HTTP binding spec

Detailed documentation on the HTTP binding component

Alternative

The service invocation API allows invoking non-Dapr HTTP endpoints and is the recommended approach. Read “How-To: Invoke Non-Dapr Endpoints using HTTP” for more information.

Setup Dapr component

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: <NAME>
spec:
  type: bindings.http
  version: v1
  metadata:
    - name: url
      value: "http://something.com"
    #- name: maxResponseBodySize
    #  value: "100Mi" # OPTIONAL maximum amount of data to read from a response
    #- name: MTLSRootCA
    #  value: "/Users/somepath/root.pem" # OPTIONAL path to root CA or PEM-encoded string
    #- name: MTLSClientCert
    #  value: "/Users/somepath/client.pem" # OPTIONAL path to client cert or PEM-encoded string
    #- name: MTLSClientKey
    #  value: "/Users/somepath/client.key" # OPTIONAL path to client key or PEM-encoded string
    #- name: MTLSRenegotiation
    #  value: "RenegotiateOnceAsClient" # OPTIONAL one of: RenegotiateNever, RenegotiateOnceAsClient, RenegotiateFreelyAsClient
    #- name: securityToken # OPTIONAL <token to include as a header on HTTP requests>
    #  secretKeyRef:
    #    name: mysecret
    #    key: "mytoken"
    #- name: securityTokenHeader
    #  value: "Authorization: Bearer" # OPTIONAL <header name for the security token>

Spec metadata fields

Field Required Binding support Details Example
url Y Output The base URL of the HTTP endpoint to invoke http://host:port/path, http://myservice:8000/customers
maxResponseBodySize N Output Maximum length of the response to read. A whole number is interpreted as bytes; units such as Ki, Mi, Gi (SI) or `k M
MTLSRootCA N Output Path to root CA certificate or PEM-encoded string
MTLSClientCert N Output Path to client certificate or PEM-encoded string
MTLSClientKey N Output Path client private key or PEM-encoded string
MTLSRenegotiation N Output Type of mTLS renegotiation to be used RenegotiateOnceAsClient
securityToken N Output The value of a token to be added to a HTTP request as a header. Used together with securityTokenHeader
securityTokenHeader N Output The name of the header for securityToken on a HTTP request

The values for MTLSRootCA, MTLSClientCert and MTLSClientKey can be provided in three ways:

  • Secret store reference:

    apiVersion: dapr.io/v1alpha1
    kind: Component
    metadata:
      name: <NAME>
    spec:
      type: bindings.http
      version: v1
      metadata:
      - name: url
        value: http://something.com
      - name: MTLSRootCA
        secretKeyRef:
          name: mysecret
          key: myrootca
    auth:
      secretStore: <NAME_OF_SECRET_STORE_COMPONENT>
    
  • Path to the file: the absolute path to the file can be provided as a value for the field.

  • PEM encoded string: the PEM-encoded string can also be provided as a value for the field.

Binding support

This component supports output binding with the following HTTP methods/verbs:

  • create : For backward compatibility and treated like a post
  • get : Read data/records
  • head : Identical to get except that the server does not return a response body
  • post : Typically used to create records or send commands
  • put : Update data/records
  • patch : Sometimes used to update a subset of fields of a record
  • delete : Delete a data/record
  • options : Requests for information about the communication options available (not commonly used)
  • trace : Used to invoke a remote, application-layer loop- back of the request message (not commonly used)

Request

Operation metadata fields

All of the operations above support the following metadata fields

Field Required Details Example
path N The path to append to the base URL. Used for accessing specific URIs. "/1234", "/search?lastName=Jones"
Field with a capitalized first letter N Any fields that have a capital first letter are sent as request headers "Content-Type", "Accept"

Retrieving data

To retrieve data from the HTTP endpoint, invoke the HTTP binding with a GET method and the following JSON body:

{
  "operation": "get"
}

Optionally, a path can be specified to interact with resource URIs:

{
  "operation": "get",
  "metadata": {
    "path": "/things/1234"
  }
}

Response

The response body contains the data returned by the HTTP endpoint. The data field contains the HTTP response body as a byte slice (Base64 encoded via curl). The metadata field contains:

Field Required Details Example
statusCode Y The HTTP status code 200, 404, 503
status Y The status description "200 OK", "201 Created"
Field with a capitalized first letter N Any fields that have a capital first letter are sent as request headers "Content-Type"

Example

Requesting the base URL


curl -d "{ \"operation\": \"get\" }" \
      http://localhost:<dapr-port>/v1.0/bindings/<binding-name>

curl -d '{ "operation": "get" }' \
      http://localhost:<dapr-port>/v1.0/bindings/<binding-name>

Requesting a specific path


curl -d "{ \"operation\": \"get\", \"metadata\": { \"path\": \"/things/1234\" } }" \
      http://localhost:<dapr-port>/v1.0/bindings/<binding-name>

curl -d '{ "operation": "get", "metadata": { "path": "/things/1234" } }' \
      http://localhost:<dapr-port>/v1.0/bindings/<binding-name>

Sending and updating data

To send data to the HTTP endpoint, invoke the HTTP binding with a POST, PUT, or PATCH method and the following JSON body:

{
  "operation": "post",
  "data": "content (default is JSON)",
  "metadata": {
    "path": "/things",
    "Content-Type": "application/json; charset=utf-8"
  }
}

Example

Posting a new record


curl -d "{ \"operation\": \"post\", \"data\": \"YOUR_BASE_64_CONTENT\", \"metadata\": { \"path\": \"/things\" } }" \
      http://localhost:<dapr-port>/v1.0/bindings/<binding-name>

curl -d '{ "operation": "post", "data": "YOUR_BASE_64_CONTENT", "metadata": { "path": "/things" } }' \
      http://localhost:<dapr-port>/v1.0/bindings/<binding-name>

Using HTTPS

The HTTP binding can also be used with HTTPS endpoints by configuring the Dapr sidecar to trust the server’s SSL certificate.

  1. Update the binding URL to use https instead of http.
  2. If you need to add a custom TLS certificate, refer How-To: Install certificates in the Dapr sidecar, to install the TLS certificates in the sidecar.

Example

Update the binding component

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: <NAME>
  namespace: <NAMESPACE>
spec:
  type: bindings.http
  version: v1
  metadata:
  - name: url
    value: https://my-secured-website.com # Use HTTPS

Install the TLS certificate in the sidecar


When the sidecar is not running inside a container, the TLS certificate can be directly installed on the host operating system.

Below is an example when the sidecar is running as a container. The SSL certificate is located on the host computer at /tmp/ssl/cert.pem.

version: '3'
services:
  my-app:
    # ...
  dapr-sidecar:
    image: "daprio/daprd:1.8.0"
    command: [
      "./daprd",
     "-app-id", "myapp",
     "-app-port", "3000",
     ]
    volumes:
        - "./components/:/components"
        - "/tmp/ssl/:/certificates" # Mount the certificates folder to the sidecar container at /certificates
    environment:
      - "SSL_CERT_DIR=/certificates" # Set the environment variable to the path of the certificates folder
    depends_on:
      - my-app

The sidecar can read the TLS certificate from a variety of sources. See How-to: Mount Pod volumes to the Dapr sidecar for more. In this example, we store the TLS certificate as a Kubernetes secret.

kubectl create secret generic myapp-cert --from-file /tmp/ssl/cert.pem

The YAML below is an example of the Kubernetes deployment that mounts the above secret to the sidecar and sets SSL_CERT_DIR to install the certificates.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
  namespace: default
  labels:
    app: myapp
spec:
  replicas: 1
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
      annotations:
        dapr.io/enabled: "true"
        dapr.io/app-id: "myapp"
        dapr.io/app-port: "8000"
        dapr.io/volume-mounts: "cert-vol:/certificates" # Mount the certificates folder to the sidecar container at /certificates
        dapr.io/env: "SSL_CERT_DIR=/certificates" # Set the environment variable to the path of the certificates folder
    spec:
      volumes:
        - name: cert-vol
          secret:
            secretName: myapp-cert
...

Invoke the binding securely


curl -d "{ \"operation\": \"get\" }" \
      https://localhost:<dapr-port>/v1.0/bindings/<binding-name>

curl -d '{ "operation": "get" }' \
      https://localhost:<dapr-port>/v1.0/bindings/<binding-name>

Using mTLS or enabling client TLS authentication along with HTTPS

You can configure the HTTP binding to use mTLS or client TLS authentication along with HTTPS by providing the MTLSRootCA, MTLSClientCert, and MTLSClientKey metadata fields in the binding component.

These fields can be passed as a file path or as a pem encoded string:

  • If the file path is provided, the file is read and the contents are used.
  • If the PEM-encoded string is provided, the string is used as is.

When these fields are configured, the Dapr sidecar uses the provided certificate to authenticate itself with the server during the TLS handshake process.

If the remote server is enforcing TLS renegotiation, you also need to set the metadata field MTLSRenegotiation. This field accepts one of following options:

  • RenegotiateNever
  • RenegotiateOnceAsClient
  • RenegotiateFreelyAsClient

For more details see the Go RenegotiationSupport documentation.

You can use this when the server with which the HTTP binding is configured to communicate requires mTLS or client TLS authentication.