cozystack/packages/apps/http-cache

Managed Nginx Caching Service

The Nginx Caching Service is designed to optimize web traffic and enhance web application performance. This service combines custom-built Nginx instances with HAproxy for efficient caching and load balancing.

Deployment infromation

The Nginx instances include the following modules and features:

• VTS module for statistics
• Integration with ip2location
• Integration with ip2proxy
• Support for 51Degrees
• Cache purge functionality

HAproxy plays a vital role in this setup by directing incoming traffic to specific Nginx instances based on a consistent hash calculated from the URL. Each Nginx instance includes a Persistent Volume Claim (PVC) for storing cached content, ensuring fast and reliable access to frequently used resources.

Deployment Details

The deployment architecture is illustrated in the diagram below:

          ┌─────────┐
          │ metallb │ arp announce
          └────┬────┘
               │
               │
       ┌───────▼───────────────────────────┐
       │  kubernetes service               │  node
       │ (externalTrafficPolicy: Local)    │  level
       └──────────┬────────────────────────┘
                  │
                  │
             ┌────▼────┐  ┌─────────┐
             │ haproxy │  │ haproxy │   loadbalancer
             │ (active)│  │ (backup)│      layer
             └────┬────┘  └─────────┘
                  │
                  │ balance uri whole
                  │ hash-type consistent
           ┌──────┴──────┬──────────────┐
       ┌───▼───┐     ┌───▼───┐      ┌───▼───┐ caching
       │ nginx │     │ nginx │      │ nginx │  layer
       └───┬───┘     └───┬───┘      └───┬───┘
           │             │              │
      ┌────┴───────┬─────┴────┬─────────┴──┐
      │            │          │            │
  ┌───▼────┐  ┌────▼───┐  ┌───▼────┐  ┌────▼───┐
  │ origin │  │ origin │  │ origin │  │ origin │
  └────────┘  └────────┘  └────────┘  └────────┘

Known issues

VTS module shows wrong upstream resonse time

• https://github.com/vozlt/nginx-module-vts/issues/198

Parameters

Common parameters

Name	Description	Value
external	Enable external access from outside the cluster	false
size	Persistent Volume size	10Gi
storageClass	StorageClass used to store the data	""
haproxy.replicas	Number of HAProxy replicas	2
nginx.replicas	Number of Nginx replicas	2
haproxy.resources		{}
haproxy.resourcesPreset	Use a common resources preset when resources is not set explicitly. (allowed values: none, nano, micro, small, medium, large, xlarge, 2xlarge)	nano
nginx.resources	Resources	{}
nginx.resourcesPreset	Use a common resources preset when resources is not set explicitly. (allowed values: none, nano, micro, small, medium, large, xlarge, 2xlarge)	nano

Configuration parameters

Name	Description	Value
endpoints	Endpoints configuration	[]