Enable lazy certificates for Elasticsearch

modules/elasticsearch/build.gradle

@@ -6,3 +6,15 @@ dependencies {
     testImplementation "org.elasticsearch.client:transport:7.17.17"
     testImplementation 'org.assertj:assertj-core:3.25.2'
 }
+
+tasks.japicmp {
+    packageExcludes = []
+
+    classExcludes = []
+
+    methodExcludes = [
+        "org.testcontainers.elasticsearch.ElasticsearchContainer#containerIsStarted(com.github.dockerjava.api.command.InspectContainerResponse)",
+    ]
+
+    fieldExcludes = []
+}

modules/elasticsearch/src/main/java/org/testcontainers/elasticsearch/ElasticsearchContainer.java

@@ -1,6 +1,5 @@
 package org.testcontainers.elasticsearch;
 
-import com.github.dockerjava.api.command.InspectContainerResponse;
 import com.github.dockerjava.api.exception.NotFoundException;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.io.IOUtils;
@@ -66,6 +65,9 @@ public class ElasticsearchContainer extends GenericContainer<ElasticsearchContai
 
     private static final DockerImageName ELASTICSEARCH_IMAGE_NAME = DockerImageName.parse("elasticsearch");
 
+    // default location of the automatically generated self-signed HTTP cert for versions >= 8
+    public static final String DEFAULT_CERT_PATH = "/usr/share/elasticsearch/config/certs/http_ca.crt";
+
     /**
      * Elasticsearch Default version
      */
@@ -77,9 +79,7 @@ public class ElasticsearchContainer extends GenericContainer<ElasticsearchContai
 
     private final boolean isAtLeastMajorVersion8;
 
-    private Optional<byte[]> caCertAsBytes = Optional.empty();
-
-    private String certPath = "/usr/share/elasticsearch/config/certs/http_ca.crt";
+    private String certPath = "";
 
     /**
      * @deprecated use {@link #ElasticsearchContainer(DockerImageName)} instead
@@ -91,6 +91,7 @@ public ElasticsearchContainer() {
 
     /**
      * Create an Elasticsearch Container by passing the full docker image name
+     *
      * @param dockerImageName Full docker image name as a {@link String}, like: docker.elastic.co/elasticsearch/elasticsearch:7.9.2
      */
     public ElasticsearchContainer(String dockerImageName) {
@@ -99,6 +100,7 @@ public ElasticsearchContainer(String dockerImageName) {
 
     /**
      * Create an Elasticsearch Container by passing the full docker image name
+     *
      * @param dockerImageName Full docker image name as a {@link DockerImageName}, like: DockerImageName.parse("docker.elastic.co/elasticsearch/elasticsearch:7.9.2")
      */
     public ElasticsearchContainer(final DockerImageName dockerImageName) {
@@ -136,23 +138,7 @@ public ElasticsearchContainer(final DockerImageName dockerImageName) {
         setWaitStrategy(new LogMessageWaitStrategy().withRegEx(regex));
         if (isAtLeastMajorVersion8) {
             withPassword(ELASTICSEARCH_DEFAULT_PASSWORD);
-        }
-    }
-
-    @Override
-    protected void containerIsStarted(InspectContainerResponse containerInfo) {
-        if (isAtLeastMajorVersion8 && StringUtils.isNotEmpty(certPath)) {
-            try {
-                byte[] bytes = copyFileFromContainer(certPath, IOUtils::toByteArray);
-                if (bytes.length > 0) {
-                    this.caCertAsBytes = Optional.of(bytes);
-                }
-            } catch (NotFoundException e) {
-                // just emit an error message, but do not throw an exception
-                // this might be ok, if the docker image is accidentally looking like version 8 or latest
-                // can happen if Elasticsearch is repackaged, i.e. with custom plugins
-                log.warn("CA cert under " + certPath + " not found.");
-            }
+            withCertPath(DEFAULT_CERT_PATH);
         }
     }
 
@@ -162,17 +148,36 @@ protected void containerIsStarted(InspectContainerResponse containerInfo) {
      * @return byte array optional containing the CA cert extracted from the docker container
      */
     public Optional<byte[]> caCertAsBytes() {
-        return caCertAsBytes;
+        if (StringUtils.isBlank(certPath)) {
+            return Optional.empty();
+        }
+        try {
+            byte[] bytes = copyFileFromContainer(certPath, IOUtils::toByteArray);
+            if (bytes.length > 0) {
+                return Optional.of(bytes);
+            }
+        } catch (NotFoundException e) {
+            // just emit an error message, but do not throw an exception
+            // this might be ok, if the docker image is accidentally looking like version 8 or latest
+            // can happen if Elasticsearch is repackaged, i.e. with custom plugins
+            log.warn("CA cert under " + certPath + " not found.");
+        }
+        return Optional.empty();
     }
 
     /**
-     * A SSL context based on the self signed CA, so that using this SSL Context allows to connect to the Elasticsearch service
+     * A SSL context based on the self-signed CA, so that using this SSL Context allows to connect to the Elasticsearch service
      * @return a customized SSL Context
      */
     public SSLContext createSslContextFromCa() {
         try {
             CertificateFactory factory = CertificateFactory.getInstance("X.509");
-            Certificate trustedCa = factory.generateCertificate(new ByteArrayInputStream(caCertAsBytes.get()));
+            Certificate trustedCa = factory.generateCertificate(
+                new ByteArrayInputStream(
+                    caCertAsBytes()
+                        .orElseThrow(() -> new IllegalStateException("CA cert under " + certPath + " not found."))
+                )
+            );
             KeyStore trustStore = KeyStore.getInstance("pkcs12");
             trustStore.load(null, null);
             trustStore.setCertificateEntry("ca", trustedCa);
@@ -190,13 +195,13 @@ public SSLContext createSslContextFromCa() {
     /**
      * Define the Elasticsearch password to set. It enables security behind the scene for major version below 8.0.0.
      * It's not possible to use security with the oss image.
-     * @param password  Password to set
+     * @param password Password to set
      * @return this
      */
     public ElasticsearchContainer withPassword(String password) {
         if (isOss) {
             throw new IllegalArgumentException(
-                "You can not activate security on Elastic OSS Image. " + "Please switch to the default distribution"
+                "You can not activate security on Elastic OSS Image. Please switch to the default distribution"
             );
         }
         withEnv("ELASTIC_PASSWORD", password);
@@ -222,7 +227,8 @@ public String getHttpHostAddress() {
         return getHost() + ":" + getMappedPort(ELASTICSEARCH_DEFAULT_PORT);
     }
 
-    @Deprecated // The TransportClient will be removed in Elasticsearch 8. No need to expose this port anymore in the future.
+    @Deprecated
+    // The TransportClient will be removed in Elasticsearch 8. No need to expose this port anymore in the future.
     public InetSocketAddress getTcpHost() {
         return new InetSocketAddress(getHost(), getMappedPort(ELASTICSEARCH_DEFAULT_TCP_PORT));
     }

modules/elasticsearch/src/test/java/org/testcontainers/elasticsearch/ElasticsearchContainerTest.java

@@ -23,6 +23,7 @@
 import org.testcontainers.containers.wait.strategy.HttpWaitStrategy;
 import org.testcontainers.containers.wait.strategy.Wait;
 import org.testcontainers.images.RemoteDockerImage;
+import org.testcontainers.images.builder.Transferable;
 import org.testcontainers.utility.DockerImageName;
 import org.testcontainers.utility.MountableFile;
 
@@ -375,6 +376,49 @@ public void testElasticsearch8SecureByDefaultFailsSilentlyOnLatestImages() throw
         }
     }
 
+    @Test
+    public void testElasticsearch7CanHaveSecurityEnabledAndUseSslContext() throws Exception {
+        String customizedCertPath = "/usr/share/elasticsearch/config/certs/http_ca_customized.crt";
+        try (
+            ElasticsearchContainer container = new ElasticsearchContainer(
+                "docker.elastic.co/elasticsearch/elasticsearch:7.17.15"
+            )
+                .withPassword(ElasticsearchContainer.ELASTICSEARCH_DEFAULT_PASSWORD)
+                .withEnv("xpack.security.enabled", "true")
+                .withEnv("xpack.security.http.ssl.enabled", "true")
+                .withEnv("xpack.security.http.ssl.key", "/usr/share/elasticsearch/config/certs/elasticsearch.key")
+                .withEnv(
+                    "xpack.security.http.ssl.certificate",
+                    "/usr/share/elasticsearch/config/certs/elasticsearch.crt"
+                )
+                .withEnv("xpack.security.http.ssl.certificate_authorities", customizedCertPath)
+                // these lines show how certificates can be created self-made way
+                // obviously this shouldn't be done in prod environment, where proper and officially signed keys should be present
+                .withCopyToContainer(
+                    Transferable.of(
+                        "#!/bin/bash\n" +
+                        "mkdir -p /usr/share/elasticsearch/config/certs;" +
+                        "openssl req -x509 -newkey rsa:4096 -keyout /usr/share/elasticsearch/config/certs/elasticsearch.key -out /usr/share/elasticsearch/config/certs/elasticsearch.crt -days 365 -nodes -subj \"/CN=localhost\";" +
+                        "openssl x509 -outform der -in /usr/share/elasticsearch/config/certs/elasticsearch.crt -out " +
+                        customizedCertPath +
+                        "; chown -R elasticsearch /usr/share/elasticsearch/config/certs/",
+                        555
+                    ),
+                    "/usr/share/elasticsearch/generate-certs.sh"
+                )
+                // because we need to generate the certificates before Elasticsearch starts, the entry command has to be tuned accordingly
+                .withCommand(
+                    "sh",
+                    "-c",
+                    "/usr/share/elasticsearch/generate-certs.sh && /usr/local/bin/docker-entrypoint.sh"
+                )
+                .withCertPath(customizedCertPath)
+        ) {
+            container.start();
+            assertClusterHealthResponse(container);
+        }
+    }
+
     @Test
     public void testElasticsearchDefaultMaxHeapSize() throws Exception {
         long defaultHeapSize = 2147483648L;