Fix alpine socket bug

.travis.yml

@@ -41,6 +41,15 @@ script:
       -w "$(pwd)" \
       openjdk:8-jre \
       ./mvnw -B -pl core test -Dtest=*GenericContainerRuleTest
+  # Run Docker-in-Docker tests inside Alpine
+  - |
+      DOCKER_HOST=unix:///var/run/docker.sock DOCKER_TLS_VERIFY= docker run --rm \
+      -v "$HOME/.m2":/root/.m2/ \
+      -v /var/run/docker.sock:/var/run/docker.sock \
+      -v "$(pwd)":"$(pwd)" \
+      -w "$(pwd)" \
+      joepjoosten/openjdk-alpine-bash \
+      ./mvnw -B -pl core test -Dtest=*GenericContainerRuleTest
   - mvn -B test -f shade-test/pom.xml
 
 cache:

core/src/main/java/org/testcontainers/DockerClientFactory.java

@@ -38,8 +38,8 @@ public class DockerClientFactory {
 
     private static final List<DockerClientProviderStrategy> CONFIGURATION_STRATEGIES =
             asList(new EnvironmentAndSystemPropertyClientProviderStrategy(),
-                    new ProxiedUnixSocketClientProviderStrategy(),
                     new UnixSocketClientProviderStrategy(),
+                    new ProxiedUnixSocketClientProviderStrategy(),
                     new DockerMachineClientProviderStrategy());
     private String activeApiVersion;
     private String activeExecutionDriver;

core/src/main/java/org/testcontainers/containers/wait/HostPortWaitStrategy.java

@@ -33,7 +33,7 @@ protected void waitUntilReady() {
         Callable<Boolean> checkStrategy;
 
         // Special case for Docker for Mac, see #160
-        if (DockerClientFactory.instance().isUsing(ProxiedUnixSocketClientProviderStrategy.class)) {
+        if (System.getProperty("os.name").toLowerCase().contains("mac")) {
             List<Integer> exposedPorts = container.getExposedPorts();
 
             Integer exposedPort = exposedPorts.stream()

core/src/main/java/org/testcontainers/dockerclient/EnvironmentAndSystemPropertyClientProviderStrategy.java

@@ -21,7 +21,7 @@ public void test() throws InvalidConfigurationException {
 
             final int timeout = Integer.parseInt(System.getProperty(PING_TIMEOUT_PROPERTY_NAME, PING_TIMEOUT_DEFAULT));
             ping(client, timeout);
-        } catch (Exception e) {
+        } catch (Exception | UnsatisfiedLinkError e) {
             LOGGER.error("ping failed with configuration {} due to {}", getDescription(), e.toString(), e);
             throw new InvalidConfigurationException("ping failed");
         }

core/src/main/java/org/testcontainers/dockerclient/ProxiedUnixSocketClientProviderStrategy.java

@@ -9,8 +9,9 @@ public class ProxiedUnixSocketClientProviderStrategy extends UnixSocketClientPro
     @Override
     public void test() throws InvalidConfigurationException {
 
-        if (!System.getProperty("os.name").toLowerCase().contains("mac")) {
-            throw new InvalidConfigurationException("this strategy is only applicable to OS X");
+        String osName = System.getProperty("os.name").toLowerCase();
+        if (!osName.contains("mac") && !osName.contains("linux")) {
+            throw new InvalidConfigurationException("this strategy is only applicable to OS X and Linux");
         }
 
         TcpToUnixSocketProxy proxy = new TcpToUnixSocketProxy(new File(DOCKER_SOCK_PATH));
@@ -20,7 +21,7 @@ public void test() throws InvalidConfigurationException {
 
             config = tryConfiguration("tcp://localhost:" + proxyPort);
 
-            LOGGER.info("Accessing Docker for Mac unix domain socket via TCP proxy (" + DOCKER_SOCK_PATH + " via localhost:" + proxyPort + ")");
+            LOGGER.info("Accessing unix domain socket via TCP proxy (" + DOCKER_SOCK_PATH + " via localhost:" + proxyPort + ")");
         } catch (Exception e) {
 
             proxy.stop();

core/src/main/java/org/testcontainers/dockerclient/UnixSocketClientProviderStrategy.java

@@ -28,7 +28,7 @@ public void test()
         try {
             config = tryConfiguration(SOCKET_LOCATION);
             LOGGER.info("Accessing docker with local Unix socket");
-        } catch (Exception e) {
+        } catch (Exception | UnsatisfiedLinkError e) {
             throw new InvalidConfigurationException("ping failed", e);
         }
     }