# Dependencies

When a driver is loaded into Engine, it becomes a *dependency*. Dependencies are available as the blueprint from which modules are created. The `/dependencies` endpoint provide methods to discover, load and update these. For more on the role the drivers play, see:

{% content-ref url="../../key-concepts/drivers" %}
[drivers](https://engine.place.technology/key-concepts/drivers)
{% endcontent-ref %}

## Model <a href="#model" id="model"></a>

| Attribute | Type | Description |
| --------- | ---- | ----------- |

| id | `string` | The dependency's unique ID. |
| -- | -------- | --------------------------- |

| name | `string` | Human readable name for the dependency. |
| ---- | -------- | --------------------------------------- |

| class\_name | `string` | The Ruby class name of the driver. |
| ----------- | -------- | ---------------------------------- |

| module\_name | `string` | The kind of module this instantiates (e.g. `Display`). |
| ------------ | -------- | ------------------------------------------------------ |

| role | `string` | One of `ssh`, `device`, `service`, or `logic`. |
| ---- | -------- | ---------------------------------------------- |

| description | `string` | Additional information that describes the dependency. |
| ----------- | -------- | ----------------------------------------------------- |

| default | <p><code>string</code> or</p><p><code>integer</code></p> | A URL or port number that is typical for modules using this. |
| ------- | -------------------------------------------------------- | ------------------------------------------------------------ |

| ignore\_connected | `boolean` | Default state of connectivity monitoring for instances. |
| ----------------- | --------- | ------------------------------------------------------- |

| settings | `object` | A JSON object containing configuration shared by all instances. |
| -------- | -------- | --------------------------------------------------------------- |

| created\_at | `integer` | Timestamp of creation. |
| ----------- | --------- | ---------------------- |

## Search

<mark style="color:blue;">`GET`</mark> `https://example.com/api/control/dependencies`

List or search for loaded dependencies.

#### Query Parameters

| Name   | Type    | Description                         |
| ------ | ------- | ----------------------------------- |
| q      | string  | A search filter to apply.           |
| limit  | integer | (default 20) Max results to return. |
| offset | integer | The offset within the result set.   |
| role   | string  | Filter to a specific role.          |

{% tabs %}
{% tab title="200 " %}

```javascript
{
  "total": 1,
  "results": [
    {
      "name": "Pexip Management API",
      "description": "Pexip VMR management",
      "role": "service",
      "default": null,
      "class_name": "::Pexip::Management",
      "module_name": "Meeting",
      "ignore_connected": false,
      "settings": {},
      "created_at": 1562041127
    }
  ]
}
```

{% endtab %}
{% endtabs %}

Queries default to searching for any of the entered terms (words). A small query language provides the ability to structure complex queries.

| Operator    | Action                                            |                       |
| ----------- | ------------------------------------------------- | --------------------- |
| `+`         | Matches both terms.                               |                       |
| \`          | \`                                                | Matches either terms. |
| `-`         | Negates a single token.                           |                       |
| `"`         | Wraps tokens to form a phrase.                    |                       |
| `(` and `)` | Provide precedence.                               |                       |
| `~N`        | Specifies edit distance (fuzziness) after a word. |                       |
| `~N`        | Specifies slop amount (deviation) after a phrase. |                       |

## Management

## Create

<mark style="color:green;">`POST`</mark> `https://example.com/api/control/dependencies`

Defines a new dependency. The driver this references must be available on the engine nodes running this instance of Engine. Available drivers can be listed by using the discovery endpoint.

#### Request Body

| Name              | Type    | Description |
| ----------------- | ------- | ----------- |
| name              | string  |             |
| class\_name       | string  |             |
| module\_name      | string  |             |
| role              | string  |             |
| description       | string  |             |
| default           | string  |             |
| ignore\_connected | boolean |             |
| settings          | object  |             |

{% tabs %}
{% tab title="200 Created." %}

```javascript
{
  "name": "Pexip Management API",
  "description": "Pexip VMR management",
  "role": "service",
  "default": null,
  "class_name": "::Pexip::Management",
  "module_name": "Meeting",
  "ignore_connected": false,
  "settings": {},
  "created_at": 1562041127
}
```

{% endtab %}

{% tab title="406 Validation exception." %}

```
```

{% endtab %}
{% endtabs %}

## Retrieve

<mark style="color:blue;">`GET`</mark> `https://example.com/api/control/dependencies/{id}`

Gets dependency information

#### Path Parameters

| Name | Type   | Description                       |
| ---- | ------ | --------------------------------- |
| id   | string | ID of the dependency to retrieve. |

{% tabs %}
{% tab title="200 " %}

```javascript
{
  "name": "Pexip Management API",
  "description": "Pexip VMR management",
  "role": "service",
  "default": null,
  "class_name": "::Pexip::Management",
  "module_name": "Meeting",
  "ignore_connected": false,
  "settings": {},
  "created_at": 1562041127
}
```

{% endtab %}
{% endtabs %}

## Update

<mark style="color:orange;">`PUT`</mark> `https://example.com/api/control/dependencies/{id}`

Updates dependency metadata.

#### Path Parameters

| Name | Type   | Description                      |
| ---- | ------ | -------------------------------- |
| id   | string | ID of the dependency to update.i |

#### Request Body

| Name              | Type    | Description |
| ----------------- | ------- | ----------- |
| name              | string  |             |
| class\_name       | string  |             |
| module\_name      | string  |             |
| role              | string  |             |
| description       | string  |             |
| default           | string  |             |
| ignore\_connected | boolean |             |
| settings          | object  |             |

{% tabs %}
{% tab title="200 Updated." %}

```javascript
{
  "name": "Pexip Management API",
  "description": "Pexip VMR management",
  "role": "service",
  "default": null,
  "class_name": "::Pexip::Management",
  "module_name": "Meeting",
  "ignore_connected": false,
  "settings": {},
  "created_at": 1562041127
}
```

{% endtab %}

{% tab title="406 Validation error." %}

```
```

{% endtab %}
{% endtabs %}

## Delete

<mark style="color:red;">`DELETE`</mark> `https://example.com/api/control/dependencies/{id}`

Unloads a driver.

#### Path Parameters

| Name | Type   | Description                     |
| ---- | ------ | ------------------------------- |
| id   | string | ID of the dependency to remove. |

{% tabs %}
{% tab title="200 " %}

```
```

{% endtab %}
{% endtabs %}

## Interaction

## Reload

<mark style="color:green;">`POST`</mark> `https://example.com/api/control/dependencies/{id}/reload`

Live reloads the latest version of the driver code and updates all modules using this.

#### Path Parameters

| Name | Type   | Description                     |
| ---- | ------ | ------------------------------- |
| id   | string | ID of the dependency to reload. |

{% tabs %}
{% tab title="200 Reload successful." %}

```
```

{% endtab %}

{% tab title="500 An error was detected in the updated driver and the reload is blocked. If this occurs, the previously operating driver will continue to run uninterrupted." %}

```
```

{% endtab %}
{% endtabs %}