Smart way to copy multiple files from different paths using scp [duplicate] - ssh

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scp or sftp copy multiple files with single command
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I would like to know an easy way to use scp to copy files and folders that are present in different paths on my file system. The SSH destination server requests a password and I cannot put this in configuration files. I know that scp doesn't have a password parameter that I could supply from a script, so for now I must copy each file or directory one by one, writing my password every time.

in addition to the already mentioned glob:
you can use {,} to define alternative paths/pathparts in one single statement
e.g.: scp user#host:/{PATH1,PATH2} DESTINATION

From this site:
Open the master
SSHSOCKET=~/.ssh/myUsername#targetServerName
ssh -M -f -N -o ControlPath=$SSHSOCKET myUsername#targetServerName
Open and close other connections without re-authenticating as you like
scp -o ControlPath=$SSHSOCKET myUsername#targetServerName:remoteFile.txt ./
Close the master connection
ssh -S $SSHSOCKET -O exit myUsername#targetServerName
It's intuitive, safer than creating a key pair, faster than creating a compressed file and worked for me!

If you can express all the names of the files you want to copy from the remote system using a single glob pattern, then you can do this in a single scp command. This usage will only support a single destination folder on the local system for all files though. For example:
scp 'RemoteHost:/tmp/[abc]*/*.tar.gz' .
copies all of the files from the remote system which are names (something).tar.gz and which are located in subdirectories of /tmp whose names begin with a, b, or c. The single quotes are to protect the glob pattern from being interpreted from the shell on the local system.
If you cannot express all the files you want to copy as a single glob pattern and you still want the copy to be done using a single command (and a single SSH connection which will ask for your passsword only once) then you can either:
Use a different command than scp, like sftp or rsync, or
Open an SSH master connection to the remote host and run several scp commands as slaves of that master. The slaves will piggyback on the master connection which stays open throughout and won't ask you for a password. Read up on master & slave connections in the ssh manpage.

create a key pair, copy the public key to the server side.
ssh-keygen -t rsa
Append content inside the file ~/.ssh/identity.pub to file ~/.ssh/authorized_keys2 of server side user. You need not to type password anymore.
However, be careful! anybody who can access your "local account" can "ssh" to the server without password as well.

Alternatively, if you cannot use public key authentication, you may add the following configuration to SSH (either to ~/.ssh/config or as the appropriate command-line arguments):
ControlMaster auto
ControlPath /tmp/ssh_mux_%h_%p_%r
ControlPersist 2m
With this config, the SSH connection will be kept open for 2 minutes so you'll only need to type the password the first time.
This post has more details on this feature.

Related

Where do I find the spec for scp -t?

So I have discovered I can do the following with scp via stdin:
Directory creation
scp -tr .
stdin -> D0755 0 <directory_name>
stdin -> \x00
File writing
scp -tr .
stdin -> C<filemode, eg. 0744> <file_size_in_bytes> <filename>
stdin -> actual file bytes
stdin -> \x00
In the man pages I can't find any mention of this, nor have I had luck with googling. Where do I find the spec for these various commands: file creation, directory creation? What else can I do? I'm curious where this is defined. I'm struggling to find where I even found this code initially. Why is there no mention of the -t flag in the scp man page?
scp transfers files by opening an SSH connection to a remote server and invoking another copy of scp on the remote system. The two scp instances communicate through a simple protocol; one instance sends commands and file data; the other instance acts on the commands to store the files on its local system.
The -t option tells scp that it was invoked by another scp instance and that it'll be receiving files. There is another option -f which tells scp that it was invoked by another instance and should send files.
You'd have to ask the OpenSSH developers why the options aren't documented. One might presume that it's because they're not intended for use by humans and so not really part of the user interface.
The best online descriptions of the SCP protocol that I know of are:
How the SCP protocol works
Ruby net-scp source code
OpenSSH scp source code

SSH from Synology NAS to remote server

When I run competitions for Icelandic Horses, I want to automatically upload the results from our Synology NAS to a remote webserver. The program we use automatically generates the html-files that needs to be uploaded.
What is the easiest way to achieve this? I have SSH access on both the NAS and the webserver.
Any help is appreciated :)
In this case you can create a cron task in the synology console with the command:
sudo -i
vi /etc/crontab
Edit the file and add a line like this at the end of the file with a scp command:
0 0 * * * root scp -r "-i/root/.ssh/mykey" 'root#serverurl.com:/some/remote/path' '/some/local/path'
Finally you have to reload the configuration restarting the service with:
synoservice -restart crond
Before all this you must to configure a pair keys to avoid the password entry:
cd to a private directory of the user which will be running the script (typically "$HOME/.ssh", to be created if needed). That directory must be protected to write acces from other users, fix the modes if needed.
generate the keypair using command "ssh-keygen"
("/usr/syno/bin/ssh-keygen" if not in your PATH)
at the prompt "Enter file in which to save the key", choose a file
name (let's say "mykey")
at the prompt "Enter passphrase (empty for no passphrase):" press
return (this will create a passwordless private key)
Two files will be created: "mykey" and "mykey.pub"
copy the contents of mykey.pub inside "$HOME/.ssh/authorized_key"
file of user account on the remote machine your script is going to
connect to.
in your script, add "-i" as argument to the
ssh command
Also in this forum is explained how to make the copy with rsync instead of scp

Connect through ssh and scp and type in password automatically

I know this question has already been asked several times but I got another problem. I have a part in my script where I connect through ssh and scp and everytime I run the script it always ask for the password. Most of you would probably answer that I should use expect or sshpass yet I don't have any of this two. I tried running:
compgen -c
and there's no expect and sshpass existing.
Are there any alternative commands? I would really appreciate your help. Thanks
Update: I also can't install any of this since I'm only an ordinary user.
First I logged in to server A as testuser and entered the ff command:
ssh-keygen -d
Do not enter any passphrase.
This will generate files in the folder ~/.ssh/
Then scp the file rsa_id.pub (public key) to server B.
scp ~/.ssh/id_dsa.pub testuser#B:/home/testuser/.ssh/authorized_keys2
Do the same vice versa (if you want access to both). Then you can now transfer from one server to the other without the being asked for your password.
source
If you don't want to set up keys for passwordless access (against the rules?), you can set up "SSH connection sharing".
Insert these lines into your .ssh/config file:
ControlMaster auto
ControlPath /tmp/ssh_%r#%n:%p
ControlPersist 8h
Now, when you log into a server from the machine with that config it will ask you your password the first time, and won't ask again until 8 hours of idle time have passed (so, you'll get asked once per day, usually).
What it's doing is keeping the connection open in the background, and then reusing the same connection for all your SSH sessions. This gives a useful connect-speed boost, and means you don't need to re-authenticate. All-in-all, it's great for accelerating scripted SSH and SCP commands.

cp: cannot create regular file ‘Users/James/Desktop’: No such file or directory

I'm trying to copy a file from a remote server to my desktop and i'm getting the above error. I've SSH'd to the server.
Here is what i'm doing:
deploy#ip-10-91-135-76 /data/project/current/lib/data $ scp customer_record.ods /Users/James/Desktop
I have very limited experience and don't understand what is going on?
Thanks a lot
man scp tells you how to use scp. In particular, most usages look like:
scp [user1#]host1:]file1 [[user2#]host2:]file2
You can omit putting the user in if its the same as your current user, and likewise for the host. Since you've SSH'd onto the server already, the start of your command is okay to be scp customer_records.ods, but the next argument has to include the user name and host of the target machine that you want to copy the file to, namely your home computer. Chances are you actually want to go the other way, since your home computer may not have a publicly accessible IP.
End the SSH session, go back to your home machine.
Do:
scp <user-you-sshd-as>#<server-you-sshd-to>:/data/project/current/lib/data/customer_records.ods /Users/James/Desktop
If you need to specify a private key, you can use the -i option: scp -i <path-to-key> ...

Automatically cd to a given remote path when connecting via ssh

I have a bunch of remote servers that I regularly connect to via ssh; which I've setup in my ~/.ssh/config file. I was wondering if it was possible to specify a remote path to cd to when I connect to some of these servers?
For example, I may have something like this in my config file:
Host testbox
HostName 192.123.456.789
User root
And when I ssh in to testbox, I'd like to also cd to /var/www/apps/myapp.
I've had a look around but cannot see an option that would do that via the .ssh/config file.
Cheers,
Diego
You can do this with a tool I've open sourced that allows you to SSH and CD – aptly named sshcd. For the example you've given, you'd simply use:
sshcd root#testbox:/var/www/apps/myapp
Hope this helps!
There's an option in the authorized_keys file.
Do a man on sshd, look under the heading "AUTHORIZED_KEYS FILE FORMAT". You can add various options to each authorized key - one is command="command". As the manpage says, "Specifies that the command is executed whenever this key is used for authentication."