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redis_script

Performs actions against Redis using LUA scripts.

Introduced in version 4.11.0.

Actions are performed for each message and the message contents are replaced with the result.

In order to merge the result into the original message compose this processor within a branch processor.

Common
Advanced

processor:
  label: ""
  redis_script:
    url: "" # No default (required)
    script: "" # No default (required)
    args_mapping: "" # No default (required)
    keys_mapping: "" # No default (required)

processor:
  label: ""
  redis_script:
    url: "" # No default (required)
    kind: simple
    master: ""
    client_name: redpanda-connect
    tls:
      enabled: false
      skip_cert_verify: false
      enable_renegotiation: false
      root_cas: ""
      root_cas_file: ""
      client_certs: []
    script: "" # No default (required)
    args_mapping: "" # No default (required)
    keys_mapping: "" # No default (required)
    retries: 3
    retry_period: 500ms

Examples

Running a script

The following example will use a script execution to get next element from a sorted set and set its score with timestamp unix nano value.

pipeline:
  processors:
    - redis_script:
        url: TODO
        script: |
          local value = redis.call("ZRANGE", KEYS[1], '0', '0')

          if next(elements) == nil then
            return ''
          end

          redis.call("ZADD", "XX", KEYS[1], ARGV[1], value)

          return value
        keys_mapping: 'root = [ meta("key") ]'
        args_mapping: 'root = [ timestamp_unix_nano() ]'

Fields

`args_mapping`

A Bloblang mapping that evaluates to an array of values passed to the script, where they are available as ARGV[1], ARGV[2], and so on.

Type: string

# Examples:
args_mapping: root = [ this.key ]

# ---

args_mapping: root = [ meta("kafka_key"), "hardcoded_value" ]

`client_name`

Set the client name for the Redis connection.

Requires version 4.82.0 or later.

Type: string

Default: redpanda-connect

`keys_mapping`

A Bloblang mapping which should evaluate to an array of keys matching in size to the number of arguments required for the specified Redis script.

Type: string

# Examples:
keys_mapping: root = [ this.key ]

# ---

keys_mapping: root = [ meta("kafka_key"), this.count ]

`kind`

Specifies a simple, cluster-aware, or failover-aware redis client.

Type: string

Default: simple

Options: simple, cluster, failover

`master`

Name of the redis master when kind is failover

Type: string

Default: ""

# Examples:
master: mymaster

`retries`

The maximum number of retries before abandoning a request.

Type: int

Default: 3

`retry_period`

The time to wait before consecutive retry attempts.

Type: string

Default: 500ms

`script`

A script to use for the target operator. It has precedence over the 'command' field.

Type: string

# Examples:
script: return redis.call('set', KEYS[1], ARGV[1])

`tls`

Custom TLS settings can be used to override system defaults.

Troubleshooting

Some cloud hosted instances of Redis (such as Azure Cache) might need some hand holding in order to establish stable connections. Unfortunately, it is often the case that TLS issues will manifest as generic error messages such as "i/o timeout". If you’re using TLS and are seeing connectivity problems consider setting enable_renegotiation to true, and ensuring that the server supports at least TLS version 1.2.

Type: object

`tls.client_certs[]`

A list of client certificates for mutual TLS (mTLS) authentication. Configure this field to enable mTLS, authenticating the client to the server with these certificates.

You must set tls.enabled: true for the client certificates to take effect.

Certificate pairing rules: For each certificate item, provide either:

Inline PEM data using both cert and key or
File paths using both cert_file and key_file.

Mixing inline and file-based values within the same item is not supported.

Type: array<object>

Default: []

# Examples:
client_certs:
  - cert: foo
    key: bar


# ---

client_certs:
  - cert_file: ./example.pem
    key_file: ./example.key

`tls.client_certs[].cert`

The plaintext certificate to use for TLS authentication. Must be paired with the corresponding private key in the key field when using inline PEM data for mTLS client certificates.

Type: string

Default: ""

`tls.client_certs[].cert_file`

The path to a file containing the certificate to use for TLS authentication. Must be paired with the corresponding private key file in the key_file field when using file-based configuration for mTLS client certificates.

Type: string

Default: ""

`tls.client_certs[].key`

Private key for mTLS client certificate as inline PEM data. Must correspond to the client certificate specified in the cert field. Use this field together with cert when providing certificate data inline rather than through files.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Type: string

Default: ""

`tls.client_certs[].key_file`

Path to private key file for mTLS client certificate in PEM format. Must correspond to the client certificate specified in the cert_file field. Use this field together with cert_file when loading certificate data from files.

Type: string

Default: ""

`tls.client_certs[].password`

The password to use for the private key (specified in the key or key_file fields), if it is password-protected. The PKCS#1 and PKCS#8 formats are supported. Supports environment variable interpolation for secure password management.

The pbeWithMD5AndDES-CBC algorithm is obsolete and not supported for the PKCS#8 format. This algorithm does not authenticate the ciphertext, making it vulnerable to padding oracle attacks that can let an attacker recover the plaintext.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Type: string

Default: ""

# Examples:
password: foo

# ---

password: ${KEY_PASSWORD}

`tls.enable_renegotiation`

Whether to allow the remote server to repeatedly request renegotiation. Enable this option if you’re seeing the error message local error: tls: no renegotiation.

Type: bool

Default: false

`tls.enabled`

Whether to enable TLS for secure connections. Set to true to enable TLS encryption. Required to be true for other TLS options (like client_certs, root_cas, etc.) to take effect.

Type: bool

Default: false

`tls.root_cas`

Specify a root certificate authority to use (optional). This is a string that represents a certificate chain from the parent-trusted root certificate, through possible intermediate signing certificates, to the host certificate. Use either this field for inline certificate data or root_cas_file for file-based certificate loading.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets.

Type: string

Default: ""

# Examples:
root_cas: |-
  -----BEGIN CERTIFICATE-----
  ...
  -----END CERTIFICATE-----

`tls.root_cas_file`

Specify the path to a root certificate authority file (optional). This is a file, often with a .pem extension, which contains a certificate chain from the parent-trusted root certificate, through possible intermediate signing certificates, to the host certificate. Use either this field for file-based certificate loading or root_cas for inline certificate data.

Type: string

Default: ""

# Examples:
root_cas_file: ./root_cas.pem

`tls.skip_cert_verify`

Whether to skip server-side certificate verification. Set to true only for testing environments as this reduces security by disabling certificate validation. When using self-signed certificates or in development, this may be necessary, but should never be used in production. Consider using root_cas or root_cas_file to specify trusted certificates instead of disabling verification entirely.

Type: bool

Default: false

`url`

The URL of the target Redis server. Database is optional and is supplied as the URL path.

Type: string

# Examples:
url: redis://:6379

# ---

url: redis://localhost:6379

# ---

url: redis://foousername:foopassword@redisplace:6379

# ---

url: redis://:foopassword@redisplace:6379

# ---

url: redis://localhost:6379/1

# ---

url: redis://localhost:6379/1,redis://localhost:6380/1

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redis_script

Examples

Running a script

Fields

args_mapping

client_name

keys_mapping

kind

master

retries

retry_period

script

tls

tls.client_certs[]

tls.client_certs[].cert

tls.client_certs[].cert_file

tls.client_certs[].key

tls.client_certs[].key_file

tls.client_certs[].password

tls.enable_renegotiation

tls.enabled

tls.root_cas

tls.root_cas_file

tls.skip_cert_verify

url

`args_mapping`

`client_name`

`keys_mapping`

`kind`

`master`

`retries`

`retry_period`

`script`

`tls`

`tls.client_certs[]`

`tls.client_certs[].cert`

`tls.client_certs[].cert_file`

`tls.client_certs[].key`

`tls.client_certs[].key_file`

`tls.client_certs[].password`

`tls.enable_renegotiation`

`tls.enabled`

`tls.root_cas`

`tls.root_cas_file`

`tls.skip_cert_verify`

`url`