linux_wiki:ansible_playbook_downloads [Owlbear Consulting

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====== Ansible Playbook Downloads ======

**General Information**

This page will contain Ansible playbook/role downloads.

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In order to install/configure Ansible, [[linux_wiki:ansible|see this page first]].

**Checklist**
  * Ansible installed and configured

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====== Playbook Downloads ======

Example Ansible playbooks/roles are maintained here: https://gitlab.com/whowe/ansible

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====== Playbook Snippets ======

Snippets of tasks to provide examples of some Ansible modules in action.

Most of these snippets are tasks that span multiple documentation sources or were discovered through searches and trial/error.

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Ansible Module Index: https://docs.ansible.com/ansible/2.4/modules_by_category.html

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===== ACLs =====

ACL module.

**Examples**
  * Set default group permissions for "awesome" group. (so any files created in the directory will get those group permissions)<code yaml>- name: my_description|ACL of MyApp config dir
  acl:
    path: "/etc/myapp"
    entity: awesome
    etype: group
    default: yes
    permissions: rw
    state: present</code>

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===== Copy Module =====

Copy module examples.

**Examples**
  * Copy a kernel tuning drop in file and load settings if file changes<code yaml>- name: tuning|MyApp kernel tuning
  copy:
    src: "sysctl_myapp_{{env}}"
    dest: "/etc/sysctl.d/55-myapp.conf"
    owner: root
    group: root
    mode: 0600
  notify: reload sysctl
  
# Handler file contents (../handlers/main.yml)
##-- Service Reloads --##
# Sysctl reload
- name: reload sysctl
  command: sysctl --system</code>

  * Copy autofs config files and restart autofs<code yaml># AutoFS: Config files
- name: mounts|Copy Master AutoFS Config
  copy:
    src: "autofs_auto.master"
    dest: "/etc/auto.master.d/master-configs.autofs"
    owner: root
    group: root
    mode: 0644
  notify: restart autofs

- name: mounts|Copy AutoFS Direct Maps
  copy:
    src: "autofs_auto.direct-maps"
    dest: "/etc/auto.direct-maps"
    owner: root
    group: root
    mode: 0644
  notify: restart autofs
  
# Handler file for autofs (../handlers/main.yml)
##-- Service Restarts --##
# AutoFS Service
- name: restart autofs
  service:
    name: autofs
    state: restarted</code>

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===== File Module =====

Some file module examples.

**Examples**
  * Recursively remove a list of directories<code yaml>- name: my_app|Remove MyApp directories
  file:
    path: "{{ item }}"
    state: absent
  with_items:
    - "/opt/MyApp/"
    - "/var/log/myapp/"
    - "/usr/local/lib/myapp/"</code>

  * Recursively set ownership to myappdaemon:awesome<code yaml>- name: my_description|Ownership of MyApp Log dir
  file:
    path: "/var/log/myapp"
    owner: myappdaemon
    group: awesome
    recurse: yes</code>
    
  * Set ownership of all /data* directories for myappdaemon:awesome<code yaml># Find all /data* directories
- name: my_description|Info Gather find all Data dirs
  find:
    paths: "/"
    patterns: 'data*'
    recurse: no
    file_type: directory
  register: dirs_data

# Set ownership of all /data* directories
- name: my_description|Ownership of Data dirs
  file:
    path: "{{item.path}}"
    owner: myappdaemon
    group: awesome
    recurse: no
  with_items: "{{dirs_data.files}}"</code>

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===== Pre Req Tests =====

Using a combination of the command module, registering variables, and the fail module, any command can be checked for a certain return code.

This can be useful for pre-req checks.

**Examples**
  * Ensure a certain mount point exists<code yaml># Info gather for /data1 to see if its a mountpoint
- name: pre_reqs|Info gather on /data1
  command: mountpoint -q /data1
  register: mount_stat
  failed_when: False
  changed_when: False

# Exit playbook if /data1 is not a configured mountpoint
- name: pre_regs|Exit if /data1 is NOT a mountpoint
  fail:
    msg: "/data1 is not a mountpoint! Exiting."
  when: mount_stat.rc != 0</code>

  * Check for a specific configured network interface<code yaml># Info gather for all ip addresses to ensure storage network is setup
- name: pre-reqs|Info gather on Storage Network (172.16.1.0/24)
  shell: ip address show | grep 172.16.1.
  register: storage_network
  failed_when: False
  changed_when: False

# Exit playbook if Storage Network interface is not configured
- name: pre-reqs|Exit if Storage Network (172.16.1.0/24) interface not found
  fail:
    msg: "Storage Network (172.16.1.0/24) interface not found! Exiting."
  when: storage_network.rc != 0</code>

  * Check for the existence of a certain package, stop service if so<code yaml>- name: my_app|Check for myapp RPM
  shell: rpm -q myapp
  register: myapp_rpm_exists
  changed_when: False
  failed_when: False
  
# EL7: Stop service if RPM exists
- name: my_app|Stop service (EL7 if RPM exists)
  systemd:
    name: myapp
    state: stopped
  when:
    - myapp_rpm_exists.rc == 0
    - ansible_distribution_major_version == "7"
</code>

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===== Python: Install Pip =====

One method of installing pip into a Python environment.

<code yaml># Check to see if pip exists, store answer in "pip_path"
- name: software|Check for pip
  stat:
    path: "/usr/bin/pip"
  register: pip_path

# Copy pip script to system if pip did not exist
- name: software|No Pip - Copy get-pip.py for pip install
  copy:
    src: "python_get-pip.py"
    dest: "/root/get-pip.py"
  when: pip_path.stat.exists == False

# Install pip into Python site packages if pip did not exist
- name: software|No Pip - Install pip using Python (/usr/bin/python)
  command: "/usr/bin/python /root/get-pip.py"
  when: pip_path.stat.exists == False

# Remove get-pip.py if pip did not exist before
- name: software|No Pip - Remove get-pip.py
  file:
    path: "/root/get-pip.py"
    state: absent
  when: pip_path.stat.exists == False</code>

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===== Python: Install Packages =====

Installing Python packages via pip.
  * Install virtualenv<code yaml># Install virtualenv python package
- name: software|Install virtualenv python package via pip
  pip:
    executable: "/usr/bin/pip"
    name: "virtualenv"</code>

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===== Remote Scripts =====

Running remote scripts and capturing results.

**Examples**
  * Copy a script to the remote system if it is different. Run the script as the app user and record as changed if the script outputs the string "Modified".<code yaml># Copy calculation script to system
- name: script|Copy Calcuation Script to System
  copy:
    src: "calc-resources.py"
    dest: "/home/{{ app_user }}/bin/calc-resources.py"
    owner: "{{ app_user }}"
    group: "{{ app_group }}"
    mode: 0700
  tags: calc_resources

# Run calculcation script - Mark as changed if std out contains 'Modified'
- name: script|Run Resource Calcuation Script
  become: yes
  become_method: su
  become_user: "{{ app_user }}"
  environment:
    LOCAL_ENV_VAR_NEEDED_IN_SCRIPT: "/home/{{ app_user }}/bin/myapp/"
  command: "/home/{{ app_user }}/bin/calc-resources.py"
  register: resource_calc_result
  changed_when: "'Modified' in resource_calc_result.stdout"
  tags: calc_resources

# Uncomment debug to see variable contents of 'resource_calc_result'
- debug:
    var: resource_calc_result
  tags: calc_resources</code>

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===== SSH Keys =====

Manipulating SSH keys on remote hosts.

**Examples**
  * Add a public key to a user's authorized_keys<code yaml>- name: ssh-access|Copy a public key to a remote users authorized_keys
  authorized_key:
    user: "{{ app_user }}"
    state: present
    key: "{{ item }}"
  with_file:
    - "ssh_{{ app_user }}-id-rsa.pub"</code>

  * Generate a SSH Key Pair (public/private) for a user<code yaml>- name: ssh-access|SSH Key Generation for App User
  user:
    name: "{{ app_user }}"
    generate_ssh_key: yes
    ssh_key_bits: 2048</code>

  * Fetch a remote SSH public key, save to the local Ansible system, then add that now local key to the remote system<code yaml># Fetch remote ssh public key
- name: ssh-access|Fetching remote ssh public key
  fetch:
    src: "/home/{{ app_user }}/.ssh/id_rsa.pub"
    dest: "/tmp/ansible-ssh-pub/{{ inventory_hostname }}_pubkey"
    flat: yes

# Add fetched key to authorized_keys
- name: ssh-access|Add Local SSH Key to authorized_keys
  authorized_key:
    user: "{{ app_user }}"
    state: present
    key: "{{ lookup('file', '/tmp/ansible-ssh-pub/{{ inventory_hostname }}_pubkey') }}"</code>

  * Add a list of system names to a remote system's SSH known_hosts (so there is no fingerprint accept prompt<code yaml># Check each item to see if its in known_hosts, save results to register variable
- name: ssh-access|Check to see if host name is in known_hosts
  shell: "ssh-keygen -f /home/{{ app_user }}/.ssh/known_hosts -F {{ item }}"
  with_items:
    - "localhost"
    - "127.0.0.1"
    - "{{ ansible_nodename|lower }}"
    - "{{ ansible_hostname|lower }}"
  register: ssh_known_host_results
  changed_when: false
  ignore_errors: yes

# Uncomment debug to see stored object
- debug:
    var: ssh_known_host_results

# If the saved results from above do not contain output, add the host to known_hosts
- name: ssh-access|Scan public keys (add to known_hosts)
  shell: "ssh-keyscan {{ item.item }} >> /home/{{ app_user }}/.ssh/known_hosts"
  when: item.stdout == ""
  with_items: "{{ ssh_known_host_results.results }}"

# Ensure known_hosts is owned by app user and group
- name: ssh-access|Ensure known_hosts is owned by the application user
  file:
    path: "/home/{{ app_user }}/.ssh/known_hosts"
    state: file
    owner: "{{ app_user }}"
    group: "{{ app_group }}"
    mode: 0644</code>

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===== Unarchive =====

Copying tarballs to a remote system only if newer and un-archiving only if the tarball changed.

<code yaml># Copy myapp tarball if source is newer
- name: my_app|MyApp tarball copy
  copy:
    src: "myapp_current.tar"
    dest: "/var/opt/myapp/"
    owner: root
    group: root
    mode: 0755
    follow: yes
  register: myapp_new_archive

# Unarchive tarball on remote system if it was changed
- name: my_app|MyApp tarball unarchive if newer
  unarchive:
    src: "/var/opt/myapp/myapp_current.tar"
    dest: "/var/opt/myapp/"
    copy: no
  when:
    - myapp_new_archive is changed</code>

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===== User =====

The user module.

**Examples**
  * Add a list of users to a local group.<code yaml># Local "awesome" group
- name: my_description|Add users to the local awesome group
  user:
    name: "{{item}}"
    groups: awesome
    append: yes
  with_items: "{{awesome_users}}"
  
# Variable file (../vars/main.yml)
# Awesome Group Users
awesome_users:
  - yoda
  - vader
  - rjones</code>

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===== When Conditional =====

Only execute certain tasks under certain conditions.

**Examples**
  * Do not execute any of the imported "mytasks.yml" if host is "server01" or "server02"<code yaml>- import_tasks: mytasks.yml
  when:
    - inventory_hostname != "server01"
    - inventory_hostname != "server02"</code>

  * Execute a task if a host is in the "special" inventory group<code yaml>- import_tasks: mytasks.yml
  when: inventory_hostname in groups.special</code>

  * Execute a task if a host is NOT in the "special" inventory group<code yaml>- import_tasks: mytasks.yml
  when: inventory_hostname not in groups.special</code>
  
  * Execute a task if the distribution major version is 7 (EL 7)<code yaml># Enable and start service (EL7)
- name: my_service|Enable and Start Service (EL7)
  systemd:
    name: myservice
    enabled: yes
    state: started
    daemon_reload: yes
  when: ansible_distribution_major_version == "7"</code>

  * Execute a task when an inventory group_var variable matches<code yaml>- import_tasks: mytasks.yml
  when: env == "prod"</code>

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===== Yum Repository =====

Adding a yum repo with the yum_repository module.

**Examples**
  * Apache Cassandra<code yaml># Apache Cassandra Repo
- name: cassandra|Add Repo
  yum_repository:
    name: cassandra
    description: Apache Cassandra
    baseurl: https://www.apache.org/dist/cassandra/redhat/311x/
    enabled: yes
    gpgcheck: yes
    repo_gpgcheck: yes
    gpgkey: https://www.apache.org/dist/cassandra/KEYS</code>

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