How to handle "UserData" in errors

[Martin Packman]

On 19/02/2013, John Arbash Meinel <john at arbash-meinel.com> wrote:
>
> Right now when we generate error messages, we include the context of
> the request that we sent. Which is often quite helpful. However one of
> those values is a "UserData []byte" which contains a fair sized data
> array (2kb?) of compressed data.

Kapil and I mildly disagreed on this. The python openstack provider
deliberately doesn't log the outgoing userdata, mostly because it
contains secrets for the zookeeper instance, but also because a big
blob isn't generally helpful to users. However, there have definitely
been bugs in the cloud config generation where inspecting the userdata
was needed for diagnosis.

> When Go reports on that array, it turns it into [0x64, 0xf6, 0x1f,
> ...]. So every byte of the array becomes ~5 bytes in the terminal.

If kept, this should just be fixed to use a better escaping format.
The actual base64 bytes sent would be good, though as we discovered
that's done inside the json encoding so might not be convenient to
log.

Martin