with two consecutive ssh authentications I mean the following:
I ssh to remote system A
from remote system A, I ssh to remote system B
There is no way to ssh to B directly.
I have no problems mounting directories from A using sshfs.
I thought about mounting directories from B on A but unfortunately A does not have sshfs installed. Even if, I would not know if it works.
Is there maybe another way to access directories on B in a convenient way?
My ~/.ssh/config looks like this now:
Host A
User user
HostName A.example.com
ControlMaster auto
ControlPath ~/.ssh/%r#%h:%p
Host B
User user
HostName B.example.com
ProxyCommand ssh -W %h:%p A
How would my sshfs command look like?
This does not work:
sshfs -o allow_other,defer_permissions -o user#B.example.com:/somedir ~/somedir
It outputs the error message:
remote host has disconnected
Use ProxyCommand or ProxyJump to do that transparently for the end application (sshfs). For example in ~/.ssh/config
Host A
# other configuration options needed
Host B
ProxyCommand ssh -W %h:%p A
Then you should be able to use sshfs transparently by directly specifying host B.
Related
Introduction. My work computer (PC-B) is accessible only from inside the network (PC-A) and I can connect to PC-B via SSH in one command: ssh -J user#PC-A user#PC-B.
Problem. I need to copy folders from remote PC-B to my local drive.
I tried:
(a) from my local PC: scp -r user#PC-A user#PC-B:/path/to/folder /home/ but it does not work.
(b) while remotely connected to PC-B: scp path/to/folder userHome#PC-HOME - connection timed out.
Is there any simple solution?
You can use ProxyJump directly in the scp command:
scp -r -o 'ProxyJump user#PC-A' user#PC-B:/path/to/folder /home/
You can also create an alias in ~/.ssh/config and do not type address
of the proxy server each time:
Host PC-A-alias
User user
Hostname PC-A
Host PC-B-alias
User user
Hostname PC-B
ProxyJump PC-A-alias
Now you can just use PC-B-alias with ssh, scp and other commands that use SSH such as rsync.
Is it possible to use Kubespray with Bastion but on custom port and with agent forwarding? If it is not supported, what changes does one need to do?
Always, since you can configure that at three separate levels: via the host user's ~/.ssh/config, via the entire playbook with group_vars, or as inline config (that is, on the command line or in the inventory file).
The ssh config is hopefully straightforward:
Host 1.2.* *.example.com # or whatever pattern matches the target instances
ProxyJump someuser#some-bastion:1234
# and then the Agent should happen automatically, unless you mean
# ForwardAgent yes
I'll speak to the inline config next, since it's a little simpler:
ansible-playbook -i whatever \
-e '{"ansible_ssh_common_args": "-o ProxyJump=\"someuser#jump-host:1234\""}' \
cluster.yaml
or via the inventory in the same way:
master-host-0 ansible_host=1.2.3.4 ansible_ssh_common_args="-o ProxyJump='someuser#jump-host:1234'"
or via group_vars, which you can either add to an existing group_vars/all.yml, or if it doesn't exist then create that group_vars directory containing the all.yml file as a child of the directory containing your inventory file
If you have more complex ssh config than you wish to encode in the inventory/command-line/group_vars, you can also instruct the ansible-invoked ssh to use a dedicated config file via the ansible_ssh_extra_args variable:
ansible-playbook -e '{"ansible_ssh_extra_args": "-F /path/to/special/ssh_config"}' ...
In my case where I needed to access the hosts on particular ports, I just had to modify the host's ~/.ssh/config to be:
Host 10.40.45.102
ForwardAgent yes
User root
ProxyCommand ssh -W %h:%p -p 44057 root#example.com
Host 10.40.45.104
ForwardAgent yes
User root
ProxyCommand ssh -W %h:%p -p 44058 root#example.com
Where 10.40.* was the internal IPs.
I am running Ansible on my machine. And my machine does not have ssh access to the remote machine. Port 22 connection originating from local machine are blocked by the institute firewall. But I have access to a machine (ssh-tunnel), through which I can login to the remote machine. Now is there a way we can run ansible playbook from local machine on remote hosts.
In a way is it possible to make Ansible/ssh connect to the remote machine, via ssh-tunnel. But not exactly login to ssh-tunnel. The connection will pass through the tunnel.
Other way is I can install ansible on ssh-tunnel, but that is not the desired and run plays from there. But that would not be a desired solution.
Please let me know if this is possible.
There are two ways to achieve this without install the Ansible on the ssh-tunnel machine.
Solution#1:
Use these variables in your inventory:
[remote_machine]
remote ansible_ssh_host=127.0.0.1 ansible_ssh_port=2222 ansible_ssh_user='username' ansible_ssh_private_key_file='/home/user/private_key'
hope you understand above parameters, if need help please ask in comments
Solution#2:
Create ~/.ssh/config file and add the following parameters:
####### Access to the Private Server through ssh-tunnel/bastion ########
Host ssh-tunnel-server
HostName x.x.x.x
StrictHostKeyChecking no
User username
ForwardAgent yes
Host private-server
HostName y.y.y.y
StrictHostKeyChecking no
User username
ProxyCommand ssh -q ssh-tunnel-server nc -q0 %h %p
Hope that help you, if you need any help, feel free to ask
No request to install ansible on the jump and remote servers, ansible is ssh service only tool :-)
First make sure you can work it directly with SSH Tunnel.
On local machine (Local_A), you can login to Remote machine (Remote_B) via jump box (Jump_C).
login server Local_A
ssh -f user#remote_B -L 2000:Jump_C:22 -N
The other options are:
-f tells ssh to background itself after it authenticates, so you don't have to sit around running something on the remote server for the tunnel to remain alive.
-N says that you want an SSH connection, but you don't actually want to run any remote commands. If all you're creating is a tunnel, then including this option saves resources.
-L [bind_address:]port:host:hostport
Specifies that the given port on the local (client) host is to be forwarded to the given host and port on the remote side.
There will be a password challenge unless you have set up DSA or RSA keys for a passwordless login.
There are lots of documents teaching you how to do the ssh tunnel.
Then try below ansible command from Local_A:
ansible -vvvv remote_B -m shell -a 'hostname -f' --ssh-extra-args="-L 2000:Jump_C:22"
You should see the remote_B hostname. Let me know the result.
Let's say you can ssh into x.x.x.x from your local machine, and ssh into y.y.y.y from x.x.x.x, while y.y.y.y is the target of your ansible playbook.
inventory:
[target]
y.y.y.y
playbook.yml
---
- hosts: target
tasks: ...
Run:
ansible-playbook --ssh-common-args="-o ProxyCommand='ssh -W %h:%p root#x.x.x.x'" -i inventory playbook.yml
I would like to use a ssh_config file instead of the traditional ~/.ssh/config. I have a simple configuration for accessing hosts through a bastion host (on port 23 for example).
ssh_config :
host bastion
hostname bastion.mydomain.com
port 23
host *.server
proxycommand ssh -W %h:%p bastion
ssh -F ssh_config test.server is not working and throw me "ssh: Could not resolve hostname bastion: Name or service not known".
But, if put this config in ~/.ssh/config, then ssh test.server works.
As I understand it, the proxycommand is unable to use the config file given in the command line.
If I want my command line config file to work, I need to put
proxycommand ssh -W %h:%p bastion.mydomain.com -p 23
but this seems to violate a simple DRY principle (the port and the domain are repeated). The config file I'm willing to build is much much longer and complex.
Is there a good way to achieve what I want, i.e. a simple, non-repeating, config file usable in command line for which proxycommand works ?
Half of an answer:
Rather than using the config file recursively, try not relying on the config at all for the proxy command.
host *.server
proxycommand ssh -W %h:%p bastion.mydomain.com -p 23
This allows it to be portable, but doesn't solve your other issue of having to do this on every line, and makes changing the bastion host address a difficult process.
you need to pass proxycommand ssh -W %h:%p bastion -F [your custom ssh config]
I currently have to SSH 3 times to get into the machine I need:
ssh gatekeeper
[passwd1]
ssh master_server
[passwd2]
ssh my_machine
[passwd3]
Is there a better way to do get into my_machine? Pretty cumbersome to have to do it every time.
Nice - this worked:
Host my_machine
Hostname my_machine
ProxyCommand ssh user2#master_server -W %h:%p
ProxyCommand ssh user1#gatekeeper -W %h:%p
I don't really know for 3 SSH, but here is my way for 2 (lets say : me -> master_server -> my_machine).
You need to add a configuration file in your home :
~/.ssh/config
Then you write in that file :
Host my_machine
Hostname my_machine.example.com
ProxyCommand ssh other_or_same_login#master_server -W %h:%p
And you call
ssh login#my_machine
Then you will have to enter twice your password (or 3 times in your case). If you don't want to type passwords, you can use the key access option.
For another ssh, I guess you need to write another section in the config file, but since I can't try I don't wan't to say something wrong.
Hope this helps.