Connect

schema_registry_encode

Available in: Cloud, Self-Managed

Automatically encodes and validates messages with schemas from a Confluent Schema Registry service.

This processor uses the Franz Kafka Schema Registry client.

Introduced in version 3.58.0.

Common
Advanced

processors:
  label: ""
  schema_registry_encode:
    url: "" # No default (required)
    subject: "" # No default (required)
    refresh_period: 10m
    schema_metadata: ""
    format: "" # No default (optional)
    avro:
      raw_json: "" # No default (optional)
      record_name: ""
      namespace: ""

processors:
  label: ""
  schema_registry_encode:
    url: "" # No default (required)
    subject: "" # No default (required)
    refresh_period: 10m
    schema_metadata: ""
    format: "" # No default (optional)
    normalize: true
    avro:
      raw_json: "" # No default (optional)
      record_name: ""
      namespace: ""
    oauth:
      enabled: false
      consumer_key: ""
      consumer_secret: ""
      access_token: ""
      access_token_secret: ""
    basic_auth:
      enabled: false
      username: ""
      password: ""
    jwt:
      enabled: false
      private_key_file: ""
      signing_method: ""
      claims: {}
      headers: {}
    tls:
      skip_cert_verify: false
      enable_renegotiation: false
      root_cas: ""
      root_cas_file: ""
      client_certs: []

Encodes messages automatically from schemas obtains from a Confluent Schema Registry service by polling the service for the latest schema version for target subjects.

If a message fails to encode under the schema then it will remain unchanged and the error can be caught using error-handling methods.

Avro, Protobuf and JSON schemas are supported, all are capable of expanding from schema references as of v4.22.0.

Avro JSON format

By default, this processor expects documents formatted as Avro JSON when encoding with Avro schemas. In this format, the value of a union is encoded in JSON as follows:

If the union’s type is null, it is encoded as a JSON null.
Otherwise, the union is encoded as a JSON object with one name/value pair. The name is the type’s name, and the value is the recursively-encoded value. The user-specified name is used for Avro’s named types (record, fixed, or enum). For other types, the type name is used.

For example, the union schema ["null","string","Transaction"], where Transaction is a record name, would encode:

A null as a JSON null
The string "a" as {"string": "a"}
A Transaction instance as {"Transaction": {…}}, where {…} indicates the JSON encoding of a Transaction instance

Alternatively, you can consume documents in standard/raw JSON format by setting the field avro_raw_json to true.

Known issues

Important! There is an outstanding issue in the avro serializing library that Redpanda Connect uses which means it doesn’t encode logical types correctly. It’s still possible to encode logical types that are in-line with the spec if avro_raw_json is set to true, though now of course non-logical types will not be in-line with the spec.

Protobuf format

This processor encodes Protobuf messages either from any format parsed within Redpanda Connect (encoded as JSON by default), or from raw JSON documents. For more information about the JSON mapping of Protobuf messages, see the Protocol Buffers documentation.

Multiple message support

When a target subject presents a Protobuf schema that contains multiple messages it becomes ambiguous which message definition a given input data should be encoded against. In such scenarios Redpanda Connect will attempt to encode the data against each of them and select the first to successfully match against the data, this process currently ignores all nested message definitions. In order to speed up this exhaustive search the last known successful message will be attempted first for each subsequent input.

We will be considering alternative approaches in future so please get in touch with thoughts and feedback.

Fields

`avro`

Configuration for Avro encoding.

Type: object

`avro.namespace`

The Avro namespace for the root record type when encoding from a common schema (schema_metadata mode).

Type: string

Default: ""

`avro.raw_json`

Whether messages encoded in Avro format should be parsed as normal JSON rather than Avro JSON. Overrides the deprecated top-level avro_raw_json when set.

Type: bool

`avro.record_name`

The name to use for the root Avro record type when encoding from a common schema (schema_metadata mode). If empty, derived from the subject.

Type: string

Default: ""

`basic_auth`

Allows you to specify basic authentication.

Requires version 4.7.0 or later.

Type: object

`basic_auth.enabled`

Whether to use basic authentication in requests.

Type: bool

Default: false

`basic_auth.password`

A password to authenticate with.

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

Type: string

Default: ""

`basic_auth.username`

A username to authenticate as.

Type: string

Default: ""

`format`

The encoding format to use when converting a common schema from metadata. Required when schema_metadata is set.

Type: string

Options: avro, json_schema

`jwt`

Beta

Configure JSON Web Token (JWT) authentication. This feature is in beta and may change in future releases. JWT tokens provide secure, stateless authentication between services.

Requires version 4.7.0 or later.

Type: object

`jwt.claims`

A value used to identify the claims that issued the JWT.

Type: object

Default: {}

`jwt.enabled`

Whether to use JWT authentication in requests.

Type: bool

Default: false

`jwt.headers`

Additional key-value pairs to include in the JWT header (optional). These headers provide extra metadata for JWT processing.

Type: object

Default: {}

`jwt.private_key_file`

Path to a file containing the PEM-encoded private key using PKCS#1 or PKCS#8 format. The private key must be compatible with the algorithm specified in the signing_method field.

Type: string

Default: ""

`jwt.signing_method`

The cryptographic algorithm used to sign the JWT token. Supported algorithms include RS256, RS384, RS512, and EdDSA. This algorithm must be compatible with the private key specified in the private_key_file field.

Type: string

Default: ""

`normalize`

Whether to normalize the schema before registering with the schema registry (schema_metadata mode only).

Type: bool

Default: true

`oauth`

Configure OAuth version 1.0 authentication for secure API access.

Requires version 4.7.0 or later.

Type: object

`oauth.access_token`

A value used to gain access to the protected resources on behalf of the user.

Type: string

Default: ""

`oauth.access_token_secret`

A secret provided in order to establish ownership of a given access token.

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

Type: string

Default: ""

`oauth.consumer_key`

A value used to identify the client to the service provider.

Type: string

Default: ""

`oauth.consumer_secret`

A secret used to establish ownership of the consumer key.

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

Type: string

Default: ""

`oauth.enabled`

Whether to use OAuth version 1 in requests.

Type: bool

Default: false

`refresh_period`

The period after which a schema is refreshed for each subject, this is done by polling the schema registry service.

Type: string

Default: 10m

# Examples:
refresh_period: 60s

# ---

refresh_period: 1h

`schema_metadata`

When set, the processor reads a schema in benthos common schema format from this metadata key on each message, converts it to the format specified by format, registers it with the schema registry under the configured subject, and encodes the message. When empty (the default), the processor pulls the latest schema from the registry instead.

Type: string

Default: ""

`subject`

The schema subject to derive schemas from. This field supports interpolation functions.

Type: string

# Examples:
subject: foo

# ---

subject: ${! meta("kafka_topic") }

`tls`

Custom TLS settings can be used to override system defaults.

Type: object

`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: object

Default: []

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


# ---

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

`tls.client_certs[].cert`

A plain text certificate to use.

Type: string

Default: ""

`tls.client_certs[].cert_file`

The path of a certificate to use.

Type: string

Default: ""

`tls.client_certs[].key`

A plain text certificate key to use.

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`

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.

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.

Requires version 3.45.0 or later.

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.

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`

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: ""

# Examples:
root_cas_file: ./root_cas.pem

`tls.skip_cert_verify`

Whether to skip server side certificate verification.

Type: bool

Default: false

`url`

The base URL of the schema registry service.

Type: string

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schema_registry_encode

Avro JSON format

Known issues

Protobuf format

Multiple message support

Fields

avro

avro.namespace

avro.raw_json

avro.record_name

basic_auth

basic_auth.enabled

basic_auth.password

basic_auth.username

format

jwt

jwt.claims

jwt.enabled

jwt.headers

jwt.private_key_file

jwt.signing_method

normalize

oauth

oauth.access_token

oauth.access_token_secret

oauth.consumer_key

oauth.consumer_secret

oauth.enabled

refresh_period

schema_metadata

subject

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.root_cas

tls.root_cas_file

tls.skip_cert_verify

url

Simple online edits

Contribution guide

`avro`

`avro.namespace`

`avro.raw_json`

`avro.record_name`

`basic_auth`

`basic_auth.enabled`

`basic_auth.password`

`basic_auth.username`

`format`

`jwt`

`jwt.claims`

`jwt.enabled`

`jwt.headers`

`jwt.private_key_file`

`jwt.signing_method`

`normalize`

`oauth`

`oauth.access_token`

`oauth.access_token_secret`

`oauth.consumer_key`

`oauth.consumer_secret`

`oauth.enabled`

`refresh_period`

`schema_metadata`

`subject`

`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.root_cas`

`tls.root_cas_file`

`tls.skip_cert_verify`

`url`