Java tutorial
/* * 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 brooklyn.entity.network.bind; import static com.google.common.base.Preconditions.checkNotNull; import java.io.ByteArrayInputStream; import java.io.StringReader; import java.util.Collection; import java.util.Map; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.common.base.CharMatcher; import com.google.common.base.Function; import com.google.common.base.Joiner; import com.google.common.base.Predicate; import com.google.common.base.Splitter; import com.google.common.collect.BiMap; import com.google.common.collect.FluentIterable; import com.google.common.collect.HashBiMap; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableListMultimap; import com.google.common.collect.ImmutableMap; import com.google.common.collect.ImmutableMultimap; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Iterables; import com.google.common.collect.Lists; import com.google.common.collect.Maps; import com.google.common.collect.Multimap; import com.google.common.collect.MultimapBuilder; import com.google.common.collect.Multimaps; import brooklyn.entity.Entity; import brooklyn.entity.basic.Attributes; import brooklyn.entity.basic.DynamicGroup; import brooklyn.entity.basic.Lifecycle; import brooklyn.entity.basic.SoftwareProcessImpl; import brooklyn.entity.group.AbstractMembershipTrackingPolicy; import brooklyn.entity.proxying.EntitySpec; import brooklyn.event.Sensor; import brooklyn.location.basic.Machines; import brooklyn.location.basic.SshMachineLocation; import brooklyn.policy.PolicySpec; import brooklyn.util.guava.Maybe; import brooklyn.util.net.Cidr; import brooklyn.util.ssh.BashCommands; import brooklyn.util.text.Strings; /** * This sets up a BIND DNS server. * <p> * <b>NOTE</b> This entity has only been certified on <i>CentOS</i>, <i>RHEL</i>, * <i>Ubuntu</i> and <i>Debian</i> operating systems. */ public class BindDnsServerImpl extends SoftwareProcessImpl implements BindDnsServer { private static final Logger LOG = LoggerFactory.getLogger(BindDnsServerImpl.class); private final Object serialMutex = new Object(); // As per RFC 952 and RFC 1123. private static final CharMatcher DOMAIN_NAME_FIRST_CHAR_MATCHER = CharMatcher.inRange('a', 'z') .or(CharMatcher.inRange('A', 'Z')).or(CharMatcher.inRange('0', '9')); private static final CharMatcher DOMAIN_NAME_MATCHER = DOMAIN_NAME_FIRST_CHAR_MATCHER.or(CharMatcher.is('-')); private class HostnameTransformer implements Function<Entity, String> { @Override public String apply(Entity input) { String hostname = input.getAttribute(getConfig(HOSTNAME_SENSOR)); hostname = DOMAIN_NAME_FIRST_CHAR_MATCHER.negate().trimFrom(hostname); hostname = DOMAIN_NAME_MATCHER.negate().trimAndCollapseFrom(hostname, '-'); if (hostname.length() > 63) { hostname = hostname.substring(0, 63); } return hostname; } } public BindDnsServerImpl() { super(); } @Override public void init() { super.init(); checkNotNull(getConfig(HOSTNAME_SENSOR), "%s requires value for %s", getClass().getName(), HOSTNAME_SENSOR); DynamicGroup entities = addChild( EntitySpec.create(DynamicGroup.class).configure(DynamicGroup.ENTITY_FILTER, getEntityFilter())); setAttribute(ENTITIES, entities); setAttribute(A_RECORDS, ImmutableMap.<String, String>of()); setAttribute(CNAME_RECORDS, ImmutableMultimap.<String, String>of()); setAttribute(PTR_RECORDS, ImmutableMap.<String, String>of()); setAttribute(ADDRESS_MAPPINGS, ImmutableMultimap.<String, String>of()); synchronized (serialMutex) { setAttribute(SERIAL, System.currentTimeMillis()); } } @Override public void postRebind() { update(); } @Override public Class<?> getDriverInterface() { return BindDnsServerDriver.class; } @Override public Multimap<String, String> getAddressMappings() { return getAttribute(ADDRESS_MAPPINGS); } @Override public Map<String, String> getReverseMappings() { return getAttribute(PTR_RECORDS); } @Override public BindDnsServerDriver getDriver() { return (BindDnsServerDriver) super.getDriver(); } @Override public void connectSensors() { connectServiceUpIsRunning(); } @Override public void disconnectSensors() { super.disconnectSensors(); disconnectServiceUpIsRunning(); } @Override protected void preStart() { String reverse = getConfig(REVERSE_LOOKUP_NETWORK); if (Strings.isBlank(reverse)) reverse = getAttribute(ADDRESS); setAttribute(REVERSE_LOOKUP_CIDR, new Cidr(reverse + "/24")); String reverseLookupDomain = Joiner.on('.') .join(Iterables.skip(Lists.reverse(Lists.newArrayList(Splitter.on('.').split(reverse))), 1)) + ".in-addr.arpa"; setAttribute(REVERSE_LOOKUP_DOMAIN, reverseLookupDomain); addPolicy(PolicySpec.create(MemberTrackingPolicy.class).displayName("Address tracker") .configure(AbstractMembershipTrackingPolicy.SENSORS_TO_TRACK, ImmutableSet.<Sensor<?>>of(getConfig(HOSTNAME_SENSOR))) .configure(AbstractMembershipTrackingPolicy.GROUP, getEntities())); } @Override public void postStart() { update(); } public static class MemberTrackingPolicy extends AbstractMembershipTrackingPolicy { @Override protected void onEntityChange(Entity member) { if (LOG.isTraceEnabled()) { LOG.trace("State of {} on change: {}", member, member.getAttribute(Attributes.SERVICE_STATE_ACTUAL).name()); } ((BindDnsServerImpl) entity).update(); } @Override protected void onEntityAdded(Entity member) { if (LOG.isTraceEnabled()) { LOG.trace("State of {} on added: {}", member, member.getAttribute(Attributes.SERVICE_STATE_ACTUAL).name()); } ((BindDnsServerImpl) entity).configureResolver(member); } } private class HasHostnameAndValidLifecycle implements Predicate<Entity> { @Override public boolean apply(Entity input) { switch (input.getAttribute(Attributes.SERVICE_STATE_ACTUAL)) { case STOPPED: case STOPPING: case DESTROYED: return false; } return input.getAttribute(getConfig(HOSTNAME_SENSOR)) != null; } } public void update() { Lifecycle serverState = getAttribute(Attributes.SERVICE_STATE_ACTUAL); if (Lifecycle.STOPPED.equals(serverState) || Lifecycle.STOPPING.equals(serverState) || Lifecycle.DESTROYED.equals(serverState) || !getAttribute(Attributes.SERVICE_UP)) { LOG.debug("Skipped update of {} when service state is {} and running is {}", new Object[] { this, getAttribute(Attributes.SERVICE_STATE_ACTUAL), getAttribute(SERVICE_UP) }); return; } synchronized (this) { Iterable<Entity> availableEntities = FluentIterable.from(getEntities().getMembers()) .filter(new HasHostnameAndValidLifecycle()); LOG.debug("{} updating with entities: {}", this, Iterables.toString(availableEntities)); ImmutableListMultimap<String, Entity> hostnameToEntity = Multimaps.index(availableEntities, new HostnameTransformer()); Map<String, String> octetToName = Maps.newHashMap(); BiMap<String, String> ipToARecord = HashBiMap.create(); Multimap<String, String> aRecordToCnames = MultimapBuilder.hashKeys().hashSetValues().build(); Multimap<String, String> ipToAllNames = MultimapBuilder.hashKeys().hashSetValues().build(); for (Map.Entry<String, Entity> e : hostnameToEntity.entries()) { String domainName = e.getKey(); Maybe<SshMachineLocation> location = Machines .findUniqueSshMachineLocation(e.getValue().getLocations()); if (!location.isPresent()) { LOG.debug("Member {} of {} does not have an SSH location so will not be configured", e.getValue(), this); continue; } else if (ipToARecord.inverse().containsKey(domainName)) { continue; } String address = location.get().getAddress().getHostAddress(); ipToAllNames.put(address, domainName); if (!ipToARecord.containsKey(address)) { ipToARecord.put(address, domainName); if (getReverseLookupNetwork().contains(new Cidr(address + "/32"))) { String octet = Iterables.get(Splitter.on('.').split(address), 3); if (!octetToName.containsKey(octet)) octetToName.put(octet, domainName); } } else { aRecordToCnames.put(ipToARecord.get(address), domainName); } } setAttribute(A_RECORDS, ImmutableMap.copyOf(ipToARecord.inverse())); setAttribute(PTR_RECORDS, ImmutableMap.copyOf(octetToName)); setAttribute(CNAME_RECORDS, Multimaps.unmodifiableMultimap(aRecordToCnames)); setAttribute(ADDRESS_MAPPINGS, Multimaps.unmodifiableMultimap(ipToAllNames)); // Update Bind configuration files and restart the service getDriver().updateBindConfiguration(); } } protected void configureResolver(Entity entity) { Maybe<SshMachineLocation> machine = Machines.findUniqueSshMachineLocation(entity.getLocations()); if (machine.isPresent()) { if (getConfig(REPLACE_RESOLV_CONF)) { machine.get().copyTo(new StringReader(getConfig(RESOLV_CONF_TEMPLATE)), "/etc/resolv.conf"); } else { appendTemplate(getConfig(INTERFACE_CONFIG_TEMPLATE), "/etc/sysconfig/network-scripts/ifcfg-eth0", machine.get()); machine.get().execScript("reload network", ImmutableList.of(BashCommands.sudo("service network reload"))); } LOG.info("configured resolver on {}", machine); } else { LOG.debug("{} can't configure resolver at {}: no SshMachineLocation", this, entity); } } protected void appendTemplate(String template, String destination, SshMachineLocation machine) { String content = ((BindDnsServerSshDriver) getDriver()).processTemplate(template); String temp = "/tmp/template-" + Strings.makeRandomId(6); machine.copyTo(new ByteArrayInputStream(content.getBytes()), temp); machine.execScript("updating file", ImmutableList.of(BashCommands.sudo(String.format("tee -a %s < %s", destination, temp)), String.format("rm -f %s", temp))); } @Override public Predicate<? super Entity> getEntityFilter() { return getConfig(ENTITY_FILTER); } // Mostly used in templates public String getManagementCidr() { return getConfig(MANAGEMENT_CIDR); } public Integer getDnsPort() { return getAttribute(DNS_PORT); } public String getDomainName() { return getConfig(DOMAIN_NAME); } /** * @return A serial number guaranteed to be valid for use in a modified domain.zone or reverse.zone file. */ public long getSerial() { synchronized (serialMutex) { long next = getAttribute(SERIAL) + 1; setAttribute(SERIAL, next); return next; } } public Cidr getReverseLookupNetwork() { return getAttribute(REVERSE_LOOKUP_CIDR); } public String getReverseLookupDomain() { return getAttribute(REVERSE_LOOKUP_DOMAIN); } public DynamicGroup getEntities() { return getAttribute(ENTITIES); } public Map<String, String> getAddressRecords() { return getAttribute(A_RECORDS); } public Multimap<String, String> getCanonicalNameRecords() { return getAttribute(CNAME_RECORDS); } public Map<String, Collection<String>> getCnamesForTemplates() { return getAttribute(CNAME_RECORDS).asMap(); } public Map<String, String> getPointerRecords() { return getAttribute(PTR_RECORDS); } }