Smoke tests fail on Ubuntu Precise 12.04/3.5.0-54-generic

[awh]

Whilst testing to see if an nsenter enabled weaveexec works properly on our oldest supported kernel (3.5.0 at this time) the smoke tests were observed to fail on recent master (4059ff6):

---= Running 200_dns_test.sh =---
Resolve names on a single host
...
test #1 "echo " failed: expected "10.2.0.34" got nothing test #2 "echo " failed: expected "seetwo.weave.local." got nothing 2 of 2 tests failed in 2.972s.

---= Running 210_dns_multicast_test.sh =---
Resolve names across hosts
...
test #1 "echo " failed: expected "10.2.3.34" got nothing test #2 "echo " failed: expected "seetwo.weave.local." got nothing 2 of 3 tests failed in 7.627s.

---= Running 220_dns_custom_test.sh =---
Resolve names in custom domain
...
test #1 "echo " failed: expected "10.2.54.91" got nothing test #2 "echo " failed: expected "seetwo.foo.bar." got nothing 2 of 2 tests failed in 3.132s.

Tested with the following Vagrant box:

config.vm.box = "ubuntu/ubuntu-12.04-amd64"
config.vm.box_url = "https://cloud-images.ubuntu.com/vagrant/precise/current/precise-server-cloudimg-amd64-vagrant-disk1.box"

and these kernel packages:

linux-image-3.5.0-54-generic linux-headers-3.5.0-54-generic

[awh]

Observed testing kernel compatability for #580.

[awh]

Handy patch for testing:

diff --git a/Vagrantfile b/Vagrantfile
index 28fb6c0..b6140eb 100644
--- a/Vagrantfile
+++ b/Vagrantfile
@@ -1,12 +1,12 @@
 VAGRANTFILE_API_VERSION = "2"

 vm_ip = "172.16.0.3" # arbitrary private IP
-pkgs = "lxc-docker aufs-tools build-essential ethtool iputils-arping libpcap-dev git mercurial bc"
+pkgs = "lxc-docker aufs-tools build-essential ethtool iputils-arping libpcap-dev git mercurial bc linux-image-3.5.0-54-generic linux-headers-3.5.0-54-generic"

 Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|

-  config.vm.box = "ubuntu/ubuntu-14.10-amd64"
-  config.vm.box_url = "https://cloud-images.ubuntu.com/vagrant/utopic/current/utopic-server-cloudimg-amd64-vagrant-disk1.box"
+  config.vm.box = "ubuntu/ubuntu-12.04-amd64"
+  config.vm.box_url = "https://cloud-images.ubuntu.com/vagrant/precise/current/precise-server-cloudimg-amd64-vagrant-disk1.box"

   config.vm.network "private_network", ip: vm_ip
   config.vm.provider :virtualbox do |vb|
diff --git a/test/Vagrantfile b/test/Vagrantfile
index 6de338c..3a20a35 100644
--- a/test/Vagrantfile
+++ b/test/Vagrantfile
@@ -10,10 +10,10 @@ ip_prefix = "192.168.48"
 ip_suffix_base = 10

 def configure_docker(host, hostname, ip)
-  pkgs = "lxc-docker ethtool"
+  pkgs = "lxc-docker ethtool linux-image-3.5.0-54-generic linux-headers-3.5.0-54-generic"

-  host.vm.box = "ubuntu/ubuntu-14.10-amd64"
-  host.vm.box_url = "https://cloud-images.ubuntu.com/vagrant/utopic/current/utopic-server-cloudimg-amd64-vagrant-disk1.box"
+  host.vm.box = "ubuntu/ubuntu-12.04-amd64"
+  host.vm.box_url = "https://cloud-images.ubuntu.com/vagrant/precise/current/precise-server-cloudimg-amd64-vagrant-disk1.box"

   host.vm.hostname = hostname
   host.vm.network "private_network", ip: ip

[awh]

The DNS tests are failing becuase containers started using --with-dns do not have their /etc/resolv.conf configured appropriately - in fact it shares the one from the host filesystem (confirmed by editing the file inside the container, and seeing those changes reflected in the host). Furthermore, it looks like the PID namespace isn't working properly - docker exec c1 ps aux lists all the host processes!

Possibly related to #470 and #202.

[awh]

Issue goes away with 3.8.0-44-generic.

[awh]

@rade @errordeveloper how do we feel about updating the minimum kernel version check in the weave script to 3.8.0?

[errordeveloper]

In the documentation Docker now recommends 3.10 and up, while the code doesn't actually reflect that.