Piping Firebase stream to Express response result in HPE_INVALID_CONSTANT - node.js

Question

I am trying to stream a video (mp4) from firebase storage to <video> on client. What I'm doing is using createReadStream and piping it to Express response object. However on the client this error is thrown:
Proxy error: Could not proxy request /movie/600d31f192e0941f9c4b4773/stream from localhost:3000 to http://localhost:5000/.
[1] See https://nodejs.org/api/errors.html#errors_common_system_errors for more information (HPE_INVALID_CONSTANT).
const streamMovie = async (req, res) => {
const range = req.headers.range
const movie = await Movie.findById(req.params.id)
const bucket = firebase.storage().bucket()
// Get video size
const videoFile = bucket.file(movie.videoFileUrl)
const [metadata] = await videoFile.getMetadata()
const videoSize = metadata.size
// Parse range
const parts = range.replace('bytes=', '').split('-')
const start = parseInt(parts[0], 10)
const end = parts[1] ? parseInt(parts[1], 10) : videoSize - 1
res.writeHead(206, {
'Content-Type': 'video/mp4',
'Content-Range': `bytes ${start}-${end}/${videoSize}`,
'Content-Length': `${end - start + 1}`,
'Accept-Ranges': 'bytes',
})
videoFile.createReadStream({ start, end }).pipe(res)
}
I could not pinpoint the source of the error since I'm pretty inexperienced with streams. Any help is appreciated. Thanks!

Answer 1

If you want to stream a video file to the express response object, you can use the code example from the client library official docs. I have tested the following sample successfully:
const express = require('express')
const app = express()
const port = 3000
app.get('/', (req, res) => {
const {Storage} = require('#google-cloud/storage');
const storage = new Storage();
const bucket = storage.bucket('bucket123');
const remoteFile = bucket.file('videotest123.mp4');
res.writeHead(200, {
'Content-Type': 'video/mp4',
'Content-Range': 'bytes=0-',
'Accept-Ranges': 'bytes',
})
remoteFile.createReadStream()
.on('error', function(err) {
res.send('there was an error');
})
.on('response', function(response) {})
.on('end', function() {})
.pipe(res);
})
app.listen(port, () => {
console.log(`App listening at http://localhost:${port}`)
})
If you want to request only certain parts of the video (aka Google Cloud Storage object), you can specify within the createReadStream method the start and end options.
const remoteFile = bucket.file('videotest123');
logFile.createReadStream({
start: 10000,
end: 20000
})
.on('error', function(err) {})
.pipe(res);
In regards to the HPE_INVALID_CONSTANT message, I have found here that the message indicates an web server response malformed. In this case the resobject from the code.
I hope you find this useful