Merge branch 'squid-cnf-quickstart' into 'master'

Add packages for squid KDU in vnf-onboarding quickstarts

See merge request !157

config.yaml

+apiVersion: v1
+clusters:
+- cluster:
+    certificate-authority-data: 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
+    server: https://192.168.0.12:16443
+  name: microk8s-cluster
+contexts:
+- context:
+    cluster: microk8s-cluster
+    user: admin
+  name: microk8s
+current-context: microk8s
+kind: Config
+preferences: {}
+users:
+- name: admin
+  user:
+    token: Nk5McmtVRFo2ZjdoQU9oVmdSOHcxVUJ4U0FycDBmSzVDZHJSaTF2L29vMD0K

squid_metrics_cnf/juju-bundles/bundle.yaml

+description: Squid Bundle
+bundle: kubernetes
+applications:
+  squid:
+    charm: ./charms/squid-operator
+    scale: 1
+    options:
+      enable-exporter: true
+  # prometheus:
+  #   charm: ./charms/prometheus-operator
+  #   scale: 1
+  # grafana:
+  #   charm: ./charms/grafana-operator
+  #   scale: 1
+# relations:
+# - - prometheus:target
+#   - squid:prometheus-target
+# - - grafana:grafana-source
+#   - prometheus:grafana-source

squid_metrics_cnf/juju-bundles/charms/grafana-operator/.flake8

+[flake8]
+max-line-length = 99
+select: E,W,F,C,N
+exclude:
+  venv
+  .git
+  build
+  dist
+  *.egg_info

squid_metrics_cnf/juju-bundles/charms/grafana-operator/.gitignore

+build
+*.charm
+.idea
+__pycache__

squid_metrics_cnf/juju-bundles/charms/grafana-operator/README.md

+# Grafana Charm
+
+## Description
+
+This is the Grafana charm for Kubernetes using the Operator Framework.
+
+## Usage
+
+Initial setup (ensure microk8s is a clean slate with `microk8s.reset` or a fresh install with `snap install microk8s --classic`:
+```bash
+microk8s.enable dns storage registry dashboard
+juju bootstrap microk8s mk8s
+juju add-model lma
+juju create-storage-pool operator-storage kubernetes storage-class=microk8s-hostpath
+```
+
+Deploy Grafana on its own:
+```bash
+git clone git@github.com:canonical/grafana-operator.git
+cd grafana-operator
+charmcraft build
+juju deploy ./grafana.charm --resource grafana-image=grafana/grafana:7.2.1
+```
+
+View the dashboard in a browser:
+1. `juju status` to check the IP of the of the running Grafana application
+2. Navigate to `http://IP_ADDRESS:3000`
+3. Log in with the default credentials username=admin, password=admin.
+
+Add Prometheus as a datasource:
+```bash
+git clone git@github.com:canonical/prometheus-operator.git
+cd prometheus-operator
+charmcraft build
+juju deploy ./prometheus.charm
+juju add-relation grafana prometheus
+watch -c juju status --color  # wait for things to settle down
+```
+> Once the deployed charm and relation settles, you should be able to see Prometheus data propagating to the Grafana dashboard.
+
+### High Availability Grafana
+
+This charm is written to support a high-availability Grafana cluster, but a database relation is required (MySQL or Postgresql).
+
+If HA is not required, there is no need to add a database relation.
+
+> NOTE: HA should not be considered for production use.
+
+...
+
+## Developing
+
+Create and activate a virtualenv,
+and install the development requirements,
+
+    virtualenv -p python3 venv
+    source venv/bin/activate
+    pip install -r requirements-dev.txt
+
+## Testing
+
+Just run `run_tests`:
+
+    ./run_tests

squid_metrics_cnf/juju-bundles/charms/grafana-operator/config.yaml

+options:
+    port:
+        description: The port grafana will be listening on
+        type: int
+        default: 3000
+    grafana_log_level:
+        type: string
+        description: |
+            Logging level for Grafana. Options are “debug”, “info”,
+            “warn”, “error”, and “critical”.
+        default: info
\ No newline at end of file

squid_metrics_cnf/juju-bundles/charms/grafana-operator/dispatch

+#!/bin/sh
+
+JUJU_DISPATCH_PATH="${JUJU_DISPATCH_PATH:-$0}" PYTHONPATH=lib:venv ./src/charm.py

squid_metrics_cnf/juju-bundles/charms/grafana-operator/hooks/install

+../dispatch
\ No newline at end of file

squid_metrics_cnf/juju-bundles/charms/grafana-operator/hooks/start

+../dispatch
\ No newline at end of file

squid_metrics_cnf/juju-bundles/charms/grafana-operator/hooks/upgrade-charm

+../dispatch
\ No newline at end of file

squid_metrics_cnf/juju-bundles/charms/grafana-operator/icon.svg

+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Generator: Adobe Illustrator 23.0.4, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
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+<style type="text/css">
+	.st0{fill:url(#SVGID_1_);}
+</style>
+<linearGradient id="SVGID_1_" y2="28.783" gradientUnits="userSpaceOnUse" x2="42.562" y1="113.26" x1="42.562">
+	<stop stop-color="#FFF200" offset="0"/>
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+</linearGradient>
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squid_metrics_cnf/juju-bundles/charms/grafana-operator/manifest.yaml

+bases:
+- architectures:
+  - amd64
+  channel: '20.04'
+  name: ubuntu
+charmcraft-started-at: '2021-05-31T06:47:43.483382Z'
+charmcraft-version: 0.10.0

squid_metrics_cnf/juju-bundles/charms/grafana-operator/metadata.yaml

+name: grafana
+summary: Data visualization and observability with Grafana
+maintainers:
+    - Justin Clark <justin.clark@canonical.com>
+description: |
+    Grafana provides dashboards for monitoring data and this
+    charm is written to allow for HA on Kubernetes and can take
+    multiple data sources (for example, Prometheus).
+tags:
+    - lma
+    - grafana
+    - prometheus
+    - monitoring
+    - observability
+series:
+    - kubernetes
+provides:
+    grafana-source:
+        interface: grafana-datasource
+    grafana-dashboard:
+        interface: grafana-dash
+requires:
+    database:
+        interface: db
+        limit: 1
+peers:
+    grafana:
+        interface: grafana-peers
+storage:
+    sqlitedb:
+        type: filesystem
+        location: /var/lib/grafana
+deployment:
+    service: loadbalancer
\ No newline at end of file

squid_metrics_cnf/juju-bundles/charms/grafana-operator/requirements-dev.txt

+-r requirements.txt
+flake8

squid_metrics_cnf/juju-bundles/charms/grafana-operator/requirements.txt

+ops
+git+https://github.com/juju-solutions/resource-oci-image/@c5778285d332edf3d9a538f9d0c06154b7ec1b0b#egg=oci-image
\ No newline at end of file

squid_metrics_cnf/juju-bundles/charms/grafana-operator/run_tests

+#!/bin/sh -e
+# Copyright 2020 Justin
+# See LICENSE file for licensing details.
+
+if [ -z "$VIRTUAL_ENV" -a -d venv/ ]; then
+    . venv/bin/activate
+fi
+
+if [ -z "$PYTHONPATH" ]; then
+    export PYTHONPATH=src
+else
+    export PYTHONPATH="src:$PYTHONPATH"
+fi
+
+flake8
+python3 -m unittest -v "$@"

squid_metrics_cnf/juju-bundles/charms/grafana-operator/src/charm.py

+#! /usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+import logging
+import hashlib
+import textwrap
+
+from oci_image import OCIImageResource, OCIImageResourceError
+from ops.charm import CharmBase
+from ops.framework import StoredState
+from ops.main import main
+from ops.model import ActiveStatus, MaintenanceStatus, BlockedStatus
+
+log = logging.getLogger()
+
+
+# These are the required and optional relation data fields
+# In other words, when relating to this charm, these are the fields
+# that will be processed by this charm.
+REQUIRED_DATASOURCE_FIELDS = {
+    'private-address',  # the hostname/IP of the data source server
+    'port',  # the port of the data source server
+    'source-type',  # the data source type (e.g. prometheus)
+}
+
+OPTIONAL_DATASOURCE_FIELDS = {
+    'source-name',  # a human-readable name of the source
+}
+
+# https://grafana.com/docs/grafana/latest/administration/configuration/#database
+REQUIRED_DATABASE_FIELDS = {
+    'type',  # mysql, postgres or sqlite3 (sqlite3 doesn't work for HA)
+    'host',  # in the form '<url_or_ip>:<port>', e.g. 127.0.0.1:3306
+    'name',
+    'user',
+    'password',
+}
+
+# verify with Grafana documentation to ensure fields have valid values
+# as this charm will not directly handle these cases
+# TODO: fill with optional fields
+OPTIONAL_DATABASE_FIELDS = set()
+
+VALID_DATABASE_TYPES = {'mysql', 'postgres', 'sqlite3'}
+
+
+def get_container(pod_spec, container_name):
+    """Find and return the first container in pod_spec whose name is
+    container_name, otherwise return None."""
+    for container in pod_spec['containers']:
+        if container['name'] == container_name:
+            return container
+    raise ValueError("Unable to find container named '{}' in pod spec".format(
+        container_name))
+
+
+class GrafanaK8s(CharmBase):
+    """Charm to run Grafana on Kubernetes.
+
+    This charm allows for high-availability
+    (as long as a non-sqlite database relation is present).
+
+    Developers of this charm should be aware of the Grafana provisioning docs:
+    https://grafana.com/docs/grafana/latest/administration/provisioning/
+    """
+
+    datastore = StoredState()
+
+    def __init__(self, *args):
+        log.debug('Initializing charm.')
+        super().__init__(*args)
+
+        # -- get image information
+        self.image = OCIImageResource(self, 'grafana-image')
+
+        # -- standard hooks
+        self.framework.observe(self.on.config_changed, self.on_config_changed)
+        self.framework.observe(self.on.update_status, self.on_update_status)
+        self.framework.observe(self.on.stop, self._on_stop)
+
+        # -- grafana-source relation observations
+        self.framework.observe(self.on['grafana-source'].relation_changed,
+                               self.on_grafana_source_changed)
+        self.framework.observe(self.on['grafana-source'].relation_broken,
+                               self.on_grafana_source_broken)
+
+        # -- grafana (peer) relation observations
+        self.framework.observe(self.on['grafana'].relation_changed,
+                               self.on_peer_changed)
+        # self.framework.observe(self.on['grafana'].relation_departed,
+        #                        self.on_peer_departed)
+
+        # -- database relation observations
+        self.framework.observe(self.on['database'].relation_changed,
+                               self.on_database_changed)
+        self.framework.observe(self.on['database'].relation_broken,
+                               self.on_database_broken)
+
+        # -- initialize states --
+        self.datastore.set_default(sources=dict())  # available data sources
+        self.datastore.set_default(source_names=set())  # unique source names
+        self.datastore.set_default(sources_to_delete=set())
+        self.datastore.set_default(database=dict())  # db configuration
+
+    @property
+    def has_peer(self) -> bool:
+        rel = self.model.get_relation('grafana')
+        return len(rel.units) > 0 if rel is not None else False
+
+    @property
+    def has_db(self) -> bool:
+        """Only consider a DB connection if we have config info."""
+        return len(self.datastore.database) > 0
+
+    def _on_stop(self, _):
+        """Go into maintenance state if the unit is stopped."""
+        self.unit.status = MaintenanceStatus('Pod is terminating.')
+
+    def on_config_changed(self, _):
+        self.configure_pod()
+
+    def on_update_status(self, _):
+        """Various health checks of the charm."""
+        self._check_high_availability()
+
+    def on_grafana_source_changed(self, event):
+        """ Get relation data for Grafana source and set k8s pod spec.
+
+        This event handler (if the unit is the leader) will get data for
+        an incoming grafana-source relation and make the relation data
+        is available in the app's datastore object (StoredState).
+        """
+
+        # if this unit is the leader, set the required data
+        # of the grafana-source in this charm's datastore
+        if not self.unit.is_leader():
+            return
+
+        # if there is no available unit, remove data-source info if it exists
+        if event.unit is None:
+            log.warning("event unit can't be None when setting data sources.")
+            return
+
+        # dictionary of all the required/optional datasource field values
+        # using this as a more generic way of getting data source fields
+        datasource_fields = \
+            {field: event.relation.data[event.unit].get(field) for field in
+             REQUIRED_DATASOURCE_FIELDS | OPTIONAL_DATASOURCE_FIELDS}
+
+        missing_fields = [field for field
+                          in REQUIRED_DATASOURCE_FIELDS
+                          if datasource_fields.get(field) is None]
+        # check the relation data for missing required fields
+        if len(missing_fields) > 0:
+            log.error("Missing required data fields for grafana-source "
+                      "relation: {}".format(missing_fields))
+            self._remove_source_from_datastore(event.relation.id)
+            return
+
+        # specifically handle optional fields if necessary
+        # check if source-name was not passed or if we have already saved the provided name
+        if datasource_fields['source-name'] is None\
+                or datasource_fields['source-name'] in self.datastore.source_names:
+            default_source_name = '{}_{}'.format(
+                event.app.name,
+                event.relation.id
+            )
+            log.warning("No name 'grafana-source' or provided name is already in use. "
+                        "Using safe default: {}.".format(default_source_name))
+            datasource_fields['source-name'] = default_source_name
+
+        self.datastore.source_names.add(datasource_fields['source-name'])
+
+        # set the first grafana-source as the default (needed for pod config)
+        # if `self.datastore.sources` is currently empty, this is the first
+        datasource_fields['isDefault'] = 'false'
+        if not dict(self.datastore.sources):
+            datasource_fields['isDefault'] = 'true'
+
+        # add unit name so the source can be removed might be a
+        # duplicate of 'source-name', but this will guarantee lookup
+        datasource_fields['unit_name'] = event.unit.name
+
+        # add the new datasource relation data to the current state
+        new_source_data = {
+            field: value for field, value in datasource_fields.items()
+            if value is not None
+        }
+        self.datastore.sources.update({event.relation.id: new_source_data})
+        self.configure_pod()
+
+    def on_grafana_source_broken(self, event):
+        """When a grafana-source is removed, delete from the datastore."""
+        if self.unit.is_leader():
+            self._remove_source_from_datastore(event.relation.id)
+        self.configure_pod()
+
+    def on_peer_changed(self, _):
+        # TODO: https://grafana.com/docs/grafana/latest/tutorials/ha_setup/
+        #       According to these docs ^, as long as we have a DB, HA should
+        #       work out of the box if we are OK with "Sticky Sessions"
+        #       but having "Stateless Sessions" could require more config
+
+        # if the config changed, set a new pod spec
+        self.configure_pod()
+
+    def on_peer_departed(self, _):
+        """Sets pod spec with new info."""
+        # TODO: setting pod spec shouldn't do anything now,
+        #       but if we ever need to change config based peer units,
+        #       we will want to make sure configure_pod() is called
+        self.configure_pod()
+
+    def on_database_changed(self, event):
+        """Sets configuration information for database connection."""
+        if not self.unit.is_leader():
+            return
+
+        if event.unit is None:
+            log.warning("event unit can't be None when setting db config.")
+            return
+
+        # save the necessary configuration of this database connection
+        database_fields = \
+            {field: event.relation.data[event.unit].get(field) for field in
+             REQUIRED_DATABASE_FIELDS | OPTIONAL_DATABASE_FIELDS}
+
+        # if any required fields are missing, warn the user and return
+        missing_fields = [field for field
+                          in REQUIRED_DATABASE_FIELDS
+                          if database_fields.get(field) is None]
+        if len(missing_fields) > 0:
+            log.error("Missing required data fields for related database "
+                      "relation: {}".format(missing_fields))
+            return
+
+        # check if the passed database type is not in VALID_DATABASE_TYPES
+        if database_fields['type'] not in VALID_DATABASE_TYPES:
+            log.error('Grafana can only accept databases of the following '
+                      'types: {}'.format(VALID_DATABASE_TYPES))
+            return
+
+        # add the new database relation data to the datastore
+        self.datastore.database.update({
+            field: value for field, value in database_fields.items()
+            if value is not None
+        })
+        self.configure_pod()
+
+    def on_database_broken(self, _):
+        """Removes database connection info from datastore.
+
+        We are guaranteed to only have one DB connection, so clearing
+        datastore.database is all we need for the change to be propagated
+        to the pod spec."""
+        if not self.unit.is_leader():
+            return
+
+        # remove the existing database info from datastore
+        self.datastore.database = dict()
+
+        # set pod spec because datastore config has changed
+        self.configure_pod()
+
+    def _remove_source_from_datastore(self, rel_id):
+        """Remove the grafana-source from the datastore.
+
+        Once removed from the datastore, this datasource will not
+        part of the next pod spec."""
+        log.info('Removing all data for relation: {}'.format(rel_id))
+        removed_source = self.datastore.sources.pop(rel_id, None)
+        if removed_source is None:
+            log.warning('Could not remove source for relation: {}'.format(
+                rel_id))
+        else:
+            # free name from charm's set of source names
+            # and save to set which will be used in set_pod_spec
+            self.datastore.source_names.remove(removed_source['source-name'])
+            self.datastore.sources_to_delete.add(removed_source['source-name'])
+
+    def _check_high_availability(self):
+        """Checks whether the configuration allows for HA."""
+        if self.has_peer:
+            if self.has_db:
+                log.info('high availability possible.')
+                status = MaintenanceStatus('Grafana ready for HA.')
+            else:
+                log.warning('high availability not possible '
+                            'with current configuration.')
+                status = BlockedStatus('Need database relation for HA.')
+        else:
+            log.info('running Grafana on single node.')
+            status = MaintenanceStatus('Grafana ready on single node.')
+
+        # make sure we don't have a maintenance status overwrite
+        # a currently active status
+        if isinstance(status, MaintenanceStatus) \
+                and isinstance(self.unit.status, ActiveStatus):
+            return status
+
+        self.unit.status = status
+        return status
+
+    def _make_delete_datasources_config_text(self) -> str:
+        """Generate text of data sources to delete."""
+        if not self.datastore.sources_to_delete:
+            return "\n"
+
+        delete_datasources_text = textwrap.dedent("""
+        deleteDatasources:""")
+        for name in self.datastore.sources_to_delete:
+            delete_datasources_text += textwrap.dedent("""
+            - name: {}
+              orgId: 1""".format(name))
+
+        # clear datastore.sources_to_delete and return text result
+        self.datastore.sources_to_delete.clear()
+        return delete_datasources_text + '\n\n'
+
+    def _make_data_source_config_text(self) -> str:
+        """Build config based on Data Sources section of provisioning docs."""
+        # get starting text for the config file and sources to delete
+        delete_text = self._make_delete_datasources_config_text()
+        config_text = textwrap.dedent("""
+        apiVersion: 1
+        """)
+        config_text += delete_text
+        if self.datastore.sources:
+            config_text += "datasources:"
+        for rel_id, source_info in self.datastore.sources.items():
+            # TODO: handle more optional fields and verify that current
+            #       defaults are what we want (e.g. "access")
+            config_text += textwrap.dedent("""
+                - name: {0}
+                  type: {1}
+                  access: proxy
+                  url: http://{2}:{3}
+                  isDefault: {4}
+                  editable: true
+                  orgId: 1""").format(
+                source_info['source-name'],
+                source_info['source-type'],
+                source_info['private-address'],
+                source_info['port'],
+                source_info['isDefault'],
+            )
+
+        # check if there these are empty
+        return config_text + '\n'
+
+    def _update_pod_data_source_config_file(self, pod_spec):
+        """Adds datasources to pod configuration."""
+        file_text = self._make_data_source_config_text()
+        data_source_file_meta = {
+            'name': 'grafana-datasources',
+            'mountPath': '/etc/grafana/provisioning/datasources',
+            'files': [{
+                'path': 'datasources.yaml',
+                'content': file_text,
+            }]
+        }
+        container = get_container(pod_spec, self.app.name)
+        container['volumeConfig'].append(data_source_file_meta)
+
+        # get hash string of the new file text and put into container config
+        # if this changes, it will trigger a pod restart
+        file_text_hash = hashlib.md5(file_text.encode()).hexdigest()
+        if 'DATASOURCES_YAML' in container['envConfig'] \
+                and container['envConfig']['DATASOURCES_YAML'] != file_text_hash:
+            log.info('datasources.yaml hash has changed. '
+                     'Triggering pod restart.')
+        container['envConfig']['DATASOURCES_YAML'] = file_text_hash
+
+    def _make_config_ini_text(self):
+        """Create the text of the config.ini file.
+
+        More information about this can be found in the Grafana docs:
+        https://grafana.com/docs/grafana/latest/administration/configuration/
+        """
+
+        config_text = textwrap.dedent("""
+        [paths]
+        provisioning = /etc/grafana/provisioning
+
+        [log]
+        mode = console
+        level = {0}
+        """.format(
+            self.model.config['grafana_log_level'],
+        ))
+
+        # if there is a database available, add that information
+        if self.datastore.database:
+            db_config = self.datastore.database
+            config_text += textwrap.dedent("""
+            [database]
+            type = {0}
+            host = {1}
+            name = {2}
+            user = {3}
+            password = {4}
+            url = {0}://{3}:{4}@{1}/{2}""".format(
+                db_config['type'],
+                db_config['host'],
+                db_config['name'],
+                db_config['user'],
+                db_config['password'],
+            ))
+        return config_text
+
+    def _update_pod_config_ini_file(self, pod_spec):
+        file_text = self._make_config_ini_text()
+        config_ini_file_meta = {
+            'name': 'grafana-config-ini',
+            'mountPath': '/etc/grafana',
+            'files': [{
+                'path': 'grafana.ini',
+                'content': file_text
+            }]
+        }
+        container = get_container(pod_spec, self.app.name)
+        container['volumeConfig'].append(config_ini_file_meta)
+
+        # get hash string of the new file text and put into container config
+        # if this changes, it will trigger a pod restart
+        file_text_hash = hashlib.md5(file_text.encode()).hexdigest()
+        if 'GRAFANA_INI' in container['envConfig'] \
+                and container['envConfig']['GRAFANA_INI'] != file_text_hash:
+            log.info('grafana.ini hash has changed. Triggering pod restart.')
+        container['envConfig']['GRAFANA_INI'] = file_text_hash
+
+    def _build_pod_spec(self):
+        """Builds the pod spec based on available info in datastore`."""
+
+        config = self.model.config
+
+        spec = {
+            'version': 3,
+            'containers': [{
+                'name': self.app.name,
+                'image': "ubuntu/grafana:latest",
+                'ports': [{
+                    'containerPort': config['port'],
+                    'protocol': 'TCP'
+                }],
+                'volumeConfig': [],
+                'envConfig': {},  # used to store hashes of config file text
+                'kubernetes': {
+                    'readinessProbe': {
+                        'httpGet': {
+                            'path': '/api/health',
+                            'port': config['port']
+                        },
+                        'initialDelaySeconds': 10,
+                        'timeoutSeconds': 30
+                    },
+                },
+            }]
+        }
+
+        return spec
+
+    def configure_pod(self):
+        """Set Juju / Kubernetes pod spec built from `_build_pod_spec()`."""
+
+        # check for valid high availability (or single node) configuration
+        self._check_high_availability()
+
+        # in the case where we have peers but no DB connection,
+        # don't set the pod spec until it is resolved
+        if self.unit.status == BlockedStatus('Need database relation for HA.'):
+            log.error('Application is in a blocked state. '
+                      'Please resolve before pod spec can be set.')
+            return
+
+        if not self.unit.is_leader():
+            self.unit.status = ActiveStatus()
+            return
+
+        # general pod spec component updates
+        self.unit.status = MaintenanceStatus('Building pod spec.')
+        pod_spec = self._build_pod_spec()
+        if not pod_spec:
+            return
+        self._update_pod_data_source_config_file(pod_spec)
+        self._update_pod_config_ini_file(pod_spec)
+
+        # set the pod spec with Juju
+        self.model.pod.set_spec(pod_spec)
+        self.unit.status = ActiveStatus()
+
+
+if __name__ == '__main__':
+    main(GrafanaK8s)