example-frontend

Overview

1. Demonstration of OAuth2 Authorization Code Grant
   See also: https://oauth.net/2/grant-types/authorization-code/
2. Demonstration of "state" parameter to authentication code request and authorization response
   See also: https://openid.net/specs/openid-connect-core-1_0.html#NonceNotes
3. Demonstration of "nonce" parameter to authentication code request and ID token claim
   See also: https://openid.net/specs/openid-connect-core-1_0.html#NonceNotes
4. Demonstration of code_challenge parameter to authentication code request and code_verifier parameter to token exchange (Proof Key for Code Exchange, PKCE)
   See also: https://oauth.net/2/pkce/
   See also (code example): https://github.com/zjutjh/User-Center/blob/main/test/test_client.go
5. Demonstration of OpenID Connect Back-Channel Logout 1.0
   See also: https://openid.net/specs/openid-connect-backchannel-1_0.html

Installation

git clone https://github.com/b1-systems/example-frontend.git
cd example-frontend
go mod tidy
go build
sudo mkdir /usr/local/example-frontend
sudo cp example-frontend /usr/local/example-frontend
sudo cp example-frontend.service /etc/systemd/system
sudo systemctl daemon-reload

Configuration

sudo cp example-frontend.ini.sample /usr/local/example-frontend/example-frontend.ini
sudo vi /usr/local/example-frontend/example-frontend.ini

Example example-frontend.ini:

[example-frontend]
# These values are provided by your IdP for your confidential client
clientID = example-frontend
clientSecret = secret_as_set_in_idp

# This URL will be used for endpoint discovery of your IdP
providerUrl = https://your_idp_url/realms/golang-oidc

# This should be the URL of the URI "/" of your "example-frontend" server:
homeUrl = https://your_frontend_url/example-frontend/

# See https://github.com/b1-systems/example-frontend
backendUrl = https://www.example.test/example-backend/

# See https://github.com/b1-systems/example-resource
resourceUrl = https://www.example.test/example-resource/

# Plain HTTP service address of this "example-frontend" server:
listenAddress = 0.0.0.0:80

Environment Variables

All configuration options can also be set using environment variables as show below. Note that setting an environment variable overrides the corresponding value in the configuration file.

CLIENT_ID=some-name \
CLIENT_SECRET=secret_as_set_in_idp \
PROVIDER_URL=https://your_idp_url/realms/golang-oidc \
HOME_URL=https://your.login/url \
BACKEND_URL=https://www.example.test/example-backend/ \
RESOURCE_URL=https://www.example.test/example-resource/ \
LISTEN_ADDRESS=0.0.0.0:80 \
  example-frontend

Start

systemctl start example-frontend.service
journalctl -xefu  example-frontend.service

Start using Docker

docker build --tag example-frontend .
docker run \
  --rm \
  --name example-frontend \
  -e CLIENT_ID=some-name \
  -e CLIENT_SECRET=secret_as_set_in_idp \
  -e PROVIDER_URL=https://your_idp_url/realms/golang-oidc \
  -e HOME_URL=https://your.login/url \
  -e BACKEND_URL=https://www.example.test/example-backend/ \
  -e RESOURCE_URL=https://www.example.test/example-resource/ \
  -e LISTEN_ADDRESS=0.0.0.0:80 \
  --publish 8080:80 \
  example-frontend

Start using Compose

Create a file clientSecret.txt containing the secret of the example-frontend client in your provider.

printf "secret123" > ./clientSecret.txt

Create a file docker-compose.yml:

services:
   example-frontend:
     image: example-frontend:latest
     build: .
     ports:
       - "8080:80"
     environment:
       CLIENT_ID: example-frontend
       PROVIDER_URL: https://your_idp_url/realms/golang-oidc
       HOME_URL: https://www.example.test/example-frontend
       BACKEND_URL: https://www.example.test/example-backend
       RESOURCE_URL: https://www.example.test/example-resource
       LISTEN_ADDRESS: 0.0.0.0:80
     secrets:
       - clientSecret
secrets:
   clientSecret:
     file: clientSecret.txt

Run the service example-frontend:

docker compose -f docker-compose.yml up

Author, Copyright and License

• Copyright: 2022-2026 B1 Systems GmbH info@b1-systems.de
• Author: Tilman Kranz kranz@b1-systems.de
• License: MIT License https://opensource.org/licenses/MIT