Mirroring Push Issue: "Failed to add ECDSA host key for ip address [x.x.x.x] to the list of known host (/tmp/something) .. permission denied"

Summary

While Mirroring repositories ssh doesn't work

Steps to reproduce

Input git ssh://... url Direction -> push Click detect host keys Authentication method -> key Click -> "Mirror Repository"

What is the current bug behavior?

Faied to add host key Error shows there is not permission in /tmp/gitlab-shell-knownhostsxxx permission denied

What is the expected correct behavior?

It should add host key with proper permission on /tmp and able login to remote server for push.

Relevant logs and/or screenshots

13:close stream to gitaly-ruby: rpc error: code = Unknown desc = Gitlab::Git::RepositoryMirroring::RemoteError: Failed to add the ECDSA host key for IP address &#39 (closed);[x.x.x.x]:xx&#39 (closed); to the list of known hosts (/tmp/gitlab-shell-known-hosts20200823-xxxx-rq74nr). Permission denied, please try again. Permission denied, please try again. Permission denied (publickey,password). fatal: Could not read from remote repository.

Please make sure you have the correct access rights and the repository exists. . debug_error_string:{"created":"@15981689xx.6479578xx","description":"Error received from peer ipv4:10.221.2.149:9999","file":"src/core/lib/surface/call.cc","file_line":1055,"grpc_message":"close stream to gitaly-ruby: rpc error: code = Unknown desc = Gitlab::Git::RepositoryMirroring::RemoteError: Failed to add the ECDSA host key for IP address &#39 (closed);[x.x.x.x]:xx&#39 (closed); to the list of known hosts (/tmp/gitlab-shell-known-hosts20200823-26878-rq74nr).\r\nPermission denied, please try again.\r\nPermission denied, please try again.\r\nPermission denied (publickey,password).\r\nfatal: Could not read from remote repository.\n\nPlease make sure you have the correct access rights\nand the repository exists.\n","grpc_status":13}