feat: hash image name

Author: hui1601

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/jordan-wright/email v4.0.1-0.20210109023952-943e75fe5223+incompatible
 	github.com/vanng822/go-premailer v1.23.0
 	goauthentik.io/api/v3 v3.2024123.4
+	golang.org/x/crypto v0.33.0
 	golang.org/x/oauth2 v0.26.0
 	gopkg.in/yaml.v3 v3.0.1
 )
@@ -19,6 +20,6 @@ require (
 	github.com/gorilla/css v1.0.1 // indirect
 	github.com/gorilla/securecookie v1.1.2 // indirect
 	github.com/vanng822/css v1.0.1 // indirect
-	golang.org/x/crypto v0.33.0 // indirect
 	golang.org/x/net v0.34.0 // indirect
+	golang.org/x/sys v0.30.0 // indirect
 )

go.sum

@@ -303,6 +303,8 @@ golang.org/x/sys v0.17.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.19.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.29.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.30.0 h1:QjkSwP/36a20jFYWkSue1YwXzLmsV5Gfq7Eiy72C1uc=
+golang.org/x/sys v0.30.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/telemetry v0.0.0-20240228155512-f48c80bd79b2/go.mod h1:TeRTkGYfJXctD9OcfyVLyj2J3IxLnKwHJR8f4D8a3YE=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=

internal/email/template.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"github.com/jordan-wright/email"
+	"golang.org/x/crypto/sha3"
 	"html/template"
 	"net/textproto"
 	"os"
@@ -68,6 +69,10 @@ func (tm *TemplateManager) RenderTemplate(name string, data interface{}) (string
 			if err != nil {
 				return template.HTML(fmt.Sprintf("Failed to read image: %s", imageSrc))
 			}
+			// Inline images must have unique names
+			// 메일 읽지도 않았는데 탈락 이미지 이름이 미리보기에 나오면 슬프지 않을까요?
+			ext := filepath.Ext(imageSrc)
+			imageSrc = fmt.Sprintf("%s%s", hashString(imageSrc), ext)
 			header := textproto.MIMEHeader{
 				"Content-ID": {fmt.Sprintf("<%s>", imageSrc)},
 			}
@@ -89,6 +94,10 @@ func (tm *TemplateManager) RenderTemplate(name string, data interface{}) (string
 			if err != nil {
 				return template.HTML(fmt.Sprintf("Failed to read image: %s", imageSrc))
 			}
+			// Inline images must have unique names
+			// 메일 읽지도 않았는데 탈락 이미지 이름이 미리보기에 나오면 슬프지 않을까요?
+			ext := filepath.Ext(imageSrc)
+			imageSrc = fmt.Sprintf("%s-%s%s", hashString(imageSrc), width, ext)
 			header := textproto.MIMEHeader{
 				"Content-ID": {fmt.Sprintf("<%s>", imageSrc)},
 			}
@@ -148,3 +157,9 @@ func (tm *TemplateManager) DeleteTemplate(name string) {
 func (tm *TemplateManager) Templates() map[string]*template.Template {
 	return tm.ExportedTemplates()
 }
+
+func hashString(s string) string {
+	h := sha3.New512()
+	h.Write([]byte(s))
+	return fmt.Sprintf("%x", h.Sum(nil))
+}