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conditional-statementsaptansible
Simply Seth
Simply Seth

Reputation: 3506

Ansible Do Task If Apt Package Is Missing

I'm looking to do a series of tasks if a specific apt package is missing.

for example:

if graphite-carbon is NOT installed do: 

- apt: name=debconf-utils state=present
- shell: echo 'graphite-carbon/postrm_remove_databases boolean false' | debconf-set-selections
- apt: name=debconf-utils state=absent

another example:

if statsd is NOT installed do: 

- file: path=/tmp/build state=directory
- shell: cd /tmp/build ; git clone https://github.com/etsy/statsd.git ; cd statsd ; dpkg-buildpackage 
- shell: dpkg -i /tmp/build/statsd*.deb

How would I begin to crack this?

I'm thinking maybe I can do a -shell: dpkg -l|grep <package name> and capture the return code somehow.

Upvotes: 21

Views: 26308

Answers (4)

sduthil
sduthil

Reputation: 839

You can use the package_facts module (requires Ansible 2.5):

- name: Gather package facts
  package_facts:
    manager: apt

- name: Install debconf-utils if graphite-carbon is absent
  apt:
    name: debconf-utils
    state: present
  when: '"graphite-carbon" not in ansible_facts.packages'

...

Upvotes: 20

dom_hutton
dom_hutton

Reputation: 158

I'm a bit late to this party but here's another example that uses exit codes - ensure you explicitly match the desired status text in the dpkg-query results:

- name: Check if SystemD is installed
  command: dpkg-query -s systemd | grep 'install ok installed'
  register: dpkg_check
  tags: ntp

- name: Update repositories cache & install SystemD if it is not installed
  apt:
    name: systemd
    update_cache: yes
  when: dpkg_check.rc == 1
  tags: ntp

Upvotes: 2

Simply Seth
Simply Seth

Reputation: 3506

It looks like my solution is working.

This is an example of how I have it working: 

- shell: dpkg-query -W 'statsd'
  ignore_errors: True
  register: is_statd

- name: create build dir
  file: path=/tmp/build state=directory
  when: is_statd|failed

- name: install dev packages for statd build
  apt:  name={{ item }} 
  with_items: 
    - git 
    - devscripts 
    - debhelper
  when: is_statd|failed

- shell: cd /tmp/build ; git clone https://github.com/etsy/statsd.git ; cd statsd ; dpkg-buildpackage 
  when: is_statd|failed

....

Here is another example: 

 - name: test if create_superuser.sh exists
  stat: path=/tmp/create_superuser.sh 
  ignore_errors: True
  register: f

- name: create graphite superuser
  command: /tmp/create_superuser.sh
  when: f.stat.exists == True

...and one more 

- stat: path=/tmp/build
  ignore_errors: True
  register: build_dir

- name: destroy build dir
  shell: rm -fvR /tmp/build 
  when: build_dir.stat.isdir is defined and build_dir.stat.isdir

Upvotes: 11

udondan
udondan

Reputation: 60029

I think you're on the right track with the dpkg | grep, only that the return code will be 0 in any case. But you can simply check the output.

- shell: dpkg-query -l '<package name>'
  register: dpkg_result

- do_something:
  when: dpkg_result.stdout != ""

Upvotes: 4

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