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redis processor

Performs actions against Redis that aren't possible using a cache processor. 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 config fields, showing default values
pipeline:
  processors:
    - label: ""
      redis:
        url: "" # No default (required)
        command: "" # No default (optional)
        args_mapping: "" # No default (optional)

Examples​

Querying Cardinality​

If given payloads containing a metadata field set_key it's possible to query and store the cardinality of the set for each message using a branch processor in order to augment rather than replace the message contents:

pipeline:
  processors:
    - branch:
        processors:
          - redis:
              url: TODO
              command: scard
              args_mapping: 'root = [ meta("set_key") ]'
        result_map: 'root.cardinality = this'

Running Total​

If we have JSON data containing number of friends visited during covid 19:

{"name":"ash","month":"feb","year":2019,"friends_visited":10}
{"name":"ash","month":"apr","year":2019,"friends_visited":-2}
{"name":"bob","month":"feb","year":2019,"friends_visited":3}
{"name":"bob","month":"apr","year":2019,"friends_visited":1}

We can add a field that contains the running total number of friends visited:

{"name":"ash","month":"feb","year":2019,"friends_visited":10,"total":10}
{"name":"ash","month":"apr","year":2019,"friends_visited":-2,"total":8}
{"name":"bob","month":"feb","year":2019,"friends_visited":3,"total":3}
{"name":"bob","month":"apr","year":2019,"friends_visited":1,"total":4}

Using the incrby command:

pipeline:
  processors:
    - branch:
        processors:
          - redis:
              url: TODO
              command: incrby
              args_mapping: 'root = [ this.name, this.friends_visited ]'
        result_map: 'root.total = this'

Fields​

url​

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

Type: string

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: ""

client_name​

Set the client name for the Redis connection.

Type: string
Default: "redpanda-connect"

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.enabled​

Whether custom TLS settings are enabled.

Type: bool
Default: false

tls.skip_cert_verify​

Whether to skip server side certificate verification.

Type: bool
Default: false

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.root_cas​

An optional root certificate authority to use. This is a string, representing a certificate chain from the parent trusted root certificate, to possible intermediate signing certificates, to the host certificate.

Secret

This field contains sensitive information. Use a secret reference rather than a literal value.

Type: string
Default: ""

tls.root_cas_file​

An optional path of a root certificate authority file to use. This is a file, often with a .pem extension, containing a certificate chain from the parent trusted root certificate, to possible intermediate signing certificates, to the host certificate.

Type: string
Default: ""

tls.client_certs​

A list of client certificates to use. For each certificate either the fields cert and key, or cert_file and key_file should be specified, but not both.

Type: array of object
Default: []

tls.client_certs[].cert​

A plain text certificate to use.

Type: string
Default: ""

tls.client_certs[].key​

A plain text certificate key to use.

Secret

This field contains sensitive information. Use a secret reference rather than a literal value.

Type: string
Default: ""

tls.client_certs[].cert_file​

The path of a certificate to use.

Type: string
Default: ""

tls.client_certs[].key_file​

The path of a certificate key to use.

Type: string
Default: ""

tls.client_certs[].password​

A plain text password for when the private key is password encrypted in PKCS#1 or PKCS#8 format. The obsolete pbeWithMD5AndDES-CBC algorithm is not supported for the PKCS#8 format.

Because the obsolete pbeWithMD5AndDES-CBC algorithm does not authenticate the ciphertext, it is vulnerable to padding oracle attacks that can let an attacker recover the plaintext.

Secret

This field contains sensitive information. Use a secret reference rather than a literal value.

Type: string
Default: ""

command​

The command to execute.

This field supports interpolation functions.

Type: string

args_mapping​

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

Type: string

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"