CODEWITHSUNDEEP
for-loopansibleansible-factsansible-template
PedroPicateclas
PedroPicateclas

Reputation: 25

How to nest variable in ansible with for

I am working with Ansible and I need to display a list of the hosts' network interfaces. In a Jinja2 format template I need the following values: Name, IP, Mask and Network for each of the interfaces. To have this information I use the ansible_facts but I have a problem when making the for.

I get the network interfaces from here:

"ansible_interfaces": [
    "eth1",
    "eth0",
    "lo"
],

So far so good, I make a for and it shows me all three. My problem is that the information I need from each interface is separated in jason:

"ansible_eth0": {
    "active": true,
    "device": "eth0",
    "hw_timestamp_filters": [],
    "ipv4": {
        "address": "x.x.x.x",
        "broadcast": "x.x.x.x",
        "netmask": "255.255.192.0",
        "network": "x.x.x.x"
    },
    "ipv4_secondaries": [
        {
            "address": "x.x.x.x",
            "broadcast": "x.x.x.x",
            "netmask": "255.255.0.0",
            "network": "x.x.x.x"
        }
    ],
    "ipv6": [
        {
            "address": "",
            "prefix": "64",
            "scope": "link"
        }
    ],
    "macaddress": "",
    "module": "virtio_net",
    "mtu": 1500,
    "pciid": "virtio0",
    "promisc": false,
    "speed": -1,
    "timestamping": [
        "tx_software",
        "rx_software",
        "software"
    ],
    "type": "ether"
},
"ansible_eth1": {
    "active": true,
    "device": "eth1",
    "hw_timestamp_filters": [],
    "ipv4": {
        "address": "x.x.x.x",
        "broadcast": "x.x.x.x",
        "netmask": "255.255.240.0",
        "network": "x.x.x.x"
    },
    "ipv6": [
        {
            "address": "",
            "prefix": "64",
            "scope": "link"
        }
    ],
    "macaddress": "",
    "module": "virtio_net",
    "mtu": 1500,
    "pciid": "virtio1",
    "promisc": false,
    "speed": -1,
    "timestamping": [
        "tx_software",
        "rx_software",
        "software"
    ],
    "type": "ether"
},

To get this information I try it in the following way:

{{% for interfaz in ansible_interfaces %}}
{{% for item in ansible_['interfaz'] %}}

Name: {{ item.device }}
IP: {{ item.ipv4.address }}
Netmask: {{ item.ipv4.metmask }}
Red: {{ item.ipv4.network }}

{{% endfor %}}
{{% endfor %}}

I've tried it in different ways and can't figure out how to do it. In my opinion, what the for returns me is a string. And I tried with the iteritems option but I can't either. If someone can help me with the problem I would appreciate it.

Upvotes: 1

Views: 289

Answers (1)

Vladimir Botka
Vladimir Botka

Reputation: 68034

Use lookup plugin vars. See the details by running in shell ansible-doc -t lookup vars. For example

    - debug:
        msg: |
          {% for i in ansible_interfaces %}
          {% set dev = lookup('vars', 'ansible_' ~ i) %}
          Name: {{ dev.device }}
          IP: {{ dev.ipv4.address|default(None) }}
          Netmask: {{ dev.ipv4.netmask|default(None) }}
          Red: {{ dev.ipv4.network|default(None) }}

          {% endfor %}

gives in my laptop

  msg: |-
    Name: lo
    IP: 127.0.0.1
    Netmask: 255.0.0.0
    Red: 127.0.0.0
  
    Name: wlan0
    IP:
    Netmask:
    Red:
  
    Name: eth0
    IP: 10.1.0.27
    Netmask: 255.255.255.0
    Red: 10.1.0.0

The attribute ipv4 might be missing. Fit the default values to your needs.

Upvotes: 1

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