Selectively disable compression based on the incoming request. Fixes #10377

[georgyberdyshev]

Hello @benjamn,

this a PR to fix #10377

Currently Auto-compress forces gzip compression, that cannot be disabled and therefore interferes with the possibility to enable a different Content-Encoding on a frontend-proxy.

Adding an environment variable to disable Auto-compress will allow to use Brotli compression through a front-end proxy, such as nginx, and provide better compression ratio than gzip.

METEOR_DISABLE_AUTO_COMPRESS=1

For more details, please see:
#10377

Thanks, Georgy

[benjamn]

@georgyberdyshev We're open to this solution (since it will solve your use case), but I was just wondering if your nginx proxy is stripping/disabling the Accept-Encoding header before forwarding the request to the Meteor server? Ideally the Meteor server (i.e. the compress() middleware) would honor (the absence of) that header, rather than blindly compressing everything. Alternatively/additionally, we could configure the compression middleware with a filter that would selectively disable compression based on the incoming request.

[georgyberdyshev]

Hello @benjamn,

thank you for your reply. Meteor behind the nginx proxy correctly receives the Accept-Encoding request HTTP header:

nginx log:
10.0.2.2 - - [21/Dec/2018:17:40:51 +0000] "GET /headers HTTP/2.0" 200 595 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.28 Safari/537.36" "-" "gzip, deflate, br"

Meteor:

{ 'x-forwarded-host': 'localhost',
  'x-forwarded-proto': 'http',
  'x-forwarded-port': '80',
  'accept-language': 'en-US,en;q=0.9',
  'accept-encoding': 'gzip, deflate, br',
  accept: 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8',
  'user-agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.28 Safari/537.36',
  'upgrade-insecure-requests': '1',
  'cache-control': 'max-age=0',
  'x-no-compression': 'x-no-compression',
  connection: 'close',
  host: 'localhost',
  'x-forwarded-for': '10.0.2.2,127.0.0.1' }

I have updated the PR to use the x-no-compression HTTP request header, as this will provide more granularity and also makes an additional environment variable for Meteor obsolete.

Thanks, Georgy

[georgyberdyshev]

Thanks @benjamn !