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json_schema

Checks messages against a provided JSONSchema definition but does not change the payload under any circumstances. If a message does not match the schema it can be caught using error handling methods outlined here.

# Config fields, showing default values
label: ""
json_schema:
  schema: ""
  schema_path: ""

Please refer to the JSON Schema website for information and tutorials regarding the syntax of the schema.

Fields​

schema​

A schema to apply. Use either this or the schema_path field.

Type: string
Default: ""

schema_path​

The path of a schema document to apply. Use either this or the schema field.

Type: string
Default: ""

Examples​

With the following JSONSchema document:

{
    "$id": "https://example.com/person.schema.json",
    "$schema": "http://json-schema.org/draft-07/schema#",
    "title": "Person",
    "type": "object",
    "properties": {
      "firstName": {
        "type": "string",
        "description": "The person's first name."
      },
      "lastName": {
        "type": "string",
        "description": "The person's last name."
      },
      "age": {
        "description": "Age in years which must be equal to or greater than zero.",
        "type": "integer",
        "minimum": 0
      }
    }
}

And the following Benthos configuration:

pipeline:
  processors:
  - json_schema:
      schema_path: "file://path_to_schema.json"
  - catch:
    - log:
        level: ERROR
        message: "Schema validation failed due to: ${!error()}"
    - bloblang: 'root = deleted()' # Drop messages that fail

If a payload being processed looked like:

{"firstName":"John","lastName":"Doe","age":-21}

Then a log message would appear explaining the fault and the payload would be dropped.