initial public commit

tools/mailer/sendmail.go

@@ -0,0 +1,79 @@
+package mailer
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"mime"
+	"net/http"
+	"net/mail"
+	"os/exec"
+)
+
+var _ Mailer = (*Sendmail)(nil)
+
+// Sendmail implements `mailer.Mailer` interface and defines a mail
+// client that sends emails via the `sendmail` *nix command.
+//
+// This client is usually recommended only for development and testing.
+type Sendmail struct {
+}
+
+// Send implements `mailer.Mailer` interface.
+//
+// Attachments are currently not supported.
+func (m *Sendmail) Send(
+	fromEmail mail.Address,
+	toEmail mail.Address,
+	subject string,
+	htmlBody string,
+	attachments map[string]io.Reader,
+) error {
+	headers := make(http.Header)
+	headers.Set("Subject", mime.QEncoding.Encode("utf-8", subject))
+	headers.Set("From", fromEmail.String())
+	headers.Set("To", toEmail.String())
+	headers.Set("Content-Type", "text/html; charset=UTF-8")
+
+	cmdPath, err := findSendmailPath()
+	if err != nil {
+		return err
+	}
+
+	var buffer bytes.Buffer
+
+	// write
+	// ---
+	if err := headers.Write(&buffer); err != nil {
+		return err
+	}
+	if _, err := buffer.Write([]byte("\r\n")); err != nil {
+		return err
+	}
+	if _, err := buffer.Write([]byte(htmlBody)); err != nil {
+		return err
+	}
+	// ---
+
+	sendmail := exec.Command(cmdPath, toEmail.Address)
+	sendmail.Stdin = &buffer
+
+	return sendmail.Run()
+}
+
+func findSendmailPath() (string, error) {
+	options := []string{
+		"/usr/sbin/sendmail",
+		"/usr/bin/sendmail",
+		"sendmail",
+	}
+
+	for _, option := range options {
+		path, err := exec.LookPath(option)
+		if err == nil {
+			return path, err
+		}
+	}
+
+	return "", errors.New("Failed to locate a sendmail executable path.")
+}