Add google authentication

.gitignore

@@ -15,3 +15,4 @@ node_modules/
 .vscode
 *.DS_Store
 kernelboard/static/v2
+uv.lock

frontend/src/components/app-layout/NavUserProfile.tsx

@@ -13,7 +13,7 @@ import {
 } from "@mui/material";
 import AccountCircleIcon from "@mui/icons-material/AccountCircle";
 import LogoutIcon from "@mui/icons-material/Logout";
-import { DiscordIcon } from "../common/DiscordDefaultIcon";
+import LoginIcon from "@mui/icons-material/Login";
 import AlertBar from "../alert/AlertBar";
 import { useAuthStore } from "../../lib/store/authStore";
 // Optional: reduce re-renders
@@ -66,13 +66,13 @@ export default function NavUserProfile() {
   };
 
   const defaultUser = () => (
-    <Tooltip title="Login with Discord">
+    <Tooltip title="Login">
       <Button
         variant="outlined"
         href={"/v2/login"}
         size="small"
         sx={styles.loginButoon}
-        startIcon={<DiscordIcon />}
+        startIcon={<LoginIcon />}
         data-testid="login-btn"
       >
         Login

frontend/src/components/common/GoogleIcon.tsx

@@ -0,0 +1,14 @@
+const GoogleIconSvg =
+  "https://cdn.jsdelivr.net/gh/simple-icons/simple-icons/icons/google.svg";
+
+export function GoogleIcon({ size = 18 }: { size?: number }) {
+  return (
+    <img
+      src={GoogleIconSvg}
+      alt="Google"
+      width={size}
+      height={size}
+      style={{ display: "block" }}
+    />
+  );
+}

frontend/src/pages/login/login.tsx

@@ -12,6 +12,7 @@ import { ConstrainedContainer } from "../../components/app-layout/ConstrainedCon
 import { useSearchParams } from "react-router-dom";
 import { useCallback, useEffect, useState } from "react";
 import { DiscordIcon } from "../../components/common/DiscordDefaultIcon";
+import { GoogleIcon } from "../../components/common/GoogleIcon";
 import AlertBar from "../../components/alert/AlertBar";
 
 export default function Login() {
@@ -20,6 +21,10 @@ export default function Login() {
     const loginDiscrodHref = `/api/auth/discord?next=/v2/`;
     return loginDiscrodHref;
   };
+  const googleLoginUrl = () => {
+    const loginGoogleHref = `/api/auth/google?next=/v2/`;
+    return loginGoogleHref;
+  };
   const error = params.get("error");
 
   const [err, setErr] = useState<{
@@ -102,6 +107,15 @@ export default function Login() {
                 >
                   Continue with Discord
                 </Button>
+                <Button
+                  variant="outlined"
+                  href={googleLoginUrl()}
+                  size="small"
+                  sx={{ borderRadius: 999 }}
+                  startIcon={<GoogleIcon />}
+                >
+                  Continue with Gmail
+                </Button>
                 <Divider>or</Divider>
                 <Stack spacing={1}>
                   <Typography

kernelboard/api/auth.py

@@ -66,7 +66,18 @@ def providers():
                 "identity": lambda json: json["id"],
             },
             "scopes": ["identify"],
-        }
+        },
+        "google": {
+            "client_id": os.getenv("GOOGLE_CLIENT_ID"),
+            "client_secret": os.getenv("GOOGLE_CLIENT_SECRET"),
+            "authorize_url": "https://accounts.google.com/o/oauth2/v2/auth",
+            "token_url": "https://oauth2.googleapis.com/token",
+            "userinfo": {
+                "url": "https://www.googleapis.com/oauth2/v2/userinfo",
+                "identity": lambda json: json["id"],
+            },
+            "scopes": ["openid", "email", "profile"],
+        },
     }
 
 
@@ -86,6 +97,35 @@ def _discord_avatar_url(uid: str, avatar_hash: str | None) -> str | None:
     return f"https://cdn.discordapp.com/avatars/{uid}/{avatar_hash}.{ext}"
 
 
+def _google_avatar_url(picture_url: str | None) -> str | None:
+    """
+    Return Google's picture URL directly (already a full URL).
+    """
+    return picture_url if picture_url else None
+
+
+def _get_username_from_provider(provider: str, data: dict) -> str:
+    """
+    Extract username from provider-specific user data.
+    """
+    if provider == "discord":
+        return data.get("global_name") or data.get("username") or "unknown"
+    elif provider == "google":
+        return data.get("name") or data.get("email", "").split("@")[0] or "unknown"
+    return "unknown"
+
+
+def _get_avatar_url_from_provider(provider: str, identity: str, data: dict) -> str | None:
+    """
+    Extract avatar URL from provider-specific user data.
+    """
+    if provider == "discord":
+        return _discord_avatar_url(identity, data.get("avatar"))
+    elif provider == "google":
+        return _google_avatar_url(data.get("picture"))
+    return None
+
+
 # ----- Routes -----
 
 
@@ -235,11 +275,11 @@ def callback(provider: str):
 
     data = me_res.json() or {}
     identity = provider_data["userinfo"]["identity"](data)
-    username = data.get("global_name") or data.get("username") or "unknown"
+    username = _get_username_from_provider(provider, data)
 
     # 4) Stash display-only info (safe for SPA header)
     session["display_name"] = username
-    session["avatar_url"] = _discord_avatar_url(identity, data.get("avatar"))
+    session["avatar_url"] = _get_avatar_url_from_provider(provider, identity, data)
 
     # ensure user exists and has web_auth_id
     # if not, update the user with the new token