MongoDBContainer: simplify loading and executing java script files to init DB

modules/mongodb/build.gradle

@@ -4,4 +4,5 @@ dependencies {
     compile project(':testcontainers')
 
     testCompile("org.mongodb:mongodb-driver-sync:4.0.2")
+    testCompile("org.assertj:assertj-core:3.19.0")
 }

modules/mongodb/src/main/java/org/testcontainers/containers/MongoDBContainer.java

@@ -8,6 +8,8 @@
 import org.testcontainers.utility.DockerImageName;
 
 import java.io.IOException;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 /**
  * Constructs a single node MongoDB replica set for testing transactions.
@@ -23,6 +25,7 @@ public class MongoDBContainer extends GenericContainer<MongoDBContainer> {
     private static final int MONGODB_INTERNAL_PORT = 27017;
     private static final int AWAIT_INIT_REPLICA_SET_ATTEMPTS = 60;
     private static final String MONGODB_DATABASE_NAME_DEFAULT = "test";
+    private static final String DOCKER_ENTRYPOINT_INIT_DIR = "docker-entrypoint-initdb.d";
 
     /**
      * @deprecated use {@link MongoDBContainer(DockerImageName)} instead
@@ -64,9 +67,7 @@ public String getReplicaSetUrl() {
      * @return a replica set url.
      */
     public String getReplicaSetUrl(final String databaseName) {
-        if (!isRunning()) {
-            throw new IllegalStateException("MongoDBContainer should be started first");
-        }
+        checkIfRunning();
         return String.format(
             "mongodb://%s:%d/%s",
             getContainerIpAddress(),
@@ -75,6 +76,34 @@ public String getReplicaSetUrl(final String databaseName) {
         );
     }
 
+    private void checkIfRunning() {
+        if (!isRunning()) {
+            throw new IllegalStateException("MongoDBContainer should be started first");
+        }
+    }
+
+    /**
+     * Loads and executes JavaScript files directly.
+     * Note that all the files are supposed to be delivered to a container via proper commands before starting.
+     * Should be used as an alternative to docker-entrypoint-initdb.d. This is because at docker-entrypoint-initdb.d
+     * stage, a replica set is not yet initialized and thus cannot accept operations.
+     *
+     * @param paths directory or file names as an array of strings.
+     * @see GenericContainer#withClasspathResourceMapping(String, String, BindMode) etc.
+     */
+    @SneakyThrows(value = {IOException.class, InterruptedException.class})
+    public void loadAndExecuteJsFiles(final String... paths) {
+        checkIfRunning();
+        final String loadCommand =
+            Stream.of(paths).map(it -> "load(\"" + it + "\")").collect(Collectors.joining(";"));
+        final ExecResult execResult = execInContainer(buildMongoEvalCommand(loadCommand));
+        if (execResult.getExitCode() != CONTAINER_EXIT_CODE_OK) {
+            final String errorMessage = String.format("An error occurred: %s", execResult.getStdout());
+            log.error(errorMessage);
+            throw new LoadAndExecuteJsFilesException(errorMessage);
+        }
+    }
+
     @Override
     protected void containerIsStarted(InspectContainerResponse containerInfo) {
         initReplicaSet();
@@ -92,6 +121,28 @@ private void checkMongoNodeExitCode(final Container.ExecResult execResult) {
         }
     }
 
+    @SneakyThrows(value = {IOException.class, InterruptedException.class})
+    private void checkDockerEntrypointDirIsEmpty() {
+        final ExecResult execResult = execInContainer(
+            "/bin/bash",
+            "-c",
+            String.format(
+                "if [ -n \"$(find \"%s\" -maxdepth 0 -type d -empty 2>/dev/null)\" ]; then exit 0; else exit -1; fi",
+                DOCKER_ENTRYPOINT_INIT_DIR
+            )
+        );
+        if (execResult.getExitCode() != CONTAINER_EXIT_CODE_OK) {
+            throw new DockerEntrypointInitDirIsNotEmptyException(
+                String.format(
+                    "%s is supposed to be empty while running with the --replSet command-line option. " +
+                        "Consider using loadAndExecuteJsFiles(...). Error: %s",
+                    DOCKER_ENTRYPOINT_INIT_DIR,
+                    execResult.getStdout()
+                )
+            );
+        }
+    }
+
     private String buildMongoWaitCommand() {
         return String.format(
             "var attempt = 0; " +
@@ -122,6 +173,7 @@ private void checkMongoNodeExitCodeAfterWaiting(
 
     @SneakyThrows(value = {IOException.class, InterruptedException.class})
     private void initReplicaSet() {
+        checkDockerEntrypointDirIsEmpty();
         log.debug("Initializing a single node node replica set...");
         final ExecResult execResultInitRs = execInContainer(
             buildMongoEvalCommand("rs.initiate();")
@@ -146,4 +198,16 @@ public static class ReplicaSetInitializationException extends RuntimeException {
             super(errorMessage);
         }
     }
+
+    public static class DockerEntrypointInitDirIsNotEmptyException extends RuntimeException {
+        DockerEntrypointInitDirIsNotEmptyException(final String errorMessage) {
+            super(errorMessage);
+        }
+    }
+
+    public static class LoadAndExecuteJsFilesException extends RuntimeException {
+        LoadAndExecuteJsFilesException(final String errorMessage) {
+            super(errorMessage);
+        }
+    }
 }

modules/mongodb/src/test/java/org/testcontainers/containers/MongoDBContainerTest.java

@@ -13,7 +13,10 @@
 import org.junit.Test;
 import org.testcontainers.utility.DockerImageName;
 
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.hamcrest.CoreMatchers.endsWith;
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.CoreMatchers.notNullValue;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertThat;
@@ -95,4 +98,49 @@ public void shouldTestDatabaseName() {
             assertThat(mongoDBContainer.getReplicaSetUrl(databaseName), endsWith(databaseName));
         }
     }
+
+    @Test
+    public void shouldTestLoadAndExecuteJsFiles() {
+        final String file1 = "mongo_init-1.js";
+        final String file2 = "mongo_init-2.js";
+        final String targetDir2 = "my-scripts-2/";
+        final String targetFile1 = "my-scripts-1/" + file1;
+        final String targetFile2 = targetDir2 + file2;
+        try (
+            final MongoDBContainer mongoDBContainer = new MongoDBContainer(DockerImageName.parse("mongo:4.0.10"))
+                .withClasspathResourceMapping(file1, targetFile1, BindMode.READ_ONLY)
+                .withClasspathResourceMapping(file2, targetFile2, BindMode.READ_ONLY)
+        ) {
+            mongoDBContainer.start();
+            mongoDBContainer.loadAndExecuteJsFiles(targetFile1, targetDir2);
+            final String mongoRsUrl = mongoDBContainer.getReplicaSetUrl();
+            assertThat(mongoRsUrl, notNullValue());
+            try (
+                final MongoClient mongoSyncClient = MongoClients.create(mongoRsUrl)
+            ) {
+                assertThat(
+                    mongoSyncClient.getDatabase("test").getCollection("foo").countDocuments(),
+                    is(3L)
+                );
+                assertThat(
+                    mongoSyncClient.getDatabase("test").getCollection("bar").countDocuments(),
+                    is(2L)
+                );
+            }
+            assertThatThrownBy(() -> mongoDBContainer.loadAndExecuteJsFiles("non-existed-file"))
+                .isExactlyInstanceOf(MongoDBContainer.LoadAndExecuteJsFilesException.class);
+        }
+    }
+
+    @Test
+    public void shouldNotStartBecauseOfDockerEntrypointInitDirectoryIsNotEmpty() {
+        try (
+            final MongoDBContainer mongoDBContainer = new MongoDBContainer(DockerImageName.parse("mongo:4.0.10"))
+                .withClasspathResourceMapping("mongo_init-1.js", "/docker-entrypoint-initdb.d/mongo_init-1.js", BindMode.READ_ONLY)
+        ) {
+            assertThatThrownBy(mongoDBContainer::start)
+                .isExactlyInstanceOf(ContainerLaunchException.class)
+                .hasRootCauseExactlyInstanceOf(MongoDBContainer.DockerEntrypointInitDirIsNotEmptyException.class);
+        }
+    }
 }

modules/mongodb/src/test/resources/mongo_init-1.js

@@ -0,0 +1,4 @@
+db.foo.insert({'id': 1});
+db.foo.insert({'id': 2});
+db.foo.insert({'id': 3});
+

modules/mongodb/src/test/resources/mongo_init-2.js

@@ -0,0 +1,3 @@
+db.bar.insert({'id': 1});
+db.bar.insert({'id': 2});
+