Using request to get snapshot from ONVIF camera

gistfile1.txt

Previous gist: https://gist.github.com/hawkeye64/a30e43c8301626f7687b985b5e7b04bd

Axios couldn't handle working with Axis camera authentication because it uses Realm Digest. I have since changed my code to use the 'request' package.

NOTE: It is very *important* to have request do `'sendImmediately': false` which means that request won't send the authentication until the server (camera) responds in the header with *www-authenticate*, then request will send the authorization at that time.

  commandFetchSnapshot (id) {
    let self = this
    return new Promise((resolve, reject) => {
      let camera = self.cameras[id]
      if (!camera) {
        reject(new Error('Not Found'))
      }
      else {
        // check that we have a snapshotUri attached to this camera
        if ('snapshotUri' in camera) {
          let snapshotUri = camera.snapshotUri.uri
          request({
            method: 'GET',
            uri: snapshotUri,
            gzip: true,
            encoding: 'binary',
            'auth': {
              'user': camera.username,
              'pass': camera.password,
              'sendImmediately': false
            }
          },
          function (error, response, body) {
            if (error) {
              console.error('commandFetchSnapshot error', error)
            }
            else {
              // example: write image to file file to test
              // const outputFilename = '/tmp/testfile.jpg'
              // fs.writeFileSync(outputFilename, body, { encoding: 'binary' })
              // body is the decompressed response body
              let mimeType = response.headers['content-type']
              let b64encoded = Buffer.from(body, 'binary').toString('base64')
              let image = 'data:' + mimeType + ';base64,' + b64encoded
              let data = {
                mimeType: mimeType,
                image: image
              }
              self.cameraOnline(camera)
              resolve(data)
            }
          })
        }
        else {
          reject(new Error('No snapshotUri in commandFetchSnapshot'))
        }
      }
    })
  }