s6-log configure "current" dir separate from archive dir

From: Brad Grissom <brad_at_bradgrissom.com>
Date: Fri, 27 Oct 2017 08:23:44 -0600

I'd like to use s6-log with "current" (and other temp files
previous/processed/state/newstate) in my RAM-disk directory, and the
archived files (.u and .s) in my /appdata directory which is NAND flash
storage.

I'm using an embedded system which has plenty of RAM (128M), but not much
storage (20M for this application). Plus, to preserve write cycles on the
NAND flash, it'd be perfect to have all the temp files in the RAM-disk and
archive to a separate non-volatile directory.

I'm new to s6 and s6-log, but I've read all the documentation and I've
looked at the s6-log.c code. I can hack the code to do what I want, but
I'd prefer not to since there are always gotchas that are learned the hard
way. Is there an option that I'm missing to achieve this, or perhaps a
processor with execlineb magic to achieve this?

Here is my s6-log line so far:

s6-log -b n20 s5242880 S15728640 !"xz" /appdata

My RAM-disk is in /run and logging to two separate dirs is of no help
because "current" is duplicated in both:

s6-log -b n20 s5242880 S15728640 !"xz" /appdata /run

Thanks so much skarnet/s6 community!

Also, as a side note, I've ported skalibs, execline, and s6 to the embedded
build system Yocto (OpenEmbedded/BitBake) for use on embedded ARM systems.
For those that aren't familiar, the Yocto is like Gentoo for embedded
systems. This basically amounted to creating 3 bitbake files for the 3
libraries which describe how to download and build the packages. There are
some big hacks so far, but at least I got it working. I could submit a
pull request, but I'm not sure where to submit them. I suppose the
respective .bb files could be checked into each repository. This would be
Laurent's call.

~~Brad Grissom -- 303.669.6806
Received on Fri Oct 27 2017 - 14:23:44 UTC