From cbb405f6aaee046c9de9ffb4f07ca824d9eedeb1 Mon Sep 17 00:00:00 2001
From: Matthew Holt <mholt@users.noreply.github.com>
Date: Mon, 23 Dec 2019 12:41:05 -0700
Subject: [PATCH] cmd: Eliminate unintended use of cgo

This means the stop command can only use the API to stop the instance;
no more signaling, unless we find a cgo-free way of doing it.
---
 cmd/commandfuncs.go | 28 ++--------------------------
 cmd/commands.go     | 10 +++-------
 go.mod              |  1 -
 go.sum              |  2 --
 4 files changed, 5 insertions(+), 36 deletions(-)

diff --git a/cmd/commandfuncs.go b/cmd/commandfuncs.go
index 5079449d..6dc7c522 100644
--- a/cmd/commandfuncs.go
+++ b/cmd/commandfuncs.go
@@ -33,7 +33,6 @@ import (
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/caddyconfig"
-	"github.com/keybase/go-ps"
 	"github.com/mholt/certmagic"
 	"go.uber.org/zap"
 )
@@ -211,34 +210,11 @@ func cmdStop(fl Flags) (int, error) {
 
 	err = apiRequest(req)
 	if err != nil {
-		// if the caddy instance doesn't have an API listener set up,
-		// or we are unable to reach it for some reason, try signaling it
-
-		caddy.Log().Warn("unable to use API to stop instance; will try to signal the process",
+		caddy.Log().Warn("failed using API to stop instance",
 			zap.String("endpoint", stopEndpoint),
 			zap.Error(err),
 		)
-
-		processList, err := ps.Processes()
-		if err != nil {
-			return caddy.ExitCodeFailedStartup, fmt.Errorf("listing processes: %v", err)
-		}
-		thisProcName := getProcessName()
-
-		var found bool
-		for _, p := range processList {
-			// the process we're looking for should have the same name as us but different PID
-			if p.Executable() == thisProcName && p.Pid() != os.Getpid() {
-				found = true
-				fmt.Printf("pid=%d\n", p.Pid())
-				if err := gracefullyStopProcess(p.Pid()); err != nil {
-					return caddy.ExitCodeFailedStartup, err
-				}
-			}
-		}
-		if !found {
-			return caddy.ExitCodeFailedStartup, fmt.Errorf("Caddy is not running")
-		}
+		return caddy.ExitCodeFailedStartup, err
 	}
 
 	return caddy.ExitCodeSuccess, nil
diff --git a/cmd/commands.go b/cmd/commands.go
index a861cdf5..971d8d93 100644
--- a/cmd/commands.go
+++ b/cmd/commands.go
@@ -134,13 +134,9 @@ not quit after printing, and can be useful for troubleshooting.`,
 		Long: `
 Stops the background Caddy process as gracefully as possible.
 
-It will first try to use the admin API's /stop endpoint; the address of
-this request can be customized using the --address flag if it is not the
-default.
-
-If that fails for any reason, it will attempt to signal the first process
-it can find named the same as this one (os.Args[0]). On Windows, such
-a stop is forceful because Windows does not have signals.`,
+It requires that the admin API is enabled and accessible, since it will
+use the API's /stop endpoint. The address of this request can be
+customized using the --address flag if it is not the default.`,
 		Flags: func() *flag.FlagSet {
 			fs := flag.NewFlagSet("stop", flag.ExitOnError)
 			fs.String("address", "", "The address to use to reach the admin API endpoint, if not the default")
diff --git a/go.mod b/go.mod
index 3d0b2411..f68cef7d 100644
--- a/go.mod
+++ b/go.mod
@@ -12,7 +12,6 @@ require (
 	github.com/ilibs/json5 v1.0.1
 	github.com/imdario/mergo v0.3.8 // indirect
 	github.com/jsternberg/zap-logfmt v1.2.0
-	github.com/keybase/go-ps v0.0.0-20190827175125-91aafc93ba19
 	github.com/klauspost/compress v1.8.6
 	github.com/klauspost/cpuid v1.2.2
 	github.com/lucas-clemente/quic-go v0.14.1
diff --git a/go.sum b/go.sum
index fa562f3e..6c6d76c2 100644
--- a/go.sum
+++ b/go.sum
@@ -143,8 +143,6 @@ github.com/jsternberg/zap-logfmt v1.2.0 h1:1v+PK4/B48cy8cfQbxL4FmmNZrjnIMr2BsnyE
 github.com/jsternberg/zap-logfmt v1.2.0/go.mod h1:kz+1CUmCutPWABnNkOu9hOHKdT2q3TDYCcsFy9hpqb0=
 github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
 github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
-github.com/keybase/go-ps v0.0.0-20190827175125-91aafc93ba19 h1:WjT3fLi9n8YWh/Ih8Q1LHAPsTqGddPcHqscN+PJ3i68=
-github.com/keybase/go-ps v0.0.0-20190827175125-91aafc93ba19/go.mod h1:hY+WOq6m2FpbvyrI93sMaypsttvaIL5nhVR92dTMUcQ=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/klauspost/compress v1.8.6 h1:970MQcQdxX7hfgc/aqmB4a3grW0ivUVV6i1TLkP8CiE=
 github.com/klauspost/compress v1.8.6/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A=