Revert "Feature 11071: Modular OSM installation. Remove charms, juju and lxd"

This reverts commit a0f0d8ef4f2aa0dd227ecb651002490b66498bab.

Change-Id: I92394e4074dad4e457c107c58e4ebc17d507f8b2
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/installers/charm/mongodb-exporter/src/charm.py b/installers/charm/mongodb-exporter/src/charm.py
new file mode 100755
index 0000000..0ee127c
--- /dev/null
+++ b/installers/charm/mongodb-exporter/src/charm.py
@@ -0,0 +1,275 @@
+#!/usr/bin/env python3
+# 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
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+##
+
+# pylint: disable=E0213
+
+from ipaddress import ip_network
+import logging
+from pathlib import Path
+from typing import NoReturn, Optional
+from urllib.parse import urlparse
+
+from ops.main import main
+from opslib.osm.charm import CharmedOsmBase, RelationsMissing
+from opslib.osm.interfaces.grafana import GrafanaDashboardTarget
+from opslib.osm.interfaces.mongo import MongoClient
+from opslib.osm.interfaces.prometheus import PrometheusScrapeTarget
+from opslib.osm.pod import (
+    ContainerV3Builder,
+    IngressResourceV3Builder,
+    PodRestartPolicy,
+    PodSpecV3Builder,
+)
+from opslib.osm.validator import ModelValidator, validator
+
+
+logger = logging.getLogger(__name__)
+
+PORT = 9216
+
+
+class ConfigModel(ModelValidator):
+    site_url: Optional[str]
+    cluster_issuer: Optional[str]
+    ingress_class: Optional[str]
+    ingress_whitelist_source_range: Optional[str]
+    tls_secret_name: Optional[str]
+    mongodb_uri: Optional[str]
+    image_pull_policy: str
+    security_context: bool
+
+    @validator("site_url")
+    def validate_site_url(cls, v):
+        if v:
+            parsed = urlparse(v)
+            if not parsed.scheme.startswith("http"):
+                raise ValueError("value must start with http")
+        return v
+
+    @validator("ingress_whitelist_source_range")
+    def validate_ingress_whitelist_source_range(cls, v):
+        if v:
+            ip_network(v)
+        return v
+
+    @validator("mongodb_uri")
+    def validate_mongodb_uri(cls, v):
+        if v and not v.startswith("mongodb://"):
+            raise ValueError("mongodb_uri is not properly formed")
+        return v
+
+    @validator("image_pull_policy")
+    def validate_image_pull_policy(cls, v):
+        values = {
+            "always": "Always",
+            "ifnotpresent": "IfNotPresent",
+            "never": "Never",
+        }
+        v = v.lower()
+        if v not in values.keys():
+            raise ValueError("value must be always, ifnotpresent or never")
+        return values[v]
+
+
+class MongodbExporterCharm(CharmedOsmBase):
+    def __init__(self, *args) -> NoReturn:
+        super().__init__(*args, oci_image="image")
+
+        # Provision Kafka relation to exchange information
+        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)
+
+        # Register relation to provide a Scraping Target
+        self.scrape_target = PrometheusScrapeTarget(self, "prometheus-scrape")
+        self.framework.observe(
+            self.on["prometheus-scrape"].relation_joined, self._publish_scrape_info
+        )
+
+        # Register relation to provide a Dasboard Target
+        self.dashboard_target = GrafanaDashboardTarget(self, "grafana-dashboard")
+        self.framework.observe(
+            self.on["grafana-dashboard"].relation_joined, self._publish_dashboard_info
+        )
+
+    def _publish_scrape_info(self, event) -> NoReturn:
+        """Publishes scraping information for Prometheus.
+
+        Args:
+            event (EventBase): Prometheus relation event.
+        """
+        if self.unit.is_leader():
+            hostname = (
+                urlparse(self.model.config["site_url"]).hostname
+                if self.model.config["site_url"]
+                else self.model.app.name
+            )
+            port = str(PORT)
+            if self.model.config.get("site_url", "").startswith("https://"):
+                port = "443"
+            elif self.model.config.get("site_url", "").startswith("http://"):
+                port = "80"
+
+            self.scrape_target.publish_info(
+                hostname=hostname,
+                port=port,
+                metrics_path="/metrics",
+                scrape_interval="30s",
+                scrape_timeout="15s",
+            )
+
+    def _publish_dashboard_info(self, event) -> NoReturn:
+        """Publish dashboards for Grafana.
+
+        Args:
+            event (EventBase): Grafana relation event.
+        """
+        if self.unit.is_leader():
+            self.dashboard_target.publish_info(
+                name="osm-mongodb",
+                dashboard=Path("templates/mongodb_exporter_dashboard.json").read_text(),
+            )
+
+    def _check_missing_dependencies(self, config: ConfigModel):
+        """Check if there is any relation missing.
+
+        Args:
+            config (ConfigModel): object with configuration information.
+
+        Raises:
+            RelationsMissing: if kafka is missing.
+        """
+        missing_relations = []
+
+        if not config.mongodb_uri and self.mongodb_client.is_missing_data_in_unit():
+            missing_relations.append("mongodb")
+
+        if missing_relations:
+            raise RelationsMissing(missing_relations)
+
+    def build_pod_spec(self, image_info):
+        """Build the PodSpec to be used.
+
+        Args:
+            image_info (str): container image information.
+
+        Returns:
+            Dict: PodSpec information.
+        """
+        # Validate config
+        config = ConfigModel(**dict(self.config))
+
+        if config.mongodb_uri and not self.mongodb_client.is_missing_data_in_unit():
+            raise Exception("Mongodb data cannot be provided via config and relation")
+
+        # Check relations
+        self._check_missing_dependencies(config)
+
+        unparsed = (
+            config.mongodb_uri
+            if config.mongodb_uri
+            else self.mongodb_client.connection_string
+        )
+        parsed = urlparse(unparsed)
+        mongodb_uri = f"mongodb://{parsed.netloc.split(',')[0]}{parsed.path}"
+        if parsed.query:
+            mongodb_uri += f"?{parsed.query}"
+
+        # Create Builder for the PodSpec
+        pod_spec_builder = PodSpecV3Builder(
+            enable_security_context=config.security_context
+        )
+
+        # Add secrets to the pod
+        mongodb_secret_name = f"{self.app.name}-mongodb-secret"
+        pod_spec_builder.add_secret(mongodb_secret_name, {"uri": mongodb_uri})
+
+        # Build container
+        container_builder = ContainerV3Builder(
+            self.app.name,
+            image_info,
+            config.image_pull_policy,
+            run_as_non_root=config.security_context,
+        )
+        container_builder.add_port(name="exporter", port=PORT)
+        container_builder.add_http_readiness_probe(
+            path="/api/health",
+            port=PORT,
+            initial_delay_seconds=10,
+            period_seconds=10,
+            timeout_seconds=5,
+            success_threshold=1,
+            failure_threshold=3,
+        )
+        container_builder.add_http_liveness_probe(
+            path="/api/health",
+            port=PORT,
+            initial_delay_seconds=60,
+            timeout_seconds=30,
+            failure_threshold=10,
+        )
+
+        container_builder.add_secret_envs(mongodb_secret_name, {"MONGODB_URI": "uri"})
+        container = container_builder.build()
+
+        # Add container to PodSpec
+        pod_spec_builder.add_container(container)
+
+        # Add Pod restart policy
+        restart_policy = PodRestartPolicy()
+        restart_policy.add_secrets(secret_names=(mongodb_secret_name,))
+        pod_spec_builder.set_restart_policy(restart_policy)
+
+        # Add ingress resources to PodSpec if site url exists
+        if config.site_url:
+            parsed = urlparse(config.site_url)
+            annotations = {}
+            if config.ingress_class:
+                annotations["kubernetes.io/ingress.class"] = config.ingress_class
+            ingress_resource_builder = IngressResourceV3Builder(
+                f"{self.app.name}-ingress", annotations
+            )
+
+            if config.ingress_whitelist_source_range:
+                annotations[
+                    "nginx.ingress.kubernetes.io/whitelist-source-range"
+                ] = config.ingress_whitelist_source_range
+
+            if config.cluster_issuer:
+                annotations["cert-manager.io/cluster-issuer"] = config.cluster_issuer
+
+            if parsed.scheme == "https":
+                ingress_resource_builder.add_tls(
+                    [parsed.hostname], config.tls_secret_name
+                )
+            else:
+                annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
+
+            ingress_resource_builder.add_rule(parsed.hostname, self.app.name, PORT)
+            ingress_resource = ingress_resource_builder.build()
+            pod_spec_builder.add_ingress_resource(ingress_resource)
+
+        return pod_spec_builder.build()
+
+
+if __name__ == "__main__":
+    main(MongodbExporterCharm)
diff --git a/installers/charm/mongodb-exporter/src/pod_spec.py b/installers/charm/mongodb-exporter/src/pod_spec.py
new file mode 100644
index 0000000..ff42e02
--- /dev/null
+++ b/installers/charm/mongodb-exporter/src/pod_spec.py
@@ -0,0 +1,305 @@
+#!/usr/bin/env python3
+# 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
+# a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# For those usages not covered by the Apache License, Version 2.0 please
+# contact: legal@canonical.com
+#
+# To get in touch with the maintainers, please contact:
+# osm-charmers@lists.launchpad.net
+##
+
+from ipaddress import ip_network
+import logging
+from typing import Any, Dict, List
+from urllib.parse import urlparse
+
+logger = logging.getLogger(__name__)
+
+
+def _validate_ip_network(network: str) -> bool:
+    """Validate IP network.
+
+    Args:
+        network (str): IP network range.
+
+    Returns:
+        bool: True if valid, false otherwise.
+    """
+    if not network:
+        return True
+
+    try:
+        ip_network(network)
+    except ValueError:
+        return False
+
+    return True
+
+
+def _validate_data(config_data: Dict[str, Any], relation_data: Dict[str, Any]) -> bool:
+    """Validates passed information.
+
+    Args:
+        config_data (Dict[str, Any]): configuration information.
+        relation_data (Dict[str, Any]): relation information
+
+    Raises:
+        ValueError: when config and/or relation data is not valid.
+    """
+    config_validators = {
+        "site_url": lambda value, _: isinstance(value, str)
+        if value is not None
+        else True,
+        "cluster_issuer": lambda value, _: isinstance(value, str)
+        if value is not None
+        else True,
+        "ingress_whitelist_source_range": lambda value, _: _validate_ip_network(value),
+        "tls_secret_name": lambda value, _: isinstance(value, str)
+        if value is not None
+        else True,
+    }
+    relation_validators = {
+        "mongodb_connection_string": lambda value, _: (
+            isinstance(value, str) and value.startswith("mongodb://")
+        )
+    }
+    problems = []
+
+    for key, validator in config_validators.items():
+        valid = validator(config_data.get(key), config_data)
+
+        if not valid:
+            problems.append(key)
+
+    for key, validator in relation_validators.items():
+        valid = validator(relation_data.get(key), relation_data)
+
+        if not valid:
+            problems.append(key)
+
+    if len(problems) > 0:
+        raise ValueError("Errors found in: {}".format(", ".join(problems)))
+
+    return True
+
+
+def _make_pod_ports(port: int) -> List[Dict[str, Any]]:
+    """Generate pod ports details.
+
+    Args:
+        port (int): port to expose.
+
+    Returns:
+        List[Dict[str, Any]]: pod port details.
+    """
+    return [
+        {
+            "name": "mongo-exporter",
+            "containerPort": port,
+            "protocol": "TCP",
+        }
+    ]
+
+
+def _make_pod_envconfig(
+    config: Dict[str, Any], relation_state: Dict[str, Any]
+) -> Dict[str, Any]:
+    """Generate pod environment configuration.
+
+    Args:
+        config (Dict[str, Any]): configuration information.
+        relation_state (Dict[str, Any]): relation state information.
+
+    Returns:
+        Dict[str, Any]: pod environment configuration.
+    """
+    parsed = urlparse(relation_state.get("mongodb_connection_string"))
+
+    envconfig = {
+        "MONGODB_URI": f"mongodb://{parsed.netloc.split(',')[0]}{parsed.path}",
+    }
+
+    if parsed.query:
+        envconfig["MONGODB_URI"] += f"?{parsed.query}"
+
+    return envconfig
+
+
+def _make_pod_ingress_resources(
+    config: Dict[str, Any], app_name: str, port: int
+) -> List[Dict[str, Any]]:
+    """Generate pod ingress resources.
+
+    Args:
+        config (Dict[str, Any]): configuration information.
+        app_name (str): application name.
+        port (int): port to expose.
+
+    Returns:
+        List[Dict[str, Any]]: pod ingress resources.
+    """
+    site_url = config.get("site_url")
+
+    if not site_url:
+        return
+
+    parsed = urlparse(site_url)
+
+    if not parsed.scheme.startswith("http"):
+        return
+
+    ingress_whitelist_source_range = config["ingress_whitelist_source_range"]
+    cluster_issuer = config["cluster_issuer"]
+
+    annotations = {}
+
+    if ingress_whitelist_source_range:
+        annotations[
+            "nginx.ingress.kubernetes.io/whitelist-source-range"
+        ] = ingress_whitelist_source_range
+
+    if cluster_issuer:
+        annotations["cert-manager.io/cluster-issuer"] = cluster_issuer
+
+    ingress_spec_tls = None
+
+    if parsed.scheme == "https":
+        ingress_spec_tls = [{"hosts": [parsed.hostname]}]
+        tls_secret_name = config["tls_secret_name"]
+        if tls_secret_name:
+            ingress_spec_tls[0]["secretName"] = tls_secret_name
+    else:
+        annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
+
+    ingress = {
+        "name": "{}-ingress".format(app_name),
+        "annotations": annotations,
+        "spec": {
+            "rules": [
+                {
+                    "host": parsed.hostname,
+                    "http": {
+                        "paths": [
+                            {
+                                "path": "/",
+                                "backend": {
+                                    "serviceName": app_name,
+                                    "servicePort": port,
+                                },
+                            }
+                        ]
+                    },
+                }
+            ]
+        },
+    }
+    if ingress_spec_tls:
+        ingress["spec"]["tls"] = ingress_spec_tls
+
+    return [ingress]
+
+
+def _make_readiness_probe(port: int) -> Dict[str, Any]:
+    """Generate readiness probe.
+
+    Args:
+        port (int): service port.
+
+    Returns:
+        Dict[str, Any]: readiness probe.
+    """
+    return {
+        "httpGet": {
+            "path": "/api/health",
+            "port": port,
+        },
+        "initialDelaySeconds": 10,
+        "periodSeconds": 10,
+        "timeoutSeconds": 5,
+        "successThreshold": 1,
+        "failureThreshold": 3,
+    }
+
+
+def _make_liveness_probe(port: int) -> Dict[str, Any]:
+    """Generate liveness probe.
+
+    Args:
+        port (int): service port.
+
+    Returns:
+        Dict[str, Any]: liveness probe.
+    """
+    return {
+        "httpGet": {
+            "path": "/api/health",
+            "port": port,
+        },
+        "initialDelaySeconds": 60,
+        "timeoutSeconds": 30,
+        "failureThreshold": 10,
+    }
+
+
+def make_pod_spec(
+    image_info: Dict[str, str],
+    config: Dict[str, Any],
+    relation_state: Dict[str, Any],
+    app_name: str = "mongodb-exporter",
+    port: int = 9216,
+) -> Dict[str, Any]:
+    """Generate the pod spec information.
+
+    Args:
+        image_info (Dict[str, str]): Object provided by
+                                     OCIImageResource("image").fetch().
+        config (Dict[str, Any]): Configuration information.
+        relation_state (Dict[str, Any]): Relation state information.
+        app_name (str, optional): Application name. Defaults to "ro".
+        port (int, optional): Port for the container. Defaults to 9090.
+
+    Returns:
+        Dict[str, Any]: Pod spec dictionary for the charm.
+    """
+    if not image_info:
+        return None
+
+    _validate_data(config, relation_state)
+
+    ports = _make_pod_ports(port)
+    env_config = _make_pod_envconfig(config, relation_state)
+    readiness_probe = _make_readiness_probe(port)
+    liveness_probe = _make_liveness_probe(port)
+    ingress_resources = _make_pod_ingress_resources(config, app_name, port)
+
+    return {
+        "version": 3,
+        "containers": [
+            {
+                "name": app_name,
+                "imageDetails": image_info,
+                "imagePullPolicy": "Always",
+                "ports": ports,
+                "envConfig": env_config,
+                "kubernetes": {
+                    "readinessProbe": readiness_probe,
+                    "livenessProbe": liveness_probe,
+                },
+            }
+        ],
+        "kubernetesResources": {
+            "ingressResources": ingress_resources or [],
+        },
+    }