In microservices, the front service should use the Authorization Code(Grant Type) to let users log in with the web browser, and other services in the background should use Client Credentials(Grant Type).

1. Simulate Password Credentials in Postman

Spring yml example, here combine  with Authorization Code

user-authorization-uri is used to compile the login url:

https://localhost:9080/auth/realms/master/protocol/openid-connect/auth?client_id=security-admin-console&redirect_uri=https%3A%2F%2Fkeycloak_url%2Fauth%2Fadmin%2Fmaster%2Fconsole%2F%23%2Frealms%2FREALM_NAME%2Fclient-scopes%2F2cba1ee2-8c73-49b1-9fc2-1d3fcb5a48fd%2Fmappers&state=17e396b4-bc5d-4514-bfe6-62576e75c617&response_mode=fragment&response_type=code&scope=openid&nonce=0d962261-63cb-49af-85a3-7f809adbcb46

 

1-1. Retrieve token for collection

Edit one collection

Then all the APIs in this collection will be injected with the token in header. For example: Bearer xxxxxxxxxxx

 

1-2. Retrieve token manually

Create one Request:

The Username-Password in Authorization here is client_id and client_secret actually.

Request body:

Then use the token to query resource:

1-3. Revoke token manually

 

 

2. Simulate Client Credentials in Postman

Spring yml example:

 

2-1. Retrieve token

Add a new request client_credentials-1-token

The Username-Password in Authorization here is client_id and client_secret actually.

If get tokenABC succesfully, copy it for further steps.

2-2. token resource

Add a new request client_credentials-2-tokeninfo

Copy tokenABC here from the first step 2.1.

2-3. User resource

Add a new request client_credentials-2-tokeninfo.

Copy tokenABC here from the first step 2.1.

 

 

Ref:

https://www.javainuse.com/spring/springboot-oauth2-client-grant

https://docs.spring.io/autorepo/docs/spring-security-oauth2-boot/2.0.0.RC2/reference/html/boot-features-security-oauth2-resource-server.html