[Duplicity-talk] No handlers could be found for logger "paramiko.transport" in cron only

[James Withers]

Hello,

I am using the following script:

#!/bin/bash
export PASSPHRASE=MYPASSPHRASE
duplicity inc --encrypt-key="MYKEY" /root/mysql-backup.sql 
scp://address@hidden/backups/mysql-backup.sql

Which when run from the command line, I get:

--------------[ Backup Statistics ]--------------
StartTime 1379440965.21 (Tue Sep 17 18:02:45 2013)
EndTime 1379440965.26 (Tue Sep 17 18:02:45 2013)
ElapsedTime 0.06 (0.06 seconds)
SourceFiles 1
SourceFileSize 1315533 (1.25 MB)
NewFiles 0
NewFileSize 0 (0 bytes)
DeletedFiles 0
ChangedFiles 1
ChangedFileSize 1315533 (1.25 MB)
ChangedDeltaSize 0 (0 bytes)
DeltaEntries 1
RawDeltaSize 218 (218 bytes)
TotalDestinationSizeChange 587 (587 bytes)
Errors 0

However when I run the script on cron I often (almost always) get:

No handlers could be found for logger "paramiko.transport"
BackendException: ssh connection to address@hidden:22 failed: Error reading SSH 
protocol banner No handlers could be found for logger "paramiko.transport"
BackendException: ssh connection to address@hidden:22 failed: Error reading SSH 
protocol banner

When I put on full verbosity I get:

Using archive dir: /root/.cache/duplicity/c6a2a47330938e1dff06a972b56ca34d
Using backup name: c6a2a47330938e1dff06a972b56ca34d
Import of duplicity.backends.botobackend Succeeded
Import of duplicity.backends.webdavbackend Succeeded
Import of duplicity.backends.ftpsbackend Succeeded
Import of duplicity.backends.localbackend Succeeded
Import of duplicity.backends.u1backend Succeeded
Import of duplicity.backends.rsyncbackend Succeeded
Import of duplicity.backends.hsibackend Succeeded
Import of duplicity.backends.cloudfilesbackend Succeeded 
Import of duplicity.backends.tahoebackend Succeeded 
Import of duplicity.backends.imapbackend Succeeded 
Import of duplicity.backends.sshbackend Succeeded 
Import of duplicity.backends.gdocsbackend Succeeded 
Import of duplicity.backends.ftpbackend Succeeded 
No handlers could be found for logger "paramiko.transport"
Using temporary directory /tmp/duplicity-XQaHqx-tempdir Backend error detail: 
Traceback (most recent call last):
  File "/usr/bin/duplicity", line 1411, in <module>
    with_tempdir(main)
  File "/usr/bin/duplicity", line 1404, in with_tempdir
    fn()
  File "/usr/bin/duplicity", line 1257, in main
    action = commandline.ProcessCommandLine(sys.argv[1:])
  File "/usr/lib64/python2.7/site-packages/duplicity/commandline.py", line 
1013, in ProcessCommandLine
    backup, local_pathname = set_backend(args[0], args[1])
  File "/usr/lib64/python2.7/site-packages/duplicity/commandline.py", line 906, 
in set_backend
    globals.backend = backend.get_backend(bend)
  File "/usr/lib64/python2.7/site-packages/duplicity/backend.py", line 161, in 
get_backend
    return _backends[pu.scheme](pu)
  File 
"/usr/lib64/python2.7/site-packages/duplicity/backends/_ssh_paramiko.py", line 
182, in __init__
    self.config['port'],e))
BackendException: ssh connection to address@hidden:22 failed: Error reading SSH 
protocol banner
BackendException: ssh connection to address@hidden:22 failed: Error reading SSH 
protocol banner

Is there a reason why this would only affect execution in a cron job and not 
direct execution of the script?

Regards,

James