zabbix-REST

A native Zabbix plugin (Loadable Module) to make REST calls and parse responses.

Why?

Zabbix integrated Web monitoring focuses on checking that a web endpoint is working, but is unable to parse the response content.

This plugin enables making an HTTP request and extract a value from the response, if the response is formatted as JSON, XML or HTML.

Usage

This plugin currently provides 2 Zabbix Item keys :

rest.request[] : makes an HTTP request and returns the parsed response value.
rest.status[] : makes an HTTP request and returns the HTTP response status code.

rest.request[`verb`=GET, `URL`, `responsePath`=/, `format`=json|xml|html, `requestHeaders`=null, `requestBody`=null ]

verb: Can be GET, POST, PUT, PATCH, DELETE. If left empty, defaults to GET.
URL: Complete URL of the HTTP endpoint to query.
responsePath (optional): "Path" to the parsed response value to extract and return. Xpath syntax is supported for XML and HTML. For JSON, a very limited syntax is available, see examples below. If left empty, defaults to / ("all").
format (optional): by default the response format is detected automatically, using the response Content-Type header. This option allows to set the content type of the request body if the requestBody option is used, as well as "forcing" the format of the response. The following values are supported: json, xml, html.
requestHeaders (optional): Request headers, as a JSON array of key-value pairs. Example: [{"Authorization":"Bearer eyJhbGciOiJIUzI1NiIsInR..."}].
requestBody (optional): Request body. Must be quoted and inner quotes escaped if it contains spaces.

Path syntax

For XML and HTML: compatible with Xpath. See for example https://www.w3schools.com/xml/xpath_syntax.asp
For JSON:

Access a document property: /propertyName

Or for nested documents: /propertyName/subPropertyName

Access Array item: /arrayPropertyName[index]

Note: for consistency with Xpath, arrays start at index 1.

Examples

rest.request[GET,https://jsonplaceholder.typicode.com/posts] : retrieves a list of posts and returns the raw JSON result:

[
{
"body": "occaecati a doloribus\niste saepe consectetur placeat eum voluptate dolorem et\nqui quo quia voluptas\nrerum ut id enim velit est perferendis",
"userId": 8,
"title": "et iusto veniam et illum aut fuga",
"id": 71
},
{
"body": "quam occaecati qui deleniti consectetur\nconsequatur aut facere quas exercitationem aliquam hic voluptas\nneque id sunt ut aut accusamus\nsunt consectetur expedita inventore velit",
"userId": 8,
"title": "sint hic doloribus consequatur eos non id",
"id": 72
},
...
]

rest.request[GET,https://jsonplaceholder.typicode.com/posts/1,/userId] : retrieves the post with id 1 and returns its userId field.

Limitations

Some important limitations are to be considered ; most of them are due to some features of the Swift Foundation library being only partially supported under Linux, as of Swift 3.1

HTTPS requests will fail if the server has an invalid SSL certificate.
Requests that returns a redirect response (3xx status code) will fail.

Installation

[TBD]

Build from source