Docker Solver: Answer all service replicas IPs (#684)

Author: mageddo

RELEASE-NOTES.md

@@ -1,3 +1,6 @@
+## 5.9.0
+* Answer all docker service replicas IPs, see #434.
+
 ## 5.8.4
 * DNS over HTTPS, see #138
 * Option to disable a specific container to be resolved from DPS, see #596.

gradle.properties

@@ -1 +1 @@
-version=5.8.4-snapshot
+version=5.9.0-snapshot

src/main/java/com/mageddo/dns/utils/Messages.java

@@ -6,6 +6,7 @@
 import java.util.List;
 import java.util.Optional;
 
+import com.mageddo.commons.Collections;
 import com.mageddo.commons.lang.Objects;
 import com.mageddo.dns.Hostname;
 import com.mageddo.dnsproxyserver.config.Config.Entry;
@@ -123,12 +124,17 @@ public static Message aAnswer(Message query, String ip) {
   }
 
   public static Message aAnswer(Message query, String ip, long ttl) {
+    // FIXME EFS esse copy deveria ser feito por quem chama
+    //  o mapper para evitar várias copias sem necessidade
     final var res = withNoErrorResponse(copy(query));
     if (StringUtils.isBlank(ip)) {
       return res;
     }
-    final var answer = new ARecord(res.getQuestion()
-        .getName(), DClass.IN, ttl, Ips.toAddress(ip)
+    final var answer = new ARecord(
+        findQuestionName(query),
+        DClass.IN,
+        ttl,
+        Ips.toAddress(ip)
     );
     res.addRecord(answer, Section.ANSWER);
     return res;
@@ -251,12 +257,12 @@ public static Message quadAnswer(Message query, String ip) {
   }
 
   public static Message quadAnswer(final Message query, final String ip, final long ttl) {
-    final var res = withNoErrorResponse(query.clone());
+    final var res = withNoErrorResponse(copy(query));
     if (StringUtils.isBlank(ip)) {
       return res;
     }
-    final var answer = new AAAARecord(res.getQuestion()
-        .getName(), DClass.IN, ttl, Ips.toAddress(ip)
+    final var answer = new AAAARecord(
+        findQuestionName(query), DClass.IN, ttl, Ips.toAddress(ip)
     );
     res.addRecord(answer, Section.ANSWER);
     return res;
@@ -273,6 +279,17 @@ public static Message answer(Message query, String ip, Entry.Type type) {
     return answer(query, ip, type, DEFAULT_TTL);
   }
 
+  public static Message answer(Message query, List<String> ips, Entry.Type type, long ttl) {
+    if (Collections.isEmptyOrNull(ips)) {
+      return answer(query, (String) null, type, ttl);
+    }
+    Message res = query;
+    for (final var ip : ips) {
+      res = answer(res, ip, type, ttl);
+    }
+    return res;
+  }
+
   public static Message answer(Message query, String ip, Entry.Type type, long ttl) {
     Validate.notNull(type, "type must not be null, query=%s", toHostnameQuery(query));
     return switch (type) {
@@ -287,10 +304,11 @@ static Message withNoErrorResponse(Message res) {
   }
 
   public static Message withResponseCode(Message res, int rRode) {
-    withDefaultResponseHeaders(res);
-    res.getHeader()
+    final var r = withDefaultResponseHeaders(res);
+    r
+        .getHeader()
         .setRcode(rRode);
-    return res;
+    return r;
   }
 
   public static int getRCode(Message m) {
@@ -368,9 +386,9 @@ public static Message authoritativeAnswer(Message query, String ip, Entry.Type t
   }
 
   public static Message authoritativeAnswer(
-      Message query, String ip, Entry.Type type, long ttl
+      Message query, List<String> ips, Entry.Type type, long ttl
   ) {
-    return authoritative(answer(query, ip, type, ttl));
+    return authoritative(answer(query, ips, type, ttl));
   }
 
   public static boolean isAuthoritative(Message m) {

src/main/java/com/mageddo/dnsproxyserver/solver/AddressResolution.java

@@ -1,12 +1,15 @@
 package com.mageddo.dnsproxyserver.solver;
 
 import java.time.Duration;
+import java.util.List;
 
+import com.mageddo.commons.Collections;
 import com.mageddo.commons.lang.Objects;
 import com.mageddo.dnsproxyserver.config.Config;
 import com.mageddo.net.IP;
 
 import lombok.Builder;
+import lombok.Singular;
 import lombok.Value;
 
 import static java.util.Objects.requireNonNullElse;
@@ -17,14 +20,11 @@ public class AddressResolution {
 
   boolean hostnameMatched;
 
-  IP ip;
+  @Singular
+  List<IP> ips;
 
   Duration ttl;
 
-  public String getIpText() {
-    return this.ip != null ? this.ip.toText() : null;
-  }
-
   public Duration getTTL(Duration def) {
     return requireNonNullElse(this.ttl, def);
   }
@@ -38,19 +38,17 @@ public boolean isHostNameNotMatched() {
   }
 
   public boolean hasNotIP() {
-    return this.ip == null;
+    return !this.hasIp();
   }
 
   public boolean hasIp() {
-    return this.ip != null;
+    return Collections.isNotEmpty(this.ips);
   }
 
-  public String getIp(Config.Entry.Type type) {
+  @SuppressWarnings("unchecked")
+  public List<String> getIps(Config.Entry.Type type) {
     final var version = type.toVersion();
-    if (this.hasNotIP() || version == null || this.ip.versionIs(version)) {
-      return this.getIpText();
-    }
-    return null;
+    return IpMapper.toText(this.ips, version);
   }
 
   public static AddressResolution matched(IP ip) {
@@ -62,6 +60,12 @@ public static AddressResolution matched(IP ip, Integer ttl) {
   }
 
   public static AddressResolution matched(IP ip, Duration ttl) {
+    if (ip == null) {
+      return builder()
+          .hostnameMatched(true)
+          .ttl(ttl)
+          .build();
+    }
     return builder()
         .hostnameMatched(true)
         .ip(ip)
@@ -75,4 +79,7 @@ public static AddressResolution notMatched() {
         .build();
   }
 
+  public String firstAsText() {
+    return IpMapper.toText(Collections.first(this.ips));
+  }
 }

src/main/java/com/mageddo/dnsproxyserver/solver/IpMapper.java

@@ -0,0 +1,32 @@
+package com.mageddo.dnsproxyserver.solver;
+
+import java.util.List;
+import java.util.Objects;
+
+import com.mageddo.commons.Collections;
+import com.mageddo.net.IP;
+
+import org.apache.commons.lang3.ObjectUtils;
+
+public class IpMapper {
+
+  public static List<String> toText(List<IP> ips) {
+    return Collections.mapNonNulls(ips, IpMapper::toText);
+  }
+
+  public static String toText(IP ip) {
+    return ip != null ? ip.toText() : null;
+  }
+
+  public static List<String> toText(List<IP> ips, IP.Version version) {
+    if (version == null) {
+      return IpMapper.toText(ips);
+    }
+    return ObjectUtils.firstNonNull(ips, Collections.<IP>emptyList())
+        .stream()
+        .filter(Objects::nonNull)
+        .filter(ip -> ip.versionIs(version))
+        .map(IpMapper::toText)
+        .toList();
+  }
+}

src/main/java/com/mageddo/dnsproxyserver/solver/QueryResponseHandler.java

@@ -57,7 +57,7 @@ public Response mapDynamicFromResolution(
     return HostnameEvaluator.eval(
         askedHost,
         version,
-        hostnameQuery -> map(query, finder, hostnameQuery, type)
+        hostnameQuery -> this.map(query, finder, hostnameQuery, type)
     );
   }
 
@@ -89,7 +89,7 @@ public Response map(Message query, AddressResolution res, Entry.Type type) {
     final var ttl = res.getTTL(this.defaultTTL);
     final var msg = Messages.authoritativeAnswer(
         query,
-        res.getIp(type),
+        res.getIps(type),
         type,
         ttl.toSeconds()
     );

src/main/java/com/mageddo/dnsproxyserver/solver/docker/SolverDocker.java

@@ -39,8 +39,8 @@ public Response handle(Message query) {
       return null;
     }
 
-    return this.handler.mapDynamicFromResolution(query,
-        this.containerSolvingService::findBestMatch
+    return this.handler.mapDynamicFromResolution(
+        query, this.containerSolvingService::findBestMatch
     );
   }
 

src/main/java/com/mageddo/dnsproxyserver/solver/docker/application/ContainerSolvingService.java

@@ -1,5 +1,6 @@
 package com.mageddo.dnsproxyserver.solver.docker.application;
 
+import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
@@ -10,9 +11,9 @@
 import javax.inject.Singleton;
 
 import com.mageddo.dnsproxyserver.config.application.Configs;
+import com.mageddo.dnsproxyserver.solver.AddressResolution;
 import com.mageddo.dnsproxyserver.solver.HostnameQuery;
 import com.mageddo.dnsproxyserver.solver.docker.Container;
-import com.mageddo.dnsproxyserver.solver.AddressResolution;
 import com.mageddo.dnsproxyserver.solver.docker.Network;
 import com.mageddo.dnsproxyserver.solver.docker.dataprovider.ContainerDAO;
 import com.mageddo.dnsproxyserver.solver.docker.dataprovider.DockerDAO;
@@ -40,24 +41,28 @@ public class ContainerSolvingService {
   public AddressResolution findBestMatch(HostnameQuery query) {
     final var stopWatch = StopWatch.createStarted();
     final var matchedContainers = this.containerDAO.findActiveContainersMatching(query);
-    final var foundIp = matchedContainers
-        .stream()
-        .map(it -> this.findBestIpMatch(it, query.getVersion()))
-        .filter(Objects::nonNull)
-        .findFirst()
-        .orElse(null);
+    final var foundIps = this.mapToIps(matchedContainers, query);
     final var hostnameMatched = !matchedContainers.isEmpty();
     log.trace(
-        "status=findDone, query={}, found={}, hostnameMatched={}, time={}",
-        query, foundIp, hostnameMatched, stopWatch.getTime()
+        "status=done, query={}, found={}, hostnameMatched={}, time={}",
+        query, foundIps, hostnameMatched, stopWatch.getTime()
     );
     return AddressResolution
         .builder()
         .hostnameMatched(hostnameMatched)
-        .ip(IP.of(foundIp))
+        .ips(foundIps)
         .build();
   }
 
+  List<IP> mapToIps(List<Container> containers, HostnameQuery query) {
+    return containers
+        .stream()
+        .map(it -> this.findBestIpMatch(it, query.getVersion()))
+        .filter(Objects::nonNull)
+        .map(IP::of)
+        .toList();
+  }
+
   public String findBestIpMatch(Container c) {
     return this.findBestIpMatch(c, IP.Version.IPV4);
   }

src/test/java/com/mageddo/dnsproxyserver/solver/IpMapperTest.java

@@ -0,0 +1,48 @@
+package com.mageddo.dnsproxyserver.solver;
+
+import java.util.List;
+
+import com.mageddo.net.IP;
+
+import org.junit.jupiter.api.Test;
+
+import testing.templates.IpTemplates;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class IpMapperTest {
+
+  @Test
+  void mustReturnAllVersionsAreMixed() {
+
+    final var mixed = List.of(IpTemplates.local(), IpTemplates.localIpv6());
+
+    final var ips = IpMapper.toText(mixed);
+
+    assertThat(ips)
+        .hasSize(2)
+        .containsExactly(
+            "10.10.0.1", "2001:db8:1:0:0:0:0:2"
+        );
+
+  }
+  @Test
+  void musGetOnlyIpv6() {
+
+    final var mixed = List.of(
+        IpTemplates.local(),
+        IpTemplates.localIpv6(),
+        IpTemplates.localIpv6_3()
+    );
+
+    final var ips = IpMapper.toText(mixed, IP.Version.IPV6);
+
+    assertThat(ips)
+        .hasSize(2)
+        .containsExactly(
+            "2001:db8:1:0:0:0:0:2",
+            "2001:db8:1:0:0:0:0:3"
+        );
+
+  }
+}