Java tutorial
/******************************************************************************* * Copyright (c) 2012-2017 Red Hat, Inc. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * Red Hat, Inc. - initial API and implementation *******************************************************************************/ package org.eclipse.che.plugin.openshift.client.kubernetes; import java.util.HashMap; import java.util.Map; import java.util.regex.Matcher; import java.util.regex.Pattern; import org.apache.commons.lang.StringUtils; import org.eclipse.che.plugin.docker.client.json.ContainerConfig; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Converter of labels defined in {@link ContainerConfig} for matching to Kubernetes * annotation requirements */ public final class KubernetesLabelConverter { private static final Logger LOG = LoggerFactory.getLogger(KubernetesLabelConverter.class); /** Prefix used for che server labels */ private static final String CHE_SERVER_LABEL_PREFIX = "che:server"; /** Padding to use when converting server label to DNS name */ private static final String CHE_SERVER_LABEL_PADDING = "0%s0"; /** Regex to use when matching converted labels -- should match {@link CHE_SERVER_LABEL_PADDING} */ private static final Pattern CHE_SERVER_LABEL_KEY = Pattern.compile("^0(.*)0$"); private static final String KUBERNETES_ANNOTATION_REGEX = "([A-Za-z0-9][-A-Za-z0-9_\\.]*)?[A-Za-z0-9]"; private KubernetesLabelConverter() { } /** * @return prefix that is used for Che server labels */ public static String getCheServerLabelPrefix() { return CHE_SERVER_LABEL_PREFIX; } /** * Converts a map of labels to match Kubernetes annotation requirements. Annotations are limited * to alphanumeric characters, {@code '.'}, {@code '_'} and {@code '-'}, and must start and end * with an alphanumeric character, i.e. they must match the regex * {@code ([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9]} * * <p>Note that entry keys should begin with {@link KubernetesLabelConverter#CHE_SERVER_LABEL_PREFIX} and * entries should not contain {@code '.'} or {@code '_'} before conversion; * otherwise label will not be converted and included in output. * * <p>This implementation is relatively fragile -- changes to how Che generates labels may cause * this method to stop working. In general, it will only be possible to convert labels that are * alphanumeric plus up to 3 special characters (by converting the special characters to {@code '_'}, * {@code '-'}, and {@code '.'} as necessary). * * @param labels Map of labels to convert * @return Map of labels converted to DNS Names */ public static Map<String, String> labelsToNames(Map<String, String> labels) { Map<String, String> names = new HashMap<>(); for (Map.Entry<String, String> label : labels.entrySet()) { if (!hasConversionProblems(label)) { String key = label.getKey(); String value = label.getValue(); // Convert keys: e.g. "che:server:4401/tcp:ref" -> // "che.server.4401-tcp.ref" key = convertLabelKey(key); // Convert values: e.g. "/api" -> ".api" -- note values may // include '-' e.g. "tomcat-debug" value = convertLabelValue(value); // Add padding since DNS names must start and end with // alphanumeric characters key = addPadding(key); value = addPadding(value); if (matchesKubernetesLabelRegex(key) && matchesKubernetesLabelRegex(value)) { names.put(key, value); } else { LOG.error( "Could not convert label {} into Kubernetes annotation: labels must be alphanumeric with ':' and '/'", label.toString()); } } } return names; } /** * Undoes the label conversion done by {@link KubernetesLabelConverter#labelsToNames(Map)} * * @param labels Map of DNS names * @return Map of unconverted labels */ public static Map<String, String> namesToLabels(Map<String, String> names) { Map<String, String> labels = new HashMap<>(); for (Map.Entry<String, String> entry : names.entrySet()) { String key = entry.getKey(); String value = entry.getValue(); // Remove padding Matcher keyMatcher = CHE_SERVER_LABEL_KEY.matcher(key); Matcher valueMatcher = CHE_SERVER_LABEL_KEY.matcher(value); if (!keyMatcher.matches() || !valueMatcher.matches()) { continue; } key = keyMatcher.group(1); value = valueMatcher.group(1); // Convert key: e.g. "che.server.4401_tcp.ref" -> "che:server:4401/tcp:ref" key = key.replaceAll("\\.", ":").replaceAll("_", "/"); // Convert value: e.g. Convert values: e.g. "_api" -> "/api" value = value.replaceAll("_", "/"); labels.put(key, value); } return labels; } /** * Checks if there are any potential problems coupled with label conversion * @param label * @return true if label has no conversion issues, false otherwise */ private static boolean hasConversionProblems(final Map.Entry<String, String> label) { boolean hasProblems = false; String key = label.getKey(); String value = label.getValue(); if (StringUtils.isBlank(value)) { LOG.error("The label {} is blank", label.toString()); hasProblems = true; } else if (key.contains(".") || key.contains("_") || value.contains("_")) { LOG.error("Cannot convert label {} to DNS Name: '-' and '.' are used as escape characters", label.toString()); hasProblems = true; } else if (!key.startsWith(CHE_SERVER_LABEL_PREFIX)) { LOG.warn("Expected CreateContainerParams label key {} to start with {}", key, CHE_SERVER_LABEL_PREFIX); } return hasProblems; } /** * Convert keys: e.g. "che:server:4401/tcp:ref" -> "che.server.4401-tcp.ref" */ private static String convertLabelKey(final String key) { return key.replaceAll(":", ".").replaceAll("/", "_"); } /** * Convert values: e.g. "/api" -> ".api" Note: values may include '-' e.g. * "tomcat-debug" */ private static String convertLabelValue(final String value) { return value.replaceAll("/", "_"); } /** * Adds padding since DNS names must start and end with alphanumeric * characters */ private static String addPadding(final String label) { return String.format(CHE_SERVER_LABEL_PADDING, label); } private static boolean matchesKubernetesLabelRegex(final String label) { return label.matches(KUBERNETES_ANNOTATION_REGEX); } }