better (?) limit email formatting (#279)

controller/emailUi/limitWarning.gohtml

@@ -135,8 +135,11 @@
         <img src="https://zrok.io/wp-content/uploads/2023/03/warning.jpg" width="363px" height="500px" style="padding-bottom: 10px;"/>
     </div>
     <div class="cta" style="text-align: center;">
-        <p style="text-align: center;">Your account is reaching a transfer limit, {{ .EmailAddress }}.</p>
+        <h3 style="text-align: center;">Your account is reaching a transfer limit, {{ .EmailAddress }}.</h3>
-        <p style="text-align: center;">{{ .Detail }}</p>
+    </div>
+
+    <div>
+        {{ .Detail }}
     </div>
 
     <table border="0" cellpadding="0" cellspacing="0" align="center" class="about">

controller/emailUi/model.go

@@ -3,7 +3,7 @@ package emailUi
 import (
 	"bytes"
 	"github.com/pkg/errors"
-	"html/template"
+	"text/template"
 )
 
 type WarningEmail struct {

controller/limits/accountWarningAction.go

@@ -1,7 +1,6 @@
 package limits
 
 import (
-	"fmt"
 	"github.com/jmoiron/sqlx"
 	"github.com/openziti/edge/rest_management_api_client"
 	"github.com/openziti/zrok/controller/emailUi"
@@ -36,9 +35,11 @@ func (a *accountWarningAction) HandleAccount(acct *store.Account, rxBytes, txByt
 	if limit.Limit.Total != Unlimited {
 		totalLimit = util.BytesToSize(limit.Limit.Total)
 	}
-	detail := fmt.Sprintf("Your account has received %v and sent %v (for a total of %v), which has triggered a transfer limit warning.", util.BytesToSize(rxBytes), util.BytesToSize(txBytes), util.BytesToSize(rxBytes+txBytes)) +
+
-		fmt.Sprintf(" This zrok instance only allows an account to receive %v, send %v, totalling not more than %v for each %v.", rxLimit, txLimit, totalLimit, limit.Period) +
+	detail := newDetailMessage()
-		fmt.Sprintf(" If you exceed the transfer limit, access to your shares will be temporarily disabled (until the last %v falls below the transfer limit)", limit.Period)
+	detail = detail.append("Your account has received %v and sent %v (for a total of %v), which has triggered a transfer limit warning.", util.BytesToSize(rxBytes), util.BytesToSize(txBytes), util.BytesToSize(rxBytes+txBytes))
+	detail = detail.append("This zrok instance only allows an account to receive %v, send %v, totalling not more than %v for each %v.", rxLimit, txLimit, totalLimit, limit.Period)
+	detail = detail.append("If you exceed the transfer limit, access to your shares will be temporarily disabled (until the last %v falls below the transfer limit)", limit.Period)
 
 	if err := sendLimitWarningEmail(a.cfg, acct.Email, detail); err != nil {
 		return errors.Wrapf(err, "error sending limit warning email to '%v'", acct.Email)

controller/limits/email.go

@@ -1,6 +1,7 @@
 package limits
 
 import (
+	"fmt"
 	"github.com/openziti/zrok/build"
 	"github.com/openziti/zrok/controller/emailUi"
 	"github.com/pkg/errors"
@@ -8,17 +9,48 @@ import (
 	"github.com/wneessen/go-mail"
 )
 
-func sendLimitWarningEmail(cfg *emailUi.Config, emailTo, detail string) error {
+type detailMessage struct {
+	lines []string
+}
+
+func newDetailMessage() *detailMessage {
+	return &detailMessage{}
+}
+
+func (m *detailMessage) append(msg string, args ...interface{}) *detailMessage {
+	m.lines = append(m.lines, fmt.Sprintf(msg, args...))
+	return m
+}
+
+func (m *detailMessage) html() string {
+	out := ""
+	for i := range m.lines {
+		out += fmt.Sprintf("<p style=\"text-align: left;\">%s</p>\n", m.lines[i])
+	}
+	return out
+}
+
+func (m *detailMessage) plain() string {
+	out := ""
+	for i := range m.lines {
+		out += fmt.Sprintf("%s\n\n", m.lines[i])
+	}
+	return out
+}
+
+func sendLimitWarningEmail(cfg *emailUi.Config, emailTo string, d *detailMessage) error {
 	emailData := &emailUi.WarningEmail{
 		EmailAddress: emailTo,
-		Detail:       detail,
 		Version:      build.String(),
 	}
 
+	emailData.Detail = d.plain()
 	plainBody, err := emailData.MergeTemplate("limitWarning.gotext")
 	if err != nil {
 		return err
 	}
+
+	emailData.Detail = d.html()
 	htmlBody, err := emailData.MergeTemplate("limitWarning.gohtml")
 	if err != nil {
 		return err

controller/limits/environmentWarningAction.go

@@ -1,7 +1,6 @@
 package limits
 
 import (
-	"fmt"
 	"github.com/jmoiron/sqlx"
 	"github.com/openziti/edge/rest_management_api_client"
 	"github.com/openziti/zrok/controller/emailUi"
@@ -42,9 +41,11 @@ func (a *environmentWarningAction) HandleEnvironment(env *store.Environment, rxB
 		if limit.Limit.Total != Unlimited {
 			totalLimit = util.BytesToSize(limit.Limit.Total)
 		}
-		detail := fmt.Sprintf("Your environment '%v' has received %v and sent %v (for a total of %v), which has triggered a transfer limit warning.", env.Description, util.BytesToSize(rxBytes), util.BytesToSize(txBytes), util.BytesToSize(rxBytes+txBytes)) +
+
-			fmt.Sprintf(" This zrok instance only allows a share to receive %v, send %v, totalling not more than %v for each %v.", rxLimit, txLimit, totalLimit, limit.Period) +
+		detail := newDetailMessage()
-			fmt.Sprintf(" If you exceed the transfer limit, access to your shares will be temporarily disabled (until the last %v falls below the transfer limit).", limit.Period)
+		detail = detail.append("Your environment '%v' has received %v and sent %v (for a total of %v), which has triggered a transfer limit warning.", env.Description, util.BytesToSize(rxBytes), util.BytesToSize(txBytes), util.BytesToSize(rxBytes+txBytes))
+		detail = detail.append("This zrok instance only allows a share to receive %v, send %v, totalling not more than %v for each %v.", rxLimit, txLimit, totalLimit, limit.Period)
+		detail = detail.append("If you exceed the transfer limit, access to your shares will be temporarily disabled (until the last %v falls below the transfer limit).", limit.Period)
 
 		if err := sendLimitWarningEmail(a.cfg, acct.Email, detail); err != nil {
 			return errors.Wrapf(err, "error sending limit warning email to '%v'", acct.Email)

controller/limits/shareWarningAction.go

@@ -1,7 +1,6 @@
 package limits
 
 import (
-	"fmt"
 	"github.com/jmoiron/sqlx"
 	"github.com/openziti/edge/rest_management_api_client"
 	"github.com/openziti/zrok/controller/emailUi"
@@ -47,9 +46,11 @@ func (a *shareWarningAction) HandleShare(shr *store.Share, rxBytes, txBytes int6
 		if limit.Limit.Total != Unlimited {
 			totalLimit = util.BytesToSize(limit.Limit.Total)
 		}
-		detail := fmt.Sprintf("Your share '%v' has received %v and sent %v (for a total of %v), which has triggered a transfer limit warning.", shr.Token, util.BytesToSize(rxBytes), util.BytesToSize(txBytes), util.BytesToSize(rxBytes+txBytes)) +
+
-			fmt.Sprintf(" This zrok instance only allows a share to receive %v, send %v, totalling not more than %v for each %v.", rxLimit, txLimit, totalLimit, limit.Period) +
+		detail := newDetailMessage()
-			fmt.Sprintf(" If you exceed the transfer limit, access to your shares will be temporarily disabled (until the last %v falls below the transfer limit).", limit.Period)
+		detail = detail.append("Your share '%v' has received %v and sent %v (for a total of %v), which has triggered a transfer limit warning.", shr.Token, util.BytesToSize(rxBytes), util.BytesToSize(txBytes), util.BytesToSize(rxBytes+txBytes))
+		detail = detail.append("This zrok instance only allows a share to receive %v, send %v, totalling not more than %v for each %v.", rxLimit, txLimit, totalLimit, limit.Period)
+		detail = detail.append("If you exceed the transfer limit, access to your shares will be temporarily disabled (until the last %v falls below the transfer limit).", limit.Period)
 
 		if err := sendLimitWarningEmail(a.cfg, acct.Email, detail); err != nil {
 			return errors.Wrapf(err, "error sending limit warning email to '%v'", acct.Email)