osm-charmers@lists.launchpad.net
 ##
 
+# pylint: disable=E0213
+
 import logging
-from typing import Dict, List, NoReturn
+from typing import NoReturn
 
-from ops.charm import CharmBase
-from ops.framework import EventBase, StoredState
 from ops.main import main
-from ops.model import ActiveStatus, Application, BlockedStatus, MaintenanceStatus, Unit
-from oci_image import OCIImageResource, OCIImageResourceError
 
-from pod_spec import make_pod_spec
+from opslib.osm.charm import CharmedOsmBase, RelationsMissing
+
+from opslib.osm.pod import (
+    ContainerV3Builder,
+    PodSpecV3Builder,
+)
+
+
+from opslib.osm.validator import (
+    ModelValidator,
+    validator,
+)
+
+from opslib.osm.interfaces.kafka import KafkaClient
+from opslib.osm.interfaces.mysql import MysqlClient
+from opslib.osm.interfaces.mongo import MongoClient
+
 
 logger = logging.getLogger(__name__)
 
-RO_PORT = 9090
+PORT = 9090
 
 
-class RelationsMissing(Exception):
-    def __init__(self, missing_relations: List):
-        self.message = ""
-        if missing_relations and isinstance(missing_relations, list):
-            self.message += f'Waiting for {", ".join(missing_relations)} relation'
-            if "," in self.message:
-                self.message += "s"
+class ConfigModel(ModelValidator):
+    enable_ng_ro: bool
+    database_commonkey: str
+    log_level: str
+    vim_database: str
+    ro_database: str
+    openmano_tenant: str
+
+    @validator("log_level")
+    def validate_log_level(cls, v):
+        if v not in {"INFO", "DEBUG"}:
+            raise ValueError("value must be INFO or DEBUG")
+        return v
 
 
-class RelationDefinition:
-    def __init__(self, relation_name: str, keys: List, source_type):
-        if source_type != Application and source_type != Unit:
-            raise TypeError(
-                "source_type should be ops.model.Application or ops.model.Unit"
-            )
-        self.relation_name = relation_name
-        self.keys = keys
-        self.source_type = source_type
-
-
-def check_missing_relation_data(
-    data: Dict,
-    expected_relations_data: List[RelationDefinition],
-):
-    missing_relations = []
-    for relation_data in expected_relations_data:
-        if not all(
-            f"{relation_data.relation_name}_{k}" in data for k in relation_data.keys
-        ):
-            missing_relations.append(relation_data.relation_name)
-    if missing_relations:
-        raise RelationsMissing(missing_relations)
-
-
-def get_relation_data(
-    charm: CharmBase,
-    relation_data: RelationDefinition,
-) -> Dict:
-    data = {}
-    relation = charm.model.get_relation(relation_data.relation_name)
-    if relation:
-        self_app_unit = (
-            charm.app if relation_data.source_type == Application else charm.unit
-        )
-        expected_type = relation_data.source_type
-        for app_unit in relation.data:
-            if app_unit != self_app_unit and isinstance(app_unit, expected_type):
-                if all(k in relation.data[app_unit] for k in relation_data.keys):
-                    for k in relation_data.keys:
-                        data[f"{relation_data.relation_name}_{k}"] = relation.data[
-                            app_unit
-                        ].get(k)
-                    break
-    return data
-
-
-class RoCharm(CharmBase):
-    """RO Charm."""
-
-    state = StoredState()
+class RoCharm(CharmedOsmBase):
+    """GrafanaCharm Charm."""
 
     def __init__(self, *args) -> NoReturn:
-        """RO Charm constructor."""
-        super().__init__(*args)
+        """Prometheus Charm constructor."""
+        super().__init__(*args, oci_image="image")
 
-        # Internal state initialization
-        self.state.set_default(pod_spec=None)
+        self.kafka_client = KafkaClient(self, "kafka")
+        self.framework.observe(self.on["kafka"].relation_changed, self.configure_pod)
+        self.framework.observe(self.on["kafka"].relation_broken, self.configure_pod)
 
-        self.port = RO_PORT
-        self.image = OCIImageResource(self, "image")
+        self.mysql_client = MysqlClient(self, "mysql")
+        self.framework.observe(self.on["mysql"].relation_changed, self.configure_pod)
+        self.framework.observe(self.on["mysql"].relation_broken, self.configure_pod)
 
-        # Registering regular events
-        self.framework.observe(self.on.start, self.configure_pod)
-        self.framework.observe(self.on.config_changed, self.configure_pod)
+        self.mongodb_client = MongoClient(self, "mongodb")
+        self.framework.observe(self.on["mongodb"].relation_changed, self.configure_pod)
+        self.framework.observe(self.on["mongodb"].relation_broken, self.configure_pod)
 
-        # Registering required relation events
-        self.framework.observe(self.on.kafka_relation_changed, self.configure_pod)
-        self.framework.observe(self.on.mongodb_relation_changed, self.configure_pod)
-        self.framework.observe(self.on.mysql_relation_changed, self.configure_pod)
+        self.framework.observe(self.on["ro"].relation_joined, self._publish_ro_info)
 
-        # Registering required relation departed events
-        self.framework.observe(self.on.kafka_relation_departed, self.configure_pod)
-        self.framework.observe(self.on.mongodb_relation_departed, self.configure_pod)
-        self.framework.observe(self.on.mysql_relation_departed, self.configure_pod)
-
-        # Registering required relation broken events
-        self.framework.observe(self.on.kafka_relation_broken, self.configure_pod)
-        self.framework.observe(self.on.mongodb_relation_broken, self.configure_pod)
-        self.framework.observe(self.on.mysql_relation_broken, self.configure_pod)
-
-        # Registering provided relation events
-        self.framework.observe(self.on.ro_relation_joined, self._publish_ro_info)
-
-    def _publish_ro_info(self, event: EventBase) -> NoReturn:
+    def _publish_ro_info(self, event):
         """Publishes RO information.
 
         Args:
@@ -138,80 +95,91 @@
         if self.unit.is_leader():
             rel_data = {
                 "host": self.model.app.name,
-                "port": str(RO_PORT),
+                "port": str(PORT),
             }
             for k, v in rel_data.items():
                 event.relation.data[self.app][k] = v
 
-    @property
-    def relations_requirements(self):
-        if self.model.config["enable_ng_ro"]:
-            return [
-                RelationDefinition("kafka", ["host", "port"], Unit),
-                RelationDefinition("mongodb", ["connection_string"], Unit),
-            ]
+    def _check_missing_dependencies(self, config: ConfigModel):
+        missing_relations = []
+
+        if config.enable_ng_ro:
+            if self.kafka_client.is_missing_data_in_unit():
+                missing_relations.append("kafka")
+            if self.mongodb_client.is_missing_data_in_unit():
+                missing_relations.append("mongodb")
         else:
-            return [
-                RelationDefinition(
-                    "mysql", ["host", "port", "user", "password", "root_password"], Unit
-                )
-            ]
+            if self.mysql_client.is_missing_data_in_unit():
+                missing_relations.append("mysql")
+        if missing_relations:
+            raise RelationsMissing(missing_relations)
 
-    def get_relation_state(self):
-        relation_state = {}
-        for relation_requirements in self.relations_requirements:
-            data = get_relation_data(self, relation_requirements)
-            relation_state = {**relation_state, **data}
-        check_missing_relation_data(relation_state, self.relations_requirements)
-        return relation_state
-
-    def configure_pod(self, _=None) -> NoReturn:
-        """Assemble the pod spec and apply it, if possible.
-
-        Args:
-            event (EventBase): Hook or Relation event that started the
-                               function.
-        """
-        if not self.unit.is_leader():
-            self.unit.status = ActiveStatus("ready")
-            return
-
-        relation_state = None
-        try:
-            relation_state = self.get_relation_state()
-        except RelationsMissing as exc:
-            logger.exception("Relation missing error")
-            self.unit.status = BlockedStatus(exc.message)
-            return
-
-        self.unit.status = MaintenanceStatus("Assembling pod spec")
-
-        # Fetch image information
-        try:
-            self.unit.status = MaintenanceStatus("Fetching image information")
-            image_info = self.image.fetch()
-        except OCIImageResourceError:
-            self.unit.status = BlockedStatus("Error fetching image information")
-            return
-
-        try:
-            pod_spec = make_pod_spec(
-                image_info,
-                self.model.config,
-                relation_state,
-                self.model.app.name,
-                self.port,
+    def build_pod_spec(self, image_info):
+        # Validate config
+        config = ConfigModel(**dict(self.config))
+        # Check relations
+        self._check_missing_dependencies(config)
+        # Create Builder for the PodSpec
+        pod_spec_builder = PodSpecV3Builder()
+        # Build Container
+        container_builder = ContainerV3Builder(self.app.name, image_info)
+        container_builder.add_port(name=self.app.name, port=PORT)
+        container_builder.add_http_readiness_probe(
+            "/ro/" if config.enable_ng_ro else "/openmano/tenants",
+            PORT,
+            initial_delay_seconds=10,
+            period_seconds=10,
+            timeout_seconds=5,
+            failure_threshold=3,
+        )
+        container_builder.add_http_liveness_probe(
+            "/ro/" if config.enable_ng_ro else "/openmano/tenants",
+            PORT,
+            initial_delay_seconds=600,
+            period_seconds=10,
+            timeout_seconds=5,
+            failure_threshold=3,
+        )
+        container_builder.add_envs(
+            {
+                "OSMRO_LOG_LEVEL": config.log_level,
+            }
+        )
+        if config.enable_ng_ro:
+            container_builder.add_envs(
+                {
+                    "OSMRO_MESSAGE_DRIVER": "kafka",
+                    "OSMRO_MESSAGE_HOST": self.kafka_client.host,
+                    "OSMRO_MESSAGE_PORT": self.kafka_client.port,
+                    # MongoDB configuration
+                    "OSMRO_DATABASE_DRIVER": "mongo",
+                    "OSMRO_DATABASE_URI": self.mongodb_client.connection_string,
+                    "OSMRO_DATABASE_COMMONKEY": config.database_commonkey,
+                }
             )
-        except ValueError as exc:
-            logger.exception("Config/Relation data validation error")
-            self.unit.status = BlockedStatus(str(exc))
-            return
 
-        if self.state.pod_spec != pod_spec:
-            self.model.pod.set_spec(pod_spec)
-            self.state.pod_spec = pod_spec
-
-        self.unit.status = ActiveStatus("ready")
+        else:
+            container_builder.add_envs(
+                {
+                    "RO_DB_HOST": self.mysql_client.host,
+                    "RO_DB_OVIM_HOST": self.mysql_client.host,
+                    "RO_DB_PORT": self.mysql_client.port,
+                    "RO_DB_OVIM_PORT": self.mysql_client.port,
+                    "RO_DB_USER": self.mysql_client.user,
+                    "RO_DB_OVIM_USER": self.mysql_client.user,
+                    "RO_DB_PASSWORD": self.mysql_client.password,
+                    "RO_DB_OVIM_PASSWORD": self.mysql_client.password,
+                    "RO_DB_ROOT_PASSWORD": self.mysql_client.root_password,
+                    "RO_DB_OVIM_ROOT_PASSWORD": self.mysql_client.root_password,
+                    "RO_DB_NAME": config.ro_database,
+                    "RO_DB_OVIM_NAME": config.vim_database,
+                    "OPENMANO_TENANT": config.openmano_tenant,
+                }
+            )
+        container = container_builder.build()
+        # Add container to pod spec
+        pod_spec_builder.add_container(container)
+        return pod_spec_builder.build()
 
 
 if __name__ == "__main__":
diff --git a/installers/charm/ro/src/pod_spec.py b/installers/charm/ro/src/pod_spec.py
index 6c91baf..1beba17 100644
--- a/installers/charm/ro/src/pod_spec.py
+++ b/installers/charm/ro/src/pod_spec.py
@@ -45,8 +45,9 @@
         )
         if values.get("enable_ng_ro", True)
         else True,
-        "log_level": lambda value, _: isinstance(value, str)
-        and value in ("INFO", "DEBUG"),
+        "log_level": lambda value, _: (
+            isinstance(value, str) and value in ("INFO", "DEBUG")
+        ),
         "vim_database": lambda value, values: (
             isinstance(value, str) and len(value) > 0
         )