gzip in gke with nginx-ingress

Question

I'm trying to configure gzip to work in a python application that runs on a kubernetes with nginx-ingress in GKE. But I discovered that it is no use to enable gzip in the ingress-controller config-map because I need to enable compression on the backend as I understand it.

How can I enable compression on the backend of my python application to run gzip on nginx controller?

My main problem is that searching here in stackoverflow I know I need to put the compression in the backend, just do not know how to do this.

Answer 1

Focusing specifically on the title of this question and extending on the example of such setup as pointed by user @Raunak Jhawar.

You can configure your nginx-ingress to compress the data by updating the ingress-nginx-controller configmap.

This would work on the path:

• Pod ----> NGINX Ingress controller - GZIP -> Client (Web browser)

To enable such setup you will need to edit the Ingress controller configmap like below:

• $ kubectl edit configmap -n ingress-nginx ingress-nginx-controller

data: # ADD IF NOT PRESENT
  use-gzip: "true" # ENABLE GZIP COMPRESSION
  gzip-types: "*" # SPECIFY MIME TYPES TO COMPRESS ("*" FOR ALL) 

You can find more reference and options to configure by following below link:

• Kubernetes.github.io: Ingress NGINX: User guide: Nginx-configuration: Configmap

A side note!

You can also use other methods of editing resources like: $ kubectl patch

This changes would make the nginx-ingress-controller Pod to be automatically reconfigured.

I've included an example of such setup below.

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To check if the compression occurs and if it's working I've used following setup:

• NGINX Ingress Controller spawned by:
  • Kubernetes.github.io: Ingress NGINX: Deploy: GCE-GKE
• NGINX pod with a 5mb.txt file filled with 0's
• Service and Ingress resource that will expose the NGINX pod with NGINX Ingress Controller

You can check if your setup with nginx-ingress supoorts gzip compression by either:

• Checking with Developer tools with a browser of your choosing:

  • Chrome -> F12 -> Network -> Go to site (or refresh) and press on example file (look on Response Header):

  

• You can also use curl command like below (source):

  • $ curl $URL$ --silent --write-out "%{size_download}\n" --output /dev/null - get size without compression
  • $ curl $URL$ --silent -H "Accept-Encoding: gzip,deflate" --write-out "%{size_download}\n" --output /dev/null - get the size with compression (if supported)

Above methods have shown the compression rate of about 99% (5MB file compressed to 50KB)

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I also encourage you to check below links for additional reference:

• Stackoverflow.com: How can I tell if my server is serving GZipped content?
• Serverfault.com: Gzip compression with nginx - link about images (I have learned the hard way)

Answer 2

This makes this as a nginx conversation. There are a lot of docs available which guides on hows and whats with nginx compression. Essentially, you have to add a bunch of gzip related settings and options in your nginx configuration file.

The tread shared above is a good starter and shows exactly what needs to be on the nginx conf. Please note that, as a good practice, do not compress any/all inbound packets as this essentially adds more compute burden on the CPU. The nginx conf has one option to only compress packets which exceed certain size.