Questions[jinja2](server)

I'm trying to dynamically configure multiple NFS servers in my system by generating their /etc/exports files using Ansible. I'm hoping to be able to do this with a jinja2 template. It's the jinja2 template that I can't figure out based on my exports list.

I have the following variables defined in my nfs role:

site_nfs_servers: ['ansibletarget1', 'ansibletarget2']

exports:
  - server: "ansibletarget1"
    shares:
      - path: "/my/first/share/path"
        client: "*"
        options: "rw,sync"
      - path: "/my/second/share/path"
        client: "*"
        options: "rw,sync,root_squash"
  - server: "ansibletarget2"
    shares:
      - path: "/another/shared/path/different/server"
        client: "*"
        options: "ro,sync"

I then have the following ansible play to generate the template:

- name: Generate the exports file.
  template:
    src: exports.j2
    dest: /etc/exports
    owner: root
    group: root
    mode: '0750'

My template currently looks like this:

{% for export in exports %}
{% if ansible_hostname in export.server %}
{% for share in shares %}
{{ share.path }} {{ share.client }} {{ share.options }}
{% endfor %}
{% endif %}
{% endfor %}

I don't think I'm anywhere near close to having the correct template structure. How on earth does one iterate through this list?

I'm looking for an expression to fetch the interface name given an ip address assigned to that iface, across Linux and FreeBSD.

This question is based on this answer: https://serverfault.com/a/948288/416946

This jinja2 expression will, on Debian, return the interface object (from ansible facts) for the given_ip

iface_for_ip: >-
  {{ ansible_facts
  | dict2items
  | selectattr('value.ipv4', 'defined')
  | selectattr('value.ipv4.address', 'equalto', given_ip)
  | first  }}

However this does not work on FreeBSD because the ipv4 structure is an array, not an object.

If you run just this snippet:

iface_for_ip: >-
  {{ ansible_facts
  | dict2items
  | selectattr('value.ipv4', 'defined') }}

You will get an output like this:

  - key: eth0
    value:
      active: true
      device: eth0
      ipv4:
        address: 10.8.20.206
        broadcast: 10.8.20.255
        netmask: 255.255.255.0
        network: 10.8.20.0
      ipv6:
      - address: fe80::84ee:35ff:fed4:a23c
        prefix: '64'
        scope: link
      macaddress: 00:ee:35:00:00:00
      mtu: 1500
      promisc: false
      speed: 10000
      type: ether

  - key: epair0b
    value:
      device: epair0b
      flags:
      - UP
      - BROADCAST
      - RUNNING
      - SIMPLEX
      - MULTICAST
      ipv4:
      - address: 10.8.20.207
        broadcast: 10.8.20.255
        netmask: 255.255.255.0
        network: 10.8.20.0
      ipv6: []
      macaddress: 00:ee:23:00:00:00
      media: Ethernet
      media_options:
      - full-duplex
      media_select: 10Gbase-T
      media_type: 10Gbase-T
      metric: '0'
      mtu: '1500'
      options:
      - PERFORMNUD
      status: active
      type: ether

How can I use a jinja2 ansible expression to fetch the interface given just the ip address cross platform? json_query could be useful here, but the method eludes me.

I have a variable containing details of host machines on my network (called 'hostlist' - I believe you call this a dictionary, but I'm not sure of the terminology. The variable is defined in a file in group_vars/all, so it's available in all playbooks (not sure if this is important).

I have a play which I would like to run only if ansible_hostname is not found in the list of host names in hostlist. The host names in hostlist are one of the attributes of the variable, but again I'm not sure if "attribute" is the right term...

Hostlist is defined as:

hostlist:
  - { name: 'host1', ip_addr: '192.168.2.31', hostgrp: 'physical_workstation' }
  - { name: 'host2', ip_addr: '192.168.2.32', hostgrp: 'physical_workstation' }
  - { name: 'host3', ip_addr: '192.168.2.33', hostgrp: 'virtual_machine' }

The play I'm using to try to get this working is:

- name: Conditional test
  debug:
    msg: "ansible_hostname not found in hostlist."
  when: ansible_hostname not in hostlist.name

I'm not sure of the syntax required in the condition, or if what I'm wanting is achieveable in this manner?

I have an inventory file named hospital.inventory and it contains following group with a single value.

[dockerSwarmManager]
hp2-3.mydomain.com

Then I have a file name security.json.j2 inside the folder call templates. In there I want to refer above mentioned value in below placeholder.

"wellKnownUrl": "https://_placeholder_value_/my-configuration",

Is there any direct way of doing that?

As an alternative, how I did was declare a variable in main.yml file inside defaults directory and use it.

swarm_hostname: "\
   {% for host in groups['dockerSwarmManager'] -%}\
   {{host}}\
   {%- if not loop.last %}, {% endif -%}\
   {%- endfor %}"

I don't think it's nice to use a loop just to extract a single value from a group inside the inventory file even though I get the expected output.

The playbook below should generate a file with the content:

a,b
ssh_host_key
ssh_rsa_host_key

However, the way I construct the variable names results in either syntax/templating errors or 'variable name does not exists':

---
- hosts: localhost
  connection: local

  vars:
    CentOS:
      ciphers: "a,b"
      hostkeys:
        - "ssh_host_key"
        - "ssh_rsa_host_key"
  tasks:
  - copy:
      dest: "{{ playbook_dir }}/test.out"
      content: |

        # This works:
        {{ CentOS.ciphers }}

        # This results in 'No variable found with this name':
        {{ lookup('vars', ansible_distribution + '.ciphers') }}

        # Templating errors:
        {% for hostkey in {{ lookup('vars', ansible_distribution + '.hostkeys') }} %}
        {{ hostkey }}
        {% endfor %}

        # Templating errors:
        {% for hostkey in {{ hostvars[inventory_hostname][ansible_distribution + '.hostkeys'] }} %}
        {{ hostkey }}
        {% endfor %}

What is the proper way to 'assemble' the variable names? Or is there a better way of doing this?