queue: Support sending to pipes

With the introduction of aliases, the queue may now be delivering mail to
pipes. This patch implements pipe delivery.

It uses a fixed 30s timeout for now, as these commands should really not take
much time, and we don't want to overly complicate the configuration for now.

internal/queue/queue.go

@@ -6,14 +6,19 @@ package queue
 //go:generate protoc --go_out=. -I=${GOPATH}/src -I. queue.proto
 
 import (
+	"context"
 	"crypto/rand"
 	"encoding/base64"
 	"fmt"
 	"os"
+	"os/exec"
 	"path/filepath"
+	"strings"
 	"sync"
 	"time"
 
+	"bytes"
+
 	"blitiri.com.ar/go/chasquid/internal/courier"
 	"blitiri.com.ar/go/chasquid/internal/envelope"
 	"blitiri.com.ar/go/chasquid/internal/protoio"
@@ -248,20 +253,10 @@ func (item *Item) SendLoop(q *Queue) {
 			wg.Add(1)
 			go func(rcpt *Recipient, oldStatus Recipient_Status) {
 				defer wg.Done()
-				// TODO: Different types of recipients.
 				to := rcpt.Address
-
 				tr.LazyPrintf("%s sending", to)
 
-				var err error
+				err := item.deliver(q, rcpt)
-				// TODO: If this is all the difference we end up having
-				// between the two couriers, consider going back to using a
-				// routing courier.
-				if envelope.DomainIn(to, q.localDomains) {
-					err = q.localC.Deliver(item.From, to, item.Data)
-				} else {
-					err = q.remoteC.Deliver(item.From, to, item.Data)
-				}
 
 				if err != nil {
 					// TODO: Local deliveries should not be retried, if they
@@ -322,6 +317,26 @@ func (item *Item) SendLoop(q *Queue) {
 	// remove item from the queue, and remove from disk.
 }
 
+func (item *Item) deliver(q *Queue, rcpt *Recipient) error {
+	if rcpt.Type == Recipient_PIPE {
+		c := strings.Fields(rcpt.Address)
+		if len(c) == 0 {
+			return fmt.Errorf("empty pipe")
+		}
+		ctx, _ := context.WithDeadline(context.Background(),
+			time.Now().Add(30*time.Second))
+		cmd := exec.CommandContext(ctx, c[0], c[1:]...)
+		cmd.Stdin = bytes.NewReader(item.Data)
+		return cmd.Run()
+	} else {
+		if envelope.DomainIn(rcpt.Address, q.localDomains) {
+			return q.localC.Deliver(item.From, rcpt.Address, item.Data)
+		} else {
+			return q.remoteC.Deliver(item.From, rcpt.Address, item.Data)
+		}
+	}
+}
+
 func nextDelay(last time.Duration) time.Duration {
 	switch {
 	case last < 1*time.Minute:

internal/queue/queue.pb.go

@@ -34,13 +34,16 @@ type Recipient_Type int32
 
 const (
 	Recipient_EMAIL Recipient_Type = 0
+	Recipient_PIPE  Recipient_Type = 1
 )
 
 var Recipient_Type_name = map[int32]string{
 	0: "EMAIL",
+	1: "PIPE",
 }
 var Recipient_Type_value = map[string]int32{
 	"EMAIL": 0,
+	"PIPE":  1,
 }
 
 func (x Recipient_Type) String() string {
@@ -124,26 +127,26 @@ func init() {
 func init() { proto.RegisterFile("queue.proto", fileDescriptor0) }
 
 var fileDescriptor0 = []byte{
-	// 329 bytes of a gzipped FileDescriptorProto
+	// 332 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x09, 0x6e, 0x88, 0x02, 0xff, 0x64, 0x8f, 0x41, 0x6b, 0xab, 0x40,
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x09, 0x6e, 0x88, 0x02, 0xff, 0x64, 0x8f, 0x51, 0x4b, 0xc3, 0x30,
-	0x14, 0x85, 0xa3, 0x31, 0xe6, 0xe5, 0xfa, 0x5e, 0xf0, 0x0d, 0x94, 0x4a, 0x56, 0x41, 0xba, 0x48,
+	0x14, 0x85, 0x6d, 0xd7, 0x75, 0xee, 0x56, 0x47, 0x09, 0x88, 0x65, 0xbe, 0x8c, 0xe2, 0xc3, 0x44,
-	0x29, 0x28, 0xa4, 0xcb, 0x42, 0x21, 0xa0, 0x2d, 0x81, 0x26, 0x94, 0x89, 0xfb, 0x30, 0xd1, 0x89,
+	0x68, 0x61, 0x3e, 0x0a, 0xc2, 0xa0, 0x55, 0x0a, 0x6e, 0x8c, 0xac, 0xef, 0x23, 0x6d, 0xb3, 0x5a,
-	0x15, 0x62, 0xc6, 0x3a, 0xd7, 0x45, 0x7f, 0x51, 0x7f, 0x47, 0xff, 0x59, 0xc7, 0x89, 0x69, 0xa1,
+	0x58, 0x97, 0xda, 0xa4, 0x0f, 0xfe, 0x22, 0x7f, 0x8c, 0x7f, 0xca, 0x34, 0xed, 0x14, 0xf4, 0xed,
-	0xdd, 0xdd, 0x3b, 0xe7, 0x9c, 0xb9, 0xdf, 0x01, 0xe7, 0xb5, 0xe1, 0x0d, 0x0f, 0xaa, 0x5a, 0xa0,
+	0xde, 0x9c, 0x73, 0x72, 0xbf, 0x03, 0xd6, 0x7b, 0x43, 0x1b, 0xea, 0x55, 0x35, 0x13, 0x0c, 0x0d,
-	0x20, 0x03, 0xbd, 0x4c, 0xee, 0xf2, 0x02, 0x5f, 0x9a, 0x5d, 0x90, 0x8a, 0x32, 0xcc, 0xc5, 0x81,
+	0xd5, 0x32, 0x7d, 0xcc, 0x0b, 0xf1, 0xd6, 0x24, 0x5e, 0xca, 0x4a, 0x3f, 0x67, 0x07, 0x72, 0xcc,
-	0x1d, 0xf3, 0x50, 0xeb, 0xbb, 0x66, 0x1f, 0x56, 0xf8, 0x56, 0x71, 0x19, 0x62, 0x51, 0x72, 0x89,
+	0x7d, 0xa5, 0x27, 0xcd, 0xde, 0xaf, 0xc4, 0x47, 0x45, 0xb9, 0x2f, 0x8a, 0x92, 0x72, 0x41, 0xca,
-	0xac, 0xac, 0xbe, 0xa7, 0xd3, 0x1f, 0xfe, 0xbb, 0x01, 0xc3, 0x15, 0x97, 0x92, 0xe5, 0x9c, 0x8c,
+	0xea, 0x77, 0xea, 0xfe, 0x70, 0x3f, 0x35, 0x18, 0xad, 0x28, 0xe7, 0x24, 0xa7, 0x68, 0x02, 0x7a,
-	0xc1, 0x5c, 0x46, 0x9e, 0x31, 0x35, 0x66, 0x23, 0x6a, 0x16, 0x11, 0x21, 0x60, 0xed, 0x6b, 0x51,
+	0x14, 0x38, 0xda, 0x4c, 0x9b, 0x8f, 0xb1, 0x5e, 0x04, 0x08, 0x81, 0xb1, 0xaf, 0x59, 0xe9, 0xe8,
-	0x7a, 0xa6, 0x7e, 0xd1, 0x33, 0xb9, 0x02, 0xab, 0x4e, 0x2b, 0xf4, 0xfa, 0xd3, 0xfe, 0xcc, 0x99,
+	0xea, 0x45, 0xcd, 0xe8, 0x16, 0x8c, 0x3a, 0xad, 0x84, 0x33, 0x98, 0x0d, 0xe6, 0xd6, 0xc2, 0xf6,
-	0xbb, 0xc1, 0x89, 0x87, 0xf2, 0xb4, 0xa8, 0x0a, 0x7e, 0x44, 0xaa, 0xd5, 0x36, 0x99, 0x31, 0x64,
+	0x3a, 0x1e, 0x4c, 0xd3, 0xa2, 0x2a, 0xe8, 0x51, 0x60, 0xa5, 0xb6, 0xc9, 0x8c, 0x08, 0xe2, 0x18,
-	0x9e, 0xa5, 0x92, 0x7f, 0xa9, 0x9e, 0xc9, 0x3d, 0xfc, 0x4b, 0x6b, 0xce, 0x90, 0x67, 0x5b, 0x86,
+	0x32, 0x79, 0x81, 0xd5, 0x8c, 0x9e, 0xe0, 0x32, 0xad, 0x29, 0x11, 0x34, 0xdb, 0x11, 0xb1, 0x13,
-	0x5b, 0x94, 0xde, 0x40, 0x89, 0xce, 0x7c, 0x12, 0xe4, 0x42, 0xe4, 0x87, 0xae, 0x93, 0x62, 0x0e,
+	0xdc, 0x19, 0x4a, 0xd1, 0x5a, 0x4c, 0xbd, 0x9c, 0xb1, 0xfc, 0xd0, 0x77, 0x92, 0xcc, 0x5e, 0x7c,
-	0x92, 0x33, 0x22, 0x75, 0xba, 0xc0, 0x02, 0x13, 0xe9, 0x7f, 0x18, 0x30, 0xfa, 0xba, 0x43, 0x3c,
+	0x42, 0xc4, 0x56, 0x1f, 0x58, 0x8a, 0x98, 0xbb, 0x5f, 0x1a, 0x8c, 0x7f, 0xee, 0x20, 0x07, 0x46,
-	0x18, 0xb2, 0x2c, 0xab, 0x15, 0x79, 0x07, 0x7c, 0x5e, 0xc9, 0x35, 0x58, 0x6d, 0x69, 0x4d, 0x3d,
+	0x24, 0xcb, 0x6a, 0x49, 0xde, 0x03, 0x9f, 0x56, 0x74, 0x07, 0x46, 0x5b, 0x5a, 0x51, 0x4f, 0x16,
-	0x9e, 0x5f, 0xfc, 0x24, 0x0c, 0x12, 0x25, 0x52, 0x6d, 0x21, 0x21, 0xd8, 0xea, 0x10, 0x36, 0x52,
+	0x57, 0x7f, 0x09, 0xbd, 0x58, 0x8a, 0x58, 0x59, 0x90, 0x0f, 0xa6, 0x3c, 0x24, 0x1a, 0x2e, 0xeb,
-	0xd5, 0x69, 0xcd, 0x97, 0xbf, 0xcc, 0x1b, 0x2d, 0xd3, 0xce, 0xe6, 0xff, 0x07, 0xab, 0x8d, 0x93,
+	0xb4, 0xe6, 0xeb, 0x7f, 0xe6, 0xad, 0x92, 0x71, 0x6f, 0x73, 0x6f, 0xc0, 0x68, 0xe3, 0x68, 0x0c,
-	0x11, 0x0c, 0xe2, 0xd5, 0x62, 0xf9, 0xe4, 0xf6, 0xfc, 0x1b, 0xb0, 0x4f, 0x26, 0xe2, 0xc0, 0xf0,
+	0xc3, 0x70, 0xb5, 0x8c, 0x5e, 0xed, 0x33, 0x74, 0x0e, 0xc6, 0x26, 0xda, 0x84, 0xb6, 0xe6, 0xde,
-	0x39, 0x5e, 0x47, 0xcb, 0xf5, 0xa3, 0xdb, 0x23, 0x7f, 0xc0, 0xda, 0xc4, 0xeb, 0xc4, 0x35, 0x08,
+	0x83, 0xd9, 0xd9, 0x91, 0x05, 0xa3, 0x4d, 0xb8, 0x0e, 0xa2, 0xf5, 0x4b, 0x67, 0xd8, 0x86, 0xeb,
-	0x80, 0xfd, 0xa0, 0xac, 0x71, 0xe4, 0x9a, 0x3b, 0x5b, 0x97, 0xbc, 0xfd, 0x0c, 0x00, 0x00, 0xff,
+	0xd8, 0xd6, 0x10, 0x80, 0xf9, 0x2c, 0x43, 0x61, 0x60, 0xeb, 0x89, 0xa9, 0xea, 0x3e, 0x7c, 0x07,
-	0xff, 0x64, 0x3a, 0x92, 0xc1, 0xc7, 0x01, 0x00, 0x00,
+	0x00, 0x00, 0xff, 0xff, 0xd1, 0x22, 0xa1, 0x0c, 0xd1, 0x01, 0x00, 0x00,
 }

internal/queue/queue.proto

@@ -25,6 +25,7 @@ message Recipient {
 
 	enum Type {
 		EMAIL = 0;
+		PIPE = 1;
 	}
 	Type type = 2;
 

internal/queue/queue_test.go

@@ -135,3 +135,27 @@ func TestFullQueue(t *testing.T) {
 	}
 	q.Remove(id)
 }
+
+func TestPipes(t *testing.T) {
+	q := New("/tmp/queue_test", set.NewString("loco"))
+	item := &Item{
+		Message: Message{
+			ID:   <-newID,
+			From: "from",
+			Rcpt: []*Recipient{
+				{"true", Recipient_PIPE, Recipient_PENDING}},
+			Data: []byte("data"),
+		},
+		CreatedAt: time.Now(),
+	}
+
+	if err := item.deliver(q, item.Rcpt[0]); err != nil {
+		t.Errorf("pipe delivery failed: %v", err)
+	}
+
+	// Make the command "false", should fail.
+	item.Rcpt[0].Address = "false"
+	if err := item.deliver(q, item.Rcpt[0]); err == nil {
+		t.Errorf("pipe delivery worked, expected failure")
+	}
+}