Ansible: How to specify an ssh key for a single task? - ssh

Question

I have a playbook that creates and ec2 instance, copies a few files over to the instance and then runs some shell commands on the instance.
The issue is that I want to be able to specify what ssh key ansible uses for the copy and shell tasks I am running and make sure it does not attempt to use this key for the other tasks, which run on the localhost. Here is my playbook:
---
- hosts: localhost
connection: local
gather_facts: false
vars:
# CentOS 7 x86_64 Devel AtomicHost EBS HVM 20150306_01 (ami-07e6c437)
# for us-west-2
- ami: 'ami-07e6c437'
- key_pair: 'my-key'
tasks:
- name: Create a centos server
ec2:
region: 'us-west-2'
key_name: '{{ key_pair }}'
group: default
instance_type: t2.micro
image: '{{ ami }}'
wait: true
exact_count: 1
count_tag:
Name: my-instance
instance_tags:
Name: my-instance
register: ec2
# shows the json data for the instances created
- name: Show ec2 instance json data
debug:
msg: "{{ ec2['tagged_instances'] }}"
- name: Wait for SSH to come up
wait_for: host={{ ec2['tagged_instances'][0]['public_ip'] }} port=22 delay=1 timeout=480 state=started
- name: Accept new ssh fingerprints
shell: ssh-keyscan -H "{{ ec2['tagged_instances'][0]['public_ip'] }}" >> ~/.ssh/known_hosts
# THE TASKS I NEED HELP ON
- name: Copy files over to ec2 instance
remote_user: centos
copy: src={{ item }} dest=/home/centos/ mode=600
with_fileglob:
- my-files/*
delegate_to: "{{ ec2['tagged_instances'][0]['public_ip'] }}"
# THE TASKS I NEED HELP ON
- name: run commands
remote_user: centos
shell: "{{ item }}"
delegate_to: "{{ ec2['tagged_instances'][0]['public_ip'] }}"
with_items:
- "sudo yum update -y"
- "sudo yum install nmap ruby"
ignore_errors: true

Answer 1

Yeah, I agree with #techraf. But the answer to the question you posted is that you have to dynamically change your inventory for the new instance that you provisioned and then run remote ansible plays on that new host. So you would add this to the end of your first play:
- local_action:
module: add_host
hostname: newhost
ansible_host: "{{ ec2['tagged_instances'][0]['public_ip'] }}"
ansible_user: centos
ansible_ssh_private_key_file: /path/to/keyfile
###### New play
- name: Configure my new instance!
hosts: newhost
tasks:
# THE TASKS I NEED HELP ON
- name: Copy files over to ec2 instance
copy: src={{ item }} dest=/home/centos/ mode=600
with_fileglob:
- my-files/*
# Use the yum module here instead, much easier
- name: run commands
shell: "{{ item }}"
with_items:
- "sudo yum update -y"
- "sudo yum install nmap ruby"
ignore_errors: true
Edit: Adding, that you can always just set the ssh host key by using:
- set_fact: ansible_ssh_private_key_file=/path/to/keyfile
with the caveat that the above set_fact will only change the ssh private key file for the currently running host (e.g., for localhost on your example play above).