Prevent the bootstrap command from leaving root credentials unrecoverable (#461)

* rebase

* autolint

Author: eric-maynard

quarkus/admin/src/main/java/org/apache/polaris/admintool/BootstrapCommand.java

@@ -57,6 +57,11 @@ static class StandardInputOptions {
           description =
               "Root principal credentials to bootstrap. Must be of the form 'realm,clientId,clientSecret'.")
       List<String> credentials;
+
+      @CommandLine.Option(
+          names = {"-p", "--print-credentials"},
+          description = "Print root credentials to stdout")
+      boolean printCredentials;
     }
 
     static class FileInputOptions {
@@ -85,6 +90,17 @@ public Integer call() {
                     || inputOptions.stdinOptions.credentials.isEmpty()
                 ? RootCredentialsSet.EMPTY
                 : RootCredentialsSet.fromList(inputOptions.stdinOptions.credentials);
+        if (inputOptions.stdinOptions.credentials == null
+            || inputOptions.stdinOptions.credentials.isEmpty()) {
+          if (!inputOptions.stdinOptions.printCredentials) {
+            spec.commandLine()
+                .getErr()
+                .println(
+                    "Specify either `--credentials` or `--print-credentials` to ensure"
+                        + " the root user is accessible after bootstrapping.");
+            return EXIT_CODE_BOOTSTRAP_ERROR;
+          }
+        }
       }
 
       // Execute the bootstrap
@@ -97,6 +113,15 @@ public Integer call() {
         if (result.getValue().isSuccess()) {
           String realm = result.getKey();
           spec.commandLine().getOut().printf("Realm '%s' successfully bootstrapped.%n", realm);
+          if (inputOptions.stdinOptions != null && inputOptions.stdinOptions.printCredentials) {
+            String msg =
+                String.format(
+                    "realm: %1s root principal credentials: %2s:%3s",
+                    result.getKey(),
+                    result.getValue().getPrincipalSecrets().getPrincipalClientId(),
+                    result.getValue().getPrincipalSecrets().getMainSecret());
+            spec.commandLine().getOut().println(msg);
+          }
         } else {
           String realm = result.getKey();
           spec.commandLine()

quarkus/admin/src/test/java/org/apache/polaris/admintool/BootstrapCommandTest.java

@@ -99,7 +99,7 @@ public void testBootstrapInvalidCredentials(LaunchResult result) {
   public void testBootstrapInvalidArguments(LaunchResult result) {
     assertThat(result.getErrorOutput())
         .contains(
-            "Error: (-r=<realm> [-r=<realm>]... [-c=<realm,clientId,clientSecret>]...) "
+            "Error: (-r=<realm> [-r=<realm>]... [-c=<realm,clientId,clientSecret>]... [-p]) "
                 + "and -f=<file> are mutually exclusive (specify only one)");
   }
 
@@ -132,6 +132,45 @@ public void testBootstrapFromInvalidFile(QuarkusMainLauncher launcher) {
         .contains("Bootstrap encountered errors during operation.");
   }
 
+  @Test
+  @Launch(
+      value = {"bootstrap", "-r", "realm1", "-c", "realm1,client1d,s3cr3t", "--print-credentials"})
+  public void testPrintCredentials(LaunchResult result) {
+    assertThat(result.getOutput()).contains("Bootstrap completed successfully.");
+    assertThat(result.getOutput()).contains("realm: realm1 root principal credentials: client1d:");
+  }
+
+  @Test
+  @Launch(value = {"bootstrap", "-r", "realm1", "--print-credentials"})
+  public void testPrintCredentialsSystemGenerated(LaunchResult result) {
+    assertThat(result.getOutput()).contains("Bootstrap completed successfully.");
+    assertThat(result.getOutput()).contains("realm: realm1 root principal credentials: ");
+  }
+
+  @Test
+  @Launch(
+      value = {"bootstrap", "-r", "realm1"},
+      exitCode = EXIT_CODE_BOOTSTRAP_ERROR)
+  public void testNoPrintCredentialsSystemGenerated(LaunchResult result) {
+    assertThat(result.getErrorOutput()).contains("--credentials");
+    assertThat(result.getErrorOutput()).contains("--print-credentials");
+  }
+
+  @Test
+  @Launch(
+      value = {
+        "bootstrap",
+        "-r",
+        "realm1",
+        "--not-real-arg",
+      },
+      exitCode = EXIT_CODE_USAGE)
+  public void testBootstrapInvalidArg(LaunchResult result) {
+    assertThat(result.getErrorOutput())
+        .contains("Unknown option: '--not-real-arg'")
+        .contains("Usage:");
+  }
+
   private static Path copyResource(Path temp, String resource) throws IOException {
     URL source = Objects.requireNonNull(BootstrapCommandTest.class.getResource(resource));
     Path dest = temp.resolve(resource);