maas-builds team mailing list archive

[Gavin Panella <gavin.panella@xxxxxxxxxxxxx>]

On 11 April 2014 11:06, Raphaël Badin <raphael.badin@xxxxxxxxxxxxx> wrote:
> There seem to be a problem with the proxy used in the lab: it's caching the
> simplestreams index too aggressively and the result is that the cluster
> doesn't get the new simplestream data which contains reference to Trusty's
> 'rc' images.
>
> I imported the images manually (not going through the proxy), ran the tests,
> and got all the nodes enlisted and commissioned all right.  I saw on the
> nodes' consoles that the 'rc' Trusty images was being used.
>
> I don't have permission to clean the proxy's cache so I'll ask Diogo to help
> me with that when he comes online.

I wonder if this might not be a cache problem:

$ curl -i http://maas.ubuntu.com/images/ephemeral-v2/daily/streams/v1/com.ubuntu.maas.daily:v2:download.json
HTTP/1.1 200 OK
Accept-Ranges: bytes
Content-Length: 27869
Content-Type: application/json
ETag: "9620d2-6cdd-4f6b9b2eb7280"
X-Cache: HIT from citrusnobilis.canonical.com
X-Cache-Lookup: HIT from citrusnobilis.canonical.com:8800
Via: 1.0 citrusnobilis.canonical.com (squid/3.1.19)
Age: 450
Date: Fri, 11 Apr 2014 11:17:40 GMT
Last-Modified: Fri, 11 Apr 2014 00:48:58 GMT
Expires: Fri, 11 Apr 2014 13:23:24 GMT
Connection: keep-alive
...

The Expires header is 2 hours in the future. However, there are ETag
and Last-Modified headers. You can also see the X-Cache headers, which
seem to indicate that there's a caching reverse proxy in front of
maas.ubuntu.com.

I don't actually know how these headers are interpreted by an
intermediate proxy, be that the lab's proxy or the reverse proxy.
However, we could add "?a=$time" to the URL to ensure we're not
getting cached responses, or figure out exactly what headers to set
(the latter is undoubtedly more hygienic).

Gavin.