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Kubee

Unable to connect/ping to the cluster hosts (via SSH or Ansible connection)?

Executing a ping command on the cluster is not successful. ie executing:

Terminal window
kubee --cluster "$KUBEE_CLUSTER_NAME" cluster ping

returns:

serverHostname | UNREACHABLE! => {
    "changed": false,
    "msg": "Task failed: Failed to connect to the host via ssh: xxx",
    "unreachable": true
}

The below steps will show you how to debug it.

Steps

Section titled “Steps”

Conceptually, how it works?

Section titled “Conceptually, how it works?”

The KUBEE_INFRA_CONNECTION_PRIVATE_KEY or KUBEE_INFRA_CONNECTION_PRIVATE_KEY_FILE will pass the key to Ansible by setting the ANSIBLE_PRIVATE_KEY_FILE variable if not yet set.

Terminal window
# /dev/shm for a temporary key
export ANSIBLE_PRIVATE_KEY_FILE="/dev/shm/ssh-key"

Then, ansible is creating an SSH command using it as IdentityFile to connect via the IP (not by DNS name).

Below we show you how to get the command.

Get the ansible ssh connection command with the debug flag

Section titled “Get the ansible ssh connection command with the debug flag”

Executing:

Terminal window
kubee --debug --cluster "$KUBEE_CLUSTER_NAME" cluster ping

will show you the ssh connection.

Example:

<x.x.x.x> ESTABLISH SSH CONNECTION FOR USER: root
<x.x.x.x> SSH: EXEC ssh -C -o ControlMaster=auto -o ControlPersist=60s -o 'IdentityFile="/dev/shm/ssh-key"' -o KbdInteractiveAuthentication=no -o PreferredAuthentications=gssapi-with-mic,gssapi-keyex,hostbased,publickey -o PasswordAuthentication=no -o 'User="root"' -o ConnectTimeout=10 -o 'ControlPath="/home/admin/.ansible/cp/3d78f1b2a9"' -o NumberOfPasswordPrompts=1 x.x.x.x '/bin/sh -c '"'"'echo ~root && sleep 0'"'"''

Replace Identity file and execute the command

Section titled “Replace Identity file and execute the command”

Replace the generated identity file ie (IdentityFile="/dev/shm/ssh-key") with your own and execute it:

Example:

Terminal window
# pass your key
pass kubee/myssh-key >| "/dev/shm/ssh-key"
# then execute
ssh -C -o ControlMaster=auto -o ControlPersist=60s -o 'IdentityFile="/dev/shm/ssh-key"'  \
  -o KbdInteractiveAuthentication=no -o PreferredAuthentications=gssapi-with-mic,gssapi-keyex,hostbased,publickey  \
  -o PasswordAuthentication=no -o 'User="root"'  \
  -o ConnectTimeout=10 -o 'ControlPath="/home/admin/.ansible/cp/3d78f1b2a9"'  \
  -o NumberOfPasswordPrompts=1 x.x.x.x
# then delete it
rm "/dev/shm/ssh-key"

Example of error:

The authenticity of host 'x.x.x.x (x.x.x.x)' can't be established.
ED25519 key fingerprint is: SHA256:yXEFAx6yZfvnsYmHusP5aECfLba/WxN04DafneUTDIE
This host key is known by the following other names/addresses:
    ::52: cluster-server-hostname.tld
Are you sure you want to continue connecting (yes/no/[fingerprint])? y
Please type 'yes', 'no' or the fingerprint: yes
Warning: Permanently added 'x.x.x.x' (ED25519) to the list of known hosts.