feat(gateway): add idle-timeout setting for client connections (#371)

Add a new setting `gateway.config.idle-timeout` to configure the idle
timeout for client connections in the Gateway. The default Caddy idle
timeout is 5 minutes, which can be too short for long-running requests.

This setting allows operators to increase the timeout for stacks that
need longer request durations (e.g., Ledger bulk operations).

Author: flemzord

docs/09-Configuration reference/01-Settings.md

@@ -61,6 +61,7 @@ While we have some basic types (string, number, bool ...), we also have some com
 | gateway.ingress.tls.enabled                                                              | bool   | true                                                                                                                                                                                                                   | Enable TLS if not enabled at Gateway CRD level                                                                                                                                                                                   |
 | gateway.caddyfile.trusted-proxies                                                        | string | 10.0.0.0/8,192.168.0.0/16                                                                                                                                                                                              | Comma-separated list of IP ranges (CIDRs) of trusted proxy servers. Caddy will parse the real client IP from HTTP headers when requests come from these proxies. Use `private_ranges` to match all private IPv4 and IPv6 ranges. |
 | gateway.caddyfile.trusted-proxies-strict                                                 | bool   | false                                                                                                                                                                                                                  | Enable strict (right-to-left) parsing of the X-Forwarded-For header. Recommended when using upstream proxies like HAProxy, Cloudflare, AWS ALB, or CloudFront.                                                                   |
+| gateway.config.idle-timeout                                                              | string | 10m                                                                                                                                                                                                                    | Configure the idle timeout for client connections (default: 5m). Use Go duration format (e.g., 30s, 5m, 1h).                                                                                                                     |
 
 ### Postgres URI format
 

internal/resources/gateways/Caddyfile.gotpl

@@ -52,6 +52,11 @@
 		{{- if .TrustedProxiesStrict }}
 		trusted_proxies_strict
 		{{- end }}
+		{{- if .IdleTimeout }}
+		timeouts {
+			idle {{ .IdleTimeout }}
+		}
+		{{- end }}
 	}
 
 	{{- if .Debug }}

internal/resources/gateways/caddyfile.go

@@ -54,3 +54,10 @@ func withTrustedProxiesStrict() func(data map[string]any) error {
 		return nil
 	}
 }
+
+func withIdleTimeout(timeout string) func(data map[string]any) error {
+	return func(data map[string]any) error {
+		data["IdleTimeout"] = timeout
+		return nil
+	}
+}

internal/resources/gateways/configuration.go

@@ -30,6 +30,14 @@ func createConfigMap(ctx core.Context, stack *v1beta1.Stack,
 		options = append(options, withTrustedProxiesStrict())
 	}
 
+	idleTimeout, err := settings.GetString(ctx, stack.Name, "gateway", "config", "idle-timeout")
+	if err != nil {
+		return nil, err
+	}
+	if idleTimeout != nil && *idleTimeout != "" {
+		options = append(options, withIdleTimeout(*idleTimeout))
+	}
+
 	caddyfile, err := CreateCaddyfile(ctx, stack, gateway, httpAPIs, broker, options...)
 	if err != nil {
 		return nil, err