When setting up a dedicated ssh key to access the annex on a host,
set IdentitiesOnly to prevent the ssh-agent from forcing use of a different
ssh key.
That behavior could result in unncessary password prompts. I remember
getting a message or two from people who got deluged with password
prompts and I couldn't at the time see why.
Also, it would prevent git-annex-shell from being run on the remote host,
when git-annex was installed there by unpacking the standalone tarball,
since the authorized_keys line for the dedicated ssh key, which sets
up calling git-annex-shell when it's not in path, wouldn't be used.
This fixes
http://git-annex.branchable.com/bugs/Internal_Server_Error:_Unknown_UUID
but I've not closed that bug yet since I should still:
1. Investigate why the ssh remote got set up despite being so broken.
2. Make the webapp not handle the NoUUID state in such an ugly way.
3. Possibly add code to fix up systems that encountered the problem.
Although since it requires changes to .ssh/config this may be one for
the release notes.
Thanks to TJ for pointing me in the right direction to understand what
was happening here.
Started with a problem when running addurl on a really long url,
because the whole url is munged into the filename. Ended up doing
a fairly extensive review for places where filenames could get too large,
although it's hard to say I'm not missed any..
Backend.Url had a 128 character limit, which is fine when the limit is 255,
but not if it's a lot shorter on some systems. So check the pathconf()
limit. Note that this could result in fromUrl creating different keys
for the same url, if run on systems with different limits. I don't see
this is likely to cause any problems. That can already happen when using
addurl --fast, or if the content of an url changes.
Both Command.AddUrl and Backend.Url assumed that urls don't contain a
lot of multi-byte unicode, and would fail to truncate an url that did
properly.
A few places use a filename as the template to make a temp file.
While that's nice in that the temp file name can be easily related back to
the original filename, it could lead to `git annex add` failing to add a
filename that was at or close to the maximum length.
Note that in Command.Add.lockdown, the template is still derived from the
filename, just with enough space left to turn it into a temp file.
This is an important optimisation, because the assistant may lock down
a bunch of files all at once, and using the same template for all of them
would cause openTempFile to iterate through the same set of names,
looking for an unused temp file. I'm not very happy with the relatedTemplate
hack, but it avoids that slowdown.
Backend.WORM does not limit the filename stored in the key.
I have not tried to change that; so git annex add will fail on really long
filenames when using the WORM backend. It seems better to preserve the
invariant that a WORM key always contains the complete filename, since
the filename is the only unique material in the key, other than mtime and
size. Since nobody has complained about add failing (I think I saw it
once?) on WORM, probably it's ok, or nobody but me uses it.
There may be compatability problems if using git annex addurl --fast
or the WORM backend on a system with the 255 limit and then trying to use
that repo in a system with a smaller limit. I have not tried to deal with
those.
This commit was sponsored by Alexander Brem. Thanks!
