openssh-server in a pod | ssh connection fails with error: Connection reset by <IP> port 30500 - docker

Question

**Logs from sshd server
`debug2: load_server_config: filename /etc/ssh/sshd_config
debug2: load_server_config: done config len = 806
debug2: parse_server_config: config /etc/ssh/sshd_config len 806
debug3: /etc/ssh/sshd_config:17 setting Port 30500
debug3: /etc/ssh/sshd_config:19 setting ListenAddress 0.0.0.0
debug3: /etc/ssh/sshd_config:22 setting HostKey /etc/ssh/ssh_host_rsa_key
debug3: /etc/ssh/sshd_config:23 setting HostKey /etc/ssh/ssh_host_ecdsa_key
debug3: /etc/ssh/sshd_config:24 setting HostKey /etc/ssh/ssh_host_ed25519_key
debug3: /etc/ssh/sshd_config:36 setting SyslogFacility AUTH
debug3: /etc/ssh/sshd_config:38 setting LogLevel VERBOSE
debug3: /etc/ssh/sshd_config:43 setting PermitRootLogin yes
debug3: /etc/ssh/sshd_config:44 setting StrictModes no
debug3: /etc/ssh/sshd_config:52 setting AuthorizedKeysFile .ssh/authorized_keys
debug3: /etc/ssh/sshd_config:60 setting HostbasedAuthentication no
debug3: /etc/ssh/sshd_config:68 setting PasswordAuthentication no
debug3: /etc/ssh/sshd_config:73 setting ChallengeResponseAuthentication no
debug3: /etc/ssh/sshd_config:83 setting GSSAPIAuthentication no
debug3: /etc/ssh/sshd_config:84 setting GSSAPICleanupCredentials no
debug3: /etc/ssh/sshd_config:105 setting X11Forwarding yes
debug3: /etc/ssh/sshd_config:131 setting AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES
debug3: /etc/ssh/sshd_config:132 setting AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT
debug3: /etc/ssh/sshd_config:133 setting AcceptEnv LC_IDENTIFICATION LC_ALL LANGUAGE
debug3: /etc/ssh/sshd_config:134 setting AcceptEnv XMODIFIERS
debug3: /etc/ssh/sshd_config:137 setting Subsystem sftp /usr/libexec/openssh/sftp-server
debug1: sshd version OpenSSH_7.4, OpenSSL 1.0.2k-fips 26 Jan 2017
debug1: private host key #0: ssh-rsa SHA256:6XsUKJrlEzspiLw1H/e5qfrzga/n4Rgs
debug1: private host key #1: ecdsa-sha2-nistp256 SHA256:yJkcJ2AX3E4dOADjCRn9EWnut+z5nW3xKhGOc
debug1: private host key #2: ssh-ed25519 SHA256:GHvEepwimuJpanKOXJx8Aacpcs8MwXxlmaU7Q
debug1: rexec_argv[0]='/usr/sbin/sshd'
debug1: rexec_argv[1]='-ddd'
debug3: oom_adjust_setup
debug1: Set /proc/self/oom_score_adj from 1000 to -1000
debug2: fd 3 setting O_NONBLOCK
debug1: Bind to port 30500 on 0.0.0.0.
Bind to port 30500 on 0.0.0.0 failed: Address already in use.
Cannot bind any address.`
Logs from ssh command:
`ssh -vvv localhost -p 30500`
`OpenSSH_7.4p1, OpenSSL 1.0.2k-fips 26 Jan 2017
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 58: Applying options for *
debug2: resolving "localhost" port 30500
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to localhost [::1] port 30500.
debug1: connect to address ::1 port 30500: Connection refused
debug1: Connecting to localhost [127.0.0.1] port 30500.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_rsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ed25519-cert type -1
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
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to localhost:30500 as 'root'
debug3: put_host_port: [localhost]:30500
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
Connection reset by 127.0.0.1 port 30500`
Server seems running fine
`netstat -anp | grep 30500`
`tcp 0 0 0.0.0.0:30500 0.0.0.0:* LISTEN 1/sshd`
Observations
The same image works fine when run as a docker container locally (with the same sshd_config temporarily allowing password auth)
The service picks the correct endpoint and we can telnet to the custom ssh port > 30500
The SSH process is running in the pod
Telnet to the ssh port works fine (from another pod, from outside the cluster)
Another container within the same pod with nginx on port 80 works just fine
At present, we get the error Connection reset by port 30500
a) NodePort or LoadBalancer(OCI) does not work
b) In fact ssh to localhost from within the pod fails as well (or from another pod, or from the worker node)
Any guidance here please?