Need to reach phpMyAdmin on an EC2 instance behind a bastion/jumpserver from local laptop.
Looking to reduce these steps into using .shh/config. The question seeks to solve the right configurations.
When connecting to EC2 without public bastion server to jump through, this is the normal way documented which does not work in my case because our deployment uses a public facing bastion:
https://docs.bitnami.com/aws/faq/get-started/access-phpmyadmin/
When you need to jump through a public facing bastion e.g.:
Local/Laptop ------> bastion/jumpserver -----> ec2
This above reference link does not follow the same workflow and documentation is sparse.
Setting up inbound/outbound rules for this capability is also sparse.
The preference is to use .ssh/config which is setup like this:
Host bastionHostTunnel
Hostname <publicBastionIp>
User <bastionusername>
ForwardAgent yes
IdentityFile <local path to .pem file>
Host ec2Host
Hostname <privateEC2IP>
User <ec2 username>
ForwardAgent yes
IdentityFile <local path to .pem file>
# -A Enable forwarding of the Authentication agent connection
# -W used on older machines instead of -J to bounce through
# %h the remote hostname
# On Windows 10(only?) seems must call ssh.exe instead of only ssh
ProxyCommand ssh.exe -A -W %h:22 bastionHostTunnel
I obviously left out vars in <> above - but I have them and have verified similar configuration is working for enabling SFTP as above with FileZilla.
Then in shell call this to bind port localhost:8888 (http://127.0.0.1:8888):
ssh ec2Host -D 8888
Then ought to be able to open browser and go to the following to access phpMyAdmin:
http://127.0.0.1:8888/phpmyadmin
Current issue is that this process is hanging and possibly refusing the connection. This points to either bad configuration above or incorrect inbound/outbound rules for either/both bastion and ec2 instance.
Has anyone here had similar issue and was able to solve and could share further, much appreciated. Plus any extra clues as far as debugging the overall process would help in the answer.
I'm most curious if it works if you specific everything on the command line...once you determine that works, you can start refactoring to put some aspects in to .ssh/config. It's usually easier for me to find errors with my configuration if everything is on the command line, plus I don't know that I see the correct forwarding options all listed there.
Unless I'm very mistaken, you don't need any reference to the ec2 host in your SSH config file because you're using the jump machine to redirect localhost traffic there, you wouldn't directly be able to reach the ec2 host machine from your local machine using an SSH tunnel.
There are many ways to do a tunnel, but when I do this, I use a command like ssh -L 8080:destination:80 -i <keyfile> me#jumpbox . destination must be reachable from jumpbox, which I can verify by first using ssh -i <keyfile> jumpbox then, once on that machine, ssh destination. If there's a problem along the way, it's easier to debug these little steps (for instance, if I can't connect by manual ssh to jumpbox then I know the tunnel will never work).
I´ve got a Server behind a firewall and the firewall only allows traffic through port 22. This server has both public and private addresses.
I´ve got also about 1K clients that I need to reverse shell to this server, and be able to choose one of them by id when I want that ssh reversed tunnel.
My goal is to make the clients connect to ssh server via port 22, and each one of this connections should be forwarded to localhost on port with the same id.
When I connect to the server with my laptop also via ssh, I would then ssh to localhost on the correct id and get the client shell.
Can someone provide me the good path to achieve this behaviour using bash, ssh and linux tools?
Note - I don´t want to use client.py and server.py cause most of my clients are android based and it could easily become a nightmare to install python on all of them.
The problem - it was solved using remote port forwarding:
ssh -R 21:localhost:8888 user#server
In this command the 8888 represents the terminal id. In order for this to work, had to add this line to my ssh conf:
GatewayPorts yes
Using ubuntu tusty, there is a service running on a remote machine, that I can access via port forwarding through an ssh tunnel from localhost:9999.
I have a docker container running. I need to access that remote service via the host's tunnel, from within the container.
I tried tunneling from the container to the host with -L 9000:host-ip:9999 , then accessing the service through 127.0.0.1:9000 from within the container fails to connect. To check wether the port mapping was on, I tried
nc -luv -p 9999 # at host
nc -luv -p 9000 # at container
following this, parag. 2 but there was no perceived communication, even when doing
nc -luv host-ip -p 9000
at the container
I also tried mapping the ports via docker run -p 9999:9000 , but this reports that the bind failed because the host port is already in use (from the host tunnel to the remote machine, presumably).
So my questions are
1 - How will I achieve the connection? Do I need to setup an ssh tunnel to the host, or can this be achieved with the docker port mapping alone?
2 - What's a quick way to test that the connection is up? Via bash, preferably.
Thanks.
Using your hosts network as network for your containers via --net=host or in docker-compose via network_mode: host is one option but this has the unwanted side effect that (a) you now expose the container ports in your host system and (b) that you cannot connect to those containers anymore that are not mapped to your host network.
In your case, a quick and cleaner solution would be to make your ssh tunnel "available" to your docker containers (e.g. by binding ssh to the docker0 bridge) instead of exposing your docker containers in your host environment (as suggested in the accepted answer).
Setting up the tunnel:
For this to work, retrieve the ip your docker0 bridge is using via:
ifconfig
you will see something like this:
docker0 Link encap:Ethernet HWaddr 03:41:4a:26:b7:31
inet addr:172.17.0.1 Bcast:172.17.255.255 Mask:255.255.0.0
Now you need to tell ssh to bind to this ip to listen for traffic directed towards port 9000 via
ssh -L 172.17.0.1:9000:host-ip:9999
Without setting the bind_address, :9000 would only be available to your host's loopback interface and not per se to your docker containers.
Side note: You could also bind your tunnel to 0.0.0.0, which will make ssh listen to all interfaces.
Setting up your application:
In your containerized application use the same docker0 ip to connect to the server: 172.17.0.1:9000. Now traffic being routed through your docker0 bridge will also reach your ssh tunnel :)
For example, if you have a "DOT.NET Core" application that needs to connect to a remote db located at :9000, your "ConnectionString" would contain "server=172.17.0.1,9000;.
Forwarding multiple connections:
When dealing with multiple outgoing connections (e.g. a docker container needs to connect to multiple remote DB's via tunnel), several valid techniques exist but an easy and straightforward way is to simply create multiple tunnels listening to traffic arriving at different docker0 bridge ports.
Within your ssh tunnel command (ssh -L [bind_address:]port:host:hostport] [user#]hostname), the port part of the bind_address does not have to match the hostport of the host and, therefore, can be freely chosen by you. So within your docker containers just channel the traffic to different ports of your docker0 bridge and then create several ssh tunnel commands (one for each port you are listening to) that intercept data at these ports and then forward it to the different hosts and hostports of your choice.
on MacOS (tested in v19.03.2),
1) create a tunnel on host
ssh -i key.pem username#jump_server -L 3336:mysql_host:3306 -N
2) from container, you can use host.docker.internal or docker.for.mac.localhost or docker.for.mac.host.internal to reference host.
example,
mysql -h host.docker.internal -P 3336 -u admin -p
note from docker-for-mac official doc
I WANT TO CONNECT FROM A CONTAINER TO A SERVICE ON THE HOST
The host has a changing IP address (or none if you have no network access).
From 18.03 onwards our recommendation is to connect to the special DNS
name host.docker.internal, which resolves to the internal IP address
used by the host. This is for development purpose and will not work in
a production environment outside of Docker Desktop for Mac.
The gateway is also reachable as gateway.docker.internal.
I think you can do it by adding --net=host to your docker run. But see also this question: Forward host port to docker container
I'd like to share my solution to this. My case was as follows: I had a PostgreSQL SSH tunnel on my host and I needed one of my containers from the stack to connect to a database through it.
I spent hours trying to find a solution (Ubuntu + Docker 19.03) and I failed. Instead of doing voodoo magic with iptables, doing modifications to the settings of the Docker engine itself I came up with a solution and was shocked I didn't thought of this earlier. The most important thing was I didn't want to use the host mode: security first.
Instead of trying to allow a container to talk to the host, I simply added another service to the stack, which would create the tunnel, so other containers could talk to easily without any hacks.
After configuring a host inside my ~/.ssh/config:
Host project-postgres-tunnel
HostName remote.server.host
User sshuser
Port 2200
ForwardAgent yes
TCPKeepAlive yes
ConnectTimeout 5
ServerAliveCountMax 10
ServerAliveInterval 15
And adding a service to the stack:
postgres:
image: cagataygurturk/docker-ssh-tunnel:0.0.1
volumes:
- $HOME/.ssh:/root/ssh:ro
environment:
TUNNEL_HOST: project-postgres-tunnel
REMOTE_HOST: localhost
LOCAL_PORT: 5432
REMOTE_PORT: 5432
# uncomment if you wish to access the tunnel on the host
#ports:
# - 5432:5432
The PHP container started talking through the tunnel without any problems:
postgresql://user:password#postgres/db?serverVersion=11&charset=utf8
Just remember to put your public key inside that host if you haven't already:
ssh-copy-id project-postgres-tunnel
I'm pretty sure this will work regardless of the OS used (MacOS / Linux).
I agree with #hlobit that #B12Toaster answer should be the accepted answer.
In case anyone hits this problem but with a slightly different setup with the SSH tunnel, here are my findings. In my case, instead of creating a tunnel from Docker host machine to remote machine using ssh -L, I was creating remote forward SSH tunnel from remote machine to Docker host machine using ssh -L.
In this setup, by default sshd does NOT allow gateway ports, i.e. in file /etc/ssh/sshd_config on Docker host, the GatewayPorts no should be uncommented and set to GatewayPorts yes or GatewayPorts clientspecified. I configured GatewayPorts clientspecified and configured the remote forward SSH tunnel by ssh -L 172.17.0.1:dockerHostPort:localhost:sshClientPort user#dockerHost. Remember to restart sshd after changing /etc/ssh/sshd_config (sudo systemctl restart sshd).
Your Docker container should be able to connect to Docker host on 172.17.0.1:dockerHostPort and this in turn gets tunnelled back to SSH client's localhost:sshClientPort.
References:
https://www.ssh.com/ssh/tunneling/example
https://docs.docker.com/network/network-tutorial-host/
https://docs.docker.com/network/host/
My 2 cents for Ubuntu 18.04 - a very simple answer, no need for extra tunnels, extra containers, extra docker options or exposing host.
Simply, when creating a reverse tunnel make sure ssh binds to all interfaces as, by default, it binds ports of the reverse tunnel to localhost only. For example, in putty make sure that option Connection->SSH->Tunnels Remote ports do the same (SSH-2 only) is ticked.
This is more or less equivalent to specifying the binding address 0.0.0.0 for the remote part of the tunnel (more details here):
-R [bind_address:]port:host:hostport
However, this did not work for me unless I allowed the GatewayPorts option in my sshd server configuration. Many thanks to Stefan Seidel for his great answer.
In short: (1) you bind the reverse tunnel to 0.0.0.0, (2) you let the sshd server to accept such tunnels.
Once this is done I can access my remote server from my docker containers via the docker gateway 172.17.0.1 and port bound to the host.
On my side, running Docker in Windows Subsystem for Linux (WSL v1), I couldn't use docker0 connection approach. host.docker.internal also doesn't resolve (latest docker version).
However, I found out I could directly use the host-ip insider my docker container.
Get your Host IP (Windows cmd: ipconfig), e.g. 192.168.0.5
Bash into your Container and test if you can ping your host ip:
- docker exec -it d6b4be5b20f7 /bin/bash
- apt-get update && apt-get install iputils-ping
- ping 192.168.0.5
PING 192.168.0.5 (192.168.0.5) 56(84) bytes of data.
64 bytes from 192.168.0.5 : icmp_seq=1 ttl=37 time=2.17 ms
64 bytes from 192.168.0.5 : icmp_seq=2 ttl=37 time=1.44 ms
64 bytes from 192.168.0.5 : icmp_seq=3 ttl=37 time=1.68 ms
Apparently, in Windows, you can directly connect from within containers to the host using the official host ip.
In case anyone needs it (like I did), solution for Windows and WSL is same as #prayagupd mentioned for Mac OS
Create an SSH tunnel to your remote service with whatever tool you prefer to whatever port you prefer, for example 3300.
Then, from Docker container you can connect to, for example, MySQL DB on tunnel port 3300 using following command:
mysql -u user -p -h host.docker.internal -P 3300
An easy example to reproduce the situation and ssh to host
Run a container. Use --network="host
docker container run --network="host" --interactive --tty --rm ubuntu bash
Now you can access your host using localhost
Now your host machine is a Linux machine that has a public-private key file to ssh into it. So copy the contents of your private key file and reproduce the key file inside your host. (However, this is just a demonstration. This is not a good way to copy key files)
Now ssh into your host. Use localhost to access it.
ssh -i key_file.pem ec2-user#localhost
I am trying to run putty on Windows 7.
I need to run some SSH commands to upgrade Magento. Every time putty gives me this fatal error:
network error: connection refused
I have even tried to use it through winSCP. Note that putty is running fine on my client's side, but for me it's giving me that error every time.
I tried using port 22, 23 and a few others without success. I have also tried with Windows Firewall both enabled and disabled.
Thank you.
Install open-ssh or ssh in target Linux machine solved my problem .
Use below commands:
sudo apt install ssh
sudo systemctl status ssh
sudo systemctl enable ssh
The following are the list of possibilities of this error:
1) Common cause is - Your IP is blocked or not whitelisted in the server which can be done by editing the file at /etc/csf/csf.conf
2) Disable the windows firewall settings and check..
The above two things should work in most of the cases
3) This is very unusual and when the above two options fails it is very difficult to find the solution
In this case the traceroute to the server host or IP works usually but putty fails
port 22 looks normal and working but connection fails and restarting SSH (service ssh restart) also does not work
reboot or restart the server but still fails
Adding IP in firewalls or whitelisting the local IP may not workout
This case generally happens when the server is migrated or new server. IP of the old server might be whitelisted locally, but don't have port 22 open, or some other local filtering is occurring for this new IP but not the old server IP..
In this case you need to change the port to some 522 or 530 some unusual port will help in sorting it out.. The same port you have to use for the SFTP connection also .. where as FTP connections works normally..
or you have to whitelist the IP locally or open the TCP in and out to port 22 if you want to use the port 22..
I'm trying to get Hadoop's Pseudo-Distributed Operation example (http://hadoop.apache.org/common/docs/stable/single_node_setup.html) to work on OS X Lion, but am having trouble getting the ssh to work without a passphrase.
The instructions say the following:
Setup passphraseless ssh
Now check that you can ssh to the localhost without a passphrase: $
ssh localhost
I'm getting connection refused:
archos:hadoop-0.20.203.0 travis$ ssh localhost
ssh: connect to host localhost port 22: Connection refused
If you cannot ssh to localhost without a passphrase, execute the
following commands:
$ ssh-keygen -t dsa -P '' -f ~/.ssh/id_dsa
$ cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
After this step I am still getting connection refused. Any ideas???
Sounds like you don't have SSH enabled. Should be in the network settings control panel somewhere.
You go to "System Preferences > Sharing > Remote Access" and there's a list of authorized users. Change it to "All Users".
That's solves this problem.
Check the permissions on your .ssh directory. Some ssh implementations require that the directory be chmod 700. Otherwise, they just ignore it.
Also, check the output of
ssh -v localhost
to see how the ssh client is trying to connect. The output is very detailed, and will help you decide if it's an authentication problem.
I had the same issue.
Please check if the ssh server is running or not.
If yes, open the /etc/init.d/ssh_config and /etc/init.d/sshd_config files. The issue is that the server is running on a different port and the client is pointing to different port.
Before this please ensure that openssh-server and client are installed.
I had the same problem and i solved it the following manner :
SSH is activated.
ssh -v localhost (as stated by Herko)
In the ouput, i identified that the authentication method by DSA is not supported.
debug1: Skipping ssh-dss key /Users/john/.ssh/id_dsa - not in PubkeyAcceptedKeyTypes
I simply re-generate an ECDSA keys and remove the DSA key pairs.
After the keys generation, the procedure given on Hadoop documentation holds.
Therefore, it is important to check, if the authentication method is supported by the Openssh configuration.