Java tutorial
/** * Copyright 2005-2016 Red Hat, Inc. * * Red Hat 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.spring.boot.condition; import io.fabric8.utils.Strings; import org.springframework.boot.autoconfigure.condition.ConditionOutcome; import org.springframework.boot.autoconfigure.condition.SpringBootCondition; import org.springframework.context.annotation.ConditionContext; import org.springframework.core.type.AnnotatedTypeMetadata; public class OnInsideKubernetesCondition extends SpringBootCondition { private final String HOSTNAME = "HOSTNAME"; private final String KUBERNETES_SERVICE_HOST = "KUBERNETES_SERVICE_HOST"; private final String KUBERNETES_SERVICE_PORT = "KUBERNETES_SERVICE_PORT"; private final String[] REQUIRED_ENV_VARIABLES = new String[] { HOSTNAME, KUBERNETES_SERVICE_HOST, KUBERNETES_SERVICE_PORT }; @Override public ConditionOutcome getMatchOutcome(ConditionContext context, AnnotatedTypeMetadata metadata) { for (String variable : REQUIRED_ENV_VARIABLES) { if (Strings.isNullOrBlank(System.getenv().get(variable))) { return ConditionOutcome.noMatch("Environment variable " + variable + " not found."); } } return ConditionOutcome.match(); } }