Content Modifier

The content_modifier processor allows you to manipulate the messages, metadata/attributes and content of Logs and Traces.

Similar to the functionality exposed by filters, this processor presents a unified mechanism to perform such operations for data manipulation. The most significant difference is that processors perform better than filters, and when chaining them, there are no encoding/decoding performance penalties.

Note that processors and this specific component can only be enabled using the new YAML configuration format. Classic mode configuration format doesn't support processors.

Contexts

The processor, works on top of what we call a context, meaning the place where the content modification will happen. We provide different contexts to manipulate the desired information, the following contexts are available:

Context Name	Signal	Description
attributes	Logs	Modify the attributes or metadata of a Log record.
body	Logs	Modify the content of a Log record.
span_name	Traces	Modify the name of a Span.
span_kind	Traces	Modify the kind of a Span.
span_status	Traces	Modify the status of a Span.
span_attributes	Traces	Modify the attributes of a Span.

OpenTelemetry Contexts

In addition, we provide special contexts to operate on data that follows an OpenTelemetry Log Schema, all of them operates on shared data across a group of records:

Context Name	Signal	Description
otel_resource_attributes	Logs	Modify the attributes of the Log Resource.
otel_scope_name	Logs	Modify the name of a Log Scope.
otel_scope_version	Logs	Modify version of a Log Scope.
otel_scope_attributes	Logs	Modify the attributes of a Log Scope.

TIP: if your data is not following the OpenTelemetry Log Schema and your backend or destination for your logs expects to be in an OpenTelemetry schema, take a look at the processor called OpenTelemetry Envelope that you can use in conjunbction with this processor to transform your data to be compatible with OpenTelemetry Log schema.

Configuration Parameters

Key	Description
context	Specify the context where the modifications will happen (more details above).The following contexts are available: attributes, body, span_name, span_kind, span_status, span_attributes, otel_resource_attributes, otel_scope_name, otel_scope_version, otel_scope_attributes.
key	Specify the name of the key that will be used to apply the modification.
value	Based on the action type, value might required and represent different things. Check the detailed information for the specific actions.
pattern	Defines a regular expression pattern. This property is only used by the extract action.
converted_type	Define the data type to perform the conversion, the available options are: string, boolean, int and double .

Actions

The actions specify the type of operation to run on top of a specific key or content from a Log or a Trace. The following actions are available:

Action	Description
insert	Insert a new key with a value into the target context. The key and value parameters are required.
upsert	Given a specific key with a value, the upsert operation will try to update the value of the key. If the key does not exist, the key will be created. The key and value parameters are required.
delete	Delete a key from the target context. The key parameter is required.
rename	Change the name of a key. The value set in the configuration will represent the new name. The key and value parameters are required.
hash	Replace the key value with a hash generated by the SHA-256 algorithm, the binary value generated is finally set as an hex string representation. The key parameter is required.
extract	Allows to extact the value of a single key as a list of key/value pairs. This action needs the configuration of a regular expression in the pattern property . The key and pattern parameters are required. For more details check the examples below.
convert	Convert the data type of a key value. The key and converted_type parameters are required.

Insert example

The following example appends the key color with the value blue to the log stream.

pipeline:
  inputs:
    - name: dummy
      dummy: '{"key1": "123.4"}'

      processors:
        logs:
          - name: content_modifier
            action: insert
            key: "color"
            value: "blue"
  outputs:
    - name : stdout
      match: '*'
      format: json_lines

Upsert example

Update the value of key1 and insert key2:

pipeline:
  inputs:
    - name: dummy
      dummy: '{"key1": "123.4"}'

      processors:
        logs:
          - name: content_modifier
            action: upsert
            key: "key1"
            value: "5678"

          - name: content_modifier
            action: upsert
            key: "key2"
            value: "example"

  outputs:
    - name : stdout
      match: '*'
      format: json_lines

Delete example

Delete key2 from the stream:

pipeline:
  inputs:
    - name: dummy
      dummy: '{"key1": "123.4", "key2": "example"}'

      processors:
        logs:
          - name: content_modifier
            action: delete
            key: "key2"

  outputs:
    - name : stdout
      match: '*'
      format: json_lines

Rename example

Change the name of key2 to test:

pipeline:
  inputs:
    - name: dummy
      dummy: '{"key1": "123.4", "key2": "example"}'

      processors:
        logs:
          - name: content_modifier
            action: rename
            key: "key2"
            value: "test"

  outputs:
    - name : stdout
      match: '*'
      format: json_lines

Hash example

Apply the SHA-256 algorithm for the value of the key password:

pipeline:
  inputs:
    - name: dummy
      dummy: '{"username": "bob", "password": "12345"}'

      processors:
        logs:
          - name: content_modifier
            action: hash
            key: "password"

  outputs:
    - name : stdout
      match: '*'
      format: json_lines

Extract example

By using a domain address, perform a extraction of the components of it as a list of key value pairs:

pipeline:
  inputs:
    - name: dummy
      dummy: '{"http.url": "https://fluentbit.io/docs?q=example"}'

      processors:
        logs:
          - name: content_modifier
            action: extract
            key: "http.url"
            pattern: ^(?<http_protocol>https?):\/\/(?<http_domain>[^\/\?]+)(?<http_path>\/[^?]*)?(?:\?(?<http_query_params>.*))?

  outputs:
    - name : stdout
      match: '*'
      format: json_lines

Convert example

Both keys in the example are strings. Convert the key1 to a double/float type and key2 to a boolean:

pipeline:
  inputs:
    - name: dummy
      dummy: '{"key1": "123.4", "key2": "true"}'

      processors:
        logs:
          - name: content_modifier
            action: convert
            key: key1
            converted_type: int

          - name: content_modifier
            action: convert
            key: key2
            converted_type: boolean

  outputs:
    - name : stdout
      match: '*'
      format: json_lines