I wonder if there is a way for me to SCP the file from remote2 host directly from my local machine by going through a remote1 host.
The networks only allow connections to remote2 host from remote1 host. Also, neither remote1 host nor remote2 host can scp to my local machine.
Is there something like:
scp user1#remote1:user2#remote2:file .
First window: ssh remote1, then scp remot2:file ..
Second shell: scp remote1:file .
First window: rm file; logout
I could write a script to do all these steps, but if there is a direct way, I would rather use it.
Thanks.
EDIT: I am thinking something like opening SSH tunnels but i'm confused on what value to put where.
At the moment, to access remote1, i have the following in $HOME/.ssh/config on my local machine.
Host remote1
User user1
Hostname localhost
Port 45678
Once on remote1, to access remote2, it's the standard local DNS and port 22. What should I put on remote1 and/or change on localhost?
I don't know of any way to copy the file directly in one single command, but if you can concede to running an SSH instance in the background to just keep a port forwarding tunnel open, then you could copy the file in one command.
Like this:
# First, open the tunnel
ssh -L 1234:remote2:22 -p 45678 user1#remote1
# Then, use the tunnel to copy the file directly from remote2
scp -P 1234 user2#localhost:file .
Note that you connect as user2#localhost in the actual scp command, because it is on port 1234 on localhost that the first ssh instance is listening to forward connections to remote2. Note also that you don't need to run the first command for every subsequent file copy; you can simply leave it running.
Double ssh
Even in your complex case, you can handle file transfer using a single command line, simply with ssh ;-)
And this is useful if remote1 cannot connect to localhost:
ssh user1#remote1 'ssh user2#remote2 "cat file"' > file
tar
But you loose file properties (ownership, permissions...).
However, tar is your friend to keep these file properties:
ssh user1#remote1 'ssh user2#remote2 "cd path2; tar c file"' | tar x
You can also compress to reduce network bandwidth:
ssh user1#remote1 'ssh user2#remote2 "cd path2; tar cj file"' | tar xj
And tar also allows you transferring a recursive directory through basic ssh:
ssh user1#remote1 'ssh user2#remote2 "cd path2; tar cj ."' | tar xj
ionice
If the file is huge and you do not want to disturb other important network applications, you may miss network throughput limitation provided by scp and rsync tools (e.g. scp -l 1024 user#remote:file does not use more than 1 Mbits/second).
But, a workaround is using ionice to keep a single command line:
ionice -c2 -n7 ssh u1#remote1 'ionice -c2 -n7 ssh u2#remote2 "cat file"' > file
Note: ionice may not be available on old distributions.
This will do the trick:
scp -o 'Host remote2' -o 'ProxyCommand ssh user#remote1 nc %h %p' \
user#remote2:path/to/file .
To SCP the file from the host remote2 directly, add the two options (Host and ProxyCommand) to your ~/.ssh/config file (see also this answer on superuser). Then you can run:
scp user#remote2:path/to/file .
from your local machine without having to think about remote1.
With openssh version 7.3 and up it is easy. Use ProxyJump option in the config file.
# Add to ~/.ssh/config
Host bastion
Hostname bastion.client.com
User userForBastion
IdentityFile ~/.ssh/bastion.pem
Host appMachine
Hostname appMachine.internal.com
User bastion
ProxyJump bastion # openssh 7.3 version new feature ProxyJump
IdentityFile ~/.ssh/appMachine.pem. #no need to copy pem file to bastion host
Commands to run to login or copy
ssh appMachine # no need to specify any tunnel.
scp helloWorld.txt appMachine:. # copy without intermediate jumphost/bastion host copy.**
ofcourse you can specify bastion Jump host using option "-J" to ssh command, if not configured in config file.
Note scp does not seems to support "-J" flag as of now. (i could not find in man pages. However above scp works with config file setting)
There is a new option in scp that add recently for exactly this same job that is very convenient, it is -3.
TL;DR For the current host that has authentication already set up in ssh config files, just do:
scp -3 remote1:file remote2:file
Your scp must be from recent versions.
All other mentioned technique requires you to set up authentication from remote1 to remote2 or vice versa, which not always is a good idea.
Argument -3 means you want to move files from two remote hosts by using current host as intermediary, and this host actually does the authentication to both remote hosts, so they don't have to have access to each other.
You just have to setup authentication in ssh config files, which is fairly easy and well documented, and then just run the command in TL;DR
The source for this answer is https://superuser.com/a/686527/713762
This configuration works nice for me:
Host jump
User username
Hostname jumphost.yourorg.intranet
Host production
User username
Hostname production.yourorg.intranet
ProxyCommand ssh -q -W %h:%p jump
Then the command
scp myfile production:~
Copies myfile to production machine.
a simpler way:
scp -o 'ProxyJump your.jump.host' /local/dir/myfile.txt remote.internal.host:/remote/dir
My goal is to be able to send a command to an old server that can only be
reached by going through the new server.
I want to be able to automate this as much as possible.
I want to be able to just run a script and it will do the work for me so
that I don't have to type.
Meaning I would have to do the following:
ssh user#newserver
and then
ssh user#oldserver
Once I reach the old server I need to be able to run
curl icanhazip.com
and
cat /var/spool/cron/user
So far I was only able to do the following:
ssh -t -t root#newserver "ssh root#oldserver"
That would only allow me to reach the server, but I would have to manually send other commands.
I would Ideally want to be able to run something like this:
ssh -t -t root#newserver 'ssh root#oldserver "cat /var/spool/cron/user"'
ssh -t -t root#newserver 'ssh root#oldserver "cat /var/spool/cron/user"'
This Actually worked. Not sure why it didn't before.
can be used postgres_fdw to connect via ssh tunnel?
The database is accessible only from the DB server, andI need to join from another remote server. The DB server log in with SSH keys.
If it's possible, how please?
Yes It is possible. I solved it for mysql_fdw like that;
I use autossh for port forwarding. With autossh, you can keep connection up all time.
Run command on Postgres server:
autossh -L 127.0.0.1:3306:mysql_ip:3306 root#mysql_ip -N -i .ssh/id_rsa.mysql
Test autossh access from Postgres to Mysql.
Run command on Postgres server;
mysql --host=127.0.0.1 --port=3306 -u mysqldbuser -p
Last different part is;
CREATE SERVER mysql_server FOREIGN DATA WRAPPER mysql_fdw OPTIONS (host '127.0.0.1', port '3306');
Other things are same.
The scenario is like:
SERVER_A="servera.com"
SERVER_A_UNAME="usera"
SERVER_B="serverb.com"
SERVER_B_UNAME="userb"
I want to write a shell script which will fist connect to server A, and then only it would be connected to server B. Like:
#!/bin/sh
ssh $SERVER_A_UNAME#$SERVER_A ...and then
ssh $SERVER_B_UNAME#$SERVER_B
But I am not able to do it. It does connect to server A only. How can I achieve it?
You may be able to find some help with this previous question:
How to use bash/expect to check if an SSH login works
Depending on your situation you might also to execute an remote ssh command and wait for positive feedback.
See:
How to use SSH to run a shell script on a remote machine?
you should have a look at ssh ProxyCommands that lets you do indirect connects automatically. basically you put the following in you .ssh/config
Host gateway1
# nichts
Host gateway2
ProxyCommand ssh -q gateway1 nc -q0 gateway2 22
Host targethost
ProxyCommand ssh -q gateway2 nc -q0 targethost 22
and then you can run ssh targethost successfully even if targethost is not reachable directly. you can read more about this e.g. here http://sshmenu.sourceforge.net/articles/transparent-mulithop.html
I have written a bash script which I should run on the remote server(ubuntu) with GUI(zenity) interface and I will issue below command on the local machine.
sshpass -p $PASS ssh root#$SERVER 'bash' < /tmp/dep.sh | tee >(zenity --progress --title "Tomcat Deployer" --text "Connecting to Tomcat Server..." --width=400 --height=150) >>/tmp/temp.log;
I want to transfer a file from my local machine to server and I want to achieve this placing an enter in bash file(/tmp/dep.sh) in the above command itself without opening a new session on server.
I prefer below command to transfer the file to server and I should place this in the bash script(/tmp/dep.sh) and it should run on server to copy the file from my local machine. I don't want to specify my local ip as a variable and use as source in the blow command as the script is used on other machines too and thus ip changes. And I should not transfer the file from my local to server writing a separate rsync & ssh creating one more ssh session.
rsync --rsh="sshpass -p '$PASS' ssh" '$local:$APPATH/$app.war' /tmp
Anybody can do any magic to transfer the file from local to server with the above connected ssh session with the help of above rsync or by other means and without opening new separate connection?
Thank you!
Edit 1:
Could this be achieved with single ssh session(single command)?:
rsync --rsh="sshpass -p serverpass ssh -o StrictHostKeyChecking=no" /home/user1/Desktop/app.war root#192.168.1.5:/tmp;
sshpass -p serverpass ssh -o StrictHostKeyChecking=no root#192.168.1.5 '/etc/init.d/tomcat start'
You'll want to use SSH multiplexing. This is done using the ControlMaster and ControlPath options. Here's an article on it.