From 7c54a212f5f87e19b1f5f80d84722aecfcc04d3e Mon Sep 17 00:00:00 2001
From: Drew DeVault <sir@cmpwn.com>
Date: Mon, 6 Jan 2020 10:58:30 -0500
Subject: [PATCH] alertmanager: add Message-ID patch

---
 ...01-email-generate-message-ID-headers.patch | 83 +++++++++++++++++++
 sr.ht/alertmanager/APKBUILD                   | 11 ++-
 2 files changed, 92 insertions(+), 2 deletions(-)
 create mode 100644 sr.ht/alertmanager/0001-email-generate-message-ID-headers.patch

diff --git a/sr.ht/alertmanager/0001-email-generate-message-ID-headers.patch b/sr.ht/alertmanager/0001-email-generate-message-ID-headers.patch
new file mode 100644
index 0000000..af38893
--- /dev/null
+++ b/sr.ht/alertmanager/0001-email-generate-message-ID-headers.patch
@@ -0,0 +1,83 @@
+From 5bea8e8c73511f90aa7c8b80fe49357862a84b92 Mon Sep 17 00:00:00 2001
+From: Drew DeVault <sir@cmpwn.com>
+Date: Mon, 6 Jan 2020 10:49:48 -0500
+Subject: [PATCH] email: generate message ID headers
+
+This GenerateMessageId is taken from go-message:
+
+https://github.com/emersion/go-message/blob/master/mail/mail.go
+
+I am the original author of this file; I agree to distribute it in
+alertmanager regardless of the original license.
+
+Signed-off-by: Drew DeVault <sir@cmpwn.com>
+---
+ notify/email/email.go | 25 +++++++++++++++++++++++++
+ 1 file changed, 25 insertions(+)
+
+diff --git a/notify/email/email.go b/notify/email/email.go
+index 73fcf577..529e4333 100644
+--- a/notify/email/email.go
++++ b/notify/email/email.go
+@@ -16,7 +16,9 @@ package email
+ import (
+ 	"bytes"
+ 	"context"
++	"crypto/rand"
+ 	"crypto/tls"
++	"encoding/binary"
+ 	"fmt"
+ 	"mime"
+ 	"mime/multipart"
+@@ -25,11 +27,13 @@ import (
+ 	"net/mail"
+ 	"net/smtp"
+ 	"net/textproto"
++	"os"
+ 	"strings"
+ 	"time"
+ 
+ 	"github.com/go-kit/kit/log"
+ 	"github.com/go-kit/kit/log/level"
++	"github.com/martinlindhe/base36"
+ 	"github.com/pkg/errors"
+ 	commoncfg "github.com/prometheus/common/config"
+ 
+@@ -241,6 +245,7 @@ func (n *Email) Notify(ctx context.Context, as ...*types.Alert) (bool, error) {
+ 
+ 	fmt.Fprintf(buffer, "Date: %s\r\n", time.Now().Format(time.RFC1123Z))
+ 	fmt.Fprintf(buffer, "Content-Type: multipart/alternative;  boundary=%s\r\n", multipartWriter.Boundary())
++	fmt.Fprintf(buffer, "Message-ID: %s\r\n", generateMessageID())
+ 	fmt.Fprintf(buffer, "MIME-Version: 1.0\r\n\r\n")
+ 
+ 	// TODO: Add some useful headers here, such as URL of the alertmanager
+@@ -314,6 +319,26 @@ func (n *Email) Notify(ctx context.Context, as ...*types.Alert) (bool, error) {
+ 	return false, nil
+ }
+ 
++// Generates an RFC 2822-compliant Message-Id based on the informational draft
++// "Recommendations for generating Message IDs", for lack of a better
++// authoritative source.
++func generateMessageID() string {
++	var (
++		now   bytes.Buffer
++		nonce []byte = make([]byte, 8)
++	)
++	binary.Write(&now, binary.BigEndian, time.Now().UnixNano())
++	rand.Read(nonce)
++	hostname, err := os.Hostname()
++	if err != nil {
++		hostname = "localhost"
++	}
++	return fmt.Sprintf("<%s.%s@%s>",
++		base36.EncodeBytes(now.Bytes()),
++		base36.EncodeBytes(nonce),
++		hostname)
++}
++
+ type loginAuth struct {
+ 	username, password string
+ }
+-- 
+2.24.1
+
diff --git a/sr.ht/alertmanager/APKBUILD b/sr.ht/alertmanager/APKBUILD
index 5bf6919..e491e5a 100644
--- a/sr.ht/alertmanager/APKBUILD
+++ b/sr.ht/alertmanager/APKBUILD
@@ -1,7 +1,7 @@
 # Maintainer: Drew DeVault <sir@cmpwn.com>
 pkgname=alertmanager
 pkgver=0.19.0
-pkgrel=5
+pkgrel=6
 pkgdesc="Prometheus Alertmanager"
 url="https://github.com/prometheus/alertmanager"
 arch="all"
@@ -12,11 +12,17 @@ source="
 	$pkgname-$pkgver.tar.gz::https://github.com/prometheus/alertmanager/archive/v$pkgver.tar.gz
 	alertmanager.confd
 	alertmanager.initd
+	0001-email-generate-message-ID-headers.patch
 "
 subpackages="$pkgname-openrc"
 builddir="$srcdir/$pkgname-$pkgver"
 options="!check" # timing-dependent upstream failures
 
+prepare() {
+	default_prepare
+	go mod vendor
+}
+
 build() {
 	go build \
 		-trimpath \
@@ -52,4 +58,5 @@ package() {
 
 sha512sums="2c21bfbb1001e07e81b1115439ad15e7c0e7089839e56a19c445177e322b8ef9aa2b85e96478f3c3d709cbbd3a5447662a8c55da370b84aa4b6b24f83848744b  alertmanager-0.19.0.tar.gz
 58420cf10ed51ec389d21ffdd5b4a0e588f0dc78b1069e32d0db1e0215f64c1c980d8f539ae902839f2f9342090b50ce1db756839f3676ee18b77548ce8f99c8  alertmanager.confd
-def36c9933e91a38d863c06679efd840952ba003a839afe5b5c6423fa6ee8f229755f758c5363564b433756af34509fef282b81dea2532500f1287c47c426787  alertmanager.initd"
+def36c9933e91a38d863c06679efd840952ba003a839afe5b5c6423fa6ee8f229755f758c5363564b433756af34509fef282b81dea2532500f1287c47c426787  alertmanager.initd
+7df6fb27a22b12f006f2f0ba0b6b807c07611a1c63fecee67de04d0899f4ba9924b62281f43289e4519ae6313a0b1bf47bce7a3401c91ef6f49e943638e84ae1  0001-email-generate-message-ID-headers.patch"
-- 
2.45.2