/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 io.fabric8.karaf.core.properties.function;
import java.util.Locale;
import io.fabric8.karaf.core.Support;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.ConfigurationPolicy;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Service;
/**
* A {@link PropertiesFunction} that lookup the property value from
* OS environment variables using the service idiom.
* <p/>
* A service is defined using two environment variables where name is name of the service:
* <ul>
* <li><tt>NAME_SERVICE_HOST</tt></li>
* <li><tt>NAME_SERVICE_PORT</tt></li>
* </ul>
* in other words the service uses <tt>_SERVICE_HOST</tt> and <tt>_SERVICE_PORT</tt> as prefix.
* <p/>
* This implementation is to return the port part only.
*
* @see ServicePropertiesFunction
* @see ServiceHostPropertiesFunction
*/
@Component(
immediate = true,
policy = ConfigurationPolicy.IGNORE,
createPid = false
)
@Property(name = "function.name", value = ServicePortPropertiesFunction.FUNCTION_NAME)
@Service(PropertiesFunction.class)
public class ServicePortPropertiesFunction implements PropertiesFunction {
public static final String FUNCTION_NAME = "service.port";
private static final String PORT_PREFIX = "_SERVICE_PORT";
@Override
public String getName() {
return FUNCTION_NAME;
}
@Override
public String apply(String remainder) {
String key = remainder;
String defaultValue = null;
if (remainder.contains(":")) {
key = Support.before(remainder, ":");
defaultValue = Support.after(remainder, ":");
}
// make sure to use upper case
if (key != null) {
// make sure to use underscore as dash is not supported as ENV variables
key = key.toUpperCase(Locale.ENGLISH).replace('-', '_');
// a service should have both the host and port defined
String port = System.getenv(key + PORT_PREFIX);
if (port != null) {
return port;
} else {
return defaultValue;
}
}
return defaultValue;
}
}