ansible playbook cannot apply, giving host unreachable error

Question

I'm completely new to ansible and I'm having a hard time with it. I have an inventory.yml file which is as the following:

EDIT: changed my inventory.yml now looks as follows inventory.yml:

[master]
master1 ansible_host=192.168.56.2 ansible_port=2222 ansible_user=deploy ansible_ssh_pass=vagrant ansible_become_pass=vagrant apt_key_master=https://packages.cloud.google.com/apt/doc/apt-key.gpg

[worker]
worker1 ansible_host=192.168.56.3 ansible_port=2200 ansible_user=deploy ansible_ssh_pass=vagrant ansible_become_pass=vagrant apt_key_worker=https://packages.cloud.google.com/apt/doc/apt-key.gpg

also I have a playbook called kube-repos.yml which is as follows:

EDIT: changed kube-repos.yml now looks as follows: kube-repos.yml:

- hosts: all
  become: yes
  tasks:

  - name: add Kubernetes apt-key
    apt_key:
      url: "{{ apt_key_master }}"
      state: present

  - name: add Kubernetes' APT repository
    apt_repository:
      repo: deb http://apt.kubernetes.io/ kubernetes-xenial main
      state: present

when I apply my ansible playbook using ansible-playbook kube-repos.yml I get the following error:

fatal: [master1]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: Permission denied (publickey).", "unreachable": true}
fatal: [worker1]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: Permission denied (publickey).", "unreachable": true}

I see my problem is getting proper authentication ansible to ssh into the host vm's. I am able to do vagrant ssh master and vagrant ssh worker and get into my vm's perfectly fine but when I apply the playbook and if I use the command ansible all -m ping I get the UNREACHABLE error. I am trying to setup a simple kubernetes cluster consisting of one master and one worker node.

I am at a loss now because I have read the ansible documentation but still cannot figure out how to correct this error. So I feel like I have no choice but to ask on here. I hope someone is kind enough to help me out and thanks in advance.

EDIT: after the changes suggested by @mikequentel I have the following error:

fatal: [worker1]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: ssh: connect to host 192.168.56.3 port 2200: Connection refused", "unreachable": true}
fatal: [master1]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: ssh: connect to host 192.168.56.2 port 2222: Connection refused", "unreachable": true}

Answer 1

Do the following for each Vagrant machine you want Ansible to work with...in this example, using the machine master1:

1. Do vagrant ssh-config > vagrant-ssh
2. Enter content from vagrant-ssh into your ~/.ssh/config, modifying it as needed, like this example for some machine named master1:

Host master1
  HostName 127.0.0.1
  User vagrant
  Port 2222
  UserKnownHostsFile /dev/null
  StrictHostKeyChecking no
  PasswordAuthentication no
  IdentityFile /home/myname/.vagrant/machines/default/virtualbox/private_key
  IdentitiesOnly yes
  LogLevel FATAL

3. Then, in your hosts (inventory) file, include the login information needed by Ansible, for each machine:

master1 ansible_host=master1 ansible_port=2222 ansible_ssh_user=vagrant ansible_ssh_pass=vagrant ansible_become_pass=vagrant

or also use IP address for ansible_host:

master1 ansible_host=192.168.56.2 ansible_port=2222 ansible_ssh_user=vagrant ansible_ssh_pass=vagrant ansible_become_pass=vagrant