New Java based Nessie CLI tool + REPL

Features & functionalities:

* SQL-ish syntax.
* REPL.
* Built-in online `HELP` command (and `HELP <command>` command ;), that also shows the commands' syntaxes in the online help. The same information is also published on the projectnessie.org site.
* Auto-completion of commands, keywords and reference names (use TAB).
* Syntax highlighting.
* Paging of long results - showing a lot of content keys or a long commit log just works like `less` on your Linux or macOS box.
* Command history, persisted in your home directory (can be turned off).
* "Just" run a one or more Nessie REPL commands - pass those as arguments on the command line or as a script.
* Supports all authentication mechanisms that the Nessie Java supports, including all OAuth2 flows.
* Relatively small, currently just ~14.5MB.
* Available commands to manage branches and tags, drop tables and views, manage namespaces, list and show tables & views, merge and help.
* Contains interactive functionality that content-generator tool and pynessie provide, but not potentially dangerous operations.

It's not based on Quarkus, but "plain" Java 11, allows a smaller uber-jar of 14.5 instead of 18.5MB, also improves startup time a bit.

Also included in this PR:

* Updates to the web site, syntax docs generated from Grammar.
* Same help texts used for online help + web site.
* Blog post.

Uses congocc Grammar and parser/lexer, really quick parsing and no runtime dependencies required. congocc also allows relatively(!) easy integration of command line completion and syntax highlighting.

To try the Nessie CLI tool: `./gradlew :nessie-cli:jar && java -jar cli/cli/build/libs/nessie-cli-0.80.1-SNAPSHOT.jar`

api/model-quarkus/build.gradle.kts

@@ -20,12 +20,12 @@ import io.smallrye.openapi.gradleplugin.SmallryeOpenApiTask
 import org.apache.tools.ant.filters.ReplaceTokens
 
 plugins {
-  id("nessie-conventions-quarkus")
+  id("nessie-conventions-server")
   id("nessie-jacoco")
   alias(libs.plugins.smallrye.openapi)
 }
 
-extra["maven.name"] = "Nessie - Model - Variant only for Java 17+ consumers"
+extra["maven.name"] = "Nessie - Model - Variant only for Java 11+ consumers"
 
 description =
   "nessie-model-jakarta is effectively the same as nessie-model, but it is _not_ a " +

bom/build.gradle.kts

@@ -27,6 +27,8 @@ dependencies {
   constraints {
     api(rootProject)
     api(project(":nessie-azurite-testcontainer"))
+    api(project(":nessie-cli"))
+    api(project(":nessie-cli-grammar"))
     api(project(":nessie-client"))
     api(project(":nessie-client-testextension"))
     api(project(":nessie-combined-cs"))

cli/cli/build.gradle.kts

@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2022 Dremio
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
+import org.apache.tools.ant.taskdefs.condition.Os
+
+plugins {
+  id("nessie-conventions-server")
+  id("nessie-jacoco")
+  id("nessie-shadow-jar")
+}
+
+extra["maven.name"] = "Nessie - CLI"
+
+configurations.all { exclude(group = "org.projectnessie.nessie", module = "nessie-model") }
+
+dependencies {
+  implementation(project(":nessie-model-quarkus"))
+  implementation(project(":nessie-client"))
+  implementation(project(":nessie-cli-grammar"))
+
+  implementation(libs.jline)
+  implementation(libs.picocli)
+
+  compileOnly(libs.immutables.value.annotations)
+  annotationProcessor(libs.immutables.value.processor)
+
+  compileOnly(libs.jakarta.annotation.api)
+  compileOnly(libs.microprofile.openapi)
+
+  implementation(platform(libs.jackson.bom))
+  implementation("com.fasterxml.jackson.core:jackson-databind")
+
+  compileOnly(libs.immutables.builder)
+  compileOnly(libs.immutables.value.annotations)
+  annotationProcessor(libs.immutables.value.processor)
+
+  runtimeOnly(libs.logback.classic)
+
+  testFixturesApi(libs.microprofile.openapi)
+
+  testFixturesApi(platform(libs.junit.bom))
+  testFixturesApi(libs.bundles.junit.testing)
+
+  testImplementation(project(":nessie-jaxrs-testextension"))
+
+  testImplementation(project(":nessie-versioned-storage-inmemory-tests"))
+
+  testCompileOnly(libs.immutables.value.annotations)
+}
+
+tasks.withType<ProcessResources>().configureEach {
+  from("src/main/resources") { duplicatesStrategy = DuplicatesStrategy.INCLUDE }
+}
+
+tasks.named<ShadowJar>("shadowJar").configure {
+  manifest { attributes["Main-Class"] = "org.projectnessie.nessie.cli.cli.NessieCliMain" }
+}
+
+// Testcontainers is not supported on Windows :(
+if (Os.isFamily(Os.FAMILY_WINDOWS)) {
+  tasks.named<Test>("intTest").configure { this.enabled = false }
+}
+
+// Issue w/ testcontainers/podman in GH workflows :(
+if (Os.isFamily(Os.FAMILY_MAC) && System.getenv("CI") != null) {
+  tasks.named<Test>("intTest").configure { this.enabled = false }
+}

cli/cli/src/main/java/org/projectnessie/nessie/cli/cli/BaseNessieCli.java

@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2024 Dremio
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.projectnessie.nessie.cli.cli;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.util.Objects.requireNonNull;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.PrintWriter;
+import java.io.UncheckedIOException;
+import java.net.URL;
+import java.util.Optional;
+import org.jline.terminal.Terminal;
+import org.jline.utils.AttributedStringBuilder;
+import org.jline.utils.AttributedStyle;
+import org.projectnessie.client.api.NessieApiV2;
+import org.projectnessie.model.Reference;
+
+public abstract class BaseNessieCli {
+
+  public static final AttributedStyle STYLE_ERROR = AttributedStyle.DEFAULT.foreground(128, 0, 0);
+  public static final AttributedStyle STYLE_FAINT = AttributedStyle.DEFAULT.faint();
+  public static final AttributedStyle STYLE_YELLOW =
+      AttributedStyle.DEFAULT.foreground(128, 128, 0);
+  public static final AttributedStyle STYLE_GREEN = AttributedStyle.DEFAULT.foreground(0, 128, 0);
+  public static final AttributedStyle STYLE_BLUE = AttributedStyle.DEFAULT.foreground(0, 0, 128);
+
+  private Integer exitWithCode;
+  private NessieApiV2 nessieApi;
+  private Reference currentReference;
+  private Terminal terminal;
+
+  public Integer exitWithCode() {
+    return exitWithCode;
+  }
+
+  public void exitWithCode(int exitCode) {
+    exitWithCode = exitCode;
+  }
+
+  public void setTerminal(Terminal terminal) {
+    this.terminal = terminal;
+  }
+
+  public PrintWriter writer() {
+    return terminal.writer();
+  }
+
+  public void exitRepl(int exitCode) {
+    exitWithCode = exitCode;
+  }
+
+  public Terminal terminal() {
+    return terminal;
+  }
+
+  public boolean dumbTerminal() {
+    return terminal.getType().equals("dumb");
+  }
+
+  public void setCurrentReference(Reference currentReference) {
+    this.currentReference = currentReference;
+  }
+
+  public Reference getCurrentReference() {
+    if (nessieApi == null) {
+      throw new NotConnectedException();
+    }
+    return currentReference;
+  }
+
+  public void connected(NessieApiV2 nessieApi) {
+    if (this.nessieApi != null) {
+      try {
+        this.nessieApi.close();
+      } catch (Exception e) {
+        @SuppressWarnings("resource")
+        PrintWriter writer = writer();
+        writer.println(
+            new AttributedStringBuilder()
+                .append("Failed to close the existing client: ")
+                .append(e.toString(), STYLE_ERROR));
+      }
+    }
+    this.nessieApi = nessieApi;
+  }
+
+  public Optional<NessieApiV2> nessieApi() {
+    return Optional.ofNullable(nessieApi);
+  }
+
+  public NessieApiV2 mandatoryNessieApi() {
+    if (nessieApi == null) {
+      throw new NotConnectedException();
+    }
+    return nessieApi;
+  }
+
+  public String readResource(String resource) {
+    URL url = NessieCliImpl.class.getResource(resource);
+    try (InputStream in =
+        requireNonNull(url, "Could not open resource from classpath " + resource)
+            .openConnection()
+            .getInputStream()) {
+      return new String(in.readAllBytes(), UTF_8);
+    } catch (IOException e) {
+      throw new UncheckedIOException(e);
+    }
+  }
+}

cli/cli/src/main/java/org/projectnessie/nessie/cli/cli/CliCommandFailedException.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2024 Dremio
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.projectnessie.nessie.cli.cli;
+
+/**
+ * "Marker" exception to tell the CLI/REPL that the command execution failed, but the error was
+ * already handled.
+ */
+public class CliCommandFailedException extends RuntimeException {
+  public CliCommandFailedException() {
+    super("Previous command failed.");
+  }
+}

cli/cli/src/main/java/org/projectnessie/nessie/cli/cli/CommandsToRun.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2024 Dremio
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.projectnessie.nessie.cli.cli;
+
+import static org.projectnessie.nessie.cli.cli.NessieCliImpl.OPTION_COMMAND;
+import static org.projectnessie.nessie.cli.cli.NessieCliImpl.OPTION_CONTINUE_ON_ERROR;
+import static org.projectnessie.nessie.cli.cli.NessieCliImpl.OPTION_KEEP_RUNNING;
+import static org.projectnessie.nessie.cli.cli.NessieCliImpl.OPTION_SCRIPT;
+
+import java.util.List;
+import picocli.CommandLine.ArgGroup;
+import picocli.CommandLine.Option;
+
+class CommandsToRun {
+
+  @ArgGroup CommandsSource commandsSource;
+
+  @Option(
+      names = {"-K", OPTION_KEEP_RUNNING},
+      description = {
+        "When running commands via the "
+            + OPTION_COMMAND
+            + " or "
+            + OPTION_SCRIPT
+            + " option the process will exit once the commands have been executed.",
+        "To keep the REPL running, specify this option."
+            + "See the "
+            + OPTION_CONTINUE_ON_ERROR
+            + " option."
+      })
+  boolean keepRunning;
+
+  @Option(
+      names = {"-E", OPTION_CONTINUE_ON_ERROR},
+      description = {
+        "When running commands via the "
+            + OPTION_COMMAND
+            + " or "
+            + OPTION_SCRIPT
+            + " option the process will stop/exit when a command could not be parsed or ran into an error.",
+        "Specifying this option lets the REPL continue executing the remaining commands after parse or runtime errors."
+      })
+  boolean continueOnError;
+
+  @Override
+  public String toString() {
+    return "CommandsToRun{"
+        + "commandsSource="
+        + commandsSource
+        + ", keepRunning="
+        + keepRunning
+        + ", continueOnError="
+        + continueOnError
+        + '}';
+  }
+
+  static class CommandsSource {
+    @Option(
+        names = {"-s", OPTION_SCRIPT},
+        description = {
+          "Run the commands in the Nessie CLI script referenced by this option.",
+          "Possible values are either a file path or use the minus character ('-') to read the script from stdin."
+        })
+    String scriptFile;
+
+    @Option(
+        names = {"-c", OPTION_COMMAND},
+        arity = "*",
+        description = {
+          "Nessie CLI commands to run. Each value represents one command.",
+          "The process will exit once all specified commands have been executed. "
+              + "To keep the REPL running in case of errors, specify the "
+              + OPTION_KEEP_RUNNING
+              + " option."
+        })
+    List<String> commands = List.of();
+
+    @Override
+    public String toString() {
+      return "CommandsSource{" + "runScript='" + scriptFile + '\'' + ", commands=" + commands + '}';
+    }
+  }
+}