HAProxy

This content bundle provides comprehensive tooling for deploying and managing HAProxy load balancers in both standalone and clustered configurations.

Design Philosophy

The content bundle follows a flexible, infrastructure-as-code approach with two key design principles:

1. Auto Discovery: The primary design leverages "Filter objects" stored in the haproxy/filters parameter to discover backend nodes. These nodes are then used to automatically generate the haproxy.cfg file. This approach enables dynamic, scalable load balancer configurations.

2. Manual Override: For scenarios requiring precise control, the bundle supports explicit configuration through override parameters, bypassing the auto-discovery mechanism.

Deployment Methods

1. Auto Discovery Mode

Deploy using built-in service discovery: - Set haproxy/role on nodes to define their roles - Define services using haproxy/backend/services on backend nodes - Configure discovery using haproxy/filters on load balancer nodes - The system automatically generates frontend and backend maps - Configuration rendered through the template system

2. Manual Override Mode

Deploy using explicit configuration: - Set haproxy/filters to an empty array - Define haproxy/frontend/map-override and haproxy/backend/map-override - Configuration renders using your explicit settings

Auto Discovery Example

This is a minimal cluster profile that leverages AutoDiscovery, with optional haproxy/backend/config and haproxy/frontend/config parameters:

Params:
  universal/application: my-ha-cluster
  universal/workflow-chain-index-override: cluster
  on-complete-work-order-mode: true
  cluster/wait-for-members: false
  cluster/machine-types:
    - load-balancer
    - backend
  cluster/machines:
    load-balancer:
      pipeline: universal-application-haproxy-server
      names: ['my-ha-proxy.local.domain']
      Params:
        haproxy/role: load-balancer
        haproxy/filters:
          - Profiles=Eq(universal-application-apache-web-server) Params.haproxy/role=Eq(backend) Profiles=Eq({{ .Machine.Name }})
        haproxy/frontend/config:  # Optional
          http:
            mode: http
        haproxy/backend/config:  # Optional
          http:
            mode: http
            balance: roundrobin
    web-backend:
      pipeline: universal-application-apache-web-server
      names: ['web01.local.domain', 'web02.local.domain']
      Params:
        haproxy/role: backend
        haproxy/backend/services:
          http: 80

Manual Override Example

This is a minimal example of a manual override deployment, with overridden config file. These profiles and params would be assigned to a machine or a profile that is assigned to a machine.

Profiles:
  - universal-application-haproxy-server
Params:
  haproxy/config-template: my-haproxy.cfg.tmpl
  haproxy/frontend/map-override:
    http:
      http: 80
      ssl: [443, 80443]
  haproxy/backend/map-override:
    http:
      - server d52-54-00-f9-6c-09.example.com 192.168.122.13:80 maxconn 32
      - server d52-54-00-08-5a-04.example.com 192.168.122.14:80 maxconn 32
      - server d52-54-00-96-b2-4a.example.com 192.168.122.15:80 maxconn 32

Cluster Pipeline Example

This is a minimal example cluster universal-application. This example is used to define a load balancer to multiple generic apache web backend using roundrobin load balancing. This configuration will provision 3 machines:

• my-ha-proxy.local.domain (load-balancer)
• web01.local.domain (apache web-backend)
• web02.local.domain (apache web-backend)

The configuration from the previous step is applied within the cluster/machines.load-balancer section, which is copied to a machine when the cluster is provisioned.

Params:
  universal/application: my-ha-cluster
  universal/workflow-chain-index-override: cluster
  on-complete-work-order-mode: true
  cluster/wait-for-members: false
  cluster/machine-types:
    - load-balancer
    - backend
  cluster/machines:
    load-balancer:
      pipeline: universal-application-haproxy-server
      names: ['my-ha-proxy.local.domain']
      Params:
        haproxy/role: load-balancer
        haproxy/filters:
          - Profiles=Eq(universal-application-apache-web-server) Params.haproxy/role=Eq(backend) Profiles=Eq({{ .Machine.Name }})
        haproxy/frontend/config:
          http:
            mode: http
        haproxy/backend/config:
          http:
            mode: http
            balance: roundrobin
    web-backend:
      pipeline: universal-application-apache-web-server
      names: ['web01.local.domain', 'web02.local.domain']
      Params:
        haproxy/role: backend
        haproxy/backend/services:
          http: 80

Configuration Customization

The bundle supports full customization of the HAProxy configuration: - Override the config template using haproxy/config-template - Customize frontend settings with haproxy/frontend/config - Customize backend settings with haproxy/backend/config - Define per-service configuration with haproxy/backend/services/config

Requirements

• Digital Rebar Provision v4.14.0 or later
• DRP Community Content Bundle
• Either Alma Linux 9 or VMware Photon 5 for target nodes
• Network access to package repositories
• Appropriate permissions for service management

Getting Started

1. Choose your deployment method (Auto Discovery or Manual Override)
2. Apply the universal-application-haproxy-server profile
3. Configure required parameters
4. Run the workflow

For detailed parameter descriptions and examples, refer to the individual component documentation.