JSON Datasource - a generic backend datasource

JSON Datasource is an enhanced version of the Simple JSON Datasource.

The JSON datasource executes JSON requests against arbitrary backends. To work with this datasource the backend needs to implement 4 urls:

• / should return 200 ok. Used for "Test connection" on the datasource config page.
• /search used by the find metric options on the query tab in panels.
• /query should return metrics based on input.
• /annotations should return annotations.

Those two urls are optional:

• /tag-keys should return tag keys for ad hoc filters.
• /tag-values should return tag values for ad hoc filters.

Example backend implementations

• https://github.com/bergquist/fake-simple-json-datasource
• https://github.com/smcquay/jsonds
• https://github.com/ContextLogic/eventmaster
• https://gist.github.com/linar-jether/95ff412f9d19fdf5e51293eb0c09b850 (Python/pandas backend)

Search API

Example request

{ "target": "upper_50" }

The search api can either return an array or map.

Example array response

["upper_25","upper_50","upper_75","upper_90","upper_95"]

Example map response

[ { "text" :"upper_25", "value": 1}, { "text" :"upper_75", "value": 2} ]

Query API

Example timeseries request

{
  "panelId": 1,
  "range": {
    "from": "2016-10-31T06:33:44.866Z",
    "to": "2016-10-31T12:33:44.866Z",
    "raw": {
      "from": "now-6h",
      "to": "now"
    }
  },
  "rangeRaw": {
    "from": "now-6h",
    "to": "now"
  },
  "interval": "30s",
  "intervalMs": 30000,
  "targets": [
     { "target": "upper_50", "refId": "A", "type": "timeseries", "data": { "additional": "optional json" } },
     { "target": "upper_75", "refId": "B", "type": "timeseries" }
  ],
  "adhocFilters": [{
    "key": "City",
    "operator": "=",
    "value": "Berlin"
  }],
  "format": "json",
  "maxDataPoints": 550
}

Example timeseries response

[
  {
    "target":"upper_75", // The field being queried for
    "datapoints":[
      [622,1450754160000],  // Metric value as a float , unixtimestamp in milliseconds
      [365,1450754220000]
    ]
  },
  {
    "target":"upper_90",
    "datapoints":[
      [861,1450754160000],
      [767,1450754220000]
    ]
  }
]

If the metric selected is "type": "table", an example table response:

[
  {
    "columns":[
      {"text":"Time","type":"time"},
      {"text":"Country","type":"string"},
      {"text":"Number","type":"number"}
    ],
    "rows":[
      [1234567,"SE",123],
      [1234567,"DE",231],
      [1234567,"US",321]
    ],
    "type":"table"
  }
]

Annotation API

The annotation request from the Simple JSON Datasource is a POST request to the /annotations endpoint in your datasource. The JSON request body looks like this:

{
  "range": {
    "from": "2016-04-15T13:44:39.070Z",
    "to": "2016-04-15T14:44:39.070Z"
  },
  "rangeRaw": {
    "from": "now-1h",
    "to": "now"
  },
  "annotation": {
    "name": "deploy",
    "datasource": "JSON Datasource",
    "iconColor": "rgba(255, 96, 96, 1)",
    "enable": true,
    "query": "#deploy"
  }
}

Grafana expects a response containing an array of annotation objects in the following format:

[
  {
    "annotation": "annotation", // The original annotation sent from Grafana.
    "time": "time", // Time since UNIX Epoch in milliseconds. (required)
    "title": "title", // The title for the annotation tooltip. (required)
    "tags": "tags", // Tags for the annotation. (optional)
    "text": "text" // Text for the annotation. (optional)
  }
]

Note: If the datasource is configured to connect directly to the backend, you also need to implement an OPTIONS endpoint at /annotations that responds with the correct CORS headers:

Access-Control-Allow-Headers:accept, content-type
Access-Control-Allow-Methods:POST
Access-Control-Allow-Origin:*

Tag Keys API

Example request

{ }

The tag keys api returns:

[
    {"type":"string","text":"City"},
    {"type":"string","text":"Country"}
]

Tag Values API

Example request

{"key": "City"}

The tag values api returns:

[
    {"text": "Eins!"},
    {"text": "Zwei"},
    {"text": "Drei!"}
]

Installation

To install this plugin using the grafana-cli tool:

sudo grafana-cli plugins install grafana-json-datasource
sudo service grafana-server restart

See here for more information.

Development setup

This plugin requires node 6.10.0

npm install -g yarn
yarn install
npm run build

Changelog

1.4.0

• Support for adhoc filters:
  • added tag-keys + tag-values api
  • added adHocFilters parameter to query body

1.3.5

• Fix for dropdowns in query editor to allow writing template variables (broke due to change in Grafana).

1.3.4

• Adds support for With Credentials (sends grafana cookies with request) when using Direct mode
• Fix for the typeahead component for metrics dropdown (/search endpoint).

1.3.3

• Adds support for basic authentication

1.2.4

• Add support returning sets in the search endpoint

1.2.3

• Allow nested templates in find metric query. #23

1.2.2

• Dont execute hidden queries
• Template support for metrics queries
• Template support for annotation queries

Copy the data source you want to /public/app/plugins/datasource/. Then restart grafana-server. The new data source should now be available in the data source type dropdown in the Add Data Source View.