Load custom templates from filesystem

cmd/tulip/serve.go

@@ -9,6 +9,8 @@ import (
 	"flag"
 	"fmt"
 	"github.com/1f349/tulip/database"
+	"github.com/1f349/tulip/mail/templates"
+	"github.com/1f349/tulip/pages"
 	"github.com/1f349/tulip/server"
 	"github.com/1f349/violet/utils"
 	"github.com/MrMelon54/exit-reload"
@@ -82,6 +84,13 @@ func normalLoad(startUp startUpConfig, wd string) {
 		log.Fatal("[Tulip] Failed check:", err)
 	}
 
+	if err = pages.LoadPages(wd); err != nil {
+		log.Fatal("[Tulip] Failed to load page templates:", err)
+	}
+	if err := templates.LoadMailTemplates(wd); err != nil {
+		log.Fatal("[Tulip] Failed to load mail templates:", err)
+	}
+
 	srv := server.NewHttpServer(startUp.Listen, startUp.BaseUrl, startUp.OtpIssuer, startUp.ServiceName, startUp.Mail, db, key)
 	log.Printf("[Tulip] Starting HTTP server on '%s'\n", srv.Addr)
 	go utils.RunBackgroundHttp("HTTP", srv)

go.mod

@@ -4,6 +4,7 @@ go 1.21.1
 
 require (
 	github.com/1f349/cache v0.0.2
+	github.com/1f349/overlapfs v0.0.1
 	github.com/1f349/twofactor v1.0.4
 	github.com/1f349/violet v0.0.9
 	github.com/MrMelon54/exit-reload v0.0.1

go.sum

@@ -1,6 +1,8 @@
 cloud.google.com/go v0.34.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 github.com/1f349/cache v0.0.2 h1:27QD6zPd9xYyvh9V1qqWq+EAt5+N+qvyGWKfnjMrhP8=
 github.com/1f349/cache v0.0.2/go.mod h1:LibAMy13dF0KO1fQA9aEjZPBCB6Y4b5kKYEQJUqc2rQ=
+github.com/1f349/overlapfs v0.0.1 h1:LAxBolrXFAgU0yqZtXg/C/aaPq3eoQSPpBc49BHuTp0=
+github.com/1f349/overlapfs v0.0.1/go.mod h1:I6aItQycr7nrzplmfNXp/QF9tTmKRSgY3fXmu/7Ky2o=
 github.com/1f349/twofactor v1.0.4 h1:kN4EEGFlKRa7fGrxS+FpgwJI+tllES6YzXqCqurk4Uk=
 github.com/1f349/twofactor v1.0.4/go.mod h1:gnG80vElwqLWNMnLT57yu4o4L1GdXGPP6pcIPlapXZs=
 github.com/1f349/violet v0.0.9 h1:eQfc5fDMKJXVFUjS2UiAGTkOVVBamppD5dguhmU4GeU=

mail/templates/mail-verify.go.html

@@ -0,0 +1,12 @@
+<!-- TODO: format this as HTML -->
+
+Hello, {{.Name}}
+
+Please open this link to verify your email address: {{.Data.VerifyUrl}}
+
+This link is valid for 10 minutes.
+
+If you did not create an account with {{.ServiceName}} then please ignore this email and the account will be deleted within a 48-hour period.
+
+Regards,
+{{.ServiceName}}

mail/templates/templates.go

@@ -2,26 +2,54 @@ package templates
 
 import (
 	"embed"
+	"errors"
+	"github.com/1f349/overlapfs"
+	htmlTemplate "html/template"
 	"io"
+	"io/fs"
 	"log"
-	"text/template"
+	"os"
+	"path/filepath"
+	"sync"
+	textTemplate "text/template"
 )
 
 var (
-	//go:embed *
+	//go:embed *.go.html *.go.txt
 	embeddedTemplates embed.FS
-
-	mailTemplate *template.Template
+	mailHtmlTemplates *htmlTemplate.Template
+	mailTextTemplates *textTemplate.Template
+	loadOnce          sync.Once
 )
 
-func LoadMailTemplates() (err error) {
-	mailTemplate, err = template.New("mail").ParseFS(embeddedTemplates, "*.go.txt")
+func LoadMailTemplates(wd string) (err error) {
+	loadOnce.Do(func() {
+		var o fs.FS = embeddedTemplates
+		if wd != "" {
+			mailDir := filepath.Join(wd, "mail-templates")
+			err = os.Mkdir(mailDir, os.ModePerm)
+			if err != nil && !errors.Is(err, os.ErrExist) {
+				return
+			}
+			wdFs := os.DirFS(mailDir)
+			o = overlapfs.OverlapFS{A: embeddedTemplates, B: wdFs}
+		}
+		mailHtmlTemplates, err = htmlTemplate.New("mail").ParseFS(o, "*.go.html")
+		if err != nil {
+			return
+		}
+		mailTextTemplates, err = textTemplate.New("mail").ParseFS(o, "*.go.txt")
+	})
 	return
 }
 
-func RenderMailTemplate(wr io.Writer, name string, data any) {
-	err := mailTemplate.ExecuteTemplate(wr, name+".go.txt", data)
+func RenderMailTemplate(wrHtml, wrTxt io.Writer, name string, data any) {
+	err := mailHtmlTemplates.ExecuteTemplate(wrHtml, name+".go.html", data)
 	if err != nil {
-		log.Printf("Failed to render mail: %s: %s\n", name, err)
+		log.Printf("Failed to render mail html: %s: %s\n", name, err)
+	}
+	err = mailTextTemplates.ExecuteTemplate(wrTxt, name+".go.txt", data)
+	if err != nil {
+		log.Printf("Failed to render mail text: %s: %s\n", name, err)
 	}
 }

pages/pages.go

@@ -3,27 +3,45 @@ package pages
 import (
 	"embed"
 	_ "embed"
+	"errors"
+	"github.com/1f349/overlapfs"
 	"html/template"
 	"io"
+	"io/fs"
 	"log"
+	"os"
+	"path/filepath"
+	"sync"
 )
 
 var (
-	//go:embed *
-	embeddedTemplates embed.FS
-
-	pageTemplate *template.Template
+	//go:embed *.go.html
+	wwwPages     embed.FS
+	wwwTemplates *template.Template
+	loadOnce     sync.Once
 )
 
-func LoadPageTemplates() (err error) {
-	pageTemplate, err = template.New("pages").Funcs(template.FuncMap{
-		"emailHide": EmailHide,
-	}).ParseFS(embeddedTemplates, "*.go.html")
-	return
+func LoadPages(wd string) (err error) {
+	loadOnce.Do(func() {
+		var o fs.FS = wwwPages
+		if wd != "" {
+			wwwDir := filepath.Join(wd, "www")
+			err = os.Mkdir(wwwDir, os.ModePerm)
+			if err != nil && !errors.Is(err, os.ErrExist) {
+				return
+			}
+			wdFs := os.DirFS(wwwDir)
+			o = overlapfs.OverlapFS{A: wwwPages, B: wdFs}
+		}
+		wwwTemplates, err = template.New("pages").Funcs(template.FuncMap{
+			"emailHide": EmailHide,
+		}).ParseFS(o, "*.go.html")
+	})
+	return err
 }
 
 func RenderPageTemplate(wr io.Writer, name string, data any) {
-	err := pageTemplate.ExecuteTemplate(wr, name+".go.html", data)
+	err := wwwTemplates.ExecuteTemplate(wr, name+".go.html", data)
 	if err != nil {
 		log.Printf("Failed to render page: %s: %s\n", name, err)
 	}

server/server.go

@@ -9,9 +9,7 @@ import (
 	clientStore "github.com/1f349/tulip/client-store"
 	"github.com/1f349/tulip/database"
 	"github.com/1f349/tulip/mail"
-	"github.com/1f349/tulip/mail/templates"
 	"github.com/1f349/tulip/openid"
-	"github.com/1f349/tulip/pages"
 	scope2 "github.com/1f349/tulip/scope"
 	"github.com/go-oauth2/oauth2/v4/errors"
 	"github.com/go-oauth2/oauth2/v4/generates"
@@ -82,13 +80,6 @@ func NewHttpServer(listen, domain, otpIssuer, serviceName string, mailer mail.Ma
 		log.Fatalln("Failed to generate OpenID configuration:", err)
 	}
 
-	if err := pages.LoadPageTemplates(); err != nil {
-		log.Fatalln("Failed to load page templates:", err)
-	}
-	if err := templates.LoadMailTemplates(); err != nil {
-		log.Fatalln("Failed to load mail templates:", err)
-	}
-
 	oauthManager := manage.NewDefaultManager()
 	oauthSrv := server.NewServer(server.NewConfig(), oauthManager)
 	hs := &HttpServer{