XYZ-35: Added Support for GlobalRelay Compliance Export Format

* Added username to ChannelMemberHistory struct in anticipation of supporting GlobalRelay in Compliance Export
* Removed translation from debug output - this makes it complicated to use utils functions from tests in the enterprise repo
* Added an advanced email function that allows for greater control over message details. Updated MessageExport config to support GlobalRelay. Added attachment support to InBucket unit tests
* Moving templates in from enterprise to solve test issues
* Added export format to diagnostics
* Changed email attachment code to use FileBackend so that S3 storage is properly supported

utils/mail_test.go

@@ -7,6 +7,10 @@ import (
 	"strings"
 	"testing"
 
+	"net/mail"
+
+	"github.com/mattermost/mattermost-server/model"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
@@ -39,9 +43,9 @@ func TestSendMailUsingConfig(t *testing.T) {
 	require.Nil(t, err)
 	T = GetUserTranslations("en")
 
-	var emailTo string = "test@example.com"
-	var emailSubject string = "Testing this email"
-	var emailBody string = "This is a test from autobot"
+	var emailTo = "test@example.com"
+	var emailSubject = "Testing this email"
+	var emailBody = "This is a test from autobot"
 
 	//Delete all the messages before check the sample email
 	DeleteMailBox(emailTo)
@@ -50,7 +54,7 @@ func TestSendMailUsingConfig(t *testing.T) {
 		t.Log(err)
 		t.Fatal("Should connect to the STMP Server")
 	} else {
-		//Check if the email was send to the rigth email address
+		//Check if the email was send to the right email address
 		var resultsMailbox JSONMessageHeaderInbucket
 		err := RetryInbucket(5, func() error {
 			var err error
@@ -75,3 +79,78 @@ func TestSendMailUsingConfig(t *testing.T) {
 		}
 	}
 }
+
+func TestSendMailUsingConfigAdvanced(t *testing.T) {
+	cfg, _, err := LoadConfig("config.json")
+	require.Nil(t, err)
+	T = GetUserTranslations("en")
+
+	var mimeTo = "test@example.com"
+	var smtpTo = "test2@example.com"
+	var from = mail.Address{Name: "Nobody", Address: "nobody@mattermost.com"}
+	var emailSubject = "Testing this email"
+	var emailBody = "This is a test from autobot"
+
+	//Delete all the messages before check the sample email
+	DeleteMailBox(smtpTo)
+
+	// create a file that will be attached to the email
+	fileBackend, err := NewFileBackend(&cfg.FileSettings)
+	assert.Nil(t, err)
+	fileContents := []byte("hello world")
+	fileName := "file.txt"
+	assert.Nil(t, fileBackend.WriteFile(fileContents, fileName))
+	defer fileBackend.RemoveFile(fileName)
+
+	attachments := make([]*model.FileInfo, 1)
+	attachments[0] = &model.FileInfo{
+		Name: fileName,
+		Path: fileName,
+	}
+
+	headers := make(map[string]string)
+	headers["TestHeader"] = "TestValue"
+
+	if err := SendMailUsingConfigAdvanced(mimeTo, smtpTo, from, emailSubject, emailBody, attachments, headers, cfg); err != nil {
+		t.Log(err)
+		t.Fatal("Should connect to the STMP Server")
+	} else {
+		//Check if the email was send to the right email address
+		var resultsMailbox JSONMessageHeaderInbucket
+		err := RetryInbucket(5, func() error {
+			var err error
+			resultsMailbox, err = GetMailBox(smtpTo)
+			return err
+		})
+		if err != nil {
+			t.Log(err)
+			t.Fatal("No emails found for address " + smtpTo)
+		}
+		if err == nil && len(resultsMailbox) > 0 {
+			if !strings.ContainsAny(resultsMailbox[0].To[0], smtpTo) {
+				t.Fatal("Wrong To recipient")
+			} else {
+				if resultsEmail, err := GetMessageFromMailbox(smtpTo, resultsMailbox[0].ID); err == nil {
+					if !strings.Contains(resultsEmail.Body.Text, emailBody) {
+						t.Log(resultsEmail.Body.Text)
+						t.Fatal("Received message")
+					}
+
+					// verify that the To header of the email message is set to the MIME recipient, even though we got it out of the SMTP recipient's email inbox
+					assert.Equal(t, mimeTo, resultsEmail.Header["To"][0])
+
+					// verify that the MIME from address is correct - unfortunately, we can't verify the SMTP from address
+					assert.Equal(t, from.String(), resultsEmail.Header["From"][0])
+
+					// check that the custom mime headers came through - header case seems to get mutated
+					assert.Equal(t, "TestValue", resultsEmail.Header["Testheader"][0])
+
+					// ensure that the attachment was successfully sent
+					assert.Len(t, resultsEmail.Attachments, 1)
+					assert.Equal(t, fileName, resultsEmail.Attachments[0].Filename)
+					assert.Equal(t, fileContents, resultsEmail.Attachments[0].Bytes)
+				}
+			}
+		}
+	}
+}