metrics: move `metrics` up, outside `servers` (#6606)

* metrics: move `metrics`  up, outside `servers`

This change moves the metrics configuration from per-server level to a single config knob within the `http` app. Enabling `metrics` in any of the configured servers inside `http` enables metrics for all servers.

Fix #6604

Signed-off-by: Mohammed Al Sahaf <[email protected]>

* normalize domain name

---------

Signed-off-by: Mohammed Al Sahaf <[email protected]>

3 files changed, 35 insertions, 0 deletions

diff --git a/caddyconfig/httpcaddyfile/httptype.go b/caddyconfig/httpcaddyfile/httptype.go
index 4dacd9058..a238a33b4 100644
--- a/caddyconfig/httpcaddyfile/httptype.go
+++ b/caddyconfig/httpcaddyfile/httptype.go
@@ -15,6 +15,7 @@
 package httpcaddyfile
 
 import (
+	"cmp"
 	"encoding/json"
 	"fmt"
 	"net"
@@ -186,12 +187,25 @@ func (st ServerType) Setup(
 		return nil, warnings, err
 	}
 
+	// hoist the metrics config from per-server to global
+	metrics, _ := options["metrics"].(*caddyhttp.Metrics)
+	for _, s := range servers {
+		if s.Metrics != nil {
+			metrics = cmp.Or[*caddyhttp.Metrics](metrics, &caddyhttp.Metrics{})
+			metrics = &caddyhttp.Metrics{
+				PerHost: metrics.PerHost || s.Metrics.PerHost,
+			}
+			s.Metrics = nil // we don't need it anymore
+		}
+	}
+
 	// now that each server is configured, make the HTTP app
 	httpApp := caddyhttp.App{
 		HTTPPort:      tryInt(options["http_port"], &warnings),
 		HTTPSPort:     tryInt(options["https_port"], &warnings),
 		GracePeriod:   tryDuration(options["grace_period"], &warnings),
 		ShutdownDelay: tryDuration(options["shutdown_delay"], &warnings),
+		Metrics:       metrics,
 		Servers:       servers,
 	}
 
diff --git a/caddyconfig/httpcaddyfile/options.go b/caddyconfig/httpcaddyfile/options.go
index 9bae760c0..03b9ba230 100644
--- a/caddyconfig/httpcaddyfile/options.go
+++ b/caddyconfig/httpcaddyfile/options.go
@@ -24,6 +24,7 @@ import (
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/caddyconfig"
 	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
 	"github.com/caddyserver/caddy/v2/modules/caddytls"
 )
 
@@ -53,6 +54,7 @@ func init() {
 	RegisterGlobalOption("local_certs", parseOptTrue)
 	RegisterGlobalOption("key_type", parseOptSingleString)
 	RegisterGlobalOption("auto_https", parseOptAutoHTTPS)
+	RegisterGlobalOption("metrics", parseMetricsOptions)
 	RegisterGlobalOption("servers", parseServerOptions)
 	RegisterGlobalOption("ocsp_stapling", parseOCSPStaplingOptions)
 	RegisterGlobalOption("cert_lifetime", parseOptDuration)
@@ -446,6 +448,24 @@ func parseOptAutoHTTPS(d *caddyfile.Dispenser, _ any) (any, error) {
 	return val, nil
 }
 
+func unmarshalCaddyfileMetricsOptions(d *caddyfile.Dispenser) (any, error) {
+	d.Next() // consume option name
+	metrics := new(caddyhttp.Metrics)
+	for d.NextBlock(0) {
+		switch d.Val() {
+		case "per_host":
+			metrics.PerHost = true
+		default:
+			return nil, d.Errf("unrecognized servers option '%s'", d.Val())
+		}
+	}
+	return metrics, nil
+}
+
+func parseMetricsOptions(d *caddyfile.Dispenser, _ any) (any, error) {
+	return unmarshalCaddyfileMetricsOptions(d)
+}
+
 func parseServerOptions(d *caddyfile.Dispenser, _ any) (any, error) {
 	return unmarshalCaddyfileServerOptions(d)
 }
diff --git a/caddyconfig/httpcaddyfile/serveroptions.go b/caddyconfig/httpcaddyfile/serveroptions.go
index b05af47f5..40a8af209 100644
--- a/caddyconfig/httpcaddyfile/serveroptions.go
+++ b/caddyconfig/httpcaddyfile/serveroptions.go
@@ -240,6 +240,7 @@ func unmarshalCaddyfileServerOptions(d *caddyfile.Dispenser) (any, error) {
 			}
 
 		case "metrics":
+			caddy.Log().Warn("The nested 'metrics' option inside `servers` is deprecated and will be removed in the next major version. Use the global 'metrics' option instead.")
 			serverOpts.Metrics = new(caddyhttp.Metrics)
 			for nesting := d.Nesting(); d.NextBlock(nesting); {
 				switch d.Val() {