Implement zfs create for new machines

When realizing a virtual machine, if the virtual machine runtime
directory is a ZFS filesystem, then a new ZFS filesystem will be
created for the virtual machine.

Fix: #23

com.io7m.waxmill.realize/src/main/java/com/io7m/waxmill/realize/WXMRealizationInstructionsType.java

@@ -25,12 +25,28 @@
 import java.util.List;
 import java.util.Objects;
 
+/**
+ * The instructions that comprise a realization.
+ */
+
 @Value.Immutable
 @ImmutablesStyleType
 public interface WXMRealizationInstructionsType
 {
+  /**
+   * @return The realization steps
+   */
+
   List<WXMRealizationStepType> steps();
 
+  /**
+   * Execute the realization.
+   *
+   * @param dryRun If this is a dry run
+   *
+   * @throws WXMException On errors
+   */
+
   default void execute(
     final WXMDryRun dryRun)
     throws WXMException

com.io7m.waxmill.realize/src/main/java/com/io7m/waxmill/realize/WXMRealizationStepType.java

@@ -22,12 +22,32 @@
 
 import java.util.List;
 
+/**
+ * A single step within a realization.
+ */
+
 public interface WXMRealizationStepType
 {
+  /**
+   * @return The description of the step
+   */
+
   String description();
 
+  /**
+   * @return The list of processes that will be executed
+   */
+
   List<WXMProcessDescription> processes();
 
+  /**
+   * Execute the step.
+   *
+   * @param dryRun A specification of whether this is a dry run or not
+   *
+   * @throws WXMException On errors
+   */
+
   void execute(
     WXMDryRun dryRun)
     throws WXMException;

com.io7m.waxmill.realize/src/main/java/com/io7m/waxmill/realize/WXMRealizationType.java

@@ -16,7 +16,18 @@
 
 package com.io7m.waxmill.realize;
 
+/**
+ * A realization operation.
+ */
+
 public interface WXMRealizationType
 {
+  /**
+   * Evaluate the realization operation, returning the list of instructions
+   * to be performed to realize the virtual machine.
+   *
+   * @return A list of instructions
+   */
+
   WXMRealizationInstructions evaluate();
 }

com.io7m.waxmill.realize/src/main/java/com/io7m/waxmill/realize/WXMRealizations.java

@@ -27,10 +27,15 @@
 import com.io7m.waxmill.process.api.WXMProcessesType;
 import com.io7m.waxmill.realize.internal.WXMFileCheck;
 import com.io7m.waxmill.realize.internal.WXMRealizeMessages;
+import com.io7m.waxmill.realize.internal.WXMRuntimeDirectoryCreate;
 import com.io7m.waxmill.realize.internal.WXMZFSVolumeCheck;
 
 import java.util.Objects;
 
+/**
+ * Functions to construct realizations.
+ */
+
 public final class WXMRealizations implements WXMRealizationType
 {
   private final WXMProcessesType processes;
@@ -54,6 +59,16 @@ private WXMRealizations(
       Objects.requireNonNull(inMachine, "machine");
   }
 
+  /**
+   * Create a realization operation for the given virtual machine.
+   *
+   * @param processes           A process interface
+   * @param clientConfiguration The client configuration
+   * @param machine             The virtual machine
+   *
+   * @return A realization operation
+   */
+
   public static WXMRealizationType create(
     final WXMProcessesType processes,
     final WXMClientConfiguration clientConfiguration,
@@ -72,6 +87,15 @@ public WXMRealizationInstructions evaluate()
   {
     final var builder = WXMRealizationInstructions.builder();
 
+    builder.addSteps(
+      new WXMRuntimeDirectoryCreate(
+        this.clientConfiguration,
+        this.messages,
+        this.processes,
+        this.machine.id()
+      )
+    );
+
     for (final var device : this.machine.devices()) {
       switch (device.kind()) {
         case WXM_AHCI_CD:

com.io7m.waxmill.realize/src/main/java/com/io7m/waxmill/realize/internal/WXMFileCheck.java

@@ -21,6 +21,8 @@
 import com.io7m.waxmill.machines.WXMDryRun;
 import com.io7m.waxmill.process.api.WXMProcessDescription;
 import com.io7m.waxmill.realize.WXMRealizationStepType;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -33,6 +35,9 @@
 
 public final class WXMFileCheck implements WXMRealizationStepType
 {
+  private static final Logger LOG =
+    LoggerFactory.getLogger(WXMFileCheck.class);
+
   private final WXMRealizeMessages messages;
   private final WXMDeviceSlot slot;
   private final UUID machineId;
@@ -75,6 +80,8 @@ public void execute(
       return;
     }
 
+    LOG.info("checking {} is regular file", this.file);
+
     if (!Files.isRegularFile(this.file, NOFOLLOW_LINKS)) {
       throw new WXMException(this.errorMissingFile(this.file));
     }

com.io7m.waxmill.realize/src/main/java/com/io7m/waxmill/realize/internal/WXMRuntimeDirectoryCreate.java

@@ -0,0 +1,150 @@
+/*
+ * Copyright © 2020 Mark Raynsford <code@io7m.com> http://io7m.com
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+ * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+package com.io7m.waxmill.realize.internal;
+
+import com.io7m.waxmill.client.api.WXMClientConfiguration;
+import com.io7m.waxmill.exceptions.WXMException;
+import com.io7m.waxmill.machines.WXMDryRun;
+import com.io7m.waxmill.process.api.WXMProcessDescription;
+import com.io7m.waxmill.process.api.WXMProcessesType;
+import com.io7m.waxmill.realize.WXMRealizationStepType;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Objects;
+import java.util.UUID;
+
+import static com.io7m.waxmill.machines.WXMDryRun.DRY_RUN;
+import static java.util.Locale.ROOT;
+
+public final class WXMRuntimeDirectoryCreate implements WXMRealizationStepType
+{
+  private static final Logger LOG =
+    LoggerFactory.getLogger(WXMRuntimeDirectoryCreate.class);
+
+  private final WXMRealizeMessages messages;
+  private final UUID machineId;
+  private final WXMClientConfiguration clientConfiguration;
+  private final WXMProcessesType processes;
+  private List<WXMProcessDescription> processesList;
+
+  public WXMRuntimeDirectoryCreate(
+    final WXMClientConfiguration inClientConfiguration,
+    final WXMRealizeMessages inMessages,
+    final WXMProcessesType inProcesses,
+    final UUID inMachineId)
+  {
+    this.clientConfiguration =
+      Objects.requireNonNull(inClientConfiguration, "clientConfiguration");
+    this.messages =
+      Objects.requireNonNull(inMessages, "messages");
+    this.processes =
+      Objects.requireNonNull(inProcesses, "inProcesses");
+    this.machineId =
+      Objects.requireNonNull(inMachineId, "inMachineId");
+
+    this.processesList = List.of();
+  }
+
+  @Override
+  public String description()
+  {
+    return this.messages.format(
+      "runtimeDirectoryCreate",
+      this.clientConfiguration.virtualMachineRuntimeDirectory()
+        .resolve(this.machineId.toString())
+    );
+  }
+
+  @Override
+  public List<WXMProcessDescription> processes()
+  {
+    return List.copyOf(this.processesList);
+  }
+
+  @Override
+  public void execute(
+    final WXMDryRun dryRun)
+    throws WXMException
+  {
+    if (dryRun == DRY_RUN) {
+      return;
+    }
+
+    final var baseDirectory =
+      this.clientConfiguration.virtualMachineRuntimeDirectory();
+    final var path =
+      baseDirectory.resolve(this.machineId.toString());
+
+    LOG.info("checking if {} is a directory", path);
+
+    if (Files.isDirectory(path)) {
+      LOG.info("{} is a directory", path);
+      return;
+    }
+
+    if (Files.exists(path)) {
+      throw new WXMException(this.notADirectory(path));
+    }
+
+    try {
+      final var store = Files.getFileStore(baseDirectory);
+      if ("ZFS".equals(store.type().toUpperCase(ROOT))) {
+        final var createPath =
+          String.format("%s/%s", store.name(), this.machineId);
+
+        LOG.info("creating ZFS filesystem {}", createPath);
+        final var process =
+          WXMProcessDescription.builder()
+            .setExecutable(this.clientConfiguration.zfsExecutable())
+            .addArguments("create")
+            .addArguments(createPath)
+            .build();
+
+        this.processesList = List.of(process);
+        this.processes.processStartAndWait(process);
+      } else {
+        LOG.info("creating directory {}", path);
+        Files.createDirectories(path);
+      }
+    } catch (final IOException | InterruptedException e) {
+      throw new WXMException(e);
+    }
+  }
+
+  private String notADirectory(
+    final Path path)
+  {
+    return this.messages.format(
+      "runtimeDirectoryNotADirectory",
+      path
+    );
+  }
+
+  @Override
+  public String toString()
+  {
+    return String.format(
+      "[WXMRuntimeDirectoryCreate 0x%s]",
+      Long.toUnsignedString(System.identityHashCode(this), 16)
+    );
+  }
+}

com.io7m.waxmill.realize/src/main/java/com/io7m/waxmill/realize/internal/WXMZFSVolumeCheck.java

@@ -72,9 +72,9 @@ public WXMZFSVolumeCheck(
       Objects.requireNonNull(inSlot, "slot");
     this.zfsVolume =
       Objects.requireNonNull(inZFSVolume, "zfsVolume");
-
     final var machineId =
       Objects.requireNonNull(inMachineId, "machineId");
+
     this.volumePath =
       WXMStorageBackends.determineZFSVolumePath(
         this.clientConfiguration.virtualMachineRuntimeDirectory(),

com.io7m.waxmill.realize/src/main/resources/com/io7m/waxmill/realize/internal/Realize.xml

@@ -29,6 +29,14 @@
   Action: Create the zfs volume manually (zfs create -V).
 ]]></entry>
 
+  <entry key="runtimeDirectoryCreate"><![CDATA[Creating a runtime directory for the virtual machine.
+  Filesystem: {0}
+]]></entry>
+
+  <entry key="runtimeDirectoryNotADirectory"><![CDATA[The runtime directory for the virtual machine is not a directory.
+  Path: {0}
+]]></entry>
+
   <entry key="errorRequiredPathsMissing"><![CDATA[One or more required files are missing.
   Machine:  {0}
   Files:    {1}

com.io7m.waxmill.tests/src/test/java/com/io7m/waxmill/tests/cmdline/WXMCommandVMRealizeTest.java

@@ -52,6 +52,7 @@ public void setup()
     this.vmDirectory = this.directory.resolve("vmDirectory");
     this.zfsDirectory = this.directory.resolve("zfsDirectory");
     Files.createDirectories(this.vmDirectory);
+    Files.createDirectories(this.zfsDirectory);
 
     this.configuration =
       WXMClientConfiguration.builder()