Add --print-uri option to "tahoe backup" to dump resulting backup URI #2135

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tahoe-lafs · 2013-12-14T20:01:55Z

amontero commented

2013-12-14 20:01:55 +00:00

When I do scripted backups to my grid, I would like to collect the resulting backup root URI to a file. I've added a "--printcap" option to "tahoe backup" to do it and works good, so far.

Off by default for backwards compatibility. Comes to mind someone using "tahoe backup" from a script piping the output to a file and mailing it. Other than this, looks like an trivial addition.

Code is at:
https://github.com/tahoe-lafs/tahoe-lafs/pull/76

When I do scripted backups to my grid, I would like to collect the resulting backup root URI to a file. I've added a "--printcap" option to "tahoe backup" to do it and works good, so far. Off by default for backwards compatibility. Comes to mind someone using "tahoe backup" from a script piping the output to a file and mailing it. Other than this, looks like an trivial addition. Code is at: <https://github.com/tahoe-lafs/tahoe-lafs/pull/76>

tahoe-lafs added the

labels 2013-12-14 20:01:55 +00:00

tahoe-lafs added this to the undecided milestone 2013-12-14 20:01:55 +00:00

amontero commented

2013-12-14 20:58:44 +00:00

Also you can accomplish David Sarah's case at /tahoe-lafs/trac-2024-07-25/issues/5897 #10 with this one-liner:

$ tahoe backup --ignore-timestamps --printcap ~/Documents/ `tahoe mkdir`

The mkdir'ed directory URI is completely ignored, we will just keep the --printcap'ed URI as the immutable backup root.

Also you can accomplish David Sarah's case at [/tahoe-lafs/trac-2024-07-25/issues/5897](/tahoe-lafs/trac-2024-07-25/issues/5897)#10 with this one-liner: ``` $ tahoe backup --ignore-timestamps --printcap ~/Documents/ `tahoe mkdir` ``` The mkdir'ed directory URI is completely ignored, we will just keep the --printcap'ed URI as the *immutable* backup root.

markberger commented

2013-12-15 23:41:45 +00:00

+1

It might be good to add this option to the docs in frontends/CLI.rst.

+1 It might be good to add this option to the docs in `frontends/CLI.rst`.

amontero commented

2013-12-16 11:25:58 +00:00

Also a doubt:
Better to print the URI alone with no surrounding text (as it's done in "tahoe put" or "tahoe mkdir")?
If there was a --quiet option it would make sense, but printed along the backup summary, I think it's not worth it.

Also a doubt: Better to print the URI alone with no surrounding text (as it's done in "tahoe put" or "tahoe mkdir")? If there was a --quiet option it would make sense, but printed along the backup summary, I think it's not worth it.

daira commented

2013-12-16 18:39:41 +00:00

Replying to amontero:

Also a doubt:
Better to print the URI alone with no surrounding text (as it's done in "tahoe put" or "tahoe mkdir")?
If there was a --quiet option it would make sense, but printed along the backup summary, I think it's not worth it.

Yes, that's a problem for use in scripts. Maybe print the URI alone on stdout, and the backup summary on stderr when --printcap is used?

Replying to [amontero](/tahoe-lafs/trac-2024-07-25/issues/2135#issuecomment-94218): > Also a doubt: > Better to print the URI alone with no surrounding text (as it's done in "tahoe put" or "tahoe mkdir")? > If there was a --quiet option it would make sense, but printed along the backup summary, I think it's not worth it. Yes, that's a problem for use in scripts. Maybe print the URI alone on `stdout`, and the backup summary on `stderr` when `--printcap` is used?

amontero commented

2013-12-16 19:51:15 +00:00

Great idea, +1. Also, it's low hanging fruit :)

Done it, stripped the "Resulting backup..." string. Sample console output below.

 4 files uploaded (0 reused), 0 files skipped, 0 directories created (1 reused), 0 directories skipped
 backup done, elapsed time: 0:00:18
URI:DIR2-CHK:35ge[...]3gze:rij[...]nka:1:2:1074

It's OK to also redirect the more verbose messages to stderr?

Great idea, +1. Also, it's low hanging fruit :) Done it, stripped the "Resulting backup..." string. Sample console output below. ``` 4 files uploaded (0 reused), 0 files skipped, 0 directories created (1 reused), 0 directories skipped backup done, elapsed time: 0:00:18 URI:DIR2-CHK:35ge[...]3gze:rij[...]nka:1:2:1074 ``` It's OK to also redirect the more verbose messages to stderr?

amontero commented

2013-12-16 19:56:12 +00:00

I mean this one:

            if self.verbosity >= 2:
                print >>stdout, (" %d files checked, %d directories checked"
                                 % (self.files_checked,
                                    self.directories_checked))

I mean this one: ``` if self.verbosity >= 2: print >>stdout, (" %d files checked, %d directories checked" % (self.files_checked, self.directories_checked)) ```

daira commented

2013-12-17 11:22:00 +00:00

Yes.

amontero commented

2013-12-17 12:09:52 +00:00

As discussed in IRC:

Renamed --printcap to --print-uri
Tentatively adding -U as option shortcut (-u conflicts with --node-url)
All verbosity messages previously sent to stdout now are sent to stderr. Only resulting backup URI goes to stdout.

Updated the pull request accordingly for review.

Also, I proposed Daira to make --print-uri the default behavior to make it consistent with "tahoe put" and "tahoe mkdir". However, this could be a security issue for existing scripts. Needs further discussion.

As discussed in IRC: * Renamed --printcap to --print-uri * Tentatively adding -U as option shortcut (-u conflicts with --node-url) * All verbosity messages previously sent to stdout now are sent to stderr. Only resulting backup URI goes to stdout. Updated the pull request accordingly for review. Also, I proposed Daira to make --print-uri the default behavior to make it consistent with "tahoe put" and "tahoe mkdir". However, this could be a security issue for existing scripts. Needs further discussion.

tahoe-lafs changed title from ~~Add --printcap option to "tahoe backup" to dump resulting backup URI~~ to Add --print-uri option to "tahoe backup" to dump resulting backup URI

2013-12-17 12:13:14 +00:00

remyroy commented

2014-03-19 01:06:26 +00:00

I'll review this patch/pull request.

remyroy commented

2014-03-19 16:17:02 +00:00

Great code so far. I feel this would be quite useful for scripting backups.

There is still 2 failing backup related tests from this patch/pull request. The cli--tahoe-backup--dump-backup-dircap-stdout--tests branch from https://github.com/pataquets/tahoe-lafs/ seems to have some attempt at fixing those failing tests but they are still present.

There should also be an additional test in allmydata.test.test_cli.Backup to test this new command option.

Reassigning back to amontero for patch changes.

Great code so far. I feel this would be quite useful for scripting backups. There is still 2 failing backup related tests from this patch/pull request. The cli--tahoe-backup--dump-backup-dircap-stdout--tests branch from <https://github.com/pataquets/tahoe-lafs/> seems to have some attempt at fixing those failing tests but they are still present. There should also be an additional test in allmydata.test.test_cli.Backup to test this new command option. Reassigning back to amontero for patch changes.

daira commented

2014-04-15 00:59:08 +00:00

This could potentially get into 1.11 if the tests were fixed, but the core developers will be focussing on other things, so that depends on amontero.

tahoe-lafs modified the milestone from undecided to soon

2014-04-15 00:59:49 +00:00

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