chore(Vagrantfile): add custom logic to revert to CoreOS 647.2.0 for stable channel

Author: carmstrong

Vagrantfile

@@ -52,16 +52,28 @@ def vm_cpus
 end
 
 Vagrant.configure("2") do |config|
-  # always use Vagrants insecure key
+  # always use Vagrant's insecure key
   config.ssh.insert_key = false
-
   config.vm.box = "coreos-%s" % $update_channel
-  config.vm.box_version = "= 647.2.0"
-  config.vm.box_url = "http://%s.release.core-os.net/amd64-usr/current/coreos_production_vagrant.json" % $update_channel
+
+  # HACK to bypass the limitation of the CoreOS "current" metadata for boxes -
+  # it only specifies the latest release, so we cannot use it for older releases.
+  # TODO(carmstrong) we can remove this once we're back to using "specific release or more recent"
+  if $update_channel == "stable"
+    config.vm.box_version = "= 647.2.0"
+    config.vm.box_url = "http://stable.release.core-os.net/amd64-usr/647.2.0/coreos_production_vagrant.json"
+  else
+    config.vm.box_version = ">= 681.2.0"
+    config.vm.box_url = "http://%s.release.core-os.net/amd64-usr/current/coreos_production_vagrant.json" % $update_channel
+  end
 
   ["vmware_fusion", "vmware_workstation"].each do |vmware|
     config.vm.provider vmware do |v, override|
-      override.vm.box_url = "http://%s.release.core-os.net/amd64-usr/current/coreos_production_vagrant_vmware_fusion.json" % $update_channel
+      if $update_channel == "stable"
+        override.vm.box_url = "http://stable.release.core-os.net/amd64-usr/647.2.0/coreos_production_vagrant_vmware_fusion.json" % $update_channel
+      else
+        override.vm.box_url = "http://%s.release.core-os.net/amd64-usr/current/coreos_production_vagrant_vmware_fusion.json" % $update_channel
+      end
     end
   end