OAuth 2.1 Password Grant Type in Golang

Implementation of standard OAuth 2.1 for Password Grant type in Golang and its native HTTP server.

Healthcheck API

GET  oauth2/healthz HTTP/1.1
Host: 127.0.0.1
Content-Type: text/plain

Request:

curl -k --location --request GET 'https://127.0.0.1/healthz'

Response: Status code 200 (OK) and a simple body response ok indicates API is working and operational.

ok

Clients API

Clients endpoint is responsible for creating a new client/user to be inserted in database.

POST  oauth2/clients HTTP/1.1
Host: 127.0.0.1
Content-Type: application/json

Request:

curl -k --location --request POST 'https://127.0.0.1/oauth2/clients' \
--header 'Content-Type: application/json' \
--data-raw '{
    "username": "johndoe",
    "password": "johnspassword1"
}'

Response:

{
  "client_id": "a9a6b145-fafe-415c-a92e-c79cbd57567d"
}

Token API

After client registration you can create a token sending a POST request to this endpoint.

POST  oauth2/token HTTP/1.1
Host: 127.0.0.1
Content-Type: application/x-www-form-urlencoded

Request:

curl -k --location --request POST 'https://127.0.0.1/oauth2/token' \
--header 'Content-Type: application/x-www-form-urlencoded' \
--data-urlencode 'grant_type=password' \
--data-urlencode 'username=johndoe' \
--data-urlencode 'password=johnspassword1'

Response:

{
  "access_token": "MmVjZGFiNmY4Y2E2OTQ1ZWNmMGYz...FkMDM=",
  "token_type": "Bearer",
  "expires_in": 3600
}

Up & Running

There are a few commands available, you could explore the available options by running make. This should give you a glossary of available methods. For example to deploy the service, you can run:

  make deploy

Debug

In order to run debugger you could create a config on your IDE and enable DEBUG env variable in your local environment. You will need database & cache storage from docker; you could enable them with:

  make debug

Todos

• Add more documents about this repository and RFC Standard for OAuth 2.1 especially for password_grant
• Convert Http Error response to JSON response errors: []
• Investigate possibility of volume share for Redis & Go (app) to share TLS certs
• Separate the Docker network for proxy and app to exclude Database (Postgres) & Cache (Redis)
• Increase code coverage

Credits

Author: Hadi Tajallaei

Copyright © 2023-2025 Syniol Limited. All rights reserved.

Please see a LICENSE file