Extract value from Ansible task output and create a variable from it - json

Question

I use elb_application_lb_info module to get info about my application load balancer. Here is the code I am using for it:
- name: Test playbook
hosts: tag_elastic_role_logstash
vars:
aws_access_key: AKIARWXXVHXJS5BOIQ6P
aws_secret_key: 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
tasks:
- name: Gather information about all ELBs
elb_application_lb_info:
aws_access_key: AKIXXXXXXXXXXXXXXXXXXX
aws_secret_key: gG6a586XXXXXXXXXXXXXXXXXX
region: ap-southeast-2
names:
- LoadBalancer
register: albinfo
- debug:
msg: "{{ albinfo }}"
This is working fine and I got the following output:
"load_balancers": [
{
"idle_timeout_timeout_seconds": "60",
"routing_http2_enabled": "true",
"created_time": "2021-01-26T23:58:27.890000+00:00",
"access_logs_s3_prefix": "",
"security_groups": [
"sg-094c894246db1bd92"
],
"waf_fail_open_enabled": "false",
"availability_zones": [
{
"subnet_id": "subnet-0195c9c0df024d221",
"zone_name": "ap-southeast-2b",
"load_balancer_addresses": []
},
{
"subnet_id": "subnet-071060fde585476e0",
"zone_name": "ap-southeast-2c",
"load_balancer_addresses": []
},
{
"subnet_id": "subnet-0d5f856afab8f0eec",
"zone_name": "ap-southeast-2a",
"load_balancer_addresses": []
}
],
"access_logs_s3_bucket": "",
"deletion_protection_enabled": "false",
"load_balancer_name": "LoadBalancer",
"state": {
"code": "active"
},
"scheme": "internet-facing",
"type": "application",
"load_balancer_arn": "arn:aws:elasticloadbalancing:ap-southeast-2:117557247443:loadbalancer/app/LoadBalancer/27cfc970d48501fd",
"access_logs_s3_enabled": "false",
"tags": {
"Name": "loadbalancer_test",
"srg:function": "Storage",
"srg:owner": "ISCloudPlatforms#superretailgroup.com",
"srg:cost-centre": "G110",
"srg:managed-by": "ISCloudPlatforms#superretailgroup.com",
"srg:environment": "TST"
},
"routing_http_desync_mitigation_mode": "defensive",
"canonical_hosted_zone_id": "Z1GM3OXH4ZPM65",
"dns_name": "LoadBalancer-203283612.ap-southeast-2.elb.amazonaws.com",
"ip_address_type": "ipv4",
"listeners": [
{
"default_actions": [
{
"target_group_arn": "arn:aws:elasticloadbalancing:ap-southeast-2:117557247443:targetgroup/test-ALBID-W04X8DBT450Q/c999ac1cda7b1d4a",
"type": "forward",
"forward_config": {
"target_group_stickiness_config": {
"enabled": false
},
"target_groups": [
{
"target_group_arn": "arn:aws:elasticloadbalancing:ap-southeast-2:117557247443:targetgroup/test-ALBID-W04X8DBT450Q/c999ac1cda7b1d4a",
"weight": 1
}
]
}
}
],
"protocol": "HTTP",
"rules": [
{
"priority": "default",
"is_default": true,
"rule_arn": "arn:aws:elasticloadbalancing:ap-southeast-2:117557247443:listener-rule/app/LoadBalancer/27cfc970d48501fd/671ad3428c35c834/5b5953a49a886c03",
"conditions": [],
"actions": [
{
"target_group_arn": "arn:aws:elasticloadbalancing:ap-southeast-2:117557247443:targetgroup/test-ALBID-W04X8DBT450Q/c999ac1cda7b1d4a",
"type": "forward",
"forward_config": {
"target_group_stickiness_config": {
"enabled": false
},
"target_groups": [
{
"target_group_arn": "arn:aws:elasticloadbalancing:ap-southeast-2:117557247443:targetgroup/test-ALBID-W04X8DBT450Q/c999ac1cda7b1d4a",
"weight": 1
}
]
}
}
]
}
],
"listener_arn": "arn:aws:elasticloadbalancing:ap-southeast-2:117557247443:listener/app/LoadBalancer/27cfc970d48501fd/671ad3428c35c834",
"load_balancer_arn": "arn:aws:elasticloadbalancing:ap-southeast-2:117557247443:loadbalancer/app/LoadBalancer/27cfc970d48501fd",
"port": 9200
}
],
"vpc_id": "vpc-0016dcdf5abe4fef0",
"routing_http_drop_invalid_header_fields_enabled": "false"
}
]
I need to fetch "dns_name" which is dns name of the load balancer and pass it in another play as a variable.
I tried with json_query but got the error. Here is the code:
- name: save the Json data to a Variable as a Fact
set_fact:
jsondata: "{{ albinfo.stdout | from_json }}"
- name: Get ALB dns name
set_fact:
dns_name: "{{ jsondata | json_query(jmesquery) }}"
vars:
jmesquery: 'load_balancers.dns_name'
- debug:
msg: "{{ dns_name }}"
And here is the error:
"msg": "The task includes an option with an undefined variable. The error was: Unable to look up a name or access an attribute in template string ({{ albinfo.stdout | from_json }}).\nMake sure your variable name does not contain invalid characters like '-': the JSON object must be str, bytes or bytearray
Any idea how to extract "dns_name" from the json above?

Answer 1

Here is the way to get the dns_name from above json output:
- name: Get Application Load Balancer DNS Name
set_fact:
rezultat: "{{ albinfo | json_query('load_balancers[*].dns_name') }}"
- debug:
msg: "{{ rezultat }}"