Re: cachemgr output normalization

On 10/28/2011 12:36 PM, Kinkie wrote:
> Hi all,
> Now that cachemgr happily responds to proper http requests, I've
> started toying with a browser-based, all-javascript/DHTML cachemgr.cgi
> replacement.
> I have a first beta available in launchpad at
> lp:~kinkie/squid/cachemgr-js.

Can you start it somewhere so that we can actually see it in action?

> It currently requires help from squid
> via a rproxy setup to serve the two HTML and one javascript file, but
> if we can have squid serve them internally, it'll be a no-brainer for
> single-instance monitoring.

Will this be a part of Squid source tarball distribution? It may make
sense to keep it separate because it may require separate translations,
have a separate release cycle, etc.

> There's a few open points which need a bit of thinking though:
> 1- what is the best way to serve a few static html and javascript files?

Same way we serve icons, I guess. IIRC, Henrik has summarized how
Squid-as-web-server should [not] work some time ago, but those changes
are probably outside this project scope so I would just reuse icons code
for now.

If this is difficult, for any reason, just put them somewhere on
squid-cache.org and hard-code the URLs in your Javascript, for now.

> 2- does cachemgr get engaged only via GET method or can we have it
> also answer to POST requests? The reason is that GET requests in
> javascript are subject to a same-origin policy, while POST are not. It
> would allow for multi-server monitoring and it would make point 1 a
> nice-to-have and not a requirement

The difference is minor from Squid code point of view so we can support
both, eventually. IIRC, we do that in Co-Advisor, with little code (that
we would be happy to copy to Squid).

> 3- we need to make the output from cachemgr handlers follow some
> common guidelines.

Sure.

How do you want to post-process that output in Javascript? Some
find-and-replace commands using regular expressions? Is it very
difficult to have action-specific post-processing?

> This poses a problem of
> compatibility with third-party software. We can either have a
> transition phase where we duplicate actions, or we can just decide
> that we don't have the resources to care, and we just warn the authors
> that we know of about our intentions so that they have time to adapt.

Indeed. Perhaps this should be discussed on squid-users as well.

> This is also in my opinion a prerequisite step to support multiple
> output formats in cachemgr.

Is there consensus that Squid itself should support multiple output
formats? I kind of doubt it is the right thing to do in general. If
Squid outputs easy-to-parse, consistent data, other applications can
post-process and beautify it in many different ways.

> I'm willing to spend the time to do this if we agree that it should be done.

Yes, the output should be standardized.

Thank you,

Alex.
Received on Fri Oct 28 2011 - 19:39:38 MDT