SearXNG Common Module

This document provides a reference for the modules/SearXNG_Common Terraform module. This is the Common tier module that provides application-specific configuration shared between SearXNG_CloudRun and SearXNG_GKE.

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1. Module Overview

SearXNG Common is the application-specific configuration layer for SearXNG. It is called by both SearXNG CloudRun and SearXNG GKE to produce the standardised config, secret_ids, and storage_buckets outputs that the Foundation Modules consume.

Responsibilities:

• Defines the SearXNG container configuration: image (searxng/searxng), container port (8080), health probe paths (/healthz), and default environment variables.
• Auto-generates SEARXNG_SECRET (session key) and stores it in Secret Manager. Outputs the secret ID and explicit value via secret_ids.
• Outputs an empty storage_buckets list (SearXNG is stateless — no GCS bucket required).
• Sets the enable_image_mirroring flag to mirror the SearXNG image into Artifact Registry.

Note on SEARXNG_SECRET: This secret is the cryptographic session key for SearXNG. All running instances must share the same value. SearXNG Common generates it once and stores it in Secret Manager. For GKE deployments, the explicit value is also output to allow the CSI driver to inject it without read-after-write consistency issues on first apply.

Outputs:

Output	Description
config	SearXNG application configuration object consumed by Foundation Modules.
secret_ids	Map containing SEARXNG_SECRET → Secret Manager secret ID.
storage_buckets	Empty list (SearXNG has no persistent storage).

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2. Variables

SearXNG Common variables are set by the calling Application Module.

Variable	Default	Description
project_id	—	GCP project ID. Required.
deployment_id	""	Deployment ID suffix.
resource_prefix	""	Optional resource prefix override. Pass App GKE's resource prefix for GKE deployments.
tenant_deployment_id	'demo'	Deployment environment identifier.
resource_labels	{}	Labels for all resources.
application_name	'searxng'	Internal application name used in resource naming.
application_version	'latest'	SearXNG image version tag.
enable_image_mirroring	true	Whether to mirror the container image into Artifact Registry.
cpu_limit	'500m'	CPU limit forwarded to the Foundation Module.
memory_limit	'512Mi'	Memory limit forwarded to the Foundation Module.
min_instance_count	0	Minimum instances.
max_instance_count	3	Maximum instances.
startup_probe	{ path="/healthz", initial_delay_seconds=10, failure_threshold=6 }	Startup probe configuration.
liveness_probe	{ path="/healthz", initial_delay_seconds=15, failure_threshold=3 }	Liveness probe configuration.
environment_variables	{}	Additional plain-text env vars.

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3. Application Module Wiring

module "searxng_app" {
  source = "../SearXNG_Common"

  deployment_id        = local.random_id
  project_id           = var.project_id
  tenant_deployment_id = var.tenant_deployment_id
  resource_labels      = var.resource_labels
  application_name     = var.application_name
  application_version  = var.application_version
  cpu_limit            = var.cpu_limit
  memory_limit         = var.memory_limit
  startup_probe        = var.startup_probe
  liveness_probe       = var.liveness_probe
  environment_variables = var.environment_variables
  enable_image_mirroring = var.enable_image_mirroring
}

locals {
  searxng_module = merge(module.searxng_app.config, {
    min_instance_count = 0   # Cloud Run: hardcoded to 0
    max_instance_count = var.max_instance_count
  })

  application_modules = { searxng = local.searxng_module }

  module_env_vars = {
    SEARXNG_BIND_ADDRESS = "0.0.0.0:8080"
    ENABLE_REDIS         = tostring(var.enable_redis)
    REDIS_URL            = var.enable_redis ? "redis://${coalesce(var.redis_host, "127.0.0.1")}:${var.redis_port}" : ""
  }

  module_secret_env_vars = { SEARXNG_SECRET = module.searxng_app.secret_ids.SEARXNG_SECRET }
  module_storage_buckets = module.searxng_app.storage_buckets
}