Node.js http2stream.pushAllowed Method
The http2stream.pushAllowed is an inbuilt application programming interface of class Http2Stream within http2 module which is used to check if the header were sent or not.
Syntax:
const http2stream.pushAllowed
Parameters: This method does not accept any parameter.
Return Value: This method returns true if the remote peer accepts push streams otherwise false.
How to generate private and public key certificate
Private key
Step – 1: Open notepad and copy and paste the following key
-----BEGIN RSA PRIVATE KEY----- MIICXQIBAAKBgQC38R9wXcUbhOd44FavgmE5R3K4JeYOHLnI7dUq1B8/Gv7l3SOg JKef/m9gM1KvUx951mapXGtcWgwB08J3vUE2YOZ4tWJArrVZES0BI/RmFAyhQFP5 HcWl3LSM9LRihP98F33oIkKaCxA5LxOrkgpV4HrUzIKTABDYah7RPex1WQIDAQAB AoGBAIXR71xxa9gUfc5L7+TqBs+EMmrUb6Vusp8CoGXzQvRHMJCMrMFySV0131Nu o0YYRDsAh1nJefYLMNcXd1BjqI+qY8IeRsxaY+9CB2KKGVVDO2uLdurdC2ZdlWXT Vwr3dDoyR0trnXJMmH2ijTeO6bush8HuXxvxJBjvEllM5QYxAkEA3jwny9JP+RFu 0rkqPBe/wi5pXpPl7PUtdNAGrh6S5958wUoR4f9bvwmTBv1nQzExKWu4EIp+7vjJ fBeRZhnBvQJBANPjjge8418PS9zAFyKlITq6cxmM4gOWeveQZwXVNvav0NH+OKdQ sZnnDiG26JWmnD/B8Audu97LcxjxcWI8Jc0CQEYA5PhLU229lA9EzI0JXhoozIBC TlcKFDuLm88VSmlHqDyqvF9YNOpEdc/p2rFLuZS2ndB4D+vu6mjwc5iZ3HECQCxy GBHRclQ3Ti9w76lpv+2kvI4IekRMZWDWnnWfwta+DGxwCgw2pfpleBZkWqdBepb5 JFQbcxQJ0wvRYXo8qaUCQQCgTvWswBj6OTP7LTvBlU1teAN2Lnrk/N5AYHZIXW6m nUG9lYvH7DztWDTioXMrruPF7bdXfZOVJD8t0I4OUzvC -----END RSA PRIVATE KEY-----
Step – 2: Save as private-key.pem
Public certificate
Step – 1: Open notepad and copy and paste the following key
-----BEGIN CERTIFICATE----- MIICfzCCAegCCQDxxeXw914Y2DANBgkqhkiG9w0BAQsFADCBgzELMAkGA1UEBhMC SU4xEzARBgNVBAgMCldlc3RiZW5nYWwxEDAOBgNVBAcMB0tvbGthdGExFDASBgNV BAoMC1BhbmNvLCBJbmMuMRUwEwYDVQQDDAxSb2hpdCBQcmFzYWQxIDAeBgkqhkiG 9w0BCQEWEXJvZm9mb2ZAZ21haWwuY29tMB4XDTIwMDkwOTA1NTExN1oXDTIwMTAw OTA1NTExN1owgYMxCzAJBgNVBAYTAklOMRMwEQYDVQQIDApXZXN0YmVuZ2FsMRAw DgYDVQQHDAdLb2xrYXRhMRQwEgYDVQQKDAtQYW5jbywgSW5jLjEVMBMGA1UEAwwM Um9oaXQgUHJhc2FkMSAwHgYJKoZIhvcNAQkBFhFyb2ZvZm9mQGdtYWlsLmNvbTCB nzANBgkqhkiG9w0BAQEFAAOBjQAwgYkCgYEAt/EfcF3FG4TneOBWr4JhOUdyuCXm Dhy5yO3VKtQfPxr+5d0joCSnn/5vYDNSr1MfedZmqVxrXFoMAdPCd71BNmDmeLVi QK61WREtASP0ZhQMoUBT+R3Fpdy0jPS0YoT/fBd96CJCmgsQOS8Tq5IKVeB61MyC kwAQ2Goe0T3sdVkCAwEAATANBgkqhkiG9w0BAQsFAAOBgQATe6ixdAjoV7BSHgRX bXM2+IZLq8kq3s7ck0EZrRVhsivutcaZwDXRCCinB+OlPedbzXwNZGvVX0nwPYHG BfiXwdiuZeVJ88ni6Fm6RhoPtu2QF1UExfBvSXuMBgR+evp+e3QadNpGx6Ppl1aC hWF6W2H9+MAlU7yvtmCQQuZmfQ== -----END CERTIFICATE-----
Step – 2: Save as public-cert.pem
Example 1: Filename: index.js
// Node.js program to demonstrate the // Http2Stream.pushAllowed method const http2 = require('http2'); const fs = require('fs'); // Private key and public certificate // for access const options = { key: fs.readFileSync('private-key.pem'), cert: fs.readFileSync('public-cert.pem'), }; // Creating and initializing server // by using http2.createServer() method const server = http2.createServer(options); server.on('stream', (stream, requestHeaders) => { stream.respond({ ':status': 200, 'content-type': 'text/plain' }); stream.write('hello '); // Checking if header is sent or not // by using pushAllowed method const status = stream.pushAllowed; if(status) stream.end("push stream is accepted"); else stream.end("push stream is not accepted"); // Stopping the server by // using the close() method server.close(()=>{ console.log("server destroyed"); }) }); server.listen(8000); // Creating and initializing client // by using tls.connect() method const client = http2.connect( 'http://localhost:8000'); const req = client.request({ ':method': 'GET', ':path': '/' }); req.on('response', (responseHeaders) => { console.log("status : " + responseHeaders[":status"]); }); req.on('data', (data) => { console.log('Received: %s ', data.toString().replace(/(\n)/gm,"")); }); req.on('end', () => { client.close(()=>{ console.log("client destroyed"); }) }); |
Output:
status : 200 Received: hello Received: push stream is accepted client destroyed server destroyed
Run the index.js file using the following command:
node index.js
Example 2:Filename: index.js
// Node.js program to demonstrate the // Http2Stream.pushAllowed method const http2 = require('http2'); const fs = require('fs'); // Private key and public certificate // for access const options = { key: fs.readFileSync('private-key.pem'), cert: fs.readFileSync('public-cert.pem'), }; // Creating and initializing server // by using http2.createServer() api const server = http2.createServer(options); server.on('stream', (stream, requestHeaders) => { // checking if header is sent or not // by using pushAllowed method const status = stream.pushAllowed; if(status) console.log("push stream is accepted"); else console.log("push stream is not accepted"); // Stopping the server by // using the close() method server.close(()=>{ console.log("server destroyed"); }) }); server.listen(8000); // Creating and initializing client // by using tls.connect() method const client = http2.connect( 'http://localhost:8000'); const req = client.request({ ':method': 'GET', ':path': '/' }); req.on('response', (responseHeaders) => { console.log("status : " + responseHeaders[":status"]); }); req.on('data', (data) => { console.log('Received: %s ', data.toString().replace(/(\n)/gm,"")); }); req.on('end', () => { client.close(()=>{ console.log("client destroyed"); }) }); |
Output:
push stream is accepted
Run the index.js file using the following command:
node index.js
Reference: https://nodejs.org/dist/latest-v12.x/docs/api/http2.html#http2_http2stream_pushallowed