Using ecFlowUI via the ECMWF Teleport gateway

You can use the native ecFlowUI client on your End User device to access remote servers via an SSH tunnel. The recommended way is using dynamic port forwarding.

Dynamic port forwarding

Authenticate via teleport

First you need to authenticate via Teleport on your End User device.

Set up dynamic port forwarding

The next step is to start dynamic port forwarding using the SOCKS (Secure Socket) protocol. Let us suppose the target host you want to access is hpc-login. In a terminal on your End User device type:

ssh -v -C -N -D 9050 -J myecuser@jump.ecmwf.int myecuser@hpc-login

and keep it running. This will forward all network traffic from local port 9050 to the target SOCKS host (hpc-login). The proxy jump option (-J) was chosen according to the Teleport setup. The port does not have to be 9050, but this is the default port used by the proxychains tool (see below) so it is the most convenient option for us.

Run ecFlowUI via proxychains

Applications which want to use dynamic port forwarding must speak SOCKS protocol. ecFlowUI can be SOCKS-ified using a third party tool called proxychains.

Installing proxychains

You need to install proxychains in your  End User device. On MacOS, you can do it with "brew install proxychains-ng". Some Linux distributions come with proxychains tool pre-installed.

Start ecFLowUI

Start ecFlowUI with this command if you are using version >= 5.9.0:

ecflow_ui -pc4

otherwise you need to use the -cmd flag:

ecflow_ui -cmd proxychains4

ecFlowUI is now behaving (in terms of client/server communication) as if it were running on the SOCKS host (hpc-login in this case) and you should be able to interact with all the ecFlow servers available from that host.

Local file access via proxychains (only in version >= 5.9.0)

ecFlowUI accesses certain local files (e.g. output and server logs in the Output, Timeline and Server Load panels) directly (standard file I/O) without using the ecFlow client-server communication. This poses a limitation if we run it via proxychains because these files are only local on the remote hosts so ecFlowUI cannot access them. To overcome this difficulty you need to use ecFlowUI version >= 5.9.0 and file fetching will automatically work for you. The only settings that you might need to change is the SOCKS port number, which by default is assumed to be 9050.  Should you set up dynamic port forwarding and use proxychains with a different port number you need to set it in Tools > Preferences > Network:

System server lists via proxychains (only in version >= 5.9.0)

When using ecflowUI outside ECMWF the system server list files are not automatically accessible and you need to configure them manually. However, when it is done they will automatically transferred from the remote SOCKS host and loaded on each start-up. To define the system server lists probably the best option is to set Tools > Preferences > Server settings > System server list. The paths specified here have to be local paths on the remote SOCKS host.  

Alternatively, you can use the ECFLOW_SYSTEM_SERVERS_LIST environment variable to specify the very same paths.

Comments

• the dynamic port forwarding sometimes stops/hangs and as a result ecFlowUI loses connection to the servers (it is indicated by the orange strip on the left and the dotted background):

If it happens just go to the terminal where the dynamic port forwarding was started up, terminate it if it still running and run the command again. You do not need to exit ecflowUI, just refresh the servers and the connection will be re-established.