add graceful shutdown for bin mode

_docs/modes.md

@@ -0,0 +1,18 @@
+## BIN
+
+Binary modes just executes any script in shell (`/bin/sh` by default). You can override shell per-unit
+by `shell: /path/to/shell` configuration param.
+
+To handle a graceful timeout, child should be able to forward signal: basically, use `exec` before last command.
+
+Danger (but will work), signals may not be handled by foo
+
+```yaml
+command: "V=1 RAIL=2 foo bar -c -y -z"
+```
+
+Good
+
+```yaml
+command: "V=1 RAIL=2 exec foo bar -c -y -z"
+```

server/mode_bin.go

@@ -3,6 +3,7 @@ package server
 import (
 	"context"
 	"io/ioutil"
+	"log"
 	"net/http"
 	"os"
 	"os/exec"
@@ -33,11 +34,12 @@ func (m *markerResponse) WriteHeader(statusCode int) {
 }
 
 type binHandler struct {
-	command     string
+	command         string
-	workDir     string
+	workDir         string
-	shell       string
+	shell           string
-	environment []string
+	environment     []string
-	timeout     time.Duration
+	timeout         time.Duration
+	gracefulTimeout time.Duration
 }
 
 func (bh *binHandler) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
@@ -75,7 +77,29 @@ func (bh *binHandler) ServeHTTP(writer http.ResponseWriter, request *http.Reques
 	cmd.Stdout = marker
 	cmd.Env = env
 	api.SetBinFlags(cmd)
+
+	var done bool
+
+	if bh.gracefulTimeout > 0 {
+		graceCtx, graceCancel := context.WithTimeout(ctx, bh.gracefulTimeout)
+		defer graceCancel()
+		go func() {
+			<-graceCtx.Done()
+			proc := cmd.Process
+			if proc == nil || done {
+				return
+			}
+			err := proc.Signal(os.Interrupt)
+			if err != nil {
+				log.Println("failed send signal to process:", err)
+			} else {
+				log.Println("sent graceful shutdown to proces")
+			}
+		}()
+	}
+
 	err := cmd.Run()
+	done = true
 
 	if codeReset, ok := writer.(interface{ Status(status int) }); ok && err != nil {
 		codeReset.Status(http.StatusBadGateway)

server/unit.go

@@ -26,17 +26,18 @@ import (
 )
 
 type Unit struct {
-	Interval      time.Duration     `yaml:"interval,omitempty"`    // interval between attempts
+	Interval        time.Duration     `yaml:"interval,omitempty"`         // interval between attempts
-	Attempts      int               `yaml:"attempts,omitempty"`    // maximum number of attempts
+	Attempts        int               `yaml:"attempts,omitempty"`         // maximum number of attempts
-	Workers       int               `yaml:"workers,omitempty"`     // concurrency level - number of parallel requests
+	Workers         int               `yaml:"workers,omitempty"`          // concurrency level - number of parallel requests
-	Mode          string            `yaml:"mode,omitempty"`        // execution mode: bin, cgi or proxy
+	Mode            string            `yaml:"mode,omitempty"`             // execution mode: bin, cgi or proxy
-	WorkDir       string            `yaml:"workdir,omitempty"`     // working directory for the worker. if empty - temporary one will generated automatically
+	WorkDir         string            `yaml:"workdir,omitempty"`          // working directory for the worker. if empty - temporary one will generated automatically
-	Command       string            `yaml:"command"`               // command in a shell to execute
+	Command         string            `yaml:"command"`                    // command in a shell to execute
-	Timeout       time.Duration     `yaml:"timeout,omitempty"`     // maximum execution timeout (enabled only for bin mode and only if positive)
+	Timeout         time.Duration     `yaml:"timeout,omitempty"`          // maximum execution timeout (enabled only for bin mode and only if positive)
-	Shell         string            `yaml:"shell,omitempty"`       // shell to execute command in bin mode (default - /bin/sh)
+	GracefulTimeout time.Duration     `yaml:"graceful_timeout,omitempty"` // maximum execution timeout after which SIGINT will be sent (enabled only for bin mode and only if positive)
-	Environment   map[string]string `yaml:"environment,omitempty"` // custom environment for executable (in addition to system)
+	Shell           string            `yaml:"shell,omitempty"`            // shell to execute command in bin mode (default - /bin/sh)
-	MaxRequest    int64             `yaml:"max_request,omitempty"` // optional maximum HTTP body size (enabled if positive)
+	Environment     map[string]string `yaml:"environment,omitempty"`      // custom environment for executable (in addition to system)
-	Authorization struct {
+	MaxRequest      int64             `yaml:"max_request,omitempty"`      // optional maximum HTTP body size (enabled if positive)
+	Authorization   struct {
 		JWT struct {
 			Enable bool `yaml:"enable"` // enable JWT verification
 			JWT    `yaml:",inline"`
@@ -242,11 +243,12 @@ func (cfg Unit) createRunner() (http.Handler, error) {
 	switch cfg.Mode {
 	case "bin":
 		return &binHandler{
-			command:     cfg.Command,
+			command:         cfg.Command,
-			workDir:     cfg.WorkDir,
+			workDir:         cfg.WorkDir,
-			shell:       cfg.Shell,
+			shell:           cfg.Shell,
-			timeout:     cfg.Timeout,
+			timeout:         cfg.Timeout,
-			environment: append(os.Environ(), makeEnvList(cfg.Environment)...),
+			gracefulTimeout: cfg.GracefulTimeout,
+			environment:     append(os.Environ(), makeEnvList(cfg.Environment)...),
 		}, nil
 	case "cgi":
 		return &cgi.Handler{

templates/unit-info.html

@@ -50,14 +50,25 @@
                             <dd class="col-sm-9">{{.Unit.Attempts}}</dd>
                             <dt class="col-sm-3">Interval</dt>
                             <dd class="col-sm-9">{{.Unit.Interval}}</dd>
-                            <dt class="col-sm-3">Timeout</dt>
+                            {{if eq .Unit.Mode "bin"}}
-                            <dd class="col-sm-9">
+                                <dt class="col-sm-3" title="Timeout after which process will be sent">Timeout</dt>
-                                {{with .Unit.Timeout}}
+                                <dd class="col-sm-9">
-                                    {{.}}
+                                    {{with .Unit.Timeout}}
-                                {{else}}
+                                        {{.}}
-                                    ∞
+                                    {{else}}
-                                {{end}}
+                                        ∞
-                            </dd>
+                                    {{end}}
+                                </dd>
+                                <dt class="col-sm-3" title="Timeout after which SIGINT will be sent">Graceful timeout
+                                </dt>
+                                <dd class="col-sm-9">
+                                    {{with .Unit.GracefulTimeout}}
+                                        {{.}}
+                                    {{else}}
+                                        ∞
+                                    {{end}}
+                                </dd>
+                            {{end}}
                             <dt class="col-sm-3">Max request size</dt>
                             <dd class="col-sm-9">
                                 {{with .Unit.MaxRequest}}