gateway implementation with Keycloak.md

Gateway Module

It is the gateway to Order Manager, a distributed app built with Spring Cloud Config and Spring Boot.

Setup

• Create a new project with Spring Init. Make sure to add the two dependencies:

• Then add the code (Java code has been added, feel free to switch to Kotlin if you prefer!).

Manual Testing and Operation, along with Keycloak Configuration

• Now sit back tight and do the dirty engineering on service endpoints, integration and parameter matching.

• Run docker-compose up -d out of Product, Order and Inventory services.

• Start (Run.../Debug...) Product, Order, Inventory and Gateway services with IDE or CLI.

• Hit Product service over the port of Gateway. You succeed to access the service endpoint:

• Query the Inventory database with mysql login in Docker CLI to copy or remember one SKU code:

• Test the inventory service for availability of that SKU twice- for true and for false:

• Now write (just type in or copy-and-edit or get help from AI assistant) ´docker-compose-yml´ for Keycloak and its database. And, start the containers with docker-compose up -d:

• When the containers have started, visit http://localhost:9090 in a web browser, login as admin (check creds in docker-compose or secrets file) and create a new realm for your app:

• The realm should get created quickly and please you with this:

• Create client with client creds ID and capability config:

• Client creation should finish smoothly as well:

• Under credentials of the new client, Client Secret is autopopulated. It may be used as such or may well be regenerated. Either choice is good at this moment:

• Click and open the link of OpenID Endpoint Config:

• You may see a page similar to the one shown below. Copy ´issuer´ value from the page:

• Use the issuer value to make the respective registry in application.properties of gateway service:

• Now try to access Product (or another) service via gateway port. 401 response code must be returned:

• Check with another HTTP request sender:

• Now, to add authorization, do the following exercise:

  • In Postman (or a similar GUI tool), under Request > Authorization, go to Configure New Token > Configuration Options. There select Client Credentials against Grant Type.

  • Then paste into Access Token URL the value (the URL) of "token endoint" header which is on OpenID Endpoint Config page:

  • Copy or remember the client creds ID from client settings in Keycload Admin and paste against Client ID in Postman dialog:

  • Copy client secret from client credentials (Keycloak Admin) against Client Secret in Postman dialog:

  • Make sure that Grant Type is Client Crendentials:

  • Click on the tempting Get New Access Token button... finally:

  • Now the Authz is complete for you. Hurray! Enjoy accessing your favorite services via gateway, now in a secure manner :) :

  • And yes, this is a no-explainer. It's obviously obvious to click on the Use Token button. Doing so gets you a credit of 300 seconds to get inside on the Mission IM-Possible:

  • Product service is now secured with gateway and Keycloak:

  • Order service is also secured with Keycloak, thanks to gateway for integrating them well:

Contact Pointers

• LinkedIn: https://www.linkedin.com/in/rishirajopenminds
• X: https://twitter.com/RishiRajDevOps
• Start Page: https://bio.link/rishiraj49de
• GitHub: https://github.com/rishiraj88

Credits and Gratitude

I thank all who have mentored, taught and guided me. Also, I appreciate who have supported my work with pair programming and more.