Ansible 动态清单脚本 - 奇怪的行为

Question

I'm trying to create a basic dynamic inventory script for ansible based on JSON output. I'm new to jq but I've hit an issue where the dynamic script on ansible v2.9.14 & 2.9.15 doesn't like the output, but if I send the output to a file and then run Ansible against the output in the file, ansible works.

This is what happens:

dynamic inventory script output:

{
  "all": {
      "hosts": {
"ip-172-31-39-30.eu-west-1.compute.internal": null,
"ip-172-31-44-224.eu-west-1.compute.internal": null,
"ip-172-31-42-6.eu-west-1.compute.internal": null,
"ip-172-31-32-68.eu-west-1.compute.internal": null,
    }
  }
}

Ansible run and error:

$ ansible -i ./dynamic1.sh all -m ping -u ubuntu
[WARNING]:  * Failed to parse /home/ubuntu/dynamic1.sh with script plugin: failed to parse executable inventory script results from /home/ubuntu/dynamic1.sh:
Expecting property name enclosed in double quotes: line 8 column 5 (char 242)
[WARNING]:  * Failed to parse /home/ubuntu/dynamic1.sh with ini plugin: /home/ubuntu/dynamic1.sh:2: Expected key=value host variable assignment, got: {
[WARNING]: Unable to parse /home/ubuntu/dynamic1.sh as an inventory source
[WARNING]: No inventory was parsed, only implicit localhost is available
[WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'

Now, if I output the dynamic script to a file, then run ansible again, it works:

$ ./dynamic1.sh > output.json

$ cat output.json
{
  "all": {
      "hosts": {
"ip-172-31-39-30.eu-west-1.compute.internal": null,
"ip-172-31-44-224.eu-west-1.compute.internal": null,
"ip-172-31-42-6.eu-west-1.compute.internal": null,
"ip-172-31-32-68.eu-west-1.compute.internal": null,
    }
  }
}

$ ansible -i output.json all -m ping -u ubuntu
[DEPRECATION WARNING]: Distribution Ubuntu 16.04 on host ip-172-31-42-6.eu-west-1.compute.internal should use /usr/bin/python3, but is using /usr/bin/python for
backward compatibility with prior Ansible releases. A future Ansible release will default to using the discovered platform python for this host. See
https://docs.ansible.com/ansible/2.9/reference_appendices/interpreter_discovery.html for more information. This feature will be removed in version 2.12. Deprecation
warnings can be disabled by setting deprecation_warnings=False in ansible.cfg.
ip-172-31-42-6.eu-west-1.compute.internal | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python"
    },
    "changed": false,
    "ping": "pong"
}
ip-172-31-39-30.eu-west-1.compute.internal | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    },
    "changed": false,
    "ping": "pong"
}
ip-172-31-32-68.eu-west-1.compute.internal | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    },
    "changed": false,
    "ping": "pong"
}
ip-172-31-44-224.eu-west-1.compute.internal | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    },
    "changed": false,
    "ping": "pong"
}

So it works...

This is the contents of dynamic1.sh. I know there will be better ways to do this but I just need a list of servers based on a matching variable in the JSON output that ansible can use.

$ cat dynamic1.sh
#!/bin/bash
echo "{"
echo "  \"all\": {"
echo "      \"hosts\": {"
curl --silent -X GET https://url.com/api/servers -H "Authorization: Token $token" -H "Content-Type: text/json"  -H "Accept:application/json" | jq -r '.Result.servers[] | select(.ansible_local.local.local_facts.instance_type | tostring | contains("t2.micro")) | (.ansible_fqdn+"\": null,")' | sed 's/^/"/g'
echo "    }"
echo "  }"
echo "}"

Can anyone give me any help on why ansible accepts the file but not the output of the script?

Answer 1

In contrary to the Ansible inventory format , the inventory plugin script.py expects the attribute hosts to be a list (eg hosts:[ host1, host2, host3 ] ) not a dictionary (eg hosts:{ host, host2, host3 } ).

---

Inventory plugin yaml.py works with dictionaries of hosts

The JSON (or YAML, because JSON is a subset of YAML) inventory works fine

shell> cat hosts.json
{
    "all": {
        "hosts": {
            "ip-172-31-39-30.eu-west-1.compute.internal",
            "ip-172-31-44-224.eu-west-1.compute.internal",
            "ip-172-31-42-6.eu-west-1.compute.internal",
            "ip-172-31-32-68.eu-west-1.compute.internal"
        }
    }
}

shell> ansible-inventory -i hosts.json --list -vvv
...
Parsed /scratch/tmp/hosts.json inventory source with yaml plugin
{
    "_meta": {
        "hostvars": {}
    },
    "all": {
        "children": [
            "ungrouped"
        ]
    },
    "ungrouped": {
        "hosts": [
            "ip-172-31-32-68.eu-west-1.compute.internal",
            "ip-172-31-39-30.eu-west-1.compute.internal",
            "ip-172-31-42-6.eu-west-1.compute.internal",
            "ip-172-31-44-224.eu-west-1.compute.internal"
        ]
    }
}

But, the same file provided by the script will fail

shell> cat hosts.sh 
#!/bin/bash
cat hosts.json

shell> ansible-inventory -i hosts.sh --list -vvv
...
Parsed /scratch/tmp/hosts.sh inventory source with script plugin

[WARNING]: Failed to parse /scratch/tmp/hosts.sh with script plugin: You defined a group 'all' with bad data for the host list: {'hosts': {'ip-172-31-39-30.eu- west-1.compute.internal': None, 'ip-172-31-44-224.eu-west-1.compute.internal': None, 'ip-172-31-42-6.eu-west-1.compute.internal': None, 'ip-172-31-32-68.eu- west-1.compute.internal': None}} ...

{
    "_meta": {
        "hostvars": {}
    },
    "all": {
        "children": [
            "ungrouped"
        ]
    }
}

---

Inventory plugin script.py works with lists of hosts

The inventory plugin script.py works as expected when the attribute hosts is a list

shell> cat hosts.json
{
    "all": {
        "hosts": [
            "ip-172-31-39-30.eu-west-1.compute.internal",
            "ip-172-31-44-224.eu-west-1.compute.internal",
            "ip-172-31-42-6.eu-west-1.compute.internal",
            "ip-172-31-32-68.eu-west-1.compute.internal"
        ]
    }
}

shell> ansible-inventory -i hosts.sh --list -vvv
...
Parsed /scratch/tmp/hosts.sh inventory source with script plugin
{
    "_meta": {
       ...
    },
    "all": {
        "children": [
            "ungrouped"
        ]
    },
    "ungrouped": {
        "hosts": [
            "ip-172-31-32-68.eu-west-1.compute.internal",
            "ip-172-31-39-30.eu-west-1.compute.internal",
            "ip-172-31-42-6.eu-west-1.compute.internal",
            "ip-172-31-44-224.eu-west-1.compute.internal"
        ]
    }
}

---

Notes

• The script hosts.sh is not implemented properly and serves the purpose of this example only. Quoting from script.py :

description: - The source provided must be an executable that returns Ansible inventory JSON - The source must accept C(--list) and C(--host ) as arguments. C(--host) will only be used if no C(_meta) key is present.