X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/6da9f3666bc0ddee2d0be079cc30ba8b82804706..3294cfcee6d9316df0d0fae9848118501f57d908:/services/api/app/models/node.rb

diff --git a/services/api/app/models/node.rb b/services/api/app/models/node.rb
index b57abfde91..3d8b91b4b6 100644
--- a/services/api/app/models/node.rb
+++ b/services/api/app/models/node.rb
@@ -1,3 +1,7 @@
+# Copyright (C) The Arvados Authors. All rights reserved.
+#
+# SPDX-License-Identifier: AGPL-3.0
+
 require 'tempfile'
 
 class Node < ArvadosModel
@@ -102,25 +106,7 @@ class Node < ArvadosModel
       end
     end
 
-    # Assign slot_number
-    if self.slot_number.nil?
-      try_slot = 1
-      begin
-        self.slot_number = try_slot
-        begin
-          self.save!
-          break
-        rescue ActiveRecord::RecordNotUnique
-          try_slot += 1
-        end
-        raise "No available node slots" if try_slot == Rails.configuration.max_compute_nodes
-      end while true
-    end
-
-    # Assign hostname
-    if self.hostname.nil? and Rails.configuration.assign_node_hostname
-      self.hostname = self.class.hostname_for_slot(self.slot_number)
-    end
+    assign_slot
 
     # Record other basic stats
     ['total_cpu_cores', 'total_ram_mb', 'total_scratch_mb'].each do |key|
@@ -134,8 +120,45 @@ class Node < ArvadosModel
     save!
   end
 
+  def assign_slot
+    return if self.slot_number.andand > 0
+    while true
+      self.slot_number = self.class.available_slot_number
+      if self.slot_number.nil?
+        raise "No available node slots"
+      end
+      begin
+        save!
+        return assign_hostname
+      rescue ActiveRecord::RecordNotUnique
+        # try again
+      end
+    end
+  end
+
   protected
 
+  def assign_hostname
+    if self.hostname.nil? and Rails.configuration.assign_node_hostname
+      self.hostname = self.class.hostname_for_slot(self.slot_number)
+    end
+  end
+
+  def self.available_slot_number
+    # Join the sequence 1..max with the nodes table. Return the first
+    # (i.e., smallest) value that doesn't match the slot_number of any
+    # existing node.
+    connection.exec_query('SELECT n FROM generate_series(1, $1) AS slot(n)
+                          LEFT JOIN nodes ON n=slot_number
+                          WHERE slot_number IS NULL
+                          LIMIT 1',
+                          # query label:
+                          'Node.available_slot_number',
+                          # [col_id, val] for $1 vars:
+                          [[nil, Rails.configuration.max_compute_nodes]],
+                         ).rows.first.andand.first
+  end
+
   def ensure_ping_secret
     self.info['ping_secret'] ||= rand(2**256).to_s(36)
   end
@@ -173,6 +196,7 @@ class Node < ArvadosModel
     }
 
     if Rails.configuration.dns_server_conf_dir and Rails.configuration.dns_server_conf_template
+      tmpfile = nil
       begin
         begin
           template = IO.read(Rails.configuration.dns_server_conf_template)
@@ -182,15 +206,20 @@ class Node < ArvadosModel
         end
 
         hostfile = File.join Rails.configuration.dns_server_conf_dir, "#{hostname}.conf"
-        tmpfile = Tempfile.open(["#{hostname}", ".conf.tmp"],
+        Tempfile.open(["#{hostname}-", ".conf.tmp"],
                                  Rails.configuration.dns_server_conf_dir) do |f|
+          tmpfile = f.path
           f.puts template % template_vars
-          f.path
         end
         File.rename tmpfile, hostfile
       rescue IOError, SystemCallError => e
         logger.error "Writing #{hostfile}: #{e.message}"
         ok = false
+      ensure
+        if tmpfile and File.file? tmpfile
+          # Cleanup remaining temporary file.
+          File.unlink tmpfile
+        end
       end
     end