io.appulse.epmd.java.server.SubcommandNames Maven / Gradle / Ivy

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/*
 * Copyright 2020 the original author or authors.
 *
 * 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 io.appulse.epmd.java.server;

import static java.util.Locale.ENGLISH;
import static java.util.concurrent.TimeUnit.SECONDS;
import static java.util.stream.Collectors.joining;

import java.util.concurrent.CompletionException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeoutException;

import io.appulse.epmd.java.client.EpmdClient;

import lombok.extern.slf4j.Slf4j;
import lombok.val;
import picocli.CommandLine.Command;
import picocli.CommandLine.ParentCommand;

@Slf4j
@Command(
    name = "names",
    sortOptions = false,
    descriptionHeading = "%n",
    parameterListHeading = "%nParameters:%n",
    optionListHeading = "%nOptions:%n",
    commandListHeading = "%nCommands:%n",
    description = "Lists names registered with the currently running epmd."
)
class SubcommandNames implements Runnable {

  @ParentCommand
  Epmd options;

  @Override
  public void run () {
    try (val client = new EpmdClient(options.port)) {
      val descriptionsString = client.getNodes()
          .get(2, SECONDS)
          .stream()
          .map(it -> String.format(ENGLISH, " - node '%s' at port %d",
                                   it.getName(),
                                   it.getPort())
          )
          .collect(joining("\n"));

      if (descriptionsString.isEmpty()) {
        log.info("EPMD up and running on port {} without any registered node",
                 client.getPort());
      } else {
        log.info("EPMD up and running on port {} with the registered node(s):\n{}",
                 client.getPort(), descriptionsString);
      }
    } catch (CompletionException | ExecutionException ex) {
      val cause = ex.getCause();
      if (options.debug) {
        log.error("{}", cause.getMessage(), cause);
      } else {
        log.error("{}", cause.getMessage());
      }
      Runtime.getRuntime().exit(1);
    } catch (TimeoutException ex) {
      log.error("EPMD server doesn't respond too long");
    } catch (InterruptedException ex) {
      log.error("Interrupted", ex);
    }
  }
}