org.springframework.cloud.deployer.spi.cloudfoundry.CloudFoundryAppNameGenerator.java Source code

Introduction

Here is the source code for org.springframework.cloud.deployer.spi.cloudfoundry.CloudFoundryAppNameGenerator.java

Source

/*
 * Copyright 2016 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
 *
 *      https://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.cloud.deployer.spi.cloudfoundry;

import java.util.Random;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.util.StringUtils;

/**
 * CloudFoundry specific implementation of {@link AppNameGenerator}.  This takes into account the
 * configuration properties {@code enableRandomAppNamePrefix} and {@code appNamePrefix}.
 *
 * If {@code enableRandomAppNamePrefix} a random short string is prefixed to the base name.
 * It is true by default. If {@code appNamePrefix} is set, it is also prefixed before the random string.
 * By default the {@code appNamePrefix} is the value of {@code spring.application.name} if available,
 * otherwise the empty string.
 *
 * As an example, if {@code enableRandomAppNamePrefix=true}, {@code spring.application.name=server},
 * and we are deploying an application whose base name is {@code time}, then the deployed name on Cloud Foundry
 * may be {@code server-ug54dh5-time}
 *
 * @author Soby Chacko
 * @author Mark Pollack
 */
public class CloudFoundryAppNameGenerator implements AppNameGenerator, InitializingBean {

    private static final Log logger = LogFactory.getLog(CloudFoundryAppNameGenerator.class);

    /* Given that appnames are by default part of a hostname, limit to 63 chars max. */
    private static final int MAX_APPNAME_LENGTH = 63;

    private String prefixToUse = "";

    private final CloudFoundryDeploymentProperties properties;

    public CloudFoundryAppNameGenerator(CloudFoundryDeploymentProperties cloudFoundryDeploymentProperties) {
        this.properties = cloudFoundryDeploymentProperties;
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        if (properties.isEnableRandomAppNamePrefix()) {
            prefixToUse = createUniquePrefix();
            if (!StringUtils.isEmpty(properties.getAppNamePrefix())) {
                prefixToUse = String.format("%s-%s", properties.getAppNamePrefix(), prefixToUse);
            }
        } else {
            if (!StringUtils.isEmpty(properties.getAppNamePrefix())) {
                prefixToUse = properties.getAppNamePrefix();
            }
        }
        logger.info(String.format("Prefix to be used for deploying apps: %s", prefixToUse));
    }

    @Override
    public String generateAppName(String appName) {
        if (StringUtils.isEmpty(prefixToUse)) {
            return appName.substring(0, Math.min(MAX_APPNAME_LENGTH, appName.length()));
        } else {
            String string = String.format("%s-%s", prefixToUse, appName);
            return string.substring(0, Math.min(MAX_APPNAME_LENGTH, string.length()));
        }
    }

    private String createUniquePrefix() {
        String alphabet = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
        char[] result = new char[7];
        Random random = new Random();
        for (int i = 0; i < result.length; i++) {
            result[i] = alphabet.charAt(random.nextInt(alphabet.length()));
        }
        return new String(result);
    }

}