Hello, I am attempting to create an auto-scaling group with Heat. The group is deployed properly along with scale up and scale down policies. When attempting to curl with POST, I get the following response. This is using the "alarm_url" from the scaling policy. Below is also the Heat template being utilized. Below the error response is the curl command. Wondering why there is an AWSAccessKeyId in the signature of the URL as well. <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <html><head> <title>500 Internal Server Error</title> </head><body> <h1>Internal Server Error</h1> <p>The server encountered an internal error or misconfiguration and was unable to complete your request.</p> <p>Please contact the server administrator at [no address given] to inform them of the time this error occurred, and the actions you performed just before this error.</p> <p>More information about this error may be available in the server error log.</p> </body></html> CURL COMMAND: curl -X POST <external-os-url>/v1/signal/arn%3Aopenstack%3Aheat%3A%omitted3Astacks/stack_1/omitted/resources/scale_down_policy\?SignatureMethod\=HmacSHA256\&SignatureVersion\=2\&AWSAccessKeyId\=omitted\&Signature\=omitted TEMPLATE: heat_template_version: 2021-04-16 description: OpenStack Heat template to deploy a autoscaling group resources: asg: type: OS::Heat::AutoScalingGroup properties: desired_capacity: 6 max_size: 8 min_size: 2 rolling_updates: min_in_service: 1 max_batch_size: 2 pause_time: 3 resource: type: OS::Nova::Server properties: flavor: m1.small image: image key_name: my-keypair networks: - network: network user_data: | #!/bin/sh echo 'hello, world123' > /tmp/test_file scale_up_policy: type: OS::Heat::ScalingPolicy properties: adjustment_type: change_in_capacity auto_scaling_group_id: { get_resource: asg } cooldown: 60 scaling_adjustment: 1 scale_down_policy: type: OS::Heat::ScalingPolicy properties: adjustment_type: change_in_capacity auto_scaling_group_id: { get_resource: asg } cooldown: 60 scaling_adjustment: -1 outputs: scale_up_url: description: > This URL is the webhook to scale up the group. You can invoke the scale-up operation by doing an HTTP POST to this URL; no body nor extra headers are needed. value: {get_attr: [scale_up_policy, alarm_url]} scale_dn_url: description: > This URL is the webhook to scale down the group. You can invoke the scale-down operation by doing an HTTP POST to this URL; no body nor extra headers are needed. value: {get_attr: [scale_down_policy, alarm_url]} asg_size: description: > This is the current size of the auto scaling group. value: {get_attr: [asg, current_size]} server_list: description: > This is a list of server names that are part of the group. value: {get_attr: [asg, outputs_list, name]} networks: description: > This is a map of server resources and their networks. value: {get_attr: [asg, outputs, networks]} server_ips: description: > This is a list of first ip addresses of the servers in the group for a specified network. value: {get_attr: [asg, outputs_list, networks, {get_param: network}, 0]} Regards, Devin