Last time we looked at the use of node-Red file classification nodes. With storage nodes, you can create files, append content to specific files, and listen for some files to be written

In this article, I will tell you about the nodes under the network classification in Node-Red. There are 12 nodes under this classification.

  • mqtt inConnect to the MQTT broker and subscribe to messages from the specified topic.
  • mqtt outConnect to the MQTT broker and publish the message.
  • http inCreate the HTTP endpoint used to create the Web service.
  • http responseSends the response back to the request received from the HTTP input node.
  • http requestSend the HTTP request and return the response.
  • websocket inWebSocket input node.
  • websocket outWebSocket output node.
  • tcp inProvides TCP input options. You can connect to a remote TCP port or accept incoming connections.
  • tcp outProvides options for TCP output. You can connect to a remote TCP port, accept incoming connections, or reply to messages received from a TCP In node.
  • tcp requestA simple TCP request node. Sends msg.payload to the server’s TCP port and expects a response.
  • udp inUDP input node. Generates a Buffer, string, or Base64 encoded string in msg.payload. Multicast is supported.
  • upd outThis object sends msg.payload to the specified UDP host and port. Multicast is supported.

This module is the core module of Node-Red. If you want to communicate with hardware and equipment, you need to use this module to achieve. HTTP in, HTTP out, HTTP request, ‘

http in

This node can be used to create an HTTP interface to a Web service in the following ways GET.POST.PUT.DELETE PATHCAlso supports POST upload files writing an interface is very simple

  • Create an Http IN node
  • Use the function node to process the data to be returned
  • Use the HTTP OUT node to return data to the client

This is a completed HTTP request link.

The output from this node is as follows

Payload GET Requests an object that contains any query string parameters. Or contain the HTTP request body. ReqHTTP request object. This object contains multiple attributes about the request information.

  • Body – The body of the incoming request. The format will depend on the request.
  • Headers – The object that contains the HTTP request header.
  • Query – An object that contains any query string arguments.
  • Params – An object that contains any routing parameters.
  • Cookies – Contains objects that request cookies.
  • Files – The object that contains the uploaded file if file upload is enabled on the node.

Res HTTP response object. This property should not be used directly; The HTTP Response node records how requests are responded to. This property must remain on the message passed to the response node.

We create such an interface

The path of the interface is/getName using the GET request

And then add one in the backfunctionnode

Then you can append the payload message body to the flow

http response

This node is used to send the HTTP response back to the client with these elements in the body of the message returned

  • Payload Indicates the body of the response.
  • StatusCode, if set, is used as the response statusCode. Default value: 200.
  • Headers, if set, provides the HTTP header to be included in the response.
  • Cookies, if set, can be used to set or delete cookies.

To create ahttp responseChase to the previous flow

After deployment, type IP :port/ getName in your browser and you’ll see a return body like this

http request

This node sends the HTTP request and returns the response. There are inputs, there are outputs and the inputs have these parameters

  • urlIf not configured in the node, this optional property sets the REQUESTED URL.
  • methodIf not configured in the node, this optional property sets the HTTP method for the request. It must be one of GET,PUT,POST,PATCH, or DELETE.
  • headersSets the HTTP header for the request.
  • cookiesIf set, it can be used to send cookies with requests.
  • payloadSend is the body of the request.
  • rejectUnauthorizedIf set to false, HTTPS sites that use self-signed certificates are allowed to make requests.
  • followRedirectsIf set to false, follow redirects are prevented (HTTP 301). The default value is true
  • requestTimeoutIf set to a positive number of milliseconds, the httpRequestTimeout parameter of the global setting will be overridden.

Output parameters

  • payloadThe body of the response. You can configure the node to return the body as a string, try to parse it as a JSON string, or leave it as a binary buffer.
  • statusCodeThe status code of the response, or an error code if the request cannot be completed.
  • headersThe object that contains the response header.
  • responseUrlThis property is the FINAL redirected URL if any redirection occurs while the request is being processed. Otherwise, the URL of the original request.
  • responseCookiesIf the response contains cookies, this property is the object of the ‘name/value’ key-value pair for each cookie.
  • redirectListIf the request is redirected once or more, the accumulated information is added to this property. “Location” is the next redirect target. A cookie is a cookie returned from a redirected source.

Here is an example

Request an interface, you can configure the certificate, select the request mode

Add inject node in front of the node, which is used to trigger the interface, and add debug node to print messages after the node

Trigger the flow after deployment