From 2772ede43c852fa50f3527dbd94ae747b6f64365 Mon Sep 17 00:00:00 2001
From: Matthew Holt <mholt@users.noreply.github.com>
Date: Mon, 1 Feb 2021 18:14:03 -0700
Subject: [PATCH] cmd: Add --force flag to reload command (close #4005)

Can be useful if user wants to reload manual certificates, for example.
---
 cmd/commandfuncs.go | 16 +++++++++++++---
 cmd/commands.go     |  1 +
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/cmd/commandfuncs.go b/cmd/commandfuncs.go
index 9640f4bc3..f3feb6105 100644
--- a/cmd/commandfuncs.go
+++ b/cmd/commandfuncs.go
@@ -282,7 +282,7 @@ func cmdRun(fl Flags) (int, error) {
 func cmdStop(fl Flags) (int, error) {
 	stopCmdAddrFlag := fl.String("address")
 
-	err := apiRequest(stopCmdAddrFlag, http.MethodPost, "/stop", nil)
+	err := apiRequest(stopCmdAddrFlag, http.MethodPost, "/stop", nil, nil)
 	if err != nil {
 		caddy.Log().Warn("failed using API to stop instance", zap.Error(err))
 		return caddy.ExitCodeFailedStartup, err
@@ -295,6 +295,7 @@ func cmdReload(fl Flags) (int, error) {
 	reloadCmdConfigFlag := fl.String("config")
 	reloadCmdConfigAdapterFlag := fl.String("adapter")
 	reloadCmdAddrFlag := fl.String("address")
+	reloadCmdForceFlag := fl.Bool("force")
 
 	if err := NotifyReloading(); err != nil {
 		caddy.Log().Error("unable to notify reloading to service manager", zap.Error(err))
@@ -328,7 +329,13 @@ func cmdReload(fl Flags) (int, error) {
 		adminAddr = tmpStruct.Admin.Listen
 	}
 
-	err = apiRequest(adminAddr, http.MethodPost, "/load", bytes.NewReader(config))
+	// optionally force a config reload
+	headers := make(http.Header)
+	if reloadCmdForceFlag {
+		headers.Set("Cache-Control", "must-revalidate")
+	}
+
+	err = apiRequest(adminAddr, http.MethodPost, "/load", headers, bytes.NewReader(config))
 	if err != nil {
 		return caddy.ExitCodeFailedStartup, fmt.Errorf("sending configuration to instance: %v", err)
 	}
@@ -827,7 +834,7 @@ func getModules() (standard, nonstandard, unknown []moduleInfo, err error) {
 // apiRequest makes an API request to the endpoint adminAddr with the
 // given HTTP method and request URI. If body is non-nil, it will be
 // assumed to be Content-Type application/json.
-func apiRequest(adminAddr, method, uri string, body io.Reader) error {
+func apiRequest(adminAddr, method, uri string, headers http.Header, body io.Reader) error {
 	// parse the admin address
 	if adminAddr == "" {
 		adminAddr = caddy.DefaultAdminListen
@@ -867,6 +874,9 @@ func apiRequest(adminAddr, method, uri string, body io.Reader) error {
 	if body != nil {
 		req.Header.Set("Content-Type", "application/json")
 	}
+	for k, v := range headers {
+		req.Header[k] = v
+	}
 
 	// make an HTTP client that dials our network type, since admin
 	// endpoints aren't always TCP, which is what the default transport
diff --git a/cmd/commands.go b/cmd/commands.go
index 176519400..a5198966a 100644
--- a/cmd/commands.go
+++ b/cmd/commands.go
@@ -178,6 +178,7 @@ config file; otherwise the default is assumed.`,
 			fs.String("config", "", "Configuration file (required)")
 			fs.String("adapter", "", "Name of config adapter to apply")
 			fs.String("address", "", "Address of the administration listener, if different from config")
+			fs.Bool("force", false, "Force config reload, even if it is the same")
 			return fs
 		}(),
 	})