# Launching interactive apps and cluster login node in ~/.ssh/known\_hosts

**URL:** <https://discourse.openondemand.org/t/launching-interactive-apps-and-cluster-login-node-in-ssh-known-hosts/967>\
**Category:** Get Help\
**Tags:** question\
**Created:** [June 9, 2020, 8:10pm UTC](https://discourse.openondemand.org/t/launching-interactive-apps-and-cluster-login-node-in-ssh-known-hosts/967 "2020-06-09T20:10:54Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![rgas20](https://sea1.discourse-cdn.com/flex015/user_avatar/discourse.openondemand.org/rgas20/32/309_2.png) [@rgas20](https://discourse.openondemand.org/u/rgas20)\
**Post date:** [June 9, 2020, 8:10pm UTC](https://discourse.openondemand.org/t/launching-interactive-apps-and-cluster-login-node-in-ssh-known-hosts/967/1 "2020-06-09T20:10:54Z")

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All,

We have been giving users access to our Open OnDemand server which is running on a VM separate from the cluster. Under the hood they use our shared cluster /home directory mounted over NFS.

The issue that we are running in to is that users cannot launch interactive apps until they log in to the cluster through the Clusters - Shell Access dropdown first via OnDemand. They have logged in to our cluster via SSH before and therefore have a /home directory, however, when they go to our OnDemand site they need to hit ‘yes’ on the [SSH: The authenticity of host loginnode.oursite.edu can’t be established] prompt that very first time to add the login node for our cluster to their ~/.ssh/known\_hosts file. Otherwise, on launching the apps they’re getting a “Host Key Verification Failed” error message if they do not.

This has been causing some confusion and we’ve been getting a few questions. How are other sites handling this? I was thinking it maybe possible somehow to add the cluster login node to the ~/.ssh/known\_hosts file on login, otherwise I don’t really know how else to bridge that issue. Any ideas are greatly appreciated.

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**Author:** ![jeff.ohrstrom](https://sea1.discourse-cdn.com/flex015/user_avatar/discourse.openondemand.org/jeff.ohrstrom/32/136_2.png) [@jeff.ohrstrom](https://discourse.openondemand.org/u/jeff.ohrstrom)\
**Post date:** [June 9, 2020, 9:13pm UTC](https://discourse.openondemand.org/t/launching-interactive-apps-and-cluster-login-node-in-ssh-known-hosts/967/2 "2020-06-09T21:13:57Z")

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You can add keys system wide at `/etc/ssh/ssh_known_hosts`. That way folks don’t need to add it to `~/.ssh` they’re able to read the system wide configuration. (At OSC we manage this file through puppet, so I have to give a shout out to automation wherever I can)

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**Author:** ![rgas20](https://sea1.discourse-cdn.com/flex015/user_avatar/discourse.openondemand.org/rgas20/32/309_2.png) [@rgas20](https://discourse.openondemand.org/u/rgas20)\
**Post date:** [June 10, 2020, 4:27pm UTC](https://discourse.openondemand.org/t/launching-interactive-apps-and-cluster-login-node-in-ssh-known-hosts/967/3 "2020-06-10T16:27:03Z")

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Ah. Thank you! We didn’t realize we could set it there system wide. That worked great. Much appreciated.

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**Author:** ![system](https://us1.discourse-cdn.com/flex015/uploads/osc/original/2X/b/bae70bd0ed39a3ae769c2108155f4cb3e9da8385.png) [@system](https://discourse.openondemand.org/u/system)\
**Post date:** [May 19, 2022, 6:04pm UTC](https://discourse.openondemand.org/t/launching-interactive-apps-and-cluster-login-node-in-ssh-known-hosts/967/4 "2022-05-19T18:04:33Z")

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