How to Specify an SSH Key with rsync

Specify identity file (id_rsa) with rsync

https://unix.stackexchange.com/questions/127352/specify-identity-file-id-rsa-with-rsync

I need to make periodic backups of a directory on a remote server which is a virtual machine hosted by a research organisation. They mandate that access to VMs is through ssh keys, which is all good, except that I can’t figure out how to point rsync to the ssh key for this server.

Rsync has no problem if the key file is ~/.ssh/id_rsa, but when it is something else I get Permission denied (publickey).

With ssh I can specify the identity file with -i, but rsync appears to have no such option.

I have also tried temporarily moving the key on the local machine to ~/.ssh/id_rsa, but that similarly does not work.

tl;dr

Can you specify an identity file with rsync?

sshrsync

Share Improve this question Follow asked May 1, 2014 at 0:15 Jangari’s user avatar Jangari 4,72822 gold badges1515 silver badges99 bronze badges

4
Useful also in order to do sudo rsync, which doesn't use one's own ssh keys, for some reason. – 
ijoseph
Commented Jul 27, 2018 at 21:19
1
@ijoseph Exactly, I use rsync -aAP "sudo -u user ssh" user@server:dir local_dir when syncing from cron scripts which run as root – 
Martin Pecka
Commented Dec 11, 2018 at 14:16

Add a comment 4 Answers Sorted by: 715

You can specify the exact ssh command via the ‘-e’ option:

rsync -Pav -e “ssh -i $HOME/.ssh/somekey” username@hostname:/from/dir/ /to/dir/

Many ssh users are unfamiliar with their ~/.ssh/config file. You can specify default settings per host via the config file.

Host hostname User username IdentityFile ~/.ssh/somekey

In the long run it is best to learn the ~/.ssh/config file. Share Improve this answer Follow edited Feb 10, 2017 at 14:18 answered May 1, 2014 at 0:23 Dan Garthwaite’s user avatar Dan Garthwaite 8,54611 gold badge1717 silver badges99 bronze badges

1
Does not help for me to have the IdentityFile in ssh_config. I can "ssh web1" without problems, but when using rsync to web1:... it fails with "Permission denied (publickey)". – 
Zitrax
Commented Oct 14, 2014 at 7:28
2
Try turning up verboseness of the ssh transport: rsync -e 'ssh -vv' web1:/etc/issue /tmp/issue – 
Dan Garthwaite
Commented Oct 14, 2014 at 14:49 

1
Ah. If you are automating this and will not be able to supply a password you will need an additional passwordless ssh key configured at both ends. If you would like rsync to work without a password in an interactive session you will need to use ssh-agent. – 
Dan Garthwaite
Commented Oct 14, 2014 at 21:48
60
Duuuuuuude! the ~/.ssh/config file - you have opened a new universe for me! – 
demaniak
Commented Jun 29, 2017 at 20:38
6
In my case for ~/.ssh/config to work I had to do chmod 600 ~/.ssh/config – 
Tono Nam
Commented Oct 21, 2019 at 4:21

Show 11 more comments 26

This can be done with SSH user config see: http://www.cyberciti.biz/faq/create-ssh-config-file-on-linux-unix/ basically edit ~/.ssh/config:

$ nano ~/.ssh/config #Add Hosts below Host server1 HostName examplehost.com User username Port 22 IdentityFile /path/to/key

$ rsync -e ssh /home/user/directory user@remote.host.net:home/user/directory/

This should work for any program using SSH, rsync, Share Improve this answer Follow answered May 1, 2014 at 0:30 Cbaker510’s user avatar Cbaker510 42344 silver badges66 bronze badges

1
You can use rsync -e ssh /home/user/directory server1:home/user/directory/ as well – 
Dexter
Commented Nov 1, 2019 at 13:12

Add a comment 16

For me it was sufficient to start the ssh-agent as follows:

eval ssh-agent -s ssh-add /path/to/mykey

See also a longer answer here https://stackoverflow.com/questions/17846529/could-not-open-a-connection-to-your-authentication-agent Share Improve this answer Follow edited May 23, 2017 at 12:40 Community’s user avatar CommunityBot 1 answered Apr 14, 2016 at 7:06 pietro’s user avatar pietro 26122 silver badges33 bronze badges Add a comment 4

FYI:

1) The public key is always in the home directory of the user logging in to remote server i.e. if you login as “backup” it is located at /home/backup/.ssh/authorized_keys. User ID when you login defines the public key used at the destination.

You can choose the user ID when making connection by two different ways:

ssh user_id@destination.server or ssh -l user_id destination_server (<– that is lower case “L”)

On the other hand at your end the private key is in a similar way in homedir of user unless you override it like described in Dan’s answer.

2) For backup purpose it may be desirable to create a restricted key which is limited to run just one command like “rsync”. There is a good description about that related to “rsnapshot” backup which allows you to remote backup entire server using non privileged user account and “sudo”:

“rsnapshot” howto

Rsnapshot can easily backup a bunch of remote or local servers making it handy scheduled & centralised backup server. Share Improve this answer Follow edited Jan 6, 2015 at 19:29

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