Error parsing metadata commands (server). Check JSON structure and network connectivity (NAT instance or Proxy)' for uniqueId

i am trying to deploy AWS spot::Fleet
via cloud formation
and i want the commands in metadata will run after the instance is up.
but got this msg:

> Error parsing metadata commands (server). Check JSON structure and
> network connectivity (NAT instance or Proxy)' for uniqueId:
> ip-10-28-6-6

what is wrong with my JSON template file?

"MyServer": {
			"Type": "AWS::EC2::SpotFleet",
			"Properties": {
				"SpotFleetRequestConfigData": {
					"IamFleetRole": "arn:aws:iam::6******2:role/aws-ec2-spot-fleet-tagging-role",
					"SpotPrice": "0.15",
					"TargetCapacity": "1",
					"LaunchSpecifications": [{
						"EbsOptimized": "false",
						"InstanceType": {
							"Ref": "myInstanceType"
						},
						"ImageId": ".....",
						"SecurityGroups": [ 
							......
						],
						"SubnetId": {
							"Ref": "mySubnet"
						},
						"WeightedCapacity": "1",
						"UserData": {
							"Fn::Base64": {
								"Fn::Join": [
									"",
									[
....
									]
								]
							}
						}
			

					}]
				}

			},
			"Metadata": {
				"AWS::CloudFormation::Init" : {
				"commands": [
					{
					  "Fn::Join":[
						 "",
						 [
							"echo ls -l /var/log > /home/MyFile.txt \n",
							"chmod 777 /var/log \n"
						 ]
					  ]
				   }
				]
			}
		}
			

Thanks for the helpers!!!!

The Metadata block has an incorrect structure. The AWS::CloudFormation::Init section should include a config section where you provide commands or other configuration details, and the commands themselves should be organized as key-value pairs, not as an array.

Here's the corrected metadata section of your template:

"Metadata": {
    "AWS::CloudFormation::Init": {
        "config": {
            "commands": {
                "command1": {
                    "command": {
                        "Fn::Join": [
                            "",
                            [
                                "echo ls -l /var/log > /home/MyFile.txt"
                            ]
                        ]
                    }
                },
                "command2": {
                    "command": "chmod 777 /var/log"
                }
            }
        }
    }
}

Userdata scripts and metadata commands run under the root by default. So you don't need to provide high-level permissions like '777' to /var/log.

Finally, your instance needs to have AWS SSM Agent installed for the AWS::CloudFormation::Init to work.