Runner exporter failed with this message while checking if file changed during backup of instances files:

    < 3226bab4cd318d30cfbde18e6530435dcae3205f94103384ce266c3c73d1afeb  ./runner/instance/slappart2/srv/backup/pbs/slaprunner-slappart1-runner-1/backup.signature
    < 3226bab4cd318d30cfbde18e6530435dcae3205f94103384ce266c3c73d1afeb  ./runner/instance/slappart3/srv/backup/runner/backup.signature
    < 3226bab4cd318d30cfbde18e6530435dcae3205f94103384ce266c3c73d1afeb  ./runner/instance/slappart5/srv/backup/runner/backup.signature
    5248d5244
    < bb3d96876d1d6cecee9878d835e7515215fc5d2a6ae6b647d0e7915c36700b54  ./runner/instance/slappart4/srv/backup/runner/backup.signature
    ERROR: Some backups are not consistent, exporter should be re-run.

This is because instance in webrunner has also backup.signature the file is excluded while doing sha256sum on backup file:

    find -type f ! -name backup.signature -print0 | xargs -0 sha256sum | sort -k 66 > backup.signature

A fix is to exclude backup.signature in `find`.

If instance/slappartXX is not a folder but file, skip chdir else import/export fail with a message like:

    /srv/slapgrid/slappart18/bin/runner-exporter run at : Thu Oct  4 04:30:03 CEST 2018
    Traceback (most recent call last):
      File "<stdin>", line 17, in <module>
    OSError: [Errno 20] Not a directory: '/srv/slapgrid/slappart18/srv//runner/instance/slappart5-mariadb.dump.sql.gz'

/reviewed-on nexedi/slapos!415

This reverts commit 1c9075a1.

The changes will be done on slapos.toolbox/runner to always create missing proxy.db file

When a file is removed while rsync is running (after build the list and before transfer the file), rsync fail with the follow message:

     rsync warning: some files vanished before they could be transferred

Long back rafael proped a solution here 387d3b7e
But it seems like adding --ignore-missing-args dont really help but just ignore the files given in args and are counldn't be found anymore.

/reviewed-on nexedi/slapos!225

  When a file is removed while rsync is running (after build the list and before transfer the file), rsync fail with the follow message:

     rsync warning: some files vanished before they could be transferred

  This commit includes   --ignore-missing-args into rsync command line to ignore this case, as it is not relevant to the resilience
if a file is removed.

Further rewrite should be done but at least there's no awk code anymore.

  In order to make an resilient backup, resilience stack wait for the internal backup finishes,
  before proceed to notify the pbs. This commit keeps the default behaviour (wait for 10 min w/o changes),
  however allows test software release adopt a much shorter waiting time (1min).

  With this commit we can accelerate resilience tests in several minutes.

Do not apply exclusions to unrelated paths ("project", "proxy.db" and
"etc").
Simplify global exclusion file generation.
Add support for absolute and partition-relative exclusion paths
(previously, only partition-relative were supported).
Pipe exclusion file to rsync, to avoid an intermediate disk write.
Remove some directory prefix duplication by using PWD-relative paths
(except in one place, for runner-import.sh.jinja2 comparison).

So avoid spawning "cat" only for this.
Also, variable expansion quoting.

More similar changes will come later as part of larger changes.
Also, fail if
  cd "$backup_directory"
fails, as it is supposed to exist by that point.

Imperfect: single-quote escaping would be good. But this at least makes
it significantly harder to accidentally end up outside variable assignment.
Users of these values will be added in a later commit.

Otherwise, performances get awful on HDD, and not far better on SSD.

Getting them from the runner backup avoids to get false positive if some
of the instance's backup files were excluded using an exporter.exclude file

slaprunner: export script shouldn't succeed if the backup of the contained instances are running at the same time

slaprunner: updates export script to make sure that etc directory exists in backup before copying into it

When it is restored on importer instance, it erases its RSA key... Which makes the sshd service to crash

slaprunner: concatenate exporter.exclude file of each partition of the runner and write it in the standard location.

Allow to exclude things from inside of the runner's partitions without knowing what instance it is.

pbs: enforce LC_ALL=C (importer/exporter as well) for proper sort collation

to mark the purpose, repeat inside the call to /usr/bin/sort,
but it's also needed for messages (i.e. we don't want /bin/cp
to write unicode chars in the pubsub feed)

Use compress for local transference is just slow.

This avoids non-ascii encoding in RSS feed