VcapServices.go

// Copyright 2016, RadiantBlue Technologies, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

/*
"VCAP_SERVICES": {
  "user-provided": [
   {
	"credentials": {
	 "host": "172.32.125.109:9200"
	},
	"label": "user-provided",
	"name": "pz-elasticsearch",
	"syslog_drain_url": "",
	"tags": []
   }
  ]
 }
}
*/

package piazza

import (
	"encoding/json"
	"os"
)

type VcapCredentials struct {
	Host string `json:"host"`
}

type VcapServiceEntry struct {
	Credentials    VcapCredentials `json:"credentials"`
	Label          string          `json:"label"`
	Name           string          `json:"name"`
	SyslogDrainUrl string          `json:"syslog_drain_url"`
	Tags           []string        `json:"tags"`
}

type VcapServices struct {
	UserProvided []VcapServiceEntry `json:"user-provided"`

	Services map[ServiceName]string
}

var localVcapServices = &VcapServices{
	UserProvided: []VcapServiceEntry{
		VcapServiceEntry{
			Name: "pz-elasticsearch",
			Credentials: VcapCredentials{
				Host: DefaultElasticsearchAddress,
			},
		},
		VcapServiceEntry{
			Name: "pz-kafka",
			Credentials: VcapCredentials{
				Host: DefaultKafkaAddress,
			},
		},
		VcapServiceEntry{
			Name: " pz-logger",
			Credentials: VcapCredentials{
				Host: DefaultPzLoggerAddress,
			},
		},
		VcapServiceEntry{
			Name: " pz-uuidgen",
			Credentials: VcapCredentials{
				Host: DefaultPzUuidgenAddress,
			},
		},
	},
}

func NewVcapServices() (*VcapServices, error) {

	var err error
	var vcap *VcapServices

	str := os.Getenv("VCAP_SERVICES")
	if str != "" {

		//log.Printf("VCAP_SERVICES:\n%s", str)
		vcap = &VcapServices{}

		err = json.Unmarshal([]byte(str), vcap)
		if err != nil {
			return nil, err
		}

	} else {
		vcap = localVcapServices
	}

	vcap.Services = make(ServicesMap)

	for _, serviceEntry := range vcap.UserProvided {
		name := ServiceName(serviceEntry.Name)
		addr := serviceEntry.Credentials.Host
		vcap.Services[name] = addr
		//log.Printf("VcapServices: added %s for %s", name, addr)
	}

	return vcap, nil
}