I'm trying to publish a nextjs app that uses 'next-auth' with aws Cognito.
When I run it locally, either using next dev OR next start it works completely fine.
When I run it on the production server (ubuntu, with nginx) it does not.
Exact Error:
After accessing the Cognito built in sign in page the redirect url https://...../api/auth/callback/cognito?code=......&state=..... displays nginx's default 502 error page.
What I've checked:
And YES the Callback URL(s) setting for the app in AWS Cognito itself is set to the correct url (https:// ....... /api/auth/callback/cognito).
CODE:
middleware.ts
export { default } from "next-auth/middleware";
export const config = { matcher: ["/dashboard/:path*"] };
next.config.js
/** @type {import('next').NextConfig} */
const nextConfig = {
reactStrictMode: true,
swcMinify: true,
compiler: {
styledComponents: true,
},
};
module.exports = nextConfig;
pages/api/auth/[...nextauth].ts
import CognitoProvider from "next-auth/providers/cognito";
import NextAuth, { NextAuthOptions, Session } from "next-auth";
import {
AuthFlowType,
CognitoIdentityProviderClient,
InitiateAuthCommand,
} from "@aws-sdk/client-cognito-identity-provider";
import { JWT } from "next-auth/jwt";
const COGNITO_AWS_REGION = process.env.COGNITO_AWS_REGION;
const COGNITO_POOL_ID = process.env.COGNITO_POOL_ID;
const COGNITO_CLIENT_ID = process.env.COGNITO_CLIENT_ID;
const COGNITO_CLIENT_SECRET = process.env.COGNITO_CLIENT_SECRET;
const NEXTAUTH_SECRET = process.env.NEXTAUTH_SECRET;
const NEXTAUTH_URL = process.env.NEXTAUTH_URL;
if (!COGNITO_AWS_REGION) throw new Error("REGION is not set");
if (!COGNITO_CLIENT_ID) throw new Error("COGNITO_CLIENT_ID is not set");
if (!COGNITO_POOL_ID) throw new Error("COGNITO_USER_POOL_ID is not set");
if (!COGNITO_CLIENT_SECRET) throw new Error("COGNITO_CLIENT_SECRET is not set");
if (!NEXTAUTH_SECRET) throw new Error("NEXTAUTH_SECRET is not set");
if (!NEXTAUTH_URL) throw new Error("NEXTAUTH_URL is not set");
const refreshCognitoAccessToken = async (token: JWT) => {
const client = new CognitoIdentityProviderClient({
region: COGNITO_AWS_REGION,
});
const command = new InitiateAuthCommand({
AuthFlow: AuthFlowType.REFRESH_TOKEN_AUTH,
ClientId: COGNITO_CLIENT_ID,
AuthParameters: {
REFRESH_TOKEN: token.refreshToken as string,
},
});
const response = await client.send(command);
return response.AuthenticationResult;
};
export const authOptions: NextAuthOptions = {
secret: NEXTAUTH_SECRET,
// @ts-expect-error -- this property is not documented properly
site: NEXTAUTH_URL,
providers: [
CognitoProvider({
clientId: COGNITO_CLIENT_ID!,
issuer: `https://cognito-idp.${COGNITO_AWS_REGION}.amazonaws.com/${COGNITO_POOL_ID!}`,
clientSecret: process.env.COGNITO_CLIENT_SECRET!,
}),
],
callbacks: {
jwt: async ({ token, account, user }) => {
// Initial sign in
if (account && user) {
return {
// save token to session for authenticating to AWS
// https://next-auth.js.org/configuration/callbacks#jwt-callback
accessToken: account.access_token,
accessTokenExpires: account.expires_at
? account.expires_at * 1000
: 0,
refreshToken: account.refresh_token,
user,
};
}
// Return previous token if the access token has not expired yet
if (Date.now() < (token as unknown as Session).accessTokenExpires) {
return token;
}
// Access token has expired, try to update it
const refreshedTokens = await refreshCognitoAccessToken(token);
return {
...token,
accessToken: refreshedTokens?.AccessToken,
accessTokenExpires: refreshedTokens?.ExpiresIn
? Date.now() + refreshedTokens?.ExpiresIn * 1000
: 0,
refreshToken: refreshedTokens?.RefreshToken ?? token.refreshToken, // Fall back to old refresh token
};
},
session: async ({ session, token }) => {
if (!session?.user || !token?.accessToken) {
console.error("No accessToken found on token or session");
return session;
}
session.user = token.user as Session["user"];
session.accessToken = token.accessToken as string;
session.error = token.error as string | undefined;
return session;
},
redirect: async ({ url, baseUrl }) => {
// allows any url
if (url.startsWith("/")) return `${baseUrl}${url}`;
return url;
},
},
};
export default NextAuth(authOptions);
Well I figured it out myself eventually, turns out I wasn't reading my nginx logs correctly, once I did it wasn't anything too hard... here is what I did:
The 502 error is most likely corresponding with a upstream sent too big header while reading response header from upstream error in the nginx error logs for that request. To solve this add this to your config, under /etc/nginx/nginx.conf in the http {... } section ...
proxy_buffers 8 16k;
proxy_buffer_size 32k;
(found this solution here: https://stackoverflow.com/a/38758325/4205839)
The above should solve the 502 error, but you may still be getting errors with next-auth, here are a few other things to try which I discovered while trying to solve this problem...
In AWS Cognito, try making, and then using, a new "App Client" in AWS Cognito WITHOUT a client secret.
If you run it now you will get errors such as signin?error=OAuthCallback and client_secret_basic client authentication method requires a client_secret. So you will also need to update the config of cognito in pages/api/auth/[...nextauth].ts to be ...
CognitoProvider({
clientId: COGNITO_CLIENT_ID,
issuer: `https://cognito-idp.${COGNITO_AWS_REGION}.amazonaws.com/${COGNITO_POOL_ID!}`,
clientSecret: "someString",
client: {
token_endpoint_auth_method: "none",
},
})
which I discovered from this discussion: https://github.com/nextauthjs/next-auth/issues/2524
Note: If you receive something like a redirect_mismatch error from Cognito it means you haven't updated the urls correctly in your AWS Cognito client app settings, which is a frequent occurrence I've found when switching between local and live for debugging.