Ansible - disable ssh password authentication

user_9720375 0
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I'm trying to make ansible task that handles sshd_config properly. I've found similar regexp from other questions but they do nothing.

name: Disable SSH password authentication
      become: true
      lineinfile:
        dest: /etc/ssh/sshd_config
        regexp: '^#?\s*PasswordAuthentication\s'
        line: 'PasswordAuthentication no'
        state: present

Problem is it should handle duplicate lanes as well as comments. For example:

  • There could be:
PasswordAuthentication no
PasswordAuthentication yes

or

PasswordAuthentication no
PasswordAuthentication no

or

PasswordAuthentication yes
PasswordAuthentication yes

or

PasswordAuthentication no
#PasswordAuthentication no

or

PasswordAuthentication no
# PasswordAuthentication no

or

# PasswordAuthentication no
# PasswordAuthentication no

etc so many combinations. But I just want to have single uncommented line PasswordAuthentication no

Is this possible?

ansible openssh shell linux
1 Answers

Q: "handle duplicate lines as well as comments ... have single uncommented line PasswordAuthentication no"

A: Given the list of the files

    my_files:
      - sshd_config.0
      - sshd_config.1
      - sshd_config.2
      - sshd_config.3
      - sshd_config.4
      - sshd_config.5

and the content

shell> for f in files-17/*; do printf "\n%s\n" $f; cat $f; done

files-17/sshd_config.0
PasswordAuthentication no
PasswordAuthentication yes

files-17/sshd_config.1
PasswordAuthentication no
PasswordAuthentication no

files-17/sshd_config.2
PasswordAuthentication yes
PasswordAuthentication yes

files-17/sshd_config.3
PasswordAuthentication no
#PasswordAuthentication no

files-17/sshd_config.4
PasswordAuthentication no
# PasswordAuthentication no

files-17/sshd_config.5
# PasswordAuthentication no
# PasswordAuthentication no

The task below removes all but the first line which includes PasswordAuthentication

    - replace:
        path: 'files-17/{{ item }}'
        after: 'PasswordAuthentication'
        regexp: '^(.*)PasswordAuthentication(.*)$'
        replace: ''
      loop: "{{ my_files }}"

gives

shell> for f in files-17/*; do printf "\n%s\n" $f; cat $f; done

files-17/sshd_config.0
PasswordAuthentication no


files-17/sshd_config.1
PasswordAuthentication no


files-17/sshd_config.2
PasswordAuthentication yes


files-17/sshd_config.3
PasswordAuthentication no


files-17/sshd_config.4
PasswordAuthentication no


files-17/sshd_config.5
# PasswordAuthentication no

The next task replaces the lines with PasswordAuthentication no

    - lineinfile:
        path: 'files-17/{{ item }}'
        regexp: '^(.*)PasswordAuthentication(.*)$'
        line: 'PasswordAuthentication no'
      loop: "{{ my_files }}"

gives

shell> for f in files-17/*; do printf "\n%s\n" $f; cat $f; done

files-17/sshd_config.0
PasswordAuthentication no


files-17/sshd_config.1
PasswordAuthentication no


files-17/sshd_config.2
PasswordAuthentication no


files-17/sshd_config.3
PasswordAuthentication no


files-17/sshd_config.4
PasswordAuthentication no


files-17/sshd_config.5
PasswordAuthentication no

The sequence of the tasks is idempotent.

user_64825610
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