com.eucalyptus.loadbalancing.dns.LoadBalancerDomainName.java Source code

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Here is the source code for com.eucalyptus.loadbalancing.dns.LoadBalancerDomainName.java

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/*************************************************************************
 * Copyright 2009-2015 Eucalyptus Systems, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 3 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see http://www.gnu.org/licenses/.
 *
 * Please contact Eucalyptus Systems, Inc., 6755 Hollister Ave., Goleta
 * CA 93117, USA or visit http://www.eucalyptus.com/licenses/ if you need
 * additional information or have any questions.
 ************************************************************************/
package com.eucalyptus.loadbalancing.dns;

import static com.eucalyptus.loadbalancing.LoadBalancer.Scheme;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.annotation.Nullable;
import org.xbill.DNS.Name;
import com.eucalyptus.loadbalancing.LoadBalancerDnsRecord;
import com.eucalyptus.util.Pair;
import com.eucalyptus.util.dns.DomainNames;
import com.google.common.base.Joiner;
import com.google.common.base.Optional;
import com.google.common.base.Predicate;

/**
 *
 */
public enum LoadBalancerDomainName implements Predicate<Name> {

    INTERNAL("internal-([a-zA-Z0-9-]{1,255})-([0-9]{12})", "internal-%s-%s"), // most specific first for matching
    EXTERNAL("([a-zA-Z0-9-]{1,255})-([0-9]{12})", "%s-%s"),;

    private final Pattern hostPattern;
    private final String hostFormat;

    private LoadBalancerDomainName(final String pattern, final String format) {
        hostPattern = Pattern.compile(pattern);
        hostFormat = format;
    }

    public static Name getLoadBalancerSubdomain() {
        return DomainNames.absolute(lookupLoadBalancerSubdomainProperty(), DomainNames.externalSubdomain());
    }

    public static LoadBalancerDomainName forScheme(@Nullable final Scheme scheme) {
        if (Scheme.Internal == scheme) {
            return INTERNAL;
        }
        return EXTERNAL;
    }

    public static Optional<LoadBalancerDomainName> findMatching(final Name name) {
        for (final LoadBalancerDomainName domainName : values()) {
            if (domainName.apply(name)) {
                return Optional.of(domainName);
            }
        }
        return Optional.absent();
    }

    public String generate(String loadBalancerName, String accountNumber) {
        final String dnsPrefix = String.format(hostFormat, loadBalancerName, accountNumber);
        return Joiner.on('.').join(dnsPrefix, getLoadBalancerSubdomain().relativize(Name.root));
    }

    private Matcher matcher(final Name name) {
        return hostPattern.matcher(name.toString());
    }

    /**
     * Extract info from a known good name.
     *
     * @param name The DNS name
     * @return A pair of account number and load balancer name
     */
    public Pair<String, String> toScopedLoadBalancerName(final Name name) {
        final Matcher nameMatcher = matcher(name);
        nameMatcher.matches();
        return Pair.pair(nameMatcher.group(2), nameMatcher.group(1));
    }

    private static Name lookupLoadBalancerSubdomainProperty() {
        return Name.fromConstantString(LoadBalancerDnsRecord.DNS_SUBDOMAIN);
    }

    @Override
    public boolean apply(@Nullable final Name name) {
        return name != null && matcher(name).matches();
    }
}