/*
* Copyright 2010-2014 the original author or authors.
*
* 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.
*/
package org.springframework.boot.cloudfoundry;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Properties;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.boot.context.config.ConfigFileApplicationListener;
import org.springframework.boot.context.event.ApplicationEnvironmentPreparedEvent;
import org.springframework.boot.json.JsonParser;
import org.springframework.boot.json.JsonParserFactory;
import org.springframework.context.ApplicationListener;
import org.springframework.core.Ordered;
import org.springframework.core.env.CommandLinePropertySource;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.Environment;
import org.springframework.core.env.MutablePropertySources;
import org.springframework.core.env.PropertiesPropertySource;
import org.springframework.util.StringUtils;
/**
* An {@link ApplicationListener} that knows where to find VCAP (a.k.a. Cloud Foundry)
* meta data in the existing environment. It parses out the VCAP_APPLICATION and
* VCAP_SERVICES meta data and dumps it in a form that is easily consumed by
* {@link Environment} users. If the app is running in Cloud Foundry then both meta data
* items are JSON objects encoded in OS environment variables. VCAP_APPLICATION is a
* shallow hash with basic information about the application (name, instance id, instance
* index, etc.), and VCAP_SERVICES is a hash of lists where the keys are service labels
* and the values are lists of hashes of service instance meta data. Examples are:
*
* <pre class="code">
* VCAP_APPLICATION: {"instance_id":"2ce0ac627a6c8e47e936d829a3a47b5b","instance_index":0,
* "version":"0138c4a6-2a73-416b-aca0-572c09f7ca53","name":"foo",
* "uris":["foo.cfapps.io"], ...}
* VCAP_SERVICES: {"rds-mysql-1.0":[{"name":"mysql","label":"rds-mysql-1.0","plan":"10mb",
* "credentials":{"name":"d04fb13d27d964c62b267bbba1cffb9da","hostname":"mysql-service-public.clqg2e2w3ecf.us-east-1.rds.amazonaws.com",
* "host":"mysql-service-public.clqg2e2w3ecf.us-east-1.rds.amazonaws.com","port":3306,"user":"urpRuqTf8Cpe6",
* "username":"urpRuqTf8Cpe6","password":"pxLsGVpsC9A5S"}
* }]}
* </pre>
*
* These objects are flattened into properties. The VCAP_APPLICATION object goes straight
* to <code>vcap.application.*</code> in a fairly obvious way, and the VCAP_SERVICES
* object is unwrapped so that it is a hash of objects with key equal to the service
* instance name (e.g. "mysql" in the example above), and value equal to that instances
* properties, and then flattened in the same way. E.g.
*
* <pre class="code">
* vcap.application.instance_id: 2ce0ac627a6c8e47e936d829a3a47b5b
* vcap.application.version: 0138c4a6-2a73-416b-aca0-572c09f7ca53
* vcap.application.name: foo
* vcap.application.uris[0]: foo.cfapps.io
*
* vcap.services.mysql.name: mysql
* vcap.services.mysql.label: rds-mysql-1.0
* vcap.services.mysql.credentials.name: d04fb13d27d964c62b267bbba1cffb9da
* vcap.services.mysql.credentials.port: 3306
* vcap.services.mysql.credentials.host: mysql-service-public.clqg2e2w3ecf.us-east-1.rds.amazonaws.com
* vcap.services.mysql.credentials.username: urpRuqTf8Cpe6
* vcap.services.mysql.credentials.password: pxLsGVpsC9A5S
* ...
* </pre>
*
* N.B. this initializer is mainly intended for informational use (the application and
* instance ids are particularly useful). For service binding you might find that Spring
* Cloud is more convenient and more robust against potential changes in Cloud Foundry.
*
* @author Dave Syer
*/
public class VcapApplicationListener implements
ApplicationListener<ApplicationEnvironmentPreparedEvent>, Ordered {
private static final Log logger = LogFactory.getLog(VcapApplicationListener.class);
private static final String VCAP_APPLICATION = "VCAP_APPLICATION";
private static final String VCAP_SERVICES = "VCAP_SERVICES";
// Before ConfigFileApplicationListener so values there can use these ones
private int order = ConfigFileApplicationListener.DEFAULT_ORDER - 1;;
private final JsonParser parser = JsonParserFactory.getJsonParser();
public void setOrder(int order) {
this.order = order;
}
@Override
public int getOrder() {
return this.order;
}
@Override
public void onApplicationEvent(ApplicationEnvironmentPreparedEvent event) {
ConfigurableEnvironment environment = event.getEnvironment();
if (!environment.containsProperty(VCAP_APPLICATION)
&& !environment.containsProperty(VCAP_SERVICES)) {
return;
}
Properties properties = new Properties();
addWithPrefix(properties, getPropertiesFromApplication(environment),
"vcap.application.");
addWithPrefix(properties, getPropertiesFromServices(environment),
"vcap.services.");
MutablePropertySources propertySources = environment.getPropertySources();
if (propertySources
.contains(CommandLinePropertySource.COMMAND_LINE_PROPERTY_SOURCE_NAME)) {
propertySources.addAfter(
CommandLinePropertySource.COMMAND_LINE_PROPERTY_SOURCE_NAME,
new PropertiesPropertySource("vcap", properties));
}
else {
propertySources.addFirst(new PropertiesPropertySource("vcap", properties));
}
}
private void addWithPrefix(Properties properties, Properties other, String prefix) {
for (String key : other.stringPropertyNames()) {
String prefixed = prefix + key;
properties.setProperty(prefixed, other.getProperty(key));
}
}
private Properties getPropertiesFromApplication(Environment environment) {
Properties properties = new Properties();
try {
Map<String, Object> map = this.parser.parseMap(environment.getProperty(
VCAP_APPLICATION, "{}"));
extractPropertiesFromApplication(properties, map);
}
catch (Exception ex) {
logger.error("Could not parse VCAP_APPLICATION", ex);
}
return properties;
}
private Properties getPropertiesFromServices(Environment environment) {
Properties properties = new Properties();
try {
Map<String, Object> map = this.parser.parseMap(environment.getProperty(
VCAP_SERVICES, "{}"));
extractPropertiesFromServices(properties, map);
}
catch (Exception ex) {
logger.error("Could not parse VCAP_SERVICES", ex);
}
return properties;
}
private void extractPropertiesFromApplication(Properties properties,
Map<String, Object> map) {
if (map != null) {
flatten(properties, map, "");
}
}
private void extractPropertiesFromServices(Properties properties,
Map<String, Object> map) {
if (map != null) {
for (Object services : map.values()) {
@SuppressWarnings("unchecked")
List<Object> list = (List<Object>) services;
for (Object object : list) {
@SuppressWarnings("unchecked")
Map<String, Object> service = (Map<String, Object>) object;
String key = (String) service.get("name");
if (key == null) {
key = (String) service.get("label");
}
flatten(properties, service, key);
}
}
}
}
private void flatten(Properties properties, Map<String, Object> input, String path) {
for (Entry<String, Object> entry : input.entrySet()) {
String key = entry.getKey();
if (StringUtils.hasText(path)) {
if (key.startsWith("[")) {
key = path + key;
}
else {
key = path + "." + key;
}
}
Object value = entry.getValue();
if (value instanceof String) {
properties.put(key, value);
}
else if (value instanceof Map) {
// Need a compound key
@SuppressWarnings("unchecked")
Map<String, Object> map = (Map<String, Object>) value;
flatten(properties, map, key);
}
else if (value instanceof Collection) {
// Need a compound key
@SuppressWarnings("unchecked")
Collection<Object> collection = (Collection<Object>) value;
properties.put(key,
StringUtils.collectionToCommaDelimitedString(collection));
int count = 0;
for (Object object : collection) {
flatten(properties,
Collections.singletonMap("[" + (count++) + "]", object), key);
}
}
else {
properties.put(key, value == null ? "" : value);
}
}
}
}