caddyhttp: Add server options keepalive_idle and keepalive_count (#7298)

* Add Server options KeepAliveIdle (keepalive_idle) and KeepAliveCount (keepalive_count)

Signed-off-by: Joshua McBeth <joshua.mcbeth@gmail.com>

* Add Server option KeepAliveDisable (keepalive_disable)

Signed-off-by: Joshua McBeth <joshua.mcbeth@gmail.com>

* Remove Server option KeepAliveDisable (keepalive_disable), disable when interval is negative

Signed-off-by: Joshua McBeth <joshua.mcbeth@gmail.com>

* Add keepalive parameters to caddyfiletest

Signed-off-by: Joshua McBeth <joshua.mcbeth@gmail.com>

---------

Signed-off-by: Joshua McBeth <joshua.mcbeth@gmail.com>

caddyconfig/httpcaddyfile/serveroptions.go

@@ -18,6 +18,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"slices"
+	"strconv"
 
 	"github.com/dustin/go-humanize"
 
@@ -42,6 +43,8 @@ type serverOptions struct {
 	WriteTimeout         caddy.Duration
 	IdleTimeout          caddy.Duration
 	KeepAliveInterval    caddy.Duration
+	KeepAliveIdle        caddy.Duration
+	KeepAliveCount       int
 	MaxHeaderBytes       int
 	EnableFullDuplex     bool
 	Protocols            []string
@@ -142,6 +145,7 @@ func unmarshalCaddyfileServerOptions(d *caddyfile.Dispenser) (any, error) {
 					return nil, d.Errf("unrecognized timeouts option '%s'", d.Val())
 				}
 			}
+
 		case "keepalive_interval":
 			if !d.NextArg() {
 				return nil, d.ArgErr()
@@ -152,6 +156,26 @@ func unmarshalCaddyfileServerOptions(d *caddyfile.Dispenser) (any, error) {
 			}
 			serverOpts.KeepAliveInterval = caddy.Duration(dur)
 
+		case "keepalive_idle":
+			if !d.NextArg() {
+				return nil, d.ArgErr()
+			}
+			dur, err := caddy.ParseDuration(d.Val())
+			if err != nil {
+				return nil, d.Errf("parsing keepalive idle duration: %v", err)
+			}
+			serverOpts.KeepAliveIdle = caddy.Duration(dur)
+
+		case "keepalive_count":
+			if !d.NextArg() {
+				return nil, d.ArgErr()
+			}
+			cnt, err := strconv.ParseInt(d.Val(), 10, 32)
+			if err != nil {
+				return nil, d.Errf("parsing keepalive count int: %v", err)
+			}
+			serverOpts.KeepAliveCount = int(cnt)
+
 		case "max_header_size":
 			var sizeStr string
 			if !d.AllArgs(&sizeStr) {
@@ -309,6 +333,8 @@ func applyServerOptions(
 		server.WriteTimeout = opts.WriteTimeout
 		server.IdleTimeout = opts.IdleTimeout
 		server.KeepAliveInterval = opts.KeepAliveInterval
+		server.KeepAliveIdle = opts.KeepAliveIdle
+		server.KeepAliveCount = opts.KeepAliveCount
 		server.MaxHeaderBytes = opts.MaxHeaderBytes
 		server.EnableFullDuplex = opts.EnableFullDuplex
 		server.Protocols = opts.Protocols

caddytest/integration/caddyfile_adapt/global_server_options_single.caddyfiletest

@@ -18,6 +18,9 @@
 		trusted_proxies static private_ranges
 		client_ip_headers Custom-Real-Client-IP X-Forwarded-For
 		client_ip_headers A-Third-One
+		keepalive_interval 20s
+		keepalive_idle 20s
+		keepalive_count 10
 	}
 }
 
@@ -45,6 +48,9 @@ foo.com {
 					"read_header_timeout": 30000000000,
 					"write_timeout": 30000000000,
 					"idle_timeout": 30000000000,
+					"keepalive_interval": 20000000000,
+					"keepalive_idle": 20000000000,
+					"keepalive_count": 10,
 					"max_header_bytes": 100000000,
 					"enable_full_duplex": true,
 					"routes": [

modules/caddyhttp/app.go

@@ -538,6 +538,8 @@ func (app *App) Start() error {
 						KeepAliveConfig: net.KeepAliveConfig{
 							Enable:   srv.KeepAliveInterval >= 0,
 							Interval: time.Duration(srv.KeepAliveInterval),
+							Idle:     time.Duration(srv.KeepAliveIdle),
+							Count:    srv.KeepAliveCount,
 						},
 					})
 					if err != nil {

modules/caddyhttp/server.go

@@ -76,9 +76,25 @@ type Server struct {
 
 	// KeepAliveInterval is the interval at which TCP keepalive packets
 	// are sent to keep the connection alive at the TCP layer when no other
-	// data is being transmitted. The default is 15s.
+	// data is being transmitted.
+	// If zero, the default is 15s.
+	// If negative, keepalive packets are not sent and other keepalive parameters
+	// are ignored.
 	KeepAliveInterval caddy.Duration `json:"keepalive_interval,omitempty"`
 
+	// KeepAliveIdle is the time that the connection must be idle before
+	// the first TCP keep-alive probe is sent when no other data is being
+	// transmitted.
+	// If zero, the default is 15s.
+	// If negative, underlying socket value is unchanged.
+	KeepAliveIdle caddy.Duration `json:"keepalive_idle,omitempty"`
+
+	// KeepAliveCount is the maximum number of TCP keep-alive probes that
+	// should be sent before dropping a connection.
+	// If zero, the default is 9.
+	// If negative, underlying socket value is unchanged.
+	KeepAliveCount int `json:"keepalive_count,omitempty"`
+
 	// MaxHeaderBytes is the maximum size to parse from a client's
 	// HTTP request headers.
 	MaxHeaderBytes int `json:"max_header_bytes,omitempty"`