Redact processor

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The Redact processor uses the Grok rules engine to obscure text in the input document matching the given Grok patterns. The processor can be used to obscure Personal Identifying Information (PII) by configuring it to detect known patterns such as email or IP addresses. Text that matches a Grok pattern is replaced with a configurable string such as <EMAIL> where an email address is matched or simply replace all matches with the text <REDACTED> if preferred.

Elasticsearch comes packaged with a number of useful predefined patterns that can be conveniently referenced by the Redact processor. If one of those does not suit your needs, create a new pattern with a custom pattern definition. The Redact processor replaces every occurrence of a match. If there are multiple matches all will be replaced with the pattern name.

The Redact processor is compatible with Elastic Common Schema (ECS) patterns. Legacy Grok patterns are not supported.

Using the Redact processor in a pipeline

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Table 34. Redact Options

Name Required Default Description

field

yes

-

The field to be redacted

patterns

yes

-

A list of grok expressions to match and redact named captures with

pattern_definitions

no

-

A map of pattern-name and pattern tuples defining custom patterns to be used by the processor. Patterns matching existing names will override the pre-existing definition

prefix

no

<

Start a redacted section with this token

suffix

no

>

End a redacted section with this token

ignore_missing

no

true

If true and field does not exist or is null, the processor quietly exits without modifying the document

description

no

-

Description of the processor. Useful for describing the purpose of the processor or its configuration.

if

no

-

Conditionally execute the processor. See Conditionally run a processor.

ignore_failure

no

false

Ignore failures for the processor. See Handling pipeline failures.

on_failure

no

-

Handle failures for the processor. See Handling pipeline failures.

tag

no

-

Identifier for the processor. Useful for debugging and metrics.

skip_if_unlicensed

no

false

If true and the current license does not support running redact processors, then the processor quietly exits without modifying the document

In this example the predefined IP Grok pattern is used to match and redact an IP addresses from the message text field. The pipeline is tested using the Simulate API.

resp = client.ingest.simulate(
    pipeline={
        "description": "Hide my IP",
        "processors": [
            {
                "redact": {
                    "field": "message",
                    "patterns": [
                        "%{IP:client}"
                    ]
                }
            }
        ]
    },
    docs=[
        {
            "_source": {
                "message": "55.3.244.1 GET /index.html 15824 0.043"
            }
        }
    ],
)
print(resp)
response = client.ingest.simulate(
  body: {
    pipeline: {
      description: 'Hide my IP',
      processors: [
        {
          redact: {
            field: 'message',
            patterns: [
              '%{IP:client}'
            ]
          }
        }
      ]
    },
    docs: [
      {
        _source: {
          message: '55.3.244.1 GET /index.html 15824 0.043'
        }
      }
    ]
  }
)
puts response
const response = await client.ingest.simulate({
  pipeline: {
    description: "Hide my IP",
    processors: [
      {
        redact: {
          field: "message",
          patterns: ["%{IP:client}"],
        },
      },
    ],
  },
  docs: [
    {
      _source: {
        message: "55.3.244.1 GET /index.html 15824 0.043",
      },
    },
  ],
});
console.log(response);
POST _ingest/pipeline/_simulate
{
  "pipeline": {
    "description" : "Hide my IP",
    "processors": [
      {
        "redact": {
          "field": "message",
          "patterns": ["%{IP:client}"]
        }
      }
    ]
  },
  "docs":[
    {
      "_source": {
        "message": "55.3.244.1 GET /index.html 15824 0.043"
      }
    }
  ]
}

The document in the response still contains the message field but now the IP address 55.3.244.1 is replaced by the text <client>.

{
  "docs": [
    {
      "doc": {
        "_index": "_index",
        "_id": "_id",
        "_version": "-3",
        "_source": {
          "message": "<client> GET /index.html 15824 0.043"
        },
        "_ingest": {
          "timestamp": "2023-02-01T16:08:39.419056008Z"
        }
      }
    }
  ]
}

The IP address is replaced with the word client because that is what is specified in the Grok pattern %{IP:client}. The < and > tokens which surround the pattern name are configurable using the prefix and suffix options.

The next example defines multiple patterns both of which are replaced with the word REDACTED and the prefix and suffix tokens are set to *

resp = client.ingest.simulate(
    pipeline={
        "description": "Hide my IP",
        "processors": [
            {
                "redact": {
                    "field": "message",
                    "patterns": [
                        "%{IP:REDACTED}",
                        "%{EMAILADDRESS:REDACTED}"
                    ],
                    "prefix": "*",
                    "suffix": "*"
                }
            }
        ]
    },
    docs=[
        {
            "_source": {
                "message": "55.3.244.1 GET /index.html 15824 0.043 test@elastic.co"
            }
        }
    ],
)
print(resp)
response = client.ingest.simulate(
  body: {
    pipeline: {
      description: 'Hide my IP',
      processors: [
        {
          redact: {
            field: 'message',
            patterns: [
              '%{IP:REDACTED}',
              '%{EMAILADDRESS:REDACTED}'
            ],
            prefix: '*',
            suffix: '*'
          }
        }
      ]
    },
    docs: [
      {
        _source: {
          message: '55.3.244.1 GET /index.html 15824 0.043 test@elastic.co'
        }
      }
    ]
  }
)
puts response
const response = await client.ingest.simulate({
  pipeline: {
    description: "Hide my IP",
    processors: [
      {
        redact: {
          field: "message",
          patterns: ["%{IP:REDACTED}", "%{EMAILADDRESS:REDACTED}"],
          prefix: "*",
          suffix: "*",
        },
      },
    ],
  },
  docs: [
    {
      _source: {
        message: "55.3.244.1 GET /index.html 15824 0.043 test@elastic.co",
      },
    },
  ],
});
console.log(response);
POST _ingest/pipeline/_simulate
{
  "pipeline": {
    "description": "Hide my IP",
    "processors": [
      {
        "redact": {
          "field": "message",
          "patterns": [
            "%{IP:REDACTED}",
            "%{EMAILADDRESS:REDACTED}"
          ],
          "prefix": "*",
          "suffix": "*"
        }
      }
    ]
  },
  "docs": [
    {
      "_source": {
        "message": "55.3.244.1 GET /index.html 15824 0.043 test@elastic.co"
      }
    }
  ]
}

In the response both the IP 55.3.244.1 and email address test@elastic.co have been replaced by *REDACTED*.

{
  "docs": [
    {
      "doc": {
        "_index": "_index",
        "_id": "_id",
        "_version": "-3",
        "_source": {
          "message": "*REDACTED* GET /index.html 15824 0.043 *REDACTED*"
        },
        "_ingest": {
          "timestamp": "2023-02-01T16:53:14.560005377Z"
        }
      }
    }
  ]
}

Custom patterns

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If one of the existing Grok patterns does not fit your requirements custom patterns can be added with the pattern_definitions option. New patterns definitions are composed of a pattern name and the pattern itself. The pattern may be a regular expression or reference existing Grok patterns.

This example defines the custom pattern GITHUB_NAME to match GitHub usernames. The pattern definition uses the existing USERNAME Grok pattern prefixed by the literal @.

The Grok Debugger is a really useful tool for building custom patterns.

resp = client.ingest.simulate(
    pipeline={
        "processors": [
            {
                "redact": {
                    "field": "message",
                    "patterns": [
                        "%{GITHUB_NAME:GITHUB_NAME}"
                    ],
                    "pattern_definitions": {
                        "GITHUB_NAME": "@%{USERNAME}"
                    }
                }
            }
        ]
    },
    docs=[
        {
            "_source": {
                "message": "@elastic-data-management the PR is ready for review"
            }
        }
    ],
)
print(resp)
response = client.ingest.simulate(
  body: {
    pipeline: {
      processors: [
        {
          redact: {
            field: 'message',
            patterns: [
              '%{GITHUB_NAME:GITHUB_NAME}'
            ],
            pattern_definitions: {
              "GITHUB_NAME": '@%<USERNAME>s'
            }
          }
        }
      ]
    },
    docs: [
      {
        _source: {
          message: '@elastic-data-management the PR is ready for review'
        }
      }
    ]
  }
)
puts response
const response = await client.ingest.simulate({
  pipeline: {
    processors: [
      {
        redact: {
          field: "message",
          patterns: ["%{GITHUB_NAME:GITHUB_NAME}"],
          pattern_definitions: {
            GITHUB_NAME: "@%{USERNAME}",
          },
        },
      },
    ],
  },
  docs: [
    {
      _source: {
        message: "@elastic-data-management the PR is ready for review",
      },
    },
  ],
});
console.log(response);
POST _ingest/pipeline/_simulate
{
  "pipeline": {
    "processors": [
      {
        "redact": {
          "field": "message",
          "patterns": [
            "%{GITHUB_NAME:GITHUB_NAME}"
          ],
          "pattern_definitions": {
            "GITHUB_NAME": "@%{USERNAME}"
          }
        }
      }
    ]
  },
  "docs": [
    {
      "_source": {
        "message": "@elastic-data-management the PR is ready for review"
      }
    }
  ]
}

The username is redacted in the response.

{
  "docs": [
    {
      "doc": {
        "_index": "_index",
        "_id": "_id",
        "_version": "-3",
        "_source": {
          "message": "<GITHUB_NAME> the PR is ready for review"
        },
        "_ingest": {
          "timestamp": "2023-02-01T16:53:14.560005377Z"
        }
      }
    }
  ]
}

Grok watchdog

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The watchdog interrupts expressions that take too long to execute. When interrupted, the Redact processor fails with an error. The same settings that control the Grok Watchdog timeout also apply to the Redact processor.

Licensing

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The redact processor is a commercial feature that requires an appropriate license. For more information, refer to https://www.elastic.co/subscriptions.

The skip_if_unlicensed option can be set on a redact processor to control behavior when the cluster’s license is not sufficient to run such a processor. skip_if_unlicensed defaults to false, and the redact processor will throw an exception if the cluster’s license is not sufficient. If you set the skip_if_unlicensed option to true, however, then the redact processor not throw an exception (it will do nothing at all) in the case of an insufficient license.