How to detect unreachable target hosts in ansible - ssh

Question

I wish to grab in a variable sshreachable if a target hosts all_hosts are reachable or not.
I wrote the below playbook for the same.
- name: Play 3- check telnet nodes
hosts: localhost
ignore_unreachable: yes
- name: Check all port numbers are accessible from current host
include_tasks: innertelnet.yml
with_items: "{{ groups['all_hosts'] }}"
cat innertelnet.yml
---
- name: Check ssh connectivity
block:
- raw: "ssh -o BatchMode=yes root#{{ item }} echo success"
ignore_errors: yes
register: sshcheck
- debug:
msg: "SSHCHECK variable:{{ sshcheck }}"
- set_fact:
sshreachable: 'SSH SUCCESS'
when: sshcheck.unreachable == 'false'
- set_fact:
sshreachable: 'SSH FAILED'
when: sshcheck.unreachable == 'true'
- debug:
msg: "INNERSSH1: {{ sshreachable }}"
Unfortunately, i get error like below:
Output:
TASK [raw] *********************************************************************
fatal: [localhost]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: Shared connection to 10.9.9.126 closed.", "skip_reason": "Host localhost is unreachable", "unreachable": true}
TASK [debug] ***********************************************************************************************************************************************************
task path:
ok: [localhost] => {
"msg": "SSHCHECK variable:{'msg': u'Failed to connect to the host via ssh: Shared connection to 10.9.9.126 closed.', 'unreachable': True, 'changed': False}"
}
TASK [set_fact] ****************************************************************
skipping: [localhost]
TASK [set_fact] ****************************************************************
skipping: [localhost]
TASK [debug] *******************************************************************
fatal: [localhost]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'sshreachable' is undefined\n\nThe error appears to be in '/app/playbook/checkssh/innertelnet.yml': line 45, column 10, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n - debug:\n ^ here\n"}
PLAY RECAP *********************************************************************
10.0.116.194 : ok=101 changed=1 unreachable=9 failed=0 skipped=12 rescued=0 ignored=95
localhost : ok=5 changed=0 unreachable=1 failed=1 skipped=4 rescued=0 ignored=0
Can you please suggest changes to my code to get this to work?

Answer 1

The error seems to indicate that sshreachable variable is not getting set as the when: condition does not match. I.e. sshcheck.unreachable might not be something returned by raw.
For this purpose, command module should be enough, and we can evaluate the return code of the command to set_fact.
You could do something like:
- block:
- command: ssh -o BatchMode=yes user#host1 echo success
ignore_errors: yes
register: sshcheck
- set_fact:
sshreachable: "{{ sshcheck is success }}"
- debug:
msg: "Host1 reachable: {{ sshreachable | string }}"
Update:
raw module seems to work the same way. Example (including #mdaniel's valuable input):
- block:
- raw: ssh -o BatchMode=yes user#host1 echo success
ignore_errors: yes
register: sshcheck
- set_fact:
sshreachable: SSH SUCCESS
when: sshcheck is success
- set_fact:
sshreachable: SSH FAILED
when: sshcheck is failed
- debug:
msg: "Host1 reachable: {{ sshreachable }}"