Using Cloud Foundry CUPS to inject Spring Security credentials into a Spring Boot Application

The following demo shows how to inject the Spring Security username/password credentials from a User Provided service on PCF, hence using the VCAP_SERVICES env variable to inject the values required to protect the application using HTTP Basic Authentication while running in PCF. Spring Boot automatically converts this data into a flat set of properties so you can easily get to the data as shown below.

The demo application can be found as follows

https://github.com/papicella/springsecurity-cf-cups

The application.yml would access the VCAP_SERVICES CF env variable using the the Spring Boot flat set of properties as shown below.

eg:

VCAP_SERVICES

System-Provided:
{
 "VCAP_SERVICES": {
  "user-provided": [
   {
    "credentials": {
     "password": "myadminpassword",
     "username": "myadminuser"
    },
    "label": "user-provided",
    "name": "my-cfcups-service",
    "syslog_drain_url": "",
    "tags": [],
    "volume_mounts": []
   }
  ]
 }
}
...

application.yml

spring:
  application:
    name: security-cf-cups-demo
security:
  user:
    name: ${vcap.services.my-cfcups-service.credentials.username:admin}
    password: ${vcap.services.my-cfcups-service.credentials.password:password}

Reading VCAP_SERVICES and VCAP_APPLICATION from a Spring Boot Rest Controller in PCF

Note for myself: Reading PCF System and ENV variables

  
package com.example;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import java.util.Map;

@RestController
public class DemoRest
{
    private static final Logger logger = LoggerFactory.getLogger(DemoRest.class);

    @RequestMapping(value = "/version", method = RequestMethod.GET)
    public String version()
    {
        return "1.0";
    }

    @RequestMapping(value = "/vcapapplication", method = RequestMethod.GET)
    public Map vcapApplication() throws Exception
    {
        return Utils.getEnvMap("VCAP_APPLICATION");
    }

    @RequestMapping(value = "/vcapservices", method = RequestMethod.GET)
    public Map vcapServices() throws Exception
    {
        return Utils.getEnvMap("VCAP_SERVICES");
    }

    @RequestMapping(value = "/vcapservices_json", method = RequestMethod.GET)
    public String vcapServicesJSON() throws Exception
    {
        return System.getenv().get("VCAP_SERVICES");
    }


    @RequestMapping(value = "/appindex", method = RequestMethod.GET)
    public String appIndex() throws Exception
    {
        String instanceIndex = "N/A";

        try
        {
            instanceIndex =
                    Utils.getEnvMap("VCAP_APPLICATION").getOrDefault("instance_index", "N/A").toString();
        }
        catch (Exception ex)
        {
           logger.info("Exception getting application index : " + ex.getMessage());
        }

        return instanceIndex;
    }

    @RequestMapping(value = "/getEnvVariable/{env_var}", method = RequestMethod.GET)
    public String getEnvVariable(@PathVariable String env_var)
    {
        return System.getenv().get(env_var);
    }

} 

Utils.java (Referenced in Code above)

  
package com.example;

import com.fasterxml.jackson.databind.ObjectMapper;

import java.util.HashMap;
import java.util.Map;

public class Utils
{
    public static Map getEnvMap(String vcap) throws Exception
    {
        String vcapEnv = System.getenv(vcap);
        ObjectMapper mapper = new ObjectMapper();

        if (vcapEnv != null) {
            Map<String, ?> vcapMap = mapper.readValue(vcapEnv, Map.class);
            return vcapMap;
        }

        return new HashMap<String, String>();
    }
}