I have an SSHD server running in docker container in Kubernetes.

It intermittently throws the following error when I try to connect to it. I am using Kubernetes with port-forwarding using fabric8io Kubernetes with Java 8 to ssh to the container to execute some commands.

It is not readily reproducible.

debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 58: Applying options for *
debug1: Connecting to 127.0.0.1 [127.0.0.1] port 38763.
debug1: Connection established.
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.4
debug1: match: OpenSSH_7.4 pat OpenSSH* compat 0x04000000
debug1: Authenticating to 127.0.0.1:38763 as 'raisin'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: curve25519-sha256 need=64 dh_need=64
debug1: kex: curve25519-sha256 need=64 dh_need=64
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:XXXXXXX
debug1: checking without port identifier
Warning: Permanently added '[127.0.0.1]:38763' (ECDSA) to the list of known hosts.
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
debug1: Next authentication method: gssapi-keyex
debug1: No valid Key exchange context
debug1: Next authentication method: gssapi-with-mic
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /var/lib/jenkins/private_key_501742004512678166.key
debug1: Server accepts key: pkalg rsa-sha2-512 blen 279
debug1: Authentication succeeded (publickey).
Authenticated to 127.0.0.1 ([127.0.0.1]:38763).
debug1: channel 0: new [client-session]
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug1: pledge: network
debug1: client_input_global_request: rtype hostkeys-00@openssh.com want_reply 0
debug1: Sending environment.
debug1: Sending env LANG = en_US.UTF-8
debug1: Sending command: sh
exec request failed on channel 0, exitCode=255}

Any help would be welcome.