diff --git a/resources/celerity/map.php b/resources/celerity/map.php
--- a/resources/celerity/map.php
+++ b/resources/celerity/map.php
@@ -7,7 +7,7 @@
  */
 return array(
   'names' => array(
-    'core.pkg.css' => 'fe2446e9',
+    'core.pkg.css' => '14b73308',
     'core.pkg.js' => 'cbdbd552',
     'darkconsole.pkg.js' => 'df001cab',
     'differential.pkg.css' => '36884139',
@@ -127,7 +127,7 @@
     'rsrc/css/phui/phui-document.css' => 'a5615198',
     'rsrc/css/phui/phui-feed-story.css' => '55dc7732',
     'rsrc/css/phui/phui-fontkit.css' => 'fff25cfa',
-    'rsrc/css/phui/phui-form-view.css' => 'a2d72756',
+    'rsrc/css/phui/phui-form-view.css' => '9365aa7c',
     'rsrc/css/phui/phui-form.css' => 'b78ec020',
     'rsrc/css/phui/phui-header-view.css' => '39594ac0',
     'rsrc/css/phui/phui-icon.css' => 'b4963a4f',
@@ -777,7 +777,7 @@
     'phui-font-icon-base-css' => 'eb84f033',
     'phui-fontkit-css' => 'fff25cfa',
     'phui-form-css' => 'b78ec020',
-    'phui-form-view-css' => 'a2d72756',
+    'phui-form-view-css' => '9365aa7c',
     'phui-header-view-css' => '39594ac0',
     'phui-icon-view-css' => 'b4963a4f',
     'phui-image-mask-css' => '5a8b09c8',
diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -599,6 +599,7 @@
     'DrydockConstants' => 'applications/drydock/constants/DrydockConstants.php',
     'DrydockController' => 'applications/drydock/controller/DrydockController.php',
     'DrydockCreateBlueprintsCapability' => 'applications/drydock/capability/DrydockCreateBlueprintsCapability.php',
+    'DrydockCustomAttributes' => 'applications/drydock/util/DrydockCustomAttributes.php',
     'DrydockDAO' => 'applications/drydock/storage/DrydockDAO.php',
     'DrydockDefaultEditCapability' => 'applications/drydock/capability/DrydockDefaultEditCapability.php',
     'DrydockDefaultViewCapability' => 'applications/drydock/capability/DrydockDefaultViewCapability.php',
@@ -2307,6 +2308,7 @@
     'PhabricatorStandardCustomFieldRemarkup' => 'infrastructure/customfield/standard/PhabricatorStandardCustomFieldRemarkup.php',
     'PhabricatorStandardCustomFieldSelect' => 'infrastructure/customfield/standard/PhabricatorStandardCustomFieldSelect.php',
     'PhabricatorStandardCustomFieldText' => 'infrastructure/customfield/standard/PhabricatorStandardCustomFieldText.php',
+    'PhabricatorStandardCustomFieldTextarea' => 'infrastructure/customfield/standard/PhabricatorStandardCustomFieldTextarea.php',
     'PhabricatorStandardCustomFieldUsers' => 'infrastructure/customfield/standard/PhabricatorStandardCustomFieldUsers.php',
     'PhabricatorStandardPageView' => 'view/page/PhabricatorStandardPageView.php',
     'PhabricatorStatusController' => 'applications/system/controller/PhabricatorStatusController.php',
@@ -3443,6 +3445,7 @@
     'DrydockConsoleController' => 'DrydockController',
     'DrydockController' => 'PhabricatorController',
     'DrydockCreateBlueprintsCapability' => 'PhabricatorPolicyCapability',
+    'DrydockCustomAttributes' => 'Phobject',
     'DrydockDAO' => 'PhabricatorLiskDAO',
     'DrydockDefaultEditCapability' => 'PhabricatorPolicyCapability',
     'DrydockDefaultViewCapability' => 'PhabricatorPolicyCapability',
@@ -5307,6 +5310,7 @@
     'PhabricatorStandardCustomFieldRemarkup' => 'PhabricatorStandardCustomField',
     'PhabricatorStandardCustomFieldSelect' => 'PhabricatorStandardCustomField',
     'PhabricatorStandardCustomFieldText' => 'PhabricatorStandardCustomField',
+    'PhabricatorStandardCustomFieldTextarea' => 'PhabricatorStandardCustomField',
     'PhabricatorStandardCustomFieldUsers' => 'PhabricatorStandardCustomFieldPHIDs',
     'PhabricatorStandardPageView' => 'PhabricatorBarePageView',
     'PhabricatorStatusController' => 'PhabricatorController',
diff --git a/src/applications/drydock/blueprint/DrydockAmazonEC2HostBlueprintImplementation.php b/src/applications/drydock/blueprint/DrydockAmazonEC2HostBlueprintImplementation.php
--- a/src/applications/drydock/blueprint/DrydockAmazonEC2HostBlueprintImplementation.php
+++ b/src/applications/drydock/blueprint/DrydockAmazonEC2HostBlueprintImplementation.php
@@ -33,15 +33,26 @@
   }
 
   public function canAllocateResourceForLease(DrydockLease $lease) {
-    return
+    $platform_match =
       $lease->getAttribute('platform') === $this->getDetail('platform');
+    $custom_match = DrydockCustomAttributes::hasRequirements(
+      $lease->getAttributes(),
+      $this->getDetail('attributes'));
+
+    return $platform_match && $custom_match;
   }
 
   protected function canAllocateLease(
     DrydockResource $resource,
     DrydockLease $lease) {
-    return
+
+    $platform_match =
       $lease->getAttribute('platform') === $resource->getAttribute('platform');
+    $custom_match = DrydockCustomAttributes::hasRequirements(
+      $lease->getAttributes(),
+      $this->getDetail('attributes'));
+
+    return $platform_match && $custom_match;
   }
 
   protected function executeAllocateResource(
@@ -644,6 +655,18 @@
           'than the On Demand price for this instance type, or you could end '.
           'up paying more than the non-spot instance price.'),
       ),
+      'attr-header' => array(
+        'name' => pht('Host Attributes'),
+        'type' => 'header'
+      ),
+      'attributes' => array(
+        'name' => pht('Host Attributes'),
+        'type' => 'textarea',
+        'caption' => pht(
+          'A newline separated list of host attributes.  Each attribute '.
+          'should be specified in a key=value format.'),
+        'monospace' => true,
+      ),
     ) + parent::getFieldSpecifications();
   }
 
diff --git a/src/applications/drydock/storage/DrydockLease.php b/src/applications/drydock/storage/DrydockLease.php
--- a/src/applications/drydock/storage/DrydockLease.php
+++ b/src/applications/drydock/storage/DrydockLease.php
@@ -69,6 +69,10 @@
     return idx($this->attributes, $key, $default);
   }
 
+  public function getAttributes() {
+    return $this->attributes;
+  }
+
   public function generatePHID() {
     return PhabricatorPHID::generateNewPHID(DrydockLeasePHIDType::TYPECONST);
   }
diff --git a/src/applications/drydock/util/DrydockCustomAttributes.php b/src/applications/drydock/util/DrydockCustomAttributes.php
new file mode 100644
--- /dev/null
+++ b/src/applications/drydock/util/DrydockCustomAttributes.php
@@ -0,0 +1,44 @@
+<?php
+
+final class DrydockCustomAttributes extends Phobject {
+
+  public static function parse($text) {
+    $pairs = phutil_split_lines($text);
+    $attributes = array();
+
+    foreach ($pairs as $line) {
+      $kv = explode('=', $line, 2);
+      if (count($kv) === 0) {
+        continue;
+      } else if (count($kv) === 1) {
+        $attributes['attr_'.$kv[0]] = true;
+      } else {
+        $attributes['attr_'.$kv[0]] = trim($kv[1]);
+      }
+    }
+
+    return $attributes;
+  }
+
+  public static function hasRequirements($attributes, $provided) {
+    $provided = self::parse($provided);
+
+    foreach ($attributes as $key => $value) {
+      // Only compare custom attributes.
+      if (substr($key, 0, 5) === 'attr_') {
+        if ($value === true) {
+          if (!array_key_exists($provided, $key)) {
+            return false;
+          }
+        } else {
+          if (idx($provided, $key) !== $value) {
+            return false;
+          }
+        }
+      }
+    }
+
+    return true;
+  }
+
+}
diff --git a/src/applications/harbormaster/step/HarbormasterLeaseHostBuildStepImplementation.php b/src/applications/harbormaster/step/HarbormasterLeaseHostBuildStepImplementation.php
--- a/src/applications/harbormaster/step/HarbormasterLeaseHostBuildStepImplementation.php
+++ b/src/applications/harbormaster/step/HarbormasterLeaseHostBuildStepImplementation.php
@@ -17,13 +17,16 @@
 
     $settings = $this->getSettings();
 
+    $custom_attributes = DrydockCustomAttributes::parse(
+      $settings['attributes']);
+
     // Create the lease.
     $lease = id(new DrydockLease())
       ->setResourceType('host')
       ->setAttributes(
         array(
           'platform' => $settings['platform'],
-        ))
+        ) + $custom_attributes)
       ->queueForActivation();
 
     // Wait until the lease is fulfilled.
@@ -63,6 +66,14 @@
         'type' => 'text',
         'required' => true,
       ),
+      'attributes' => array(
+        'name' => pht('Required Attributes'),
+        'type' => 'textarea',
+        'caption' => pht(
+          'A newline separated list of required host attributes.  Each '.
+          'attribute should be specified in a key=value format.'),
+        'monospace' => true,
+      ),
     );
   }
 
diff --git a/src/infrastructure/customfield/standard/PhabricatorStandardCustomFieldTextarea.php b/src/infrastructure/customfield/standard/PhabricatorStandardCustomFieldTextarea.php
new file mode 100644
--- /dev/null
+++ b/src/infrastructure/customfield/standard/PhabricatorStandardCustomFieldTextarea.php
@@ -0,0 +1,74 @@
+<?php
+
+final class PhabricatorStandardCustomFieldTextarea
+  extends PhabricatorStandardCustomField {
+
+  public function getFieldType() {
+    return 'textarea';
+  }
+
+  public function renderEditControl(array $handles) {
+    $monospace = $this->getFieldConfigValue('monospace', false);
+    $custom_class =
+      $monospace ? 'aphront-form-control-textarea-monospace' : null;
+
+    return id(new AphrontFormTextAreaControl())
+      ->setLabel($this->getFieldName())
+      ->setName($this->getFieldKey())
+      ->setCaption($this->getCaption())
+      ->setValue($this->getFieldValue())
+      ->setCustomClass($custom_class);
+  }
+
+  public function getStyleForPropertyView() {
+    return 'block';
+  }
+
+  public function getApplicationTransactionRemarkupBlocks(
+    PhabricatorApplicationTransaction $xaction) {
+    return array(
+      $xaction->getNewValue(),
+    );
+  }
+
+  public function renderPropertyViewValue(array $handles) {
+    $value = $this->getFieldValue();
+
+    if (!strlen($value)) {
+      return null;
+    }
+
+    return phutil_tag(
+      'pre',
+      array(),
+      $value);
+  }
+
+  public function getApplicationTransactionTitle(
+    PhabricatorApplicationTransaction $xaction) {
+    $author_phid = $xaction->getAuthorPHID();
+
+    // TODO: Expose fancy transactions.
+
+    return pht(
+      '%s edited %s.',
+      $xaction->renderHandleLink($author_phid),
+      $this->getFieldName());
+  }
+
+  public function shouldAppearInHerald() {
+    return true;
+  }
+
+  public function getHeraldFieldConditions() {
+    return array(
+      HeraldAdapter::CONDITION_CONTAINS,
+      HeraldAdapter::CONDITION_NOT_CONTAINS,
+      HeraldAdapter::CONDITION_IS,
+      HeraldAdapter::CONDITION_IS_NOT,
+      HeraldAdapter::CONDITION_REGEXP,
+    );
+  }
+
+
+}
diff --git a/webroot/rsrc/css/phui/phui-form-view.css b/webroot/rsrc/css/phui/phui-form-view.css
--- a/webroot/rsrc/css/phui/phui-form-view.css
+++ b/webroot/rsrc/css/phui/phui-form-view.css
@@ -137,6 +137,10 @@
   height: 24em;
 }
 
+.aphront-form-control-textarea-monospace {
+  font-family: monospace;
+}
+
 .aphront-form-control-select .aphront-form-input {
   padding-top: 2px;
 }