Max retries exceeded?

[James Henstridge]

On 6 February 2017 at 11:47, Michael Nelson
<michael.nelson at canonical.com> wrote:
> On Mon, Feb 6, 2017 at 1:25 PM Michi Henning <michi.henning at canonical.com>
> wrote:
>>
>> I keep getting this error when doing a snapcraft cleanbuild. Any
>> suggestions? I checked name resolution, and my DNS resolves
>> parts.snapcraft.io just fine.
>>
>
> Hi Michi
>
> Have you verified your DNS resolution and/or curling from within your
> container? That is:
>
>>
>> Thanks,
>>
>> Michi.
>>
>> Setting up python3-lxml (3.5.0-1build1) ...
>> Setting up python3-petname (2.0-0ubuntu1~16.04) ...
>> Setting up python3-progressbar (2.3-2) ...
>> Setting up python3-pymacaroons (0.9.2-0ubuntu1) ...
>> Setting up python3-requests-toolbelt (0.6.0-2) ...
>> Setting up python3-simplejson (3.8.1-1ubuntu2) ...
>> Setting up python3-tabulate (0.7.5-1) ...
>> Setting up python3-xdg (0.25-4) ...
>> Setting up xdelta3 (3.0.8-dfsg-1ubuntu2) ...
>> Setting up python3-libarchive-c (2.1-3) ...
>> Setting up python3-magic (1:5.25-2ubuntu1) ...
>> Setting up snapcraft (2.26) ...
>> Processing triggers for libc-bin (2.23-0ubuntu5) ...
>> HTTPSConnectionPool(host='parts.snapcraft.io', port=443): Max retries
>> exceeded with url: /v1/parts.yaml (Caused by
>> NewConnectionError('<requests.packages.urllib3.connection.VerifiedHTTPSConnection
>> object at 0x7f5537c29ba8>: Failed to establish a new connection: [Errno -3]
>> Temporary failure in name resolution',))
>> Stopping snapcraft-merely-model-ewe
>> Command '['lxc', 'exec', 'snapcraft-merely-model-ewe', '--', 'snapcraft',
>> 'snap', '--output', 'thumbnailer_2.4_amd64.snap']' returned non-zero exit
>> status 1
>>
>>
>
> Can you try:
> $ lxc exec snapcraft-merely-model-ewe -- curl
> https://parts.snapcraft.io/v1/parts.yaml
>
> ? I can only confirm that curling that from various machines here responds
> fine (and that there haven't been any alerts for that service for the past
> day).

I was able to reproduce Michi's result.  I reran the command as
"snapcraft cleanbuild -d", which drops to a shell within the container
on the failure.  Using "getent hosts $hostname", I can get an IP
address for archive.ubuntu.com, but not parts.snapcraft.io.

Running strace, I disected the DNS communication here:
http://paste.ubuntu.com/23938750/ -- it is performing a query with
recursion desired, but the response only comes back with the CNAME
record and no A records.  If I perform the same request against
Google's public DNS (8.8.8.8), I get the CNAME and a bunch of A
records.

I'm guessing this is coming from the system resolver on the host
system.  I'm on zesty, so this could be a systemd-resolve problem.

James.