Uploading files (scp) to a trusted cluster (reverse SSH tunnel) fails

[MrSaints]

What happened:

When uploading a file to a node in a trusted cluster (reverse SSH tunnel) via the web interface, it fails with an error: ssh: subsystem request failed.

When doing the same on a node in the main cluster, it works fine.

What you expected to happen:

The file should be uploaded, and the UI should show a status of completed.

How to reproduce it (as minimally and precisely as possible):

See the above.

Environment:

Main: Teleport v3.0.1 git:v3.0.1-0-g4ff9a7b0

Trusted Cluster (pending upgrade):

• Teleport version (use teleport version): Teleport v2.7.4 git:v2.7.4-0-g2fff1056
• Tsh version (use tsh version): Teleport v2.7.4 git:v2.7.4-0-g2fff1056
• OS (e.g. from /etc/os-release): Ubuntu 18.04 LTS (Bionic Beaver)

Browser environment

• Browser Version (for UI-related issues): Version 69.0.3497.57 (Official Build) beta (64-bit)
• Install tools:
• Others: running on ArchLinux, and login via Github

Relevant Debug Logs If Applicable

• tsh --debug
• teleport --debug

DEBU [HTTP:PROX] No valid environment variables found. proxy/proxy.go:217
DEBU [HTTP:PROX] No proxy set in environment, returning direct dialer. proxy/proxy.go:137
WARN [PROXY]     [SSH] failed executing request: dial tcp: lookup <node host> on <omitted>:53: no such host id:41 local:127.0.0.1:3023 login:<omitted> remote:127.0.0.1:<omitted> teleportUser:<omitted> regular/sshserver.go:1045

It looks like it is trying to connect directly to the node that is behind a firewall. It is failing because it cannot translate the host name of the trusted cluster node to a physical address.

UPDATE: I just upgraded my trusted cluster to match the main cluster version, it is still failing to upload files for the same reason.

[Out-of-topic] Apart from that, the upgrade was fairly seamless. Great job!

[MrSaints]

Thank you @russjones 👍 One-liners FTW.