### Start and enable Ceilometer services

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-compute-rdo.md

Starts the Ceilometer agent and configures it to start on system boot. Also starts and enables the optional IPMI service.

```bash
# systemctl enable openstack-ceilometer-compute.service
# systemctl start openstack-ceilometer-compute.service
# systemctl enable openstack-ceilometer-ipmi.service (optional)
# systemctl start openstack-ceilometer-ipmi.service (optional)
```

--------------------------------

### Install Ceilometer packages

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Installs the necessary ceilometer agent packages using apt-get.

```console
# apt-get install ceilometer-agent-notification \
  ceilometer-agent-central
```

--------------------------------

### Install Gnocchi packages

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Installs the Gnocchi API, metric daemon, and client using apt-get.

```bash
# apt-get install gnocchi-api gnocchi-metricd python3-gnocchiclient
```

--------------------------------

### Install uWSGI packages

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Installs uWSGI packages required for the Gnocchi API.

```bash
# apt-get install uwsgi-plugin-python3 uwsgi
```

--------------------------------

### Start and enable Ceilometer services

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-rdo.md

Starts the Ceilometer notification and central services and configures them to start on system boot.

```bash
# systemctl enable openstack-ceilometer-notification.service \
  openstack-ceilometer-central.service
# systemctl start openstack-ceilometer-notification.service \
  openstack-ceilometer-central.service
```

--------------------------------

### Enable and start Gnocchi services

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-rdo.md

Enables the Gnocchi API and metricd services to start on boot and then starts them.

```bash
# systemctl enable gnocchi-api.service gnocchi-metricd.service
# systemctl start gnocchi-api.service gnocchi-metricd.service
```

--------------------------------

### Install tox

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/contributor/testing.md

Command to install the tox testing tool.

```bash
$ sudo pip install tox

```

--------------------------------

### Initialize Gnocchi

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Runs the Gnocchi database upgrade command.

```bash
gnocchi-upgrade
```

--------------------------------

### Create ceilometer user

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Creates the 'ceilometer' user and displays its details.

```bash
$ openstack user create --domain default --password-prompt ceilometer
User Password:
Repeat User Password:
+-----------+----------------------------------+
| Field     | Value                            |
+-----------+----------------------------------+
| domain_id | e0353a670a9e496da891347c589539e9 |
| enabled   | True                             |
| id        | c859c96f57bd4989a8ea1a0b1d8ff7cd |
| name      | ceilometer                       |
+-----------+----------------------------------+
```

--------------------------------

### Install ceilometer-agent-compute and ceilometer-agent-ipmi

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-compute-ubuntu.md

Installs the necessary Ceilometer agent packages for compute nodes.

```bash
# apt-get install ceilometer-agent-compute
# apt-get install ceilometer-agent-ipmi (optional)
```

--------------------------------

### Install python-ceilometermiddleware package

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/swift/install-swift-ubuntu.md

Install the necessary Python package for Ceilometer middleware.

```bash
# apt-get install python-ceilometermiddleware
```

--------------------------------

### Create ceilometer service entity

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Creates the 'ceilometer' service entity with type 'metering'.

```bash
$ openstack service create --name ceilometer \
  --description "Telemetry" metering
+-------------+----------------------------------+
| Field       | Value                            |
+-------------+----------------------------------+
| description | Telemetry                        |
| enabled     | True                             |
| id          | 5fb7fd1bb2954fddb378d4031c28c0e4 |
| name        | ceilometer                       |
| type        | metering                         |
+-------------+----------------------------------+
```

--------------------------------

### Create Gnocchi database

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Creates a new database named 'gnocchi'.

```sql
CREATE DATABASE gnocchi;
```

--------------------------------

### Create Ceilometer resources in Gnocchi

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Runs the ceilometer-upgrade command to create necessary resources in Gnocchi.

```console
# ceilometer-upgrade
```

--------------------------------

### Install Ceilometer packages

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-rdo.md

Installs the notification and central packages for Ceilometer using dnf.

```bash
# dnf install openstack-ceilometer-notification \
  openstack-ceilometer-central
```

--------------------------------

### Connect to MySQL database

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Connects to the MySQL server as the root user.

```bash
$ mysql -u root -p
```

--------------------------------

### Install Ceilometer compute packages

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-compute-rdo.md

Installs the necessary Ceilometer compute packages, including an optional IPMI package.

```bash
# dnf install openstack-ceilometer-compute
# dnf install openstack-ceilometer-ipmi (optional)
```

--------------------------------

### Create gnocchi user

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Creates the 'gnocchi' user and displays its details.

```bash
$ openstack user create --domain default --password-prompt gnocchi
User Password:
Repeat User Password:
+-----------+----------------------------------+
| Field     | Value                            |
+-----------+----------------------------------+
| domain_id | e0353a670a9e496da891347c589539e9 |
| enabled   | True                             |
| id        | 8bacd064f6434ef2b6bbfbedb79b0318 |
| name      | gnocchi                          |
+-----------+----------------------------------+
```

--------------------------------

### Example Definitions File

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/contributor/events.md

An example YAML file defining event types and traits, including nested structures and trait plugins.

```yaml
---
- event_type: compute.instance.*
  traits: &instance_traits
    user_id:
      fields: payload.user_id
    instance_id:
      fields: payload.instance_id
    host:
      fields: publisher_id
      plugin:
        name: split
        parameters:
          segment: 1
          max_split: 1
    service_name:
      fields: publisher_id
      plugin: split
    instance_type_id:
      type: int
      fields: payload.instance_type_id
    os_architecture:
      fields: payload.image_meta.'org.openstack__1__architecture'
    launched_at:
      type: datetime
      fields: payload.launched_at
    deleted_at:
      type: datetime
      fields: payload.deleted_at
- event_type:
    - compute.instance.exists
    - compute.instance.update
  traits:
    <<: *instance_traits
    audit_period_beginning:
      type: datetime
      fields: payload.audit_period_beginning
    audit_period_ending:
      type: datetime
      fields: payload.audit_period_ending

```

--------------------------------

### Install uWSGI packages

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-rdo.md

Installs the necessary uWSGI packages for running the Gnocchi API.

```bash
# dnf install uwsgi-plugin-common uwsgi-plugin-python3 uwsgi
```

--------------------------------

### Install Gnocchi packages

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-rdo.md

Installs the Gnocchi API, metric daemon, and client using dnf.

```bash
# dnf install gnocchi-api gnocchi-metricd python3-gnocchiclient
```

--------------------------------

### Create Metric Endpoint

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

This snippet shows how to create an OpenStack endpoint for the metric service and the resulting output.

```bash
     | url          | http://controller:8041           |
     +--------------+----------------------------------+

     $ openstack endpoint create --region RegionOne \
       metric admin http://controller:8041
     +--------------+----------------------------------+
     | Field        | Value                            |
     +--------------+----------------------------------+
     | enabled      | True                             |
     | id           | b2c00566d0604551b5fe1540c699db3d |
     | interface    | admin                            |
     | region       | RegionOne                        |
     | region_id    | RegionOne                        |
     | service_id   | 205978b411674e5a9990428f81d69384 |
     | service_name | gnocchi                          |
     | service_type | metric                           |
     | url          | http://controller:8041           |
     +--------------+----------------------------------+
```

--------------------------------

### Install python3-ceilometermiddleware package

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/swift/install-swift-rdo.md

Install the necessary Python package for Ceilometer middleware.

```bash
# dnf install python3-ceilometermiddleware
```

--------------------------------

### Create public endpoint for Metric service

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Creates the public endpoint for the Metric service (Gnocchi).

```bash
$ openstack endpoint create --region RegionOne \
  metric public http://controller:8041
+--------------+----------------------------------+
| Field        | Value                            |
+--------------+----------------------------------+
| enabled      | True                             |
| id           | b808b67b848d443e9eaaa5e5d796970c |
| interface    | public                           |
| region       | RegionOne                        |
| region_id    | RegionOne                        |
| service_id   | 205978b411674e5a9990428f81d69384 |
| service_name | gnocchi                          |
| service_type | metric                           |
| url          | http://controller:8041           |
+--------------+----------------------------------+
```

--------------------------------

### Create gnocchi service entity

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Creates the 'gnocchi' service entity with type 'metric'.

```bash
$ openstack service create --name gnocchi \
  --description "Metric Service" metric
+-------------+----------------------------------+
| Field       | Value                            |
+-------------+----------------------------------+
| description | Metric Service                   |
| enabled     | True                             |
| id          | 205978b411674e5a9990428f81d69384 |
| name        | gnocchi                          |
| type        | metric                           |
+-------------+----------------------------------+
```

--------------------------------

### Restart Gnocchi services

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Restarts the Apache and Gnocchi metricd services.

```bash
# systemctl restart apache2
# systemctl restart gnocchi-metricd
```

--------------------------------

### Restart Telemetry services

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Restarts the ceilometer agent services.

```console
# systemctl restart ceilometer-agent-central
# systemctl restart ceilometer-agent-notification
```

--------------------------------

### Create internal endpoint for Metric service

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Creates the internal endpoint for the Metric service (Gnocchi).

```bash
$ openstack endpoint create --region RegionOne \
  metric internal http://controller:8041
+--------------+----------------------------------+
| Field        | Value                            |
+--------------+----------------------------------+
| enabled      | True                             |
| id           | c7009b1c2ee54b71b771fa3d0ae4f948 |
| interface    | internal                         |
| region       | RegionOne                        |
| region_id    | RegionOne                        |
| service_id   | 205978b411674e5a9990428f81d69384 |
| service_name | gnocchi                          |
| service_type | metric                           |

```

--------------------------------

### Configure Ceilometer service credentials

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Configures service credentials for Ceilometer in the [service_credentials] section of /etc/ceilometer/ceilometer.conf.

```ini
[service_credentials]
...
auth_type = password
auth_url = http://controller:5000/v3
project_domain_id = default
user_domain_id = default
project_name = service
username = ceilometer
password = CEILOMETER_PASS
interface = internalURL
region_name = RegionOne
```

--------------------------------

### Add admin role to ceilometer user

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/install-base-ubuntu.md

Adds the 'admin' role to the 'ceilometer' user for the 'service' project.

```bash
$ openstack role add --project service --user ceilometer admin
```

--------------------------------

### JSON response handler example

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/admin/telemetry-dynamic-pollster.md

Example of configuring the JSON response handler for dynamic pollsters.

```yaml
---

- name: "dynamic.json.response"
  sample_type: "gauge"
  [...]
  response_handlers:

```

--------------------------------

### Simple linked response example

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/admin/telemetry-dynamic-pollster.md

Example of a simple linked API response and its corresponding pollster configuration.

```json
{
  "server_link": "http://test.com/v1/test-volumes/marker=c3",
  "servers": [
    {
      "volume": [
        {
          "name": "a",
          "tmp": "ra"
        }
      ],
      "id": 1,
      "name": "a1"
    },
    {
      "volume": [
        {
          "name": "b",
          "tmp": "rb"
        }
      ],
      "id": 2,
      "name": "b2"
    },
    {
      "volume": [
        {
          "name": "c",
          "tmp": "rc"
        }
      ],
      "id": 3,
      "name": "c3"
    }
  ]
}
```

```yaml
---

- name: "dynamic.linked.response"
  sample_type: "gauge"
  unit: "request"
  value_attribute: "[volume].tmp"
  url_path: "v1/test-volumes"
  response_entries_key: "servers"
  next_sample_url_attribute: "server_link"
```

--------------------------------

### Configure keystoneauth section in proxy-server.conf

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/swift/install-swift-ubuntu.md

Add the ResellerAdmin role to the keystoneauth section in the swift proxy-server.conf file.

```ini
[filter:keystoneauth]
... 
operator_roles = admin, user, ResellerAdmin
```

--------------------------------

### Polling rule definition example

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/admin/telemetry-data-collection.md

Example of a polling.yaml file defining sources, intervals, meters, resources, and discovery.

```yaml
---
sources:
  - name: 'source name'
    interval: 'how often the samples should be generated'
    meters:
      - 'meter filter'
    resources:
      - 'list of resource URLs'
    discovery:
      - 'list of discoverers'
```

--------------------------------

### Example YAML for VPN connections data

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/admin/telemetry-dynamic-pollster.md

An example configuration to gather VPN connections data, adapting to different statuses.

```yaml
---

- name: "dynamic.network.services.vpn.connection"
  sample_type: "gauge"
  unit: "ipsec_site_connection"
  value_attribute: "status"
  endpoint_type: "network"
  url_path: "v2.0/vpn/ipsec-site-connections"
  metadata_fields:
      - "name"
      - "vpnservice_id"
      - "description"
      - "status"
      - "peer_address"
  value_mapping:
      ACTIVE: "1"
  metadata_mapping:
      name: "display_name"
  default_value: 0
```

--------------------------------

### Skip sample values example

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/admin/telemetry-dynamic-pollster.md

Example of skip_sample_values configuration for a dynamic pollster, defining values to ignore in the collected data.

```yaml
skip_sample_values:
  - "CREATE_FAILED"
  - "DELETE_FAILED"
```

--------------------------------

### Metadata fields example

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/admin/telemetry-dynamic-pollster.md

Example of metadata_fields configuration for a dynamic pollster, specifying which fields to retrieve from the component's response.

```yaml
metadata_fields:
  - "labels"
  - "updated_at"
  - "keypair"
  - "master_flavor_id"
  - "api_address"
  - "master_addresses"
  - "node_count"
  - "docker_volume_size"
  - "master_count"
  - "node_addresses"
  - "status_reason"
  - "coe_version"
  - "cluster_template_id"
  - "name"
  - "stack_id"
  - "created_at"
  - "discovery_url"
  - "container_version"
```

--------------------------------

### Complex linked response example

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/admin/telemetry-dynamic-pollster.md

Example of a complex linked API response (where the link is an object in a list) and its corresponding pollster configuration.

```json
{
  "server_link": [
    {
      "href": "http://test.com/v1/test-volumes/marker=c3",
      "rel": "next"
    },
    {
      "href": "http://test.com/v1/test-volumes/marker=b1",
      "rel": "prev"
    }
  ],
  "servers": [
    {
      "volume": [
        {
          "name": "a",
          "tmp": "ra"
        }
      ],
      "id": 1,
      "name": "a1"
    },
    {
      "volume": [
        {
          "name": "b",
          "tmp": "rb"
        }
      ],
      "id": 2,
      "name": "b2"
    },
    {
      "volume": [
        {
          "name": "c",
          "tmp": "rc"
        }
      ],
      "id": 3,
      "name": "c3"
    }
  ]
}
```

```yaml
---

- name: "dynamic.linked.response"
  sample_type: "gauge"
  unit: "request"
  value_attribute: "[volume].tmp"
  url_path: "v1/test-volumes"
  response_entries_key: "servers"
  next_sample_url_attribute: "server_link | filter(lambda v: v.get('rel') == 'next', value) | list(value) | value[0] | value.get('href')"
```

--------------------------------

### Value mapping example

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/admin/telemetry-dynamic-pollster.md

Example of value_mapping configuration for a dynamic pollster, mapping raw values to specific values for backend storage.

```yaml
value_mapping:
  CREATE_IN_PROGRESS: "0"
  CREATE_FAILED: "1"
  CREATE_COMPLETE: "2"
  UPDATE_IN_PROGRESS: "3"
  UPDATE_FAILED: "4"
  UPDATE_COMPLETE: "5"
  DELETE_IN_PROGRESS: "6"
  DELETE_FAILED: "7"
  DELETE_COMPLETE: "8"
  RESUME_COMPLETE: "9"
  RESUME_FAILED: "10"
  RESTORE_COMPLETE: "11"
  ROLLBACK_IN_PROGRESS: "12"
  ROLLBACK_FAILED: "13"
  ROLLBACK_COMPLETE: "14"
  SNAPSHOT_COMPLETE: "15"
  CHECK_COMPLETE: "16"
  ADOPT_COMPLETE: "17"
```

--------------------------------

### RadosGW API JSON Response Example

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/admin/telemetry-dynamic-pollster.md

An example of a JSON response from the RadosGW API, illustrating the structure of user categories and summary data.

```json
{
    "entries": [
        {
            "buckets": [
                {
                    "bucket": "",
                    "categories": [
                        {
                            "bytes_received": 0,
                            "bytes_sent": 40,
                            "category": "list_buckets",
                            "ops": 2,
                            "successful_ops": 2
                        }
                    ],
                    "epoch": 1572969600,
                    "owner": "user",
                    "time": "2019-11-21 00:00:00.000000Z"
                },
                {
                    "bucket": "-",
                    "categories": [
                        {
                            "bytes_received": 0,
                            "bytes_sent": 0,
                            "category": "get_obj",
                            "ops": 1,
                            "successful_ops": 0
                        }
                    ],
                    "epoch": 1572969600,
                    "owner": "someOtherUser",
                    "time": "2019-11-21 00:00:00.000000Z"
                }
            ]
        }
    ]
    "summary": [
        {
            "categories": [
                {
                    "bytes_received": 0,
                    "bytes_sent": 0,
                    "category": "create_bucket",
                    "ops": 2,
                    "successful_ops": 2
                },
                {
                    "bytes_received": 0,
                    "bytes_sent": 2120428,
                    "category": "get_obj",
                    "ops": 46,
                    "successful_ops": 46
                },
                {
                    "bytes_received": 0,
                    "bytes_sent": 21484,
                    "category": "list_bucket",
                    "ops": 8,
                    "successful_ops": 8
                },
                {
                    "bytes_received": 6889056,
                    "bytes_sent": 0,
                    "category": "put_obj",
                    "ops": 46,
                    "successful_ops": 46
                }
            ],
            "total": {
                "bytes_received": 6889056,
                "bytes_sent": 2141912,
                "ops": 102,
                "successful_ops": 102
            },
            "user": "user"
        },
        {
            "categories": [
                {
                    "bytes_received": 0,
                    "bytes_sent": 0,
                    "category": "create_bucket",
                    "ops": 1,
                    "successful_ops": 1
                },
                {
                    "bytes_received": 0,
                    "bytes_sent": 0,
                    "category": "delete_obj",
                    "ops": 23,
                    "successful_ops": 23
                },
                {
                    "bytes_received": 0,
                    "bytes_sent": 5371,
                    "category": "list_bucket",
                    "ops": 2,
                    "successful_ops": 2
                },
                {
                    "bytes_received": 3444350,
                    "bytes_sent": 0,
                    "category": "put_obj",
                    "ops": 23,
                    "successful_ops": 23
                }
            ],
            "total": {
                "bytes_received": 3444350,
                "bytes_sent": 5371,
                "ops": 49,
                "successful_ops": 49
            },
            "user": "someOtherUser"
        }
    ]
}

```

--------------------------------

### Create ResellerAdmin role

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/install/swift/install-swift-ubuntu.md

Create the ResellerAdmin role for Object Storage access.

```bash
$ openstack role create ResellerAdmin
+-----------+----------------------------------+
| Field     | Value                            |
+-----------+----------------------------------+
| domain_id | None                             |
| id        | 462fa46c13fd4798a95a3bfbe27b5e54 |
| name      | ResellerAdmin                    |
+-----------+----------------------------------+
```

--------------------------------

### Metadata mapping example

Source: https://github.com/openstack/ceilometer/blob/master/doc/source/admin/telemetry-dynamic-pollster.md

Example of metadata_mapping configuration for a dynamic pollster, used to create new metadata fields from existing response data.

```yaml
metadata_mapping:
  name: "display_name"
  some_attribute: "new_attribute_name"
```

--------------------------------

### Running Unit Tests with tox

Source: https://github.com/openstack/ceilometer/blob/master/HACKING.rst

Examples of how to run unit tests using tox with different log capture and debug settings.

```bash
tox -e py3
```

```bash
OS_LOG_CAPTURE=1 OS_DEBUG=True tox -e py3
```

```bash
OS_LOG_CAPTURE=1 tox -e py3
```

```bash
tox -e py3
```