Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.apache.brooklyn.core.location; import static com.google.common.base.Preconditions.checkNotNull; import java.io.BufferedReader; import java.io.IOException; import java.util.List; import java.util.Map; import javax.annotation.Nonnull; import javax.annotation.concurrent.Immutable; import org.apache.brooklyn.api.location.HardwareDetails; import org.apache.brooklyn.api.location.MachineDetails; import org.apache.brooklyn.api.location.OsDetails; import org.apache.brooklyn.api.mgmt.Task; import org.apache.brooklyn.location.ssh.SshMachineLocation; import org.apache.brooklyn.util.core.ResourceUtils; import org.apache.brooklyn.util.core.task.DynamicTasks; import org.apache.brooklyn.util.core.task.TaskTags; import org.apache.brooklyn.util.core.task.ssh.internal.PlainSshExecTaskFactory; import org.apache.brooklyn.util.core.task.system.ProcessTaskWrapper; import org.apache.brooklyn.util.stream.Streams; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.common.annotations.Beta; import com.google.common.base.CharMatcher; import com.google.common.base.Function; import com.google.common.base.Joiner; import com.google.common.base.Objects; import com.google.common.base.Splitter; import com.google.common.base.Throwables; import com.google.common.collect.Maps; import com.google.common.io.CharStreams; @Immutable public class BasicMachineDetails implements MachineDetails { public static final Logger LOG = LoggerFactory.getLogger(BasicMachineDetails.class); private final HardwareDetails hardwareDetails; private final OsDetails osDetails; public BasicMachineDetails(HardwareDetails hardwareDetails, OsDetails osDetails) { this.hardwareDetails = checkNotNull(hardwareDetails, "hardwareDetails"); this.osDetails = checkNotNull(osDetails, "osDetails"); } @Nonnull @Override public HardwareDetails getHardwareDetails() { return hardwareDetails; } @Nonnull @Override public OsDetails getOsDetails() { return osDetails; } @Override public String toString() { return Objects.toStringHelper(MachineDetails.class).add("os", osDetails).add("hardware", hardwareDetails) .toString(); } /** * Creates a MachineDetails for the given location by SSHing to the machine and * running a Bash script to gather data. Should only be called from within a * task context. If this might not be the case then use {@link * #taskForSshMachineLocation(SshMachineLocation)} instead. */ @Beta public static BasicMachineDetails forSshMachineLocationLive(SshMachineLocation location) { return TaskTags .markInessential( DynamicTasks.queueIfPossible(taskForSshMachineLocation(location)).orSubmitAsync().asTask()) .getUnchecked(); } /** * @return A task that gathers machine details by SSHing to the machine and running * a Bash script to gather data. */ public static Task<BasicMachineDetails> taskForSshMachineLocation(SshMachineLocation location) { BufferedReader reader = new BufferedReader(Streams.reader(new ResourceUtils(BasicMachineDetails.class) .getResourceFromUrl("classpath://org/apache/brooklyn/location/basic/os-details.sh"))); List<String> script; try { script = CharStreams.readLines(reader); } catch (IOException e) { LOG.error("Error reading os-details script", e); throw Throwables.propagate(e); } finally { try { reader.close(); } catch (IOException e) { // Not rethrowing e because it might obscure an exception caught by the first catch LOG.error("Error closing os-details script reader", e); } } Task<BasicMachineDetails> task = new PlainSshExecTaskFactory<String>(location, script) .summary("Getting machine details for: " + location).requiringZeroAndReturningStdout() .returning(taskToMachineDetailsFunction(location)).newTask().asTask(); return task; } private static Function<ProcessTaskWrapper<?>, BasicMachineDetails> taskToMachineDetailsFunction( final SshMachineLocation location) { return new Function<ProcessTaskWrapper<?>, BasicMachineDetails>() { @Override public BasicMachineDetails apply(ProcessTaskWrapper<?> input) { if (input.getExitCode() != 0) { LOG.warn("Non-zero exit code when fetching machine details for {}; guessing anonymous linux", location); return new BasicMachineDetails(new BasicHardwareDetails(null, null), BasicOsDetails.Factory.ANONYMOUS_LINUX); } String stdout = input.getStdout(); if (LOG.isDebugEnabled()) { LOG.debug("Found following details at {}: {}", location, stdout); } Map<String, String> details = Maps.newHashMap(Splitter.on(CharMatcher.anyOf("\r\n")) .omitEmptyStrings().withKeyValueSeparator(":").split(stdout)); String name = details.remove("name"); String version = details.remove("version"); String architecture = details.remove("architecture"); Integer ram = intOrNull(details, "ram"); Integer cpuCount = intOrNull(details, "cpus"); if (!details.isEmpty()) { LOG.debug("Unused keys from os-details script: " + Joiner.on(", ").join(details.keySet())); } OsDetails osDetails = new BasicOsDetails(name, architecture, version); HardwareDetails hardwareDetails = new BasicHardwareDetails(cpuCount, ram); BasicMachineDetails machineDetails = new BasicMachineDetails(hardwareDetails, osDetails); if (LOG.isDebugEnabled()) LOG.debug("Machine details for {}: {}", location, machineDetails); return machineDetails; } private Integer intOrNull(Map<String, String> details, String key) { try { return Integer.valueOf(details.remove(key)); } catch (NumberFormatException e) { return null; } } }; } }