Re: [Libguestfs] [PATCH virt-v2v v2 2/2] v2v: Allow large temporary directory to be set on a global basis.

On Monday, 6 April 2020 11:19:12 CEST Richard W.M. Jones wrote: > Previously we placed large files in g#get_cachedir () (usually > /var/tmp). However the problem is this ties the libguestfs appliance > and the virt-v2v overlay files to the same location. > > When virt-v2v is run in a container, or any other situation where > local storage is limited, it's helpful to be able to put the overlay > files on an externally mounted PVC, which might be using NFS and > shared between containers. But putting the libguestfs appliance on > NFS in a shared location is certainly not recommended. > > This allows the two locations to be set separately: > > VIRT_V2V_TMPDIR - location of large temporary files, can use NFS > and may be shared > > LIBGUESTFS_CACHEDIR - location of libguestfs appliance > > Another motivation for this patch is to allow more reliable cleanup of > large temporary files by an external process, as described in the > updated documentation. > > Small temporary files are placed in $TMPDIR (usually /tmp). I cleaned > up some existing code which used /var/tmp for small temporaries. (^ this last change reverts 0bc1411fc8693dd981efef0088b3d335a11332cf ) > --- This is mostly a repost of v1, with even few things that got worse (I'll mention it later on). Since my requests [1][2] for actual use cases and motivations behind this went unanswered other than with - "because containers" - "because why not" then, I'll keep NACK-ing this patch. [1] https://www.redhat.com/archives/libguestfs/2020-April/msg00008.html [2] https://www.redhat.com/archives/libguestfs/2020-April/msg00010.html

Since the problem is "let's find out what to clean on failure", I propose a different approach, as also looking at this patch pointed out to me: - create a single virt-v2v.XXXXXX temporary directory in LIBGUESTFS_TMPDIR for small files, like the vmx file, the rhv-upload Python scripts, etc - create a single virt-v2v.XXXXXX temporary directory in LIBGUESTFS_CACHEDIR for big files Advantages: - no more need for the various Mkdtemp.temp_dir all around - only two well-defined names for temporary stuff that virt-v2v saves - similar to what done in other tools (eg virt-builder, 75fbe4511e05df)