#474 Fixing error when fallback to host machine IP (#477)

* logging net name

* leading with no ipam config and testing

* dont use networks without ip

* release notes

* [Gradle Release Plugin] - new version commit:  '3.19.5-snapshot'.

RELEASE-NOTES.md

@@ -1,3 +1,6 @@
+## 3.19.5
+* #474: Fixing errors log occurs when fallback to host machine IP.
+
 ## 3.19.4
 * #476: Fixing invalid IP parsing usecase
 

gradle.properties

@@ -1 +1 @@
-version=3.19.4-snapshot
+version=3.19.5-snapshot

src/main/java/com/mageddo/dnsproxyserver/docker/domain/Drivers.java

@@ -3,4 +3,5 @@
 public class Drivers {
   public static final String BRIDGE = "bridge";
   public static final String OVERLAY = "overlay";
+  public static final String HOST = "host";
 }

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

@@ -34,6 +34,17 @@ public IP getGateway(IP.Version version) {
       .orElse(null);
   }
 
+  public boolean hasAnyGateway() {
+    return !this.gateways.isEmpty();
+  }
+
+  public boolean hasAnyGatewayWith(IP.Version version) {
+    return this.gateways
+      .stream()
+      .anyMatch(it -> Objects.equals(it.version(), version))
+      ;
+  }
+
   public enum Name {
 
     DPS,

src/main/java/com/mageddo/dnsproxyserver/solver/docker/dataprovider/DockerDAODefault.java

@@ -36,9 +36,8 @@ public IP findHostMachineIp(IP.Version version) {
   }
 
   Network findBestNetwork(IP.Version version) {
-    final var network = this.findNetworks()
+    final var network = this.findNetworksWithIp(version)
       .stream()
-      .filter(it -> java.util.Objects.equals(it.isIpv6Active(), version.isIpv6()))
       .min(NetworkComparator::compare)
       .orElse(null);
     log.debug("status=bestNetwork, network={}", network);
@@ -52,4 +51,11 @@ List<Network> findNetworks() {
       .map(NetworkMapper::of)
       .toList();
   }
+
+  List<Network> findNetworksWithIp(IP.Version version) {
+    return this.findNetworks()
+      .stream()
+      .filter(it -> it.hasAnyGatewayWith(version))
+      .toList();
+  }
 }

src/main/java/com/mageddo/dnsproxyserver/solver/docker/dataprovider/mapper/NetworkMapper.java

@@ -2,13 +2,16 @@
 
 import com.mageddo.dnsproxyserver.solver.docker.Network;
 import com.mageddo.net.IP;
+import lombok.extern.slf4j.Slf4j;
 
 import java.util.Objects;
 import java.util.stream.Stream;
 
+@Slf4j
 public class NetworkMapper {
 
   public static Network of(com.github.dockerjava.api.model.Network n) {
+    log.debug("status=mapping, networkName={}", n.getName());
     return Network.builder()
       .name(n.getName())
       .driver(n.getDriver())
@@ -33,15 +36,18 @@ static IP findGatewayIp(com.github.dockerjava.api.model.Network network, IP.Vers
     if (network == null) {
       return null;
     }
-    return network
-      .getIpam()
-      .getConfig()
-      .stream()
-      .map(com.github.dockerjava.api.model.Network.Ipam.Config::getGateway)
-      .map(IP::of)
-      .filter(it -> it.version() == version)
-      .findFirst()
-      .orElse(null)
-      ;
+    final var ipam = network.getIpam();
+    if (ipam != null && ipam.getConfig() != null) {
+      return ipam
+        .getConfig()
+        .stream()
+        .map(com.github.dockerjava.api.model.Network.Ipam.Config::getGateway)
+        .map(IP::of)
+        .filter(it -> it.version() == version)
+        .findFirst()
+        .orElse(null)
+        ;
+    }
+    return null;
   }
 }

src/test/java/com/mageddo/dnsproxyserver/solver/docker/dataprovider/DockerDAODefaultTest.java

@@ -1,6 +1,5 @@
 package com.mageddo.dnsproxyserver.solver.docker.dataprovider;
 
-import com.mageddo.dnsproxyserver.solver.docker.dataprovider.DockerDAODefault;
 import com.mageddo.net.IP;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
@@ -64,4 +63,28 @@ void mustRespectPriorityOrder() {
 
   }
 
+  @Test
+  void mustIgnoreNetworksWithoutIP() {
+
+    // arrange
+    final var version = IP.Version.IPV4;
+    final var networks = List.of(
+      NetworkTemplates.withHostDriverWithoutIps(),
+      NetworkTemplates.withBridgeIpv4AndIpv6Network()
+    );
+
+    doReturn(networks)
+      .when(this.dockerDAO)
+      .findNetworks();
+
+    // act
+    final var ip = this.dockerDAO.findHostMachineIp(version);
+
+    // assert
+    assertNotNull(ip);
+    assertEquals(IP.of("172.21.0.1"), ip);
+
+  }
+
+
 }

src/test/java/com/mageddo/dnsproxyserver/solver/docker/dataprovider/mapper/NetworkMapperTest.java

@@ -1,17 +1,18 @@
 package com.mageddo.dnsproxyserver.solver.docker.dataprovider.mapper;
 
 import com.mageddo.dnsproxyserver.docker.domain.Drivers;
-import com.mageddo.dnsproxyserver.solver.docker.dataprovider.mapper.NetworkMapper;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.junit.jupiter.MockitoExtension;
 import testing.templates.docker.NetworkTemplates;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static testing.templates.docker.NetworkTemplates.buildBridgeIpv4AndIpv6Network;
 import static testing.templates.docker.NetworkTemplates.buildBridgeIpv4OnlyNetwork;
+import static testing.templates.docker.NetworkTemplates.buildHostNetworkWithNoIpam;
 
 @ExtendWith(MockitoExtension.class)
 class NetworkMapperTest {
@@ -60,4 +61,19 @@ void mustLeadWhenNoIpv6IsReturned(){
     assertEquals("[172.21.0.1]", network.getGateways().toString());
   }
 
+  @Test
+  void mustLeadWhenNoIpamConfigIsAvailable(){
+
+    // arrange
+    final var dockerNetwork = buildHostNetworkWithNoIpam();
+
+    // act
+    final var network = NetworkMapper.of(dockerNetwork);
+
+    // assert
+    assertNotNull(network);
+    assertFalse(network.hasAnyGateway());
+    assertEquals("[]", network.getGateways().toString());
+  }
+
 }

src/test/java/testing/templates/docker/NetworkTemplates.java

@@ -40,4 +40,8 @@ public static Network buildBridgeIpv4OnlyNetwork() {
     return JsonUtils.readValue(readString("/templates/docker/network/002.json"), Network.class);
   }
 
+  public static Network buildHostNetworkWithNoIpam() {
+    return JsonUtils.readValue(readString("/templates/docker/network/003.json"), Network.class);
+  }
+
 }

src/test/java/testing/templates/server/dns/solver/docker/NetworkTemplates.java

@@ -45,6 +45,16 @@ public static Network withOverlayIpv4AndIpv6Network() {
       ;
   }
 
+  public static Network withHostDriverWithoutIps() {
+    return builder()
+      .name("host")
+      .driver(Drivers.HOST)
+      .gateways(Collections.emptyList())
+      .ipv6Active(false)
+      .build()
+      ;
+  }
+
   static Network.NetworkBuilder builder() {
     return Network.builder()
       .gateways(Collections.emptyList())

src/test/resources/templates/docker/network/003.json

@@ -0,0 +1,23 @@
+{
+  "Name": "host",
+  "Id": "c0e229b3e0dfc6265fe508026ad5e71199abac6f4dda240d9dd53c2192b3e5ed",
+  "Created": "2022-03-24T15:56:28.398813695Z",
+  "Scope": "local",
+  "Driver": "host",
+  "EnableIPv6": false,
+  "IPAM": {
+    "Driver": "default",
+    "Options": null,
+    "Config": null
+  },
+  "Internal": false,
+  "Attachable": false,
+  "Ingress": false,
+  "ConfigFrom": {
+    "Network": ""
+  },
+  "ConfigOnly": false,
+  "Containers": {},
+  "Options": {},
+  "Labels": {}
+}