From 251a00da4cb5073b9e38f40348835a194a68e6ca Mon Sep 17 00:00:00 2001
From: Thomas Strobel <ts468@cam.ac.uk>
Date: Thu, 24 Sep 2015 12:44:07 +0200
Subject: [PATCH] openvswitch module: add option to reset db on start

---
 nixos/modules/virtualisation/openvswitch.nix | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/nixos/modules/virtualisation/openvswitch.nix b/nixos/modules/virtualisation/openvswitch.nix
index 1c77945a6cb5..4d6123e4ce51 100644
--- a/nixos/modules/virtualisation/openvswitch.nix
+++ b/nixos/modules/virtualisation/openvswitch.nix
@@ -19,6 +19,15 @@ in {
         '';
     };
 
+    resetOnStart = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Whether to reset the Open vSwitch configuration database to a default
+        configuration on every start of the systemd <literal>ovsdb.service</literal>.
+        '';
+    };
+
     package = mkOption {
       type = types.package;
       default = pkgs.openvswitch;
@@ -75,6 +84,7 @@ in {
         mkdir -p ${runDir}
         mkdir -p /var/db/openvswitch
         chmod +w /var/db/openvswitch
+        ${optionalString cfg.resetOnStart "rm -f /var/db/openvswitch/conf.db"}
         if [[ ! -e /var/db/openvswitch/conf.db ]]; then
           ${cfg.package}/bin/ovsdb-tool create \
             "/var/db/openvswitch/conf.db" \