logout: add support of logout flow

internal/web/templates.go

@@ -0,0 +1,321 @@
+// Code generated by go-bindata. DO NOT EDIT.
+// sources:
+// templates/login.tmpl (1.216kB)
+// templates/static/script.js (1.24kB)
+// templates/static/style.css (4.316kB)
+
+package web
+
+import (
+	"bytes"
+	"compress/gzip"
+	"crypto/sha256"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+func bindataRead(data []byte, name string) ([]byte, error) {
+	gz, err := gzip.NewReader(bytes.NewBuffer(data))
+	if err != nil {
+		return nil, fmt.Errorf("read %q: %v", name, err)
+	}
+
+	var buf bytes.Buffer
+	_, err = io.Copy(&buf, gz)
+	clErr := gz.Close()
+
+	if err != nil {
+		return nil, fmt.Errorf("read %q: %v", name, err)
+	}
+	if clErr != nil {
+		return nil, err
+	}
+
+	return buf.Bytes(), nil
+}
+
+type asset struct {
+	bytes  []byte
+	info   os.FileInfo
+	digest [sha256.Size]byte
+}
+
+type bindataFileInfo struct {
+	name    string
+	size    int64
+	mode    os.FileMode
+	modTime time.Time
+}
+
+func (fi bindataFileInfo) Name() string {
+	return fi.name
+}
+func (fi bindataFileInfo) Size() int64 {
+	return fi.size
+}
+func (fi bindataFileInfo) Mode() os.FileMode {
+	return fi.mode
+}
+func (fi bindataFileInfo) ModTime() time.Time {
+	return fi.modTime
+}
+func (fi bindataFileInfo) IsDir() bool {
+	return false
+}
+func (fi bindataFileInfo) Sys() interface{} {
+	return nil
+}
+
+var _loginTmpl = []byte("\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\xff\x84\x93\x4f\x6f\xdb\x3c\x0c\xc6\xcf\xce\xa7\x20\x74\x78\x6f\x8d\x3f\xc0\x6b\xe7\x52\x6c\x40\x81\x02\x2b\xda\x0e\x3b\x16\xb2\x44\xc7\x4a\x64\xc9\x20\x15\xaf\x81\xe1\xef\x3e\xc8\xb6\xf2\x67\x4d\xb0\x93\xa5\x87\x0f\x7f\x22\x25\x7a\x18\x40\x63\x6d\x1c\x82\x08\x26\x58\x14\x30\x8e\xab\xec\xd9\x6f\x8d\x83\x17\xf2\xbd\xd1\x48\xf0\x0b\x29\x34\x48\xab\x61\x00\x74\x3a\x3a\x56\x17\x79\x1c\x8e\x29\xaf\xb0\xc6\xed\x81\xd0\x96\xb3\xca\x0d\x62\x10\xd0\x10\xd6\x51\x91\xc1\xa8\x7c\x0a\xac\x15\xb3\xd8\xdc\x01\xee\x78\xa1\xb1\x22\xd3\x05\x08\xc7\x0e\x4b\x11\xf0\x33\xe4\x3b\xd9\xcb\x59\x15\xc0\xa4\xce\xd0\x49\x5b\xef\x58\x6c\x8a\x65\x73\x8f\xae\xbc\x0b\xe8\xc2\x72\x84\x36\x3d\x28\x2b\x99\x4b\x61\x63\xd3\x0f\x9d\xdc\xa2\xd8\xac\xb2\xab\x50\xed\xa9\x9d\xc4\xac\xe8\x92\xd6\x22\x73\xf2\x66\xc3\x00\xa6\x86\xf5\x13\x3f\xb9\x5e\x5a\xa3\x1f\x09\x35\xba\x60\xa4\xe5\xe9\x9c\x2c\xcb\x96\x08\x1c\x18\xc9\xc9\x16\xc1\x13\x74\x92\xf9\xb7\x27\xbd\x20\xd0\x32\x9e\x38\x21\xda\xec\x37\x22\x4f\x67\xc4\x2c\x02\x23\xf5\x48\x80\x31\x78\x99\xbb\xf8\xfe\x73\x15\x77\xff\xa7\xc0\x7c\x05\xb1\xf6\xbc\x9b\x7b\x88\xed\x5c\x77\x3d\x35\x08\x52\x05\xe3\x5d\x29\x86\x01\xd6\xd3\x08\xfc\x7c\x7d\x86\x71\x14\xd0\x62\x68\xbc\x2e\xc5\xcb\x8f\xb7\xf7\xb9\xe1\xac\x30\xae\x3b\xa4\xb7\x69\x8c\xd6\xe8\x04\xc4\xbe\x4a\xa1\x98\xea\x8f\xe0\xf7\x51\xe9\xa5\x3d\x60\x19\x81\x8f\x6f\xaf\xdf\xdf\xa3\x08\xe3\xf8\x4f\xc4\x54\xd5\x87\x6a\xa4\xb5\xe8\xb6\x78\xc5\x49\xe2\xc4\xf9\x0a\x8a\x73\x22\xa0\xb3\x52\x61\xe3\xad\x46\x2a\x45\xba\xf2\x44\x3f\xed\xf3\x1b\x85\xa4\x37\xf9\x8b\x71\x96\x67\xc6\x69\x9f\xa7\x22\x2e\xe6\x45\x35\xa8\xf6\x95\xff\x04\xc2\x16\xdb\x0a\xe9\x21\x4e\x9d\x34\x0e\x69\xb9\xbe\x9b\xf6\x07\xdf\x23\x59\x79\x4c\x9e\xeb\xc2\x92\x2b\x55\x90\xd8\x02\xf2\x93\xff\x16\xf4\xcb\xd1\xf7\x7c\x71\xd1\x4a\xda\xc7\x7f\x48\x9b\xfe\x04\xbd\xda\x58\x59\xa1\x85\xda\xd3\x45\x01\x9b\xd7\x65\x05\x2d\x16\xf9\xe4\x48\x5d\x9e\x73\x2f\x97\xd5\x21\x04\xef\x96\xbe\xf8\x50\xb5\x26\x88\xcd\xf4\xe6\x45\x3e\xc7\xe6\x41\xcd\xe3\x5c\x4e\x3f\xe3\x92\xbc\x7c\xcf\x63\xfd\x27\x00\x00\xff\xff\x7b\xe3\xda\xaf\xc0\x04\x00\x00")
+
+func loginTmplBytes() ([]byte, error) {
+	return bindataRead(
+		_loginTmpl,
+		"login.tmpl",
+	)
+}
+
+func loginTmpl() (*asset, error) {
+	bytes, err := loginTmplBytes()
+	if err != nil {
+		return nil, err
+	}
+
+	info := bindataFileInfo{name: "login.tmpl", size: 1216, mode: os.FileMode(0644), modTime: time.Unix(1557837078, 0)}
+	a := &asset{bytes: bytes, info: info, digest: [32]uint8{0x57, 0xfc, 0x84, 0x28, 0x53, 0xbc, 0x7e, 0xe8, 0xf7, 0x63, 0x72, 0x3, 0x51, 0x21, 0xda, 0x48, 0x1f, 0x45, 0x63, 0xe8, 0x32, 0x66, 0x1b, 0xfd, 0x47, 0xca, 0x33, 0x3c, 0x36, 0x79, 0xe4, 0xf9}}
+	return a, nil
+}
+
+var _staticScriptJs = []byte("\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\xff\x9c\x52\xcb\x6e\xdb\x30\x10\xbc\xeb\x2b\x16\xba\x44\x0e\x54\xe6\x92\x53\x0d\xdd\x9a\xa2\x05\xd2\x53\xda\x53\xd1\x03\x23\x8e\x54\xa2\x7c\x38\x7c\xc8\x28\x6a\xff\x7b\x41\xdb\x7a\xf7\x11\x98\x07\x81\x10\x77\x66\x67\x67\xe7\xee\x96\x3a\xa9\xdf\x92\x47\x50\x84\x40\xc1\x57\xf7\xe4\xcf\xdf\x7d\x75\x4f\xb7\x77\xd9\x5e\x1a\x61\xf7\xcc\x1a\x65\xb9\xa0\x8a\x9a\x68\xea\x20\xad\x29\x36\xf4\x2b\x23\x22\xea\xb8\xa3\xe8\xe1\x1e\x14\x34\x55\x24\x6c\x1d\x35\x4c\x60\x2f\x11\xee\xe7\x13\x14\xea\x60\x5d\x91\x33\x65\x5b\x69\xde\x34\xd6\x69\x92\x66\x17\xc3\x57\xc3\x35\xaa\x9b\x04\x4d\xb7\x9b\x6f\xf9\xa6\x3c\x11\xa6\xb3\xe3\xde\x5f\x49\x98\xa0\x7b\xeb\xc4\x9c\xd0\x41\xe3\x4a\xc2\x04\xd5\xcf\x70\x73\xc2\x53\xf1\xfb\x54\xfb\x2a\xc6\x7c\xb3\xcd\x4e\xd8\xde\x2a\xd6\x71\x15\x41\x15\x79\x78\x2f\xad\x79\x0a\xd6\xf1\x16\xac\x45\xf8\x18\xa0\x8b\xd1\x98\xcd\x36\x9b\x4e\xc0\xea\xef\xa8\x7f\x40\xfc\x03\x3a\x28\xee\x9b\xca\x86\x8a\x65\xe3\x8a\x4c\x54\x8a\x0e\x87\x95\xa4\x8a\xf2\xbc\xdf\xee\x4c\x72\x63\xeb\xe8\x8b\x8b\x9e\x23\x41\x79\x4c\xca\xfa\x9d\x2d\xca\xce\x0a\x06\xbb\x18\x17\xe2\xa1\x83\x09\x8f\xd2\x07\x18\xb8\x22\xf7\xf1\x59\xcb\x90\x97\x63\xb6\x30\x6d\x9f\x02\xa6\x7d\xfb\x9f\xed\xed\x98\x86\xf7\xbc\xc5\xe0\xf4\x75\x83\xd3\xe1\x30\xa0\x67\x53\xad\xd0\xeb\x97\xb9\x6d\xe9\x5c\x74\x33\x69\x0c\xdc\x87\xcf\x9f\x1e\xa9\xa2\xfc\xcb\x65\xb3\xc4\x8d\xa0\x3e\xae\xc4\x1d\xc8\xe1\x25\x4a\x07\x91\x6f\x67\x2c\x60\x3b\x87\xe4\xd9\x3b\x34\x3c\xaa\xd0\x7b\x3b\x86\x3b\x44\x67\xc6\x7f\xc7\xe1\xb6\x48\x88\x5f\x85\xab\x5c\x98\x30\x61\x4e\xde\x2d\x43\xb7\x9c\xef\x6f\xfc\x43\x02\xcb\x55\x6e\x27\x1d\x56\x11\xfa\x03\xa5\x83\xb6\x1d\xd6\xb9\x1e\x67\x3d\xc7\xac\xa4\x86\x2b\x9f\xf4\x1f\xb7\xd9\xef\x00\x00\x00\xff\xff\xf0\x3d\xdb\x34\xd8\x04\x00\x00")
+
+func staticScriptJsBytes() ([]byte, error) {
+	return bindataRead(
+		_staticScriptJs,
+		"static/script.js",
+	)
+}
+
+func staticScriptJs() (*asset, error) {
+	bytes, err := staticScriptJsBytes()
+	if err != nil {
+		return nil, err
+	}
+
+	info := bindataFileInfo{name: "static/script.js", size: 1240, mode: os.FileMode(0644), modTime: time.Unix(1557837078, 0)}
+	a := &asset{bytes: bytes, info: info, digest: [32]uint8{0x21, 0x83, 0x40, 0xc4, 0xb1, 0x4e, 0x2c, 0xf8, 0x84, 0x11, 0x9b, 0x80, 0xc2, 0xe6, 0xab, 0xb5, 0xf8, 0xd5, 0x3b, 0xc9, 0x2e, 0x5b, 0x12, 0x7, 0x29, 0x2f, 0x21, 0x5f, 0x59, 0x35, 0xf7, 0xad}}
+	return a, nil
+}
+
+var _staticStyleCss = []byte("\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\xff\xbc\x57\xfb\x6e\xa3\xb8\x17\xfe\x9f\xa7\x38\xea\x4f\x95\x9a\x9f\x02\x63\x20\xe9\x24\x44\xbb\x3b\xcf\xb0\x6f\x60\xc0\x80\x55\xb0\x91\xed\x4c\x49\x57\xdd\x67\x5f\xf9\xc2\xb5\x24\xcd\xac\xaa\x4d\x66\x2a\x6c\x8e\xcf\xe5\x3b\x9f\x3f\x3b\x3f\x68\xd3\x72\xa1\xe0\x2c\xea\xa7\x4a\xa9\x56\x26\xdf\xbe\x15\x9c\x29\x19\x94\x9c\x97\x35\xc1\x2d\x95\x41\xc6\x9b\x6f\x99\x94\x7f\x14\xb8\xa1\xf5\xe5\xb7\x3f\x79\xca\x15\x4f\x62\x84\x36\x27\xcf\xab\x54\x53\xc3\x5f\x1e\x40\xca\x3b\x5f\xd2\x37\xca\xca\x04\x52\x2e\x72\x22\xfc\x94\x77\x27\xef\xdd\xf3\xfe\xbf\xf5\x92\x04\x17\x8a\x08\xfd\x90\x92\x82\x0b\xf2\x61\x0d\x65\x15\x11\x54\x99\x05\x41\xcd\x4b\xca\xfc\x16\x97\xd6\xee\x95\xe6\xaa\x4a\x20\x7e\x46\x6d\x77\xf2\x00\x5a\x9c\xe7\x66\xd1\xe1\x11\x10\x20\x3d\xd5\x60\x51\x52\x96\x00\x3e\x2b\x6e\x7c\xfc\x68\x48\x4e\x31\x3c\x35\xb8\xf3\xdd\xfa\xdd\x01\xb5\xdd\xc6\x78\x5c\x46\x18\x62\x84\x08\x3d\x9e\xcc\xc4\x34\xc8\xfe\xd1\x46\x79\x37\xd9\x15\x5c\x34\x66\x55\xcb\x25\x55\x94\xb3\x04\x04\xa9\xb1\xa2\x3f\x89\x36\x7a\xf3\x29\xcb\x49\x97\x40\xa8\x47\x29\xce\x5e\x4a\xc1\xcf\x2c\x4f\xe0\x7f\x85\xf9\xd8\x7c\x87\xb4\x86\xb2\xfa\x1a\x90\xa9\x42\xa7\xb2\x28\x37\x0a\x0e\xe1\x9e\x34\x7a\x4e\x91\x4e\xf9\xb8\xa6\x25\x4b\x20\x23\x4c\x11\x71\xea\x01\xad\x70\xce\x5f\xb5\x17\x04\x11\x6a\x3b\x40\x20\xca\x14\x3f\xa1\x2d\xb8\x7f\x41\xb4\xd9\x02\x82\x7d\xdb\x99\xff\x2b\xef\x77\x9b\x7b\x30\x1c\x70\x18\x53\x0f\xf7\x8f\x36\x79\x74\x72\xf3\xc3\xca\x15\x64\x9d\xd1\x34\x6b\xc6\x19\x59\x20\x4d\x59\x7b\x56\x26\x8e\xa6\xa6\x6f\x69\x98\xc0\x83\x25\xe2\xc3\x16\x24\x66\xd2\x97\x44\x50\x83\x2c\x3f\xab\x9a\x32\xe2\xbc\xcf\xe1\x8f\xf4\xf7\xe4\x7d\xe8\xb6\x25\x6c\x32\xa7\x92\x06\x30\xdc\x2f\x5a\xd0\x4f\x5c\xa3\xbb\x4b\x52\xd2\x37\x92\x40\xb8\x6b\xbb\xbb\x81\x1c\xcb\x9c\xfb\x08\x5c\xc7\x27\x88\xa4\x67\xa5\x38\xbb\x1f\x12\x43\x16\x25\x30\x93\x7a\x79\x02\xe7\xb6\x25\x22\xc3\x92\x7c\x82\x57\x94\xe2\xe7\x2c\xfd\x0c\xaf\x11\x9b\x00\x1d\x6c\xae\x19\xaf\xb9\x98\xf1\xfd\x03\x2a\x00\xfe\x2b\x49\x5f\xa8\x4b\xcc\xed\x23\x5c\xd7\x80\x82\x18\x88\x4b\xee\xd6\xbb\xec\x2c\xa4\x8e\xd2\x72\x6a\xf9\x7f\x27\xd0\x13\xf4\xa6\x5c\x0c\x5c\xee\x0b\xf4\xe3\x2b\xe8\x27\x15\xff\x49\x84\x95\xb1\x19\x66\xdf\x8f\xfb\xf4\xfb\xe9\x83\x39\xce\xb4\x3e\xac\xd8\xc7\x87\x1d\x8e\x4f\x30\x2e\x08\x1a\x22\x65\x2f\x4c\x6b\x64\x1c\xd1\x7d\x3e\x3e\x87\x4b\x74\xf7\xbf\xc0\xb9\x59\x28\x80\x86\x32\xbf\x22\xb4\xac\x54\x02\xf1\x2a\x1a\x33\x2e\x66\x9c\x29\x4c\x99\x43\xe1\x1e\x31\x9c\xaa\x1e\x5a\x55\xbd\xd3\xdc\xb3\x3b\x2d\xb6\xd3\x29\x73\x92\x98\x90\x7a\x8e\x30\x95\xc0\xc3\x83\xf6\x94\x53\xd9\xd6\xf8\x92\x40\x5a\xf3\xec\xc5\x20\x55\x13\x2c\xf4\x06\x55\xd5\xc2\x31\x04\x94\x15\x7c\x06\xf1\x5e\x8b\xa5\xcd\x61\x5d\x5f\xd7\x1c\x54\xe1\xd5\x36\xcd\x65\x6e\x02\x63\xfc\xdc\x8e\x4a\xf1\xda\xe3\x8d\xd0\xb4\xb7\x21\xd6\xdf\xf5\x98\xb2\xc5\xcc\xd5\x6f\x8d\x77\xb9\xfe\x2e\x89\x10\x39\x22\xac\xaf\xc7\x33\x0f\xc8\x7c\x86\xc2\x73\x92\x71\x81\x6d\x37\xad\x22\x5f\xf5\x13\x14\x73\x4f\xa4\x88\xd3\xd8\x26\x9e\xf2\xfc\x72\xbf\x48\xf5\x72\x60\x4b\x68\x38\x57\x95\x41\x0f\x33\x45\x71\x4d\xb1\x24\xa6\x42\xbf\xe1\x6f\x3e\x97\xdd\x07\xbb\x52\xe0\x8b\xcc\x70\xed\x92\x15\xa4\x21\x4d\x4a\x84\xbf\x60\xa9\x6d\x8a\x9f\x72\xa5\x78\x93\x40\x64\x09\x3d\xc1\xed\xa8\x25\xce\x94\x5b\x91\xec\x25\xe5\x9d\x2d\x6f\x45\x6c\x46\x8b\x9c\xfe\x1c\x06\xbe\xd6\x85\x1a\x5f\x6e\x6c\x0a\x6d\x51\xd4\xfa\xb8\xab\x68\x9e\x13\xb6\xf0\x36\x9e\x04\xbc\xc5\x19\x55\x97\x5e\x68\x07\x67\x38\x95\xbc\x3e\xab\x75\x19\x04\xa8\x49\xa1\x96\x87\x99\xe9\x2d\x6f\xdd\xd3\x7c\x5b\x2e\xd4\xbd\x97\x00\x3b\x9e\xa5\x56\xe3\x94\xd8\xfb\x5e\x51\x73\xac\x12\x13\xca\x84\xa4\x8c\x0c\xda\x41\x19\xd5\x3d\x5b\x00\x8b\x82\xa3\x05\x7b\xa2\xb9\xe1\x8e\x34\x10\xea\xe9\xcf\x15\x6b\x25\x89\xa9\xff\x30\x88\xf6\xbd\x66\xf5\x11\x50\x10\x1d\x48\x33\x6a\xfb\xfb\x8d\xb6\xcd\x79\x32\x2b\xef\x9e\x45\x93\x39\xfd\xd0\x60\xf1\x72\x83\x01\xe3\x11\xe0\x0f\x1b\x87\x90\x49\x2f\x22\xa7\x8e\x3d\xa4\x76\x7c\x23\x91\x3e\x68\x32\xd1\xc7\x41\x10\xfb\x5b\xd5\x15\x06\xcd\x65\xb4\x3f\xdc\x25\xaf\x69\x0e\xaf\x15\xb5\x56\xb3\xe3\xda\xde\x23\x04\x57\x58\x91\xa7\xdd\x3e\x27\xe5\xc6\x6e\x4e\x79\xf3\xfd\xad\x77\x03\xeb\x22\x5b\xb9\x03\xc2\x69\xa5\xa5\xf4\x77\x3b\x30\x3c\x8e\xfb\x8b\x98\xb9\x7c\x39\x6b\x04\x51\xdb\xe9\x57\x9a\xe6\xbf\x40\xa9\x5f\x6c\xea\xf8\x93\xc4\xdd\x65\xc6\xf4\xfb\x99\x77\xef\x5f\x06\x98\xf4\x6f\xda\xfe\x60\x88\x34\xec\xd6\x20\xea\xa7\x2c\x3a\x61\x18\x1c\xfb\x19\x03\xd1\xb0\x64\x09\x52\xdc\x5f\xfd\x57\x36\x85\x51\x9f\xc4\x0c\x49\x0e\x7f\xc3\x5a\xda\xbf\x5f\x45\x66\x85\xd8\xe3\x2d\x72\x72\x6d\xfc\x9a\x90\x6b\x5c\x1f\xc4\xe7\x7a\x08\x77\x77\xfb\x2f\x6a\xf3\x60\x2d\xb4\x07\xeb\xc1\x3d\xf8\xb4\x4e\xd7\x4a\x97\x80\xdb\x9d\x2b\xa5\x7e\x59\x89\x79\x9e\x7f\x4d\x80\x9b\xcd\x5a\x16\x66\x7e\x92\x86\x47\xb4\x85\xc9\x9f\xcd\xc4\xce\x9e\x65\x33\x0d\x70\xc7\x9e\x13\xca\x7f\x02\x00\x00\xff\xff\x23\x57\xc6\x0d\xdc\x10\x00\x00")
+
+func staticStyleCssBytes() ([]byte, error) {
+	return bindataRead(
+		_staticStyleCss,
+		"static/style.css",
+	)
+}
+
+func staticStyleCss() (*asset, error) {
+	bytes, err := staticStyleCssBytes()
+	if err != nil {
+		return nil, err
+	}
+
+	info := bindataFileInfo{name: "static/style.css", size: 4316, mode: os.FileMode(0644), modTime: time.Unix(1557837078, 0)}
+	a := &asset{bytes: bytes, info: info, digest: [32]uint8{0xf8, 0x53, 0xba, 0x33, 0x44, 0x16, 0x28, 0xdc, 0x9c, 0x4f, 0x69, 0xd7, 0x30, 0x5, 0x56, 0x8f, 0x1f, 0x78, 0xe3, 0x53, 0x41, 0xe6, 0x42, 0x95, 0x4, 0xaa, 0x5b, 0x40, 0xc, 0x30, 0x4d, 0x68}}
+	return a, nil
+}
+
+// Asset loads and returns the asset for the given name.
+// It returns an error if the asset could not be found or
+// could not be loaded.
+func Asset(name string) ([]byte, error) {
+	canonicalName := strings.Replace(name, "\\", "/", -1)
+	if f, ok := _bindata[canonicalName]; ok {
+		a, err := f()
+		if err != nil {
+			return nil, fmt.Errorf("Asset %s can't read by error: %v", name, err)
+		}
+		return a.bytes, nil
+	}
+	return nil, fmt.Errorf("Asset %s not found", name)
+}
+
+// AssetString returns the asset contents as a string (instead of a []byte).
+func AssetString(name string) (string, error) {
+	data, err := Asset(name)
+	return string(data), err
+}
+
+// MustAsset is like Asset but panics when Asset would return an error.
+// It simplifies safe initialization of global variables.
+func MustAsset(name string) []byte {
+	a, err := Asset(name)
+	if err != nil {
+		panic("asset: Asset(" + name + "): " + err.Error())
+	}
+
+	return a
+}
+
+// MustAssetString is like AssetString but panics when Asset would return an
+// error. It simplifies safe initialization of global variables.
+func MustAssetString(name string) string {
+	return string(MustAsset(name))
+}
+
+// AssetInfo loads and returns the asset info for the given name.
+// It returns an error if the asset could not be found or
+// could not be loaded.
+func AssetInfo(name string) (os.FileInfo, error) {
+	canonicalName := strings.Replace(name, "\\", "/", -1)
+	if f, ok := _bindata[canonicalName]; ok {
+		a, err := f()
+		if err != nil {
+			return nil, fmt.Errorf("AssetInfo %s can't read by error: %v", name, err)
+		}
+		return a.info, nil
+	}
+	return nil, fmt.Errorf("AssetInfo %s not found", name)
+}
+
+// AssetDigest returns the digest of the file with the given name. It returns an
+// error if the asset could not be found or the digest could not be loaded.
+func AssetDigest(name string) ([sha256.Size]byte, error) {
+	canonicalName := strings.Replace(name, "\\", "/", -1)
+	if f, ok := _bindata[canonicalName]; ok {
+		a, err := f()
+		if err != nil {
+			return [sha256.Size]byte{}, fmt.Errorf("AssetDigest %s can't read by error: %v", name, err)
+		}
+		return a.digest, nil
+	}
+	return [sha256.Size]byte{}, fmt.Errorf("AssetDigest %s not found", name)
+}
+
+// Digests returns a map of all known files and their checksums.
+func Digests() (map[string][sha256.Size]byte, error) {
+	mp := make(map[string][sha256.Size]byte, len(_bindata))
+	for name := range _bindata {
+		a, err := _bindata[name]()
+		if err != nil {
+			return nil, err
+		}
+		mp[name] = a.digest
+	}
+	return mp, nil
+}
+
+// AssetNames returns the names of the assets.
+func AssetNames() []string {
+	names := make([]string, 0, len(_bindata))
+	for name := range _bindata {
+		names = append(names, name)
+	}
+	return names
+}
+
+// _bindata is a table, holding each asset generator, mapped to its name.
+var _bindata = map[string]func() (*asset, error){
+	"login.tmpl": loginTmpl,
+
+	"static/script.js": staticScriptJs,
+
+	"static/style.css": staticStyleCss,
+}
+
+// AssetDir returns the file names below a certain
+// directory embedded in the file by go-bindata.
+// For example if you run go-bindata on data/... and data contains the
+// following hierarchy:
+//     data/
+//       foo.txt
+//       img/
+//         a.png
+//         b.png
+// then AssetDir("data") would return []string{"foo.txt", "img"},
+// AssetDir("data/img") would return []string{"a.png", "b.png"},
+// AssetDir("foo.txt") and AssetDir("notexist") would return an error, and
+// AssetDir("") will return []string{"data"}.
+func AssetDir(name string) ([]string, error) {
+	node := _bintree
+	if len(name) != 0 {
+		canonicalName := strings.Replace(name, "\\", "/", -1)
+		pathList := strings.Split(canonicalName, "/")
+		for _, p := range pathList {
+			node = node.Children[p]
+			if node == nil {
+				return nil, fmt.Errorf("Asset %s not found", name)
+			}
+		}
+	}
+	if node.Func != nil {
+		return nil, fmt.Errorf("Asset %s not found", name)
+	}
+	rv := make([]string, 0, len(node.Children))
+	for childName := range node.Children {
+		rv = append(rv, childName)
+	}
+	return rv, nil
+}
+
+type bintree struct {
+	Func     func() (*asset, error)
+	Children map[string]*bintree
+}
+
+var _bintree = &bintree{nil, map[string]*bintree{
+	"login.tmpl": &bintree{loginTmpl, map[string]*bintree{}},
+	"static": &bintree{nil, map[string]*bintree{
+		"script.js": &bintree{staticScriptJs, map[string]*bintree{}},
+		"style.css": &bintree{staticStyleCss, map[string]*bintree{}},
+	}},
+}}
+
+// RestoreAsset restores an asset under the given directory.
+func RestoreAsset(dir, name string) error {
+	data, err := Asset(name)
+	if err != nil {
+		return err
+	}
+	info, err := AssetInfo(name)
+	if err != nil {
+		return err
+	}
+	err = os.MkdirAll(_filePath(dir, filepath.Dir(name)), os.FileMode(0755))
+	if err != nil {
+		return err
+	}
+	err = ioutil.WriteFile(_filePath(dir, name), data, info.Mode())
+	if err != nil {
+		return err
+	}
+	return os.Chtimes(_filePath(dir, name), info.ModTime(), info.ModTime())
+}
+
+// RestoreAssets restores an asset under the given directory recursively.
+func RestoreAssets(dir, name string) error {
+	children, err := AssetDir(name)
+	// File
+	if err != nil {
+		return RestoreAsset(dir, name)
+	}
+	// Dir
+	for _, child := range children {
+		err = RestoreAssets(dir, filepath.Join(name, child))
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func _filePath(dir, name string) string {
+	canonicalName := strings.Replace(name, "\\", "/", -1)
+	return filepath.Join(append([]string{dir}, strings.Split(canonicalName, "/")...)...)
+}

internal/web/templates/login.tmpl

@@ -0,0 +1,45 @@
+{{ define "title" }}
+	Login Provider Werther
+{{ end }}
+
+{{ define "style" }}
+	<link rel="stylesheet" href="static/style.css">
+{{ end }}
+
+{{ define "js" }}
+	<script type="text/javascript" src="static/script.js"></script>
+{{ end }}
+
+{{ define "content" }}
+	<div class="login-page">
+		<div class="form">
+			<p class="message">
+			{{ if .IsInvalidCredentials }}
+				Invalid username or password
+			{{ else if .IsInternalError }}
+				Internal server error
+			{{ else }}
+				&nbsp;
+			{{ end }}
+			</p>
+			<form class="login-form" action="{{ .LoginURL }}" method="POST">
+				<input type="hidden" name="csrf_token" value={{ .CSRFToken }}>
+				<input type="hidden" name="login_challenge" value={{ .Challenge }}>
+
+				<input type="text" placeholder="username" name="username"/>
+				<input type="password" placeholder="password" name="password"/>
+
+				<div class="checkbox remember-container">
+					<div class="checkbox-overlay">
+						<input type="checkbox" name="remember" />
+						<div class="checkbox-container">
+							<div class="checkbox-checkmark"></div>
+						</div>
+						<label for="remember">Remember me</label>
+					</div>
+				</div>
+				<button type="submit">login</button>
+			</form>
+		</div>
+	</div>
+{{ end }}

internal/web/templates/static/script.js

@@ -0,0 +1,34 @@
+/* vim: setl et ts=4 sts=4 sw=4 */
+window.onload = function() {
+    var userElem = document.querySelector(".login-form input[name='username']"),
+        passElem = document.querySelector(".login-form input[name='password']"),
+        remeElem = document.querySelector(".login-form input[name='remember']"),
+        loginForm = document.querySelector(".login-form");
+
+    userElem.value = sessionStorage.getItem('username');
+    remeElem.checked = sessionStorage.getItem('remember');
+
+    if (userElem.value == null || userElem.value == "") {
+        userElem.focus();
+    } else {
+        passElem.focus();
+    }
+
+    loginForm.addEventListener("submit", function(e) {
+        var msgElem = document.querySelector("p.message");
+
+        if (userElem.value == null || userElem.value == "" ||
+            passElem.value == null || passElem.value == "") {
+            msgElem.innerHTML = "Username and password are required";
+            e.preventDefault();
+            return;
+        }
+        sessionStorage.setItem('username', userElem.value);
+        if (remeElem.checked) {
+            sessionStorage.setItem('remember', remeElem.checked);
+        } else {
+            sessionStorage.removeItem('remember');
+        }
+
+    }, false);
+};

internal/web/templates/static/style.css

@@ -0,0 +1,266 @@
+@import url(https://fonts.googleapis.com/css?family=Roboto:300);
+
+html {
+  box-sizing: border-box;
+}
+
+*,
+::after,
+::before {
+  box-sizing: inherit;
+}
+
+.login-page {
+  width: 360px;
+  padding: 8% 0 0;
+  margin: auto;
+}
+
+@media (max-width: 480px) {
+  .login-page {
+    width: 100%;
+    padding: 8% 5% 0;
+  }
+}
+
+.form {
+  position: relative;
+  z-index: 1;
+  background: #ffffff;
+  max-width: 360px;
+  margin: 0 auto 100px;
+  padding: 2.815em;
+  text-align: center;
+  box-shadow: 0 0 20px 0 rgba(0, 0, 0, 0.2), 0 5px 5px 0 rgba(0, 0, 0, 0.24);
+}
+
+@media (max-width: 480px) {
+  .form {
+    margin: 15% auto 0;
+    max-width: 100%;
+    padding: 0;
+    box-shadow: none;
+  }
+}
+
+.form input {
+  font-family: "Roboto", sans-serif;
+  outline: 0;
+  background: #f2f2f2;
+  width: 100%;
+  border: 0;
+  margin: 0 0 15px;
+  padding: 15px;
+  box-sizing: border-box;
+  font-size: 14px;
+}
+
+@media (max-width: 480px) {
+  .form input {
+    font-size: 1.5em;
+  }
+}
+
+.form button {
+  font-family: "Roboto", sans-serif;
+  text-transform: uppercase;
+  outline: 0;
+  background: #2ba6cb;
+  width: 100%;
+  border: 0;
+  padding: 1.08em;
+  color: #ffffff;
+  font-size: 14px;
+  -webkit-transition: all 0.3 ease;
+  transition: all 0.3 ease;
+  cursor: pointer;
+}
+
+@media (max-width: 480px) {
+  .form button {
+    padding: 0.8em;
+    font-size: 1.3em;
+  }
+}
+
+.form button:hover {
+  background: #2795b7;
+}
+
+.form button:active {
+  background: #2384a3; 
+}
+
+.form .message {
+  margin: 0 0 15px;
+  color: #ff6961;
+  font-size: 15px;
+}
+
+@media (max-width: 480px) {
+  .form .message {
+    min-height: 3em;
+    font-size: 1.5em;
+  }
+}
+
+.container {
+  position: relative;
+  z-index: 1;
+  max-width: 300px;
+  margin: 0 auto;
+}
+
+.container:before,
+.container:after {
+  content: "";
+  display: block;
+  clear: both;
+}
+
+.container .info {
+  margin: 50px auto;
+  text-align: center;
+}
+
+.container .info h1 {
+  margin: 0 0 15px;
+  padding: 0;
+  font-size: 36px;
+  font-weight: 300;
+  color: #1a1a1a;
+}
+
+.container .info span {
+  color: #4d4d4d;
+  font-size: 12px;
+}
+
+.container .info span a {
+  color: #000000;
+  text-decoration: none;
+}
+
+.container .info span .fa {
+  color: #ef3b3a;
+}
+
+body {
+  font-family: "Roboto", sans-serif;
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
+}
+
+.remember-container {
+  padding-bottom: 2em;
+  font-size: 90%;
+}
+
+.checkbox {
+  cursor: pointer;
+}
+
+.checkbox div.checkbox-overlay {
+  position: relative;
+  overflow: hidden;
+}
+
+.checkbox input {
+  opacity: 0;
+  position: absolute;
+  cursor: pointer;
+  left: 0;
+  margin: 0;
+  top: 0;
+  z-index: 1;
+  width: 100%;
+  height: 100%;
+}
+
+.checkbox label {
+  float: left;
+  line-height: initial;
+  font-size: 0.9em;
+  padding: 0.14em 1em;
+}
+
+@media (max-width: 480px) {
+  .checkbox label {
+    font-size:1.25em;
+    padding:0.28em 0.8em;
+  }
+}
+
+.checkbox div.checkbox-container {
+  float: left;
+}
+
+.checkbox div.checkbox-container .checkbox-checkmark {
+  position: relative;
+  background-color: #eee;
+  width: 20px;
+  height: 20px;
+}
+
+.checkbox div.checkbox-checkmark::after {
+  display: none;
+  position: absolute;
+  content: "";
+  border: solid white;
+  -webkit-transform: rotate(45deg);
+  -ms-transform: rotate(45deg);
+  transform: rotate(45deg);
+  height: 12px;
+  width: 6px;
+  left: 7px;
+  top: 3px;
+  border-width: 0 2px 3px 0;
+}
+
+@media (max-width: 480px) {
+  .checkbox div.checkbox-container .checkbox-checkmark {
+    width: 34px;
+    height: 34px;
+  }
+
+  .checkbox div.checkbox-container .checkbox-checkmark:after {
+    height: 20.4px;
+    width: 10.2px;
+    left: 11.9px;
+    top: 4px;
+    border-width: 0 3px 5px 0;
+  }
+}
+
+.checkbox input:checked ~ .checkbox-container > .checkbox-checkmark {
+  background-color: #2ba6cb;
+  border: 0;
+}
+
+.checkbox input:checked ~ .checkbox-container > .checkbox-checkmark:after {
+  display: initial;
+}
+
+.checkbox input:checked:hover ~ .checkbox-container > .checkbox-checkmark {
+  background-color: #2ba6cb;
+  border: 0;
+}
+
+.checkbox
+  input:checked:hover
+  ~ .checkbox-container
+  > .checkbox-checkmark:after {
+  border-color: white;
+}
+
+.checkbox input:hover ~ .checkbox-container > .checkbox-checkmark {
+  background-color: #ddd;
+}
+
+.checkbox input:hover ~ .checkbox-container > .checkbox-checkmark:after {
+  display: initial;
+  border-color: rgba(190, 190, 190, 1);
+  border-top: 0px;
+  border-left: 0px;
+}
+

internal/web/testdata/TestHTMLRenderer/external_template_happy_path/golden.file

@@ -0,0 +1,34 @@
+external template
+WebBasePath: testBasePath;
+
+Title:
+
+CSRFToken: testCSRFToken;
+Challenge: testChalenge;
+LoginURL: testLoginURL;
+IsInvalidCredentials: true;
+IsInternalError: true;
+
+Style:
+
+CSRFToken: testCSRFToken;
+Challenge: testChalenge;
+LoginURL: testLoginURL;
+IsInvalidCredentials: true;
+IsInternalError: true;
+
+Js:
+
+CSRFToken: testCSRFToken;
+Challenge: testChalenge;
+LoginURL: testLoginURL;
+IsInvalidCredentials: true;
+IsInternalError: true;
+
+Content:
+
+CSRFToken: testCSRFToken;
+Challenge: testChalenge;
+LoginURL: testLoginURL;
+IsInvalidCredentials: true;
+IsInternalError: true;

internal/web/testdata/TestHTMLRenderer/external_template_happy_path/login.tmpl

@@ -0,0 +1,31 @@
+{{- define "title" }}
+CSRFToken: {{ .CSRFToken }};
+Challenge: {{ .Challenge }};
+LoginURL: {{ .LoginURL }};
+IsInvalidCredentials: {{ .IsInvalidCredentials }};
+IsInternalError: {{ .IsInternalError }};
+{{- end }}
+
+{{- define "style" }}
+CSRFToken: {{ .CSRFToken }};
+Challenge: {{ .Challenge }};
+LoginURL: {{ .LoginURL }};
+IsInvalidCredentials: {{ .IsInvalidCredentials }};
+IsInternalError: {{ .IsInternalError }};
+{{- end }}
+
+{{- define "js" }}
+CSRFToken: {{ .CSRFToken }};
+Challenge: {{ .Challenge }};
+LoginURL: {{ .LoginURL }};
+IsInvalidCredentials: {{ .IsInvalidCredentials }};
+IsInternalError: {{ .IsInternalError }};
+{{- end }}
+
+{{- define "content" }}
+CSRFToken: {{ .CSRFToken }};
+Challenge: {{ .Challenge }};
+LoginURL: {{ .LoginURL }};
+IsInvalidCredentials: {{ .IsInvalidCredentials }};
+IsInternalError: {{ .IsInternalError }};
+{{- end }}

internal/web/testdata/TestHTMLRenderer/external_template_happy_path/main.tmpl

@@ -0,0 +1,15 @@
+{{- define "main" }}external template
+WebBasePath: {{ .WebBasePath }};
+
+Title:
+{{ block "title" .Data }}{{ end }}
+
+Style:
+{{ block "style" .Data }}{{ end }}
+
+Js:
+{{ block "js" .Data }}{{ end }}
+
+Content:
+{{ block "content" .Data }}{{ end }}
+{{- end }}

internal/web/testdata/TestHTMLRenderer/external_template_not_found/main.tmpl

@@ -0,0 +1,16 @@
+{{ define "main" }}
+external template
+WebBasePath: {{ .WebBasePath }};
+
+Title:
+{{ block "title" .Data }}{{ end }}
+
+Style:
+{{ block "style" .Data }}{{ end }}
+
+Js:
+{{ block "js" .Data }}{{ end }}
+
+Content:
+{{ block "content" .Data }}{{ end }}
+{{ end }}

internal/web/testdata/TestHTMLRenderer/internal_template_happy_path/golden.file

@@ -0,0 +1,34 @@
+internal template
+WebBasePath: testBasePath;
+
+Title:
+
+CSRFToken: testCSRFToken;
+Challenge: testChalenge;
+LoginURL: testLoginURL;
+IsInvalidCredentials: true;
+IsInternalError: true;
+
+Style:
+
+CSRFToken: testCSRFToken;
+Challenge: testChalenge;
+LoginURL: testLoginURL;
+IsInvalidCredentials: true;
+IsInternalError: true;
+
+Js:
+
+CSRFToken: testCSRFToken;
+Challenge: testChalenge;
+LoginURL: testLoginURL;
+IsInvalidCredentials: true;
+IsInternalError: true;
+
+Content:
+
+CSRFToken: testCSRFToken;
+Challenge: testChalenge;
+LoginURL: testLoginURL;
+IsInvalidCredentials: true;
+IsInternalError: true;

internal/web/testdata/TestHTMLRenderer/internal_template_happy_path/login.tmpl

@@ -0,0 +1,31 @@
+{{- define "title" }}
+CSRFToken: {{ .CSRFToken }};
+Challenge: {{ .Challenge }};
+LoginURL: {{ .LoginURL }};
+IsInvalidCredentials: {{ .IsInvalidCredentials }};
+IsInternalError: {{ .IsInternalError }};
+{{- end }}
+
+{{- define "style" }}
+CSRFToken: {{ .CSRFToken }};
+Challenge: {{ .Challenge }};
+LoginURL: {{ .LoginURL }};
+IsInvalidCredentials: {{ .IsInvalidCredentials }};
+IsInternalError: {{ .IsInternalError }};
+{{- end }}
+
+{{- define "js" }}
+CSRFToken: {{ .CSRFToken }};
+Challenge: {{ .Challenge }};
+LoginURL: {{ .LoginURL }};
+IsInvalidCredentials: {{ .IsInvalidCredentials }};
+IsInternalError: {{ .IsInternalError }};
+{{- end }}
+
+{{- define "content" }}
+CSRFToken: {{ .CSRFToken }};
+Challenge: {{ .Challenge }};
+LoginURL: {{ .LoginURL }};
+IsInvalidCredentials: {{ .IsInvalidCredentials }};
+IsInternalError: {{ .IsInternalError }};
+{{- end }}

internal/web/testdata/TestHTMLRenderer/internal_template_happy_path/main.tmpl

@@ -0,0 +1,15 @@
+{{- define "main" }}internal template
+WebBasePath: {{ .WebBasePath }};
+
+Title:
+{{ block "title" .Data }}{{ end }}
+
+Style:
+{{ block "style" .Data }}{{ end }}
+
+Js:
+{{ block "js" .Data }}{{ end }}
+
+Content:
+{{ block "content" .Data }}{{ end }}
+{{- end }}

internal/web/testdata/TestHTMLRenderer/internal_template_not_found/main.tmpl

@@ -0,0 +1,16 @@
+{{ define "main" }}
+internal template
+WebBasePath: {{ .WebBasePath }};
+
+Title:
+{{ block "title" .Data }}{{ end }}
+
+Style:
+{{ block "style" .Data }}{{ end }}
+
+Js:
+{{ block "js" .Data }}{{ end }}
+
+Content:
+{{ block "content" .Data }}{{ end }}
+{{ end }}

internal/web/testdata/TestStaticHandler/external_resource_happy_path/static/test.file

@@ -0,0 +1 @@
+test

internal/web/testdata/TestStaticHandler/external_resource_not_found/static/stub.file

@@ -0,0 +1 @@
+The file is needed to commit the parent directory to Git.

internal/web/testdata/TestStaticHandler/internal_resource_happy_path/static/test.file

@@ -0,0 +1 @@
+test

internal/web/testdata/TestStaticHandler/internal_resource_not_found/static/stub.file

@@ -0,0 +1 @@
+The file is needed to commit the parent directory to Git.

internal/web/web.go

@@ -0,0 +1,155 @@
+/*
+Copyright (C) JSC iCore - All Rights Reserved
+
+Unauthorized copying of this file, via any medium is strictly prohibited
+Proprietary and confidential
+*/
+
+//go:generate go run github.com/kevinburke/go-bindata/go-bindata -o templates.go -pkg web -prefix templates/ templates/...
+
+package web
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"html/template"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"path"
+
+	assetfs "github.com/elazarl/go-bindata-assetfs"
+	"github.com/pkg/errors"
+	"gopkg.i-core.ru/httputil"
+)
+
+// The file systems provide templates and their resources that are stored in the application's internal assets.
+// The variables are needed to be able to override them in tests.
+var (
+	intTmplsFS  http.FileSystem = &assetfs.AssetFS{Asset: Asset, AssetDir: AssetDir, AssetInfo: AssetInfo}
+	intStaticFS http.FileSystem = &assetfs.AssetFS{Asset: Asset, AssetDir: AssetDir, AssetInfo: AssetInfo, Prefix: "static"}
+)
+
+// Config is a configuration of a template's renderer and HTTP handler for static files.
+type Config struct {
+	Dir      string `envconfig:"dir" desc:"a path to an external web directory"`
+	BasePath string `envconfig:"base_path" default:"/" desc:"a base path of web pages"`
+}
+
+// HTMLRenderer renders a HTML page from a Go template.
+//
+// A template's source for a HTML page should contains four blocks:
+// "title", "style", "js", "content". Block "title" should contain the content of the "title" HTML tag.
+// Block "style" should contain "link" HTML tags that are injected to the head of the page.
+// Block "js" should contain "script" HTML tags that are injected to the bottom of the page's body.
+// Block "content" should contain HTML content that is injected to the start of the page's body.
+// Each block has access to data that is specified using the method "RenderTemplate" of HTMLRenderer.
+//
+// By default, HTMLRenderer loads a template's source from the application's internal assets.
+// The application's internal assets include the login page's template only (template with name "login.tmpl").
+//
+// Besides it, HTMLRenderer can load templates' sources from an external directory.
+// The external directory is specified via a config.
+//
+// Templates can contain links to resources (styles and scripts). In that case, the template's directory has to
+// contain directory "static" with these resources. To provide these resources to a user you should register
+// StaticHandler in the application's HTTP router with path "/static".
+type HTMLRenderer struct {
+	Config
+	mainTmpl *template.Template
+	fs       http.FileSystem
+}
+
+// NewHTMLRenderer returns a new instance of HTMLRenderer.
+func NewHTMLRenderer(cnf Config) (*HTMLRenderer, error) {
+	mainTmpl, err := template.New("main").Parse(mainT)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to create template's renderer")
+	}
+	fs := intTmplsFS
+	if cnf.Dir != "" {
+		fs = http.Dir(cnf.Dir)
+	}
+	return &HTMLRenderer{Config: cnf, mainTmpl: mainTmpl, fs: fs}, nil
+}
+
+// RenderTemplate renders a HTML page from a template with the specified name using the specified data.
+func (r *HTMLRenderer) RenderTemplate(w http.ResponseWriter, name string, data interface{}) error {
+	f, err := r.fs.Open(name)
+	if err != nil {
+		if v, ok := err.(*os.PathError); ok {
+			if os.IsNotExist(v.Err) {
+				return fmt.Errorf("the template %q does not exist", name)
+			}
+		}
+		return fmt.Errorf("failed to open template %q: %s", name, err)
+	}
+	b, err := ioutil.ReadAll(f)
+	if err != nil {
+		return fmt.Errorf("failed to read template %q: %s", name, err)
+	}
+	t, err := r.mainTmpl.Clone()
+	if err != nil {
+		return errors.Wrapf(err, "failed to clone the main template for template %q: %s", name, err)
+	}
+	t, err = t.Parse(string(b))
+	if err != nil {
+		return errors.Wrapf(err, "failed to parse template %q: %s", name, err)
+	}
+
+	var (
+		buf bytes.Buffer
+		bw  = bufio.NewWriter(&buf)
+	)
+	if err = t.Execute(bw, map[string]interface{}{"WebBasePath": r.BasePath, "Data": data}); err != nil {
+		return err
+	}
+	if err = bw.Flush(); err != nil {
+		return err
+	}
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	_, err = buf.WriteTo(w)
+	return err
+
+}
+
+var mainT = `{{ define "main" }}
+<!DOCTYPE html>
+<html>
+	<head>
+		<meta name="viewport" content="width=device-width, initial-scale=1">
+		<title>{{ block "title" .Data }}{{ end }}</title>
+		<base href={{ .WebBasePath }}>
+		{{ block "style" .Data }}{{ end }}
+	</head>
+	<body>
+		{{ block "content" .Data }}<h1>NO CONTENT</h1>{{ end }}
+		{{ block "js" .Data }}{{ end }}
+	</body>
+</html>
+{{ end }}
+`
+
+// StaticHandler provides HTTP handler that serves static files.
+type StaticHandler struct {
+	fs http.FileSystem
+}
+
+// NewStaticHandler creates a new instance of StaticHandler.
+func NewStaticHandler(cnf Config) *StaticHandler {
+	fs := intStaticFS
+	if cnf.Dir != "" {
+		fs = http.Dir(path.Join(cnf.Dir, "static"))
+	}
+	return &StaticHandler{fs: fs}
+}
+
+// AddRoutes registers a route that serves static files.
+func (h *StaticHandler) AddRoutes(apply func(m, p string, h http.Handler, mws ...func(http.Handler) http.Handler)) {
+	fileServer := http.FileServer(h.fs)
+	apply(http.MethodGet, "/*filepath", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		r.URL.Path = httputil.PathParam(r.Context(), "filepath")
+		fileServer.ServeHTTP(w, r)
+	}))
+}

internal/web/web_test.go

@@ -0,0 +1,187 @@
+/*
+Copyright (C) JSC iCore - All Rights Reserved
+
+Unauthorized copying of this file, via any medium is strictly prohibited
+Proprietary and confidential
+*/
+
+package web
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path"
+	"testing"
+
+	"github.com/andreyvit/diff"
+	"gopkg.i-core.ru/httputil"
+)
+
+func TestHTMLRenderer(t *testing.T) {
+	testCases := []struct {
+		name     string
+		ext      bool
+		basePath string
+		data     interface{}
+		wantErr  error
+	}{
+		{
+			name:    "internal template not found",
+			wantErr: fmt.Errorf(`the template "login.tmpl" does not exist`),
+		},
+		{
+			name:     "internal template happy path",
+			basePath: "testBasePath",
+			data: map[string]interface{}{
+				"CSRFToken":            "testCSRFToken",
+				"Challenge":            "testChalenge",
+				"LoginURL":             "testLoginURL",
+				"IsInvalidCredentials": true,
+				"IsInternalError":      true,
+			},
+		},
+		{
+			name:    "external template not found",
+			ext:     true,
+			wantErr: fmt.Errorf(`the template "login.tmpl" does not exist`),
+		},
+		{
+			name:     "external template happy path",
+			ext:      true,
+			basePath: "testBasePath",
+			data: map[string]interface{}{
+				"CSRFToken":            "testCSRFToken",
+				"Challenge":            "testChalenge",
+				"LoginURL":             "testLoginURL",
+				"IsInvalidCredentials": true,
+				"IsInternalError":      true,
+			},
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			tstDir := path.Join("testdata", t.Name())
+
+			// Read the main template.
+			var originMainT = mainT
+			defer func() { mainT = originMainT }()
+			f, err := os.Open(path.Join(tstDir, "main.tmpl"))
+			if err != nil {
+				t.Fatalf("failed to open main template: %s", err)
+			}
+			fc, err := ioutil.ReadAll(f)
+			if err != nil {
+				t.Fatalf("failed to read main template: %s", err)
+			}
+			mainT = string(fc)
+
+			// Create the template renderer.
+			cnf := Config{BasePath: tc.basePath}
+			if tc.ext {
+				cnf.Dir = tstDir
+			} else {
+				origin := intTmplsFS
+				defer func() { intTmplsFS = origin }()
+				intTmplsFS = http.Dir(tstDir)
+			}
+			r, err := NewHTMLRenderer(cnf)
+			if err != nil {
+				t.Fatalf("failed to create the template renderer: %s", err)
+			}
+
+			rr := httptest.NewRecorder()
+			err = r.RenderTemplate(rr, "login.tmpl", tc.data)
+
+			if tc.wantErr != nil {
+				if err == nil {
+					t.Fatalf("\ngot not errors\nwant error\n\t%s", tc.wantErr)
+				}
+				if err.Error() != tc.wantErr.Error() {
+					t.Fatalf("\ngot error:\n\t%s\nwant error\n\t%s", err, tc.wantErr)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("\ngot error\n\t%s\nwant no errors", err)
+			}
+			f, err = os.Open(path.Join(tstDir, "golden.file"))
+			if err != nil {
+				t.Fatalf("failed to open golden file: %s", err)
+			}
+			fc, err = ioutil.ReadAll(f)
+			if err != nil {
+				t.Fatalf("failed to read golden file: %s", err)
+			}
+			if got, want := rr.Body.String(), string(fc); got != want {
+				t.Errorf("\nbody diff (-want +got):\n%s", diff.LineDiff(want, got))
+			}
+		})
+	}
+}
+
+func TestStaticHandler(t *testing.T) {
+	testCases := []struct {
+		name       string
+		ext        bool
+		file       string
+		wantStatus int
+		wantBody   string
+	}{
+		{
+			name:       "internal resource not found",
+			file:       "not.found",
+			wantStatus: http.StatusNotFound,
+		},
+		{
+			name:       "internal resource happy path",
+			file:       "test.file",
+			wantStatus: http.StatusOK,
+			wantBody:   "test",
+		},
+		{
+			name:       "external resource not found",
+			ext:        true,
+			file:       "not.found",
+			wantStatus: http.StatusNotFound,
+		},
+		{
+			name:       "external resource happy path",
+			ext:        true,
+			file:       "test.file",
+			wantStatus: http.StatusOK,
+			wantBody:   "test",
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			tstDir := path.Join("testdata", t.Name())
+			cnf := Config{}
+			if tc.ext {
+				cnf.Dir = tstDir
+			} else {
+				origin := intStaticFS
+				defer func() { intStaticFS = origin }()
+				intStaticFS = http.Dir(path.Join(tstDir, "static"))
+			}
+
+			r := httptest.NewRequest(http.MethodGet, "/static/"+tc.file, nil)
+			rr := httptest.NewRecorder()
+
+			router := httputil.NewRouter()
+			router.AddRoutes(NewStaticHandler(cnf), "/static")
+			router.ServeHTTP(rr, r)
+
+			if rr.Code != tc.wantStatus {
+				t.Errorf("got status %d, want status %d", rr.Code, tc.wantStatus)
+			}
+			if tc.wantBody != "" {
+				if got := rr.Body.String(); got != tc.wantBody {
+					t.Errorf("got body %q, want body %q", got, tc.wantBody)
+				}
+			}
+		})
+	}
+}