18F/e-QIP-prototype

package cloudfoundry

import (
    "encoding/json"
    "os"
)

// vcapJSON represents the JSON structure found in the CloudFoundry
// VCAP_SERVICES environment variable
type vcapJSON struct {
    UserProvided []service `json:"user-provided"`
}

// service represents the JSON structure which is common between the
// user provided services as well as other services
type service struct {
    Name        string            `json:"name"`
    Label       string            `json:"label"`
    Credentials map[string]string `json:"credentials"`
}

// native calls the native environment call for environment variable
func native(name string) string {
    return os.Getenv(name)
}

// vcap extracts the proper service credentials from the VCAP_SERVICES
func vcap(name, credential string) string {
    // Return early if there is not a VCAP_SERVICES environment variable
    services := native("VCAP_SERVICES")
    if services == "" {
        return ""
    }

    // The VCAP_SERVICES stores a JSON value which we can parse
    var v vcapJSON
    if err := json.Unmarshal([]byte(services), &v); err == nil {
        // Look for the user provided service and it's specific credential
        for _, s := range v.UserProvided {
            if s.Name == name {
                return s.Credentials[credential]
            }
        }
    }

    return ""
}