From f381d0af984d0ff0c4928e36335793d1a2712722 Mon Sep 17 00:00:00 2001
From: Matthias Radestock <matthias.radestock@gmail.com>
Date: Fri, 19 Dec 2014 12:18:01 +0000
Subject: [PATCH] gracefully deal with missing/old ip utility

---
 weave | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/weave b/weave
index 1d3be358..bf6c2b5f 100755
--- a/weave
+++ b/weave
@@ -390,6 +390,17 @@ uname -s -r | sed -n 's|^\([^ ]*\) \([0-9]\+\)\.\([0-9]\+\).*|\1 \2 \3|p' | {
     fi
 }
 
+if ! command_exists ip ; then
+    echo "ERROR: ip utility is missing. Please install it." >&2
+    exit 1
+fi
+
+if ! ip netns list >/dev/null 2>&1 ; then
+    echo "ERROR:" $(ip -V) "does not support network namespaces." >&2
+    echo "       Please install iproute2-ss111010 or later." >&2
+    exit 1
+fi
+
 if ! DOCKER_VERSION=$(docker -v | sed -n 's|^Docker version \([0-9]\+\.[0-9]\+.[0-9]\+\),.*|\1|p') || [ -z "$DOCKER_VERSION" ] ; then
     echo "ERROR: Unable to parse docker version" >&2
     exit 1