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grpc_client

EXPERIMENTAL

This component is experimental and therefore subject to change or removal outside of major version releases.

Sends messages to a GRPC server.

# Common config fields, showing default values
output:
  label: ""
  grpc_client:
    address: localhost:50051 # No default (required)
    service: helloworld.Greeter # No default (required)
    method: SayHello # No default (required)
    rpc_type: unary
    reflection: false
    proto_files: []
    health_check: {}
    max_in_flight: 64
    batching:
      count: 0
      byte_size: 0
      period: ""
      jitter: 0
      check: ""

Expected Message Format​

Either the field reflection or proto_files must be supplied, which will provide the protobuf schema Bento will use to marshall the Bento message into protobuf.

Propagating Responses​

It's possible to propagate the response(s) from each gRPC method invocation back to the input source by setting propagate_response to true. Only inputs that support synchronous responses are able to make use of these propagated responses. Also the rpc_typeeffects the behavior of what is returned via a sync_response:

  • unary: The response propagated is a single message.
  • client_stream: The response propagated is a single message.
  • server_stream: The response propagated is a batch of messages.
  • bidi: Any inbound message from the server is discarded.

Examples​

Use Bento as a reverse proxy to translate HTTP requests into gRPC calls and return the response

input:
  http_server:
    path: /post

output:
  grpc_client:
    address: localhost:51286
    service: helloworld.Greeter
    method: SayHello
    propagate_response: true
    reflection: true

Fields​

address​

The URI of the gRPC target to connect to.

Type: string

# Examples

address: localhost:50051

service​

The name of the service.

Type: string

# Examples

service: helloworld.Greeter

method​

The name of the method to invoke

Type: string

# Examples

method: SayHello

rpc_type​

The type of the rpc method.

Type: string
Default: "unary"
Options: unary, client_stream, server_stream, bidi.

reflection​

If set to true, Bento will acquire the protobuf schema for the method from the server via gRPC Reflection.

Type: bool
Default: false

proto_files​

A list of filepaths of .proto files that should contain the schemas necessary for the gRPC method.

Type: array
Default: []

# Examples

proto_files:
  - ./grpc_test_server/helloworld.proto

propagate_response​

Whether responses from the server should be propagated back to the input.

Type: bool
Default: false

health_check​

Sorry! This field is missing documentation.

Type: object

health_check.enabled​

Whether Bento should healthcheck the unary Check rpc endpoint on init connection: gRPC Health Checking

Type: bool
Default: false

health_check.service​

The name of the service to healthcheck, note that the default value of "", will attempt to check the health of the whole server

Type: string
Default: ""

tls​

Custom TLS settings can be used to override system defaults.

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
Requires version 1.0.0 or newer

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 that usually shouldn't be added to a config directly, read our secrets page for more info.

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.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
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[].key​

A plain text certificate key to use.

Secret

This field contains sensitive information that usually shouldn't be added to a config directly, read our secrets page for more info.

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. Warning: Since it 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 that usually shouldn't be added to a config directly, read our secrets page for more info.

Type: string
Default: ""

# Examples

password: foo

password: ${KEY_PASSWORD}

oauth2​

Allows you to specify open authentication via OAuth version 2 using the client credentials token flow.

Type: object

oauth2.enabled​

Whether to use OAuth version 2 in requests.

Type: bool
Default: false

oauth2.client_key​

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

Type: string
Default: ""

oauth2.client_secret​

A secret used to establish ownership of the client key.

Secret

This field contains sensitive information that usually shouldn't be added to a config directly, read our secrets page for more info.

Type: string
Default: ""

oauth2.token_url​

The URL of the token provider.

Type: string
Default: ""

oauth2.scopes​

A list of optional requested permissions.

Type: array
Default: []

oauth2.endpoint_params​

A list of optional endpoint parameters, values should be arrays of strings.

Type: object
Default: {}

# Examples

endpoint_params:
  bar:
    - woof
  foo:
    - meow
    - quack

max_in_flight​

The maximum number of messages to have in flight at a given time. Increase this to improve throughput.

Type: int
Default: 64

batching​

Allows you to configure a batching policy.

Type: object

# Examples

batching:
  byte_size: 5000
  count: 0
  period: 1s

batching:
  count: 10
  period: 1s

batching:
  check: this.contains("END BATCH")
  count: 0
  period: 1m

batching:
  count: 10
  jitter: 0.1
  period: 10s

batching.count​

A number of messages at which the batch should be flushed. If 0 disables count based batching.

Type: int
Default: 0

batching.byte_size​

An amount of bytes at which the batch should be flushed. If 0 disables size based batching.

Type: int
Default: 0

batching.period​

A period in which an incomplete batch should be flushed regardless of its size.

Type: string
Default: ""

# Examples

period: 1s

period: 1m

period: 500ms

batching.jitter​

A non-negative factor that adds random delay to batch flush intervals, where delay is determined uniformly at random between 0 and jitter * period. For example, with period: 100ms and jitter: 0.1, each flush will be delayed by a random duration between 0-10ms.

Type: float
Default: 0

# Examples

jitter: 0.01

jitter: 0.1

jitter: 1

batching.check​

A Bloblang query that should return a boolean value indicating whether a message should end a batch.

Type: string
Default: ""

# Examples

check: this.type == "end_of_transaction"

batching.processors​

A list of processors to apply to a batch as it is flushed. This allows you to aggregate and archive the batch however you see fit. Please note that all resulting messages are flushed as a single batch, therefore splitting the batch into smaller batches using these processors is a no-op.

Type: array

# Examples

processors:
  - archive:
      format: concatenate

processors:
  - archive:
      format: lines

processors:
  - archive:
      format: json_array