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dex/server/templates.go

326 lines
8.6 KiB
Go

package server
import (
"fmt"
"html/template"
"io"
"io/ioutil"
"net/http"
"net/url"
"os"
"path"
"path/filepath"
"sort"
"strings"
)
const (
tmplApproval = "approval.html"
tmplLogin = "login.html"
tmplPassword = "password.html"
tmplOOB = "oob.html"
tmplError = "error.html"
)
var requiredTmpls = []string{
tmplApproval,
tmplLogin,
tmplPassword,
tmplOOB,
tmplError,
}
type templates struct {
loginTmpl *template.Template
approvalTmpl *template.Template
passwordTmpl *template.Template
oobTmpl *template.Template
errorTmpl *template.Template
}
type webConfig struct {
dir string
logoURL string
issuer string
theme string
issuerURL string
extra map[string]string
}
func dirExists(dir string) error {
stat, err := os.Stat(dir)
if err != nil {
if os.IsNotExist(err) {
return fmt.Errorf("directory %q does not exist", dir)
}
return fmt.Errorf("stat directory %q: %v", dir, err)
}
if !stat.IsDir() {
return fmt.Errorf("path %q is a file not a directory", dir)
}
return nil
}
// loadWebConfig returns static assets, theme assets, and templates used by the frontend by
// reading the directory specified in the webConfig.
//
// The directory layout is expected to be:
//
// ( web directory )
// |- static
// |- themes
// | |- (theme name)
// |- templates
//
func loadWebConfig(c webConfig) (static, theme http.Handler, templates *templates, err error) {
if c.theme == "" {
c.theme = "coreos"
}
if c.issuer == "" {
c.issuer = "dex"
}
if c.dir == "" {
c.dir = "./web"
}
if c.logoURL == "" {
c.logoURL = "theme/logo.png"
}
if err := dirExists(c.dir); err != nil {
return nil, nil, nil, fmt.Errorf("load web dir: %v", err)
}
staticDir := filepath.Join(c.dir, "static")
templatesDir := filepath.Join(c.dir, "templates")
themeDir := filepath.Join(c.dir, "themes", c.theme)
for _, dir := range []string{staticDir, templatesDir, themeDir} {
if err := dirExists(dir); err != nil {
return nil, nil, nil, fmt.Errorf("load dir: %v", err)
}
}
static = http.FileServer(http.Dir(staticDir))
theme = http.FileServer(http.Dir(themeDir))
templates, err = loadTemplates(c, templatesDir)
return
}
// loadTemplates parses the expected templates from the provided directory.
func loadTemplates(c webConfig, templatesDir string) (*templates, error) {
files, err := ioutil.ReadDir(templatesDir)
if err != nil {
return nil, fmt.Errorf("read dir: %v", err)
}
filenames := []string{}
for _, file := range files {
if file.IsDir() {
continue
}
filenames = append(filenames, filepath.Join(templatesDir, file.Name()))
}
if len(filenames) == 0 {
return nil, fmt.Errorf("no files in template dir %q", templatesDir)
}
issuerURL, err := url.Parse(c.issuerURL)
if err != nil {
return nil, fmt.Errorf("error parsing issuerURL: %v", err)
}
funcs := map[string]interface{}{
"issuer": func() string { return c.issuer },
"logo": func() string { return c.logoURL },
"url": func(reqPath, assetPath string) string { return relativeURL(issuerURL.Path, reqPath, assetPath) },
"lower": strings.ToLower,
"extra": func(k string) string { return c.extra[k] },
}
tmpls, err := template.New("").Funcs(funcs).ParseFiles(filenames...)
if err != nil {
return nil, fmt.Errorf("parse files: %v", err)
}
missingTmpls := []string{}
for _, tmplName := range requiredTmpls {
if tmpls.Lookup(tmplName) == nil {
missingTmpls = append(missingTmpls, tmplName)
}
}
if len(missingTmpls) > 0 {
return nil, fmt.Errorf("missing template(s): %s", missingTmpls)
}
return &templates{
loginTmpl: tmpls.Lookup(tmplLogin),
approvalTmpl: tmpls.Lookup(tmplApproval),
passwordTmpl: tmpls.Lookup(tmplPassword),
oobTmpl: tmpls.Lookup(tmplOOB),
errorTmpl: tmpls.Lookup(tmplError),
}, nil
}
// relativeURL returns the URL of the asset relative to the URL of the request path.
// The serverPath is consulted to trim any prefix due in case it is not listening
// to the root path.
//
// Algorithm:
// 1. Remove common prefix of serverPath and reqPath
// 2. Remove common prefix of assetPath and reqPath
// 3. For each part of reqPath remaining(minus one), go up one level (..)
// 4. For each part of assetPath remaining, append it to result
//
//eg
//server listens at localhost/dex so serverPath is dex
//reqPath is /dex/auth
//assetPath is static/main.css
//relativeURL("/dex", "/dex/auth", "static/main.css") = "../static/main.css"
func relativeURL(serverPath, reqPath, assetPath string) string {
splitPath := func(p string) []string {
res := []string{}
parts := strings.Split(path.Clean(p), "/")
for _, part := range parts {
if part != "" {
res = append(res, part)
}
}
return res
}
stripCommonParts := func(s1, s2 []string) ([]string, []string) {
min := len(s1)
if len(s2) < min {
min = len(s2)
}
splitIndex := min
for i := 0; i < min; i++ {
if s1[i] != s2[i] {
splitIndex = i
break
}
}
return s1[splitIndex:], s2[splitIndex:]
}
server, req, asset := splitPath(serverPath), splitPath(reqPath), splitPath(assetPath)
// Remove common prefix of request path with server path
server, req = stripCommonParts(server, req)
// Remove common prefix of request path with asset path
asset, req = stripCommonParts(asset, req)
// For each part of the request remaining (minus one) -> go up one level (..)
// For each part of the asset remaining -> append it
var relativeURL string
for i := 0; i < len(req)-1; i++ {
relativeURL = path.Join("..", relativeURL)
}
relativeURL = path.Join(relativeURL, path.Join(asset...))
return relativeURL
}
var scopeDescriptions = map[string]string{
"offline_access": "Have offline access",
"profile": "View basic profile information",
"email": "View your email address",
}
type connectorInfo struct {
ID string
Name string
URL string
}
type byName []connectorInfo
func (n byName) Len() int { return len(n) }
func (n byName) Less(i, j int) bool { return n[i].Name < n[j].Name }
func (n byName) Swap(i, j int) { n[i], n[j] = n[j], n[i] }
func (t *templates) login(r *http.Request, w http.ResponseWriter, connectors []connectorInfo, reqPath string) error {
sort.Sort(byName(connectors))
data := struct {
Connectors []connectorInfo
ReqPath string
}{connectors, r.URL.Path}
return renderTemplate(w, t.loginTmpl, data)
}
func (t *templates) password(r *http.Request, w http.ResponseWriter, postURL, lastUsername, usernamePrompt string, lastWasInvalid, showBacklink bool, reqPath string) error {
data := struct {
PostURL string
BackLink bool
Username string
UsernamePrompt string
Invalid bool
ReqPath string
}{postURL, showBacklink, lastUsername, usernamePrompt, lastWasInvalid, r.URL.Path}
return renderTemplate(w, t.passwordTmpl, data)
}
func (t *templates) approval(r *http.Request, w http.ResponseWriter, authReqID, username, clientName string, scopes []string, reqPath string) error {
accesses := []string{}
for _, scope := range scopes {
access, ok := scopeDescriptions[scope]
if ok {
accesses = append(accesses, access)
}
}
sort.Strings(accesses)
data := struct {
User string
Client string
AuthReqID string
Scopes []string
ReqPath string
}{username, clientName, authReqID, accesses, r.URL.Path}
return renderTemplate(w, t.approvalTmpl, data)
}
func (t *templates) oob(r *http.Request, w http.ResponseWriter, code string, reqPath string) error {
data := struct {
Code string
ReqPath string
}{code, r.URL.Path}
return renderTemplate(w, t.oobTmpl, data)
}
func (t *templates) err(r *http.Request, w http.ResponseWriter, errCode int, errMsg string) error {
w.WriteHeader(errCode)
data := struct {
ErrType string
ErrMsg string
ReqPath string
}{http.StatusText(errCode), errMsg, r.URL.Path}
if err := t.errorTmpl.Execute(w, data); err != nil {
return fmt.Errorf("Error rendering template %s: %s", t.errorTmpl.Name(), err)
}
return nil
}
// small io.Writer utility to determine if executing the template wrote to the underlying response writer.
type writeRecorder struct {
wrote bool
w io.Writer
}
func (w *writeRecorder) Write(p []byte) (n int, err error) {
w.wrote = true
return w.w.Write(p)
}
func renderTemplate(w http.ResponseWriter, tmpl *template.Template, data interface{}) error {
wr := &writeRecorder{w: w}
if err := tmpl.Execute(wr, data); err != nil {
if !wr.wrote {
// TODO(ericchiang): replace with better internal server error.
http.Error(w, "Internal server error", http.StatusInternalServerError)
}
return fmt.Errorf("Error rendering template %s: %s", tmpl.Name(), err)
}
return nil
}