setUserMetadata.json

{
    "description": " Set a metadata to VSI",
    "link": "no link",
    "priority": "critical",
    "type": "[POST][GET][PUT]",
    "url": "https://USERNAME:apikey_goes_here@api.softlayer.com/v3/sldn/rest/SoftLayer_Virtual_Guest/87777/setUserMetadata.json",
    "parameters": [
        [
            "userMetadata1"
        ]
    ],
    "response" : "true"
}