server kills subprocesses correctly on cancel

1 files changed, 54 insertions, 19 deletions

diff --git a/internal/server/handlers/serverhandler.go b/internal/server/handlers/serverhandler.go
index b840c77..946ae83 100644
--- a/internal/server/handlers/serverhandler.go
+++ b/internal/server/handlers/serverhandler.go
@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -37,28 +38,31 @@ type ServerHandler struct {
 	payload            []byte
 	hostname           string
 	user               *user.User
-	catLimiter         chan struct{}
-	tailLimiter        chan struct{}
-	ackCloseReceived   chan struct{}
-	ctx                context.Context
-	done               chan struct{}
-	activeReaders      int
+	// TODO: Move all these channels into a separate struct for readability!
+	catLimiter          chan struct{}
+	tailLimiter         chan struct{}
+	globalServerWaitFor chan struct{}
+	ackCloseReceived    chan struct{}
+	ctx                 context.Context
+	done                chan struct{}
+	activeReaders       int
 }
 
 // NewServerHandler returns the server handler.
-func NewServerHandler(ctx context.Context, user *user.User, catLimiter chan struct{}, tailLimiter chan struct{}) (*ServerHandler, <-chan struct{}) {
+func NewServerHandler(ctx context.Context, user *user.User, catLimiter, tailLimiter, globalServerWaitFor chan struct{}) (*ServerHandler, <-chan struct{}) {
 	h := ServerHandler{
-		ctx:                ctx,
-		done:               make(chan struct{}),
-		mutex:              &sync.Mutex{},
-		lines:              make(chan line.Line, 100),
-		serverMessages:     make(chan string, 10),
-		aggregatedMessages: make(chan string, 10),
-		ackCloseReceived:   make(chan struct{}),
-		catLimiter:         catLimiter,
-		tailLimiter:        tailLimiter,
-		regex:              ".",
-		user:               user,
+		ctx:                 ctx,
+		done:                make(chan struct{}),
+		mutex:               &sync.Mutex{},
+		lines:               make(chan line.Line, 100),
+		serverMessages:      make(chan string, 10),
+		aggregatedMessages:  make(chan string, 10),
+		ackCloseReceived:    make(chan struct{}),
+		catLimiter:          catLimiter,
+		tailLimiter:         tailLimiter,
+		globalServerWaitFor: globalServerWaitFor,
+		regex:               ".",
+		user:                user,
 	}
 
 	fqdn, err := os.Hostname()
@@ -135,6 +139,7 @@ func (h *ServerHandler) Write(p []byte) (n int, err error) {
 
 func (h *ServerHandler) handleCommand(ctx context.Context, commandStr string) {
 	logger.Debug(h.user, commandStr)
+	var timeout time.Duration
 
 	args, argc, err := h.handleProtocolVersion(strings.Split(commandStr, " "))
 	if err != nil {
@@ -148,11 +153,28 @@ func (h *ServerHandler) handleCommand(ctx context.Context, commandStr string) {
 		return
 	}
 
+	args, argc, timeout, err = h.handleTimeout(args, argc)
+	if err != nil {
+		h.send(h.serverMessages, logger.Error(h.user, err))
+		return
+	}
+
 	if h.user.Name == config.ControlUser {
 		h.handleControlCommand(argc, args)
 		return
 	}
 
+	if timeout > 0 {
+		logger.Debug("Command with timeout context", argc, args, timeout)
+		commandCtx, cancel := context.WithTimeout(ctx, timeout)
+		go func() {
+			<-commandCtx.Done()
+			cancel()
+		}()
+		h.handleUserCommand(commandCtx, argc, args)
+		return
+	}
+
 	h.handleUserCommand(ctx, argc, args)
 }
 
@@ -191,6 +213,16 @@ func (h *ServerHandler) handleBase64(args []string, argc int) ([]string, int, er
 	return args, argc, nil
 }
 
+func (h *ServerHandler) handleTimeout(args []string, argc int) ([]string, int, time.Duration, error) {
+	if argc <= 2 || args[0] != "timeout" {
+		// No timeout specified
+		return args, argc, time.Duration(0) * time.Second, nil
+	}
+
+	timeout, err := strconv.Atoi(args[1])
+	return args[2:], argc - 2, time.Duration(timeout) * time.Second, err
+}
+
 func (h *ServerHandler) handleControlCommand(argc int, args []string) {
 	switch args[0] {
 	case "debug":
@@ -241,8 +273,10 @@ func (h *ServerHandler) handleUserCommand(ctx context.Context, argc int, args []
 	case "run":
 		command := newRunCommand(h)
 		h.incrementActiveReaders()
+		go func() { h.globalServerWaitFor <- struct{}{} }()
 		go func() {
 			command.Start(ctx, argc, args)
+			<-h.globalServerWaitFor
 			if h.decrementActiveReaders() == 0 {
 				h.shutdown()
 			}
@@ -332,12 +366,13 @@ func (h *ServerHandler) incrementActiveReaders() {
 	// TODO: Use atomic counter variable instead, so we can get rid of the mutex
 	h.mutex.Lock()
 	defer h.mutex.Unlock()
+
 	h.activeReaders++
 }
 func (h *ServerHandler) decrementActiveReaders() int {
 	h.mutex.Lock()
 	defer h.mutex.Unlock()
-	h.activeReaders--
 
+	h.activeReaders--
 	return h.activeReaders
 }