Try the following please:
Python Command Line (SLCLI)
slcli call-api Virtual_Guest mountIsoImage --id $vsiId $diskImageId
e.g:
slcli call-api Virtual_Guest mountIsoImage --id 22892000 14121207
Rest:
https://$user:$apiKey@api.softlayer.com/rest/v3.1/SoftLayer_Virtual_Guest/22892000/mountIsoImage
Method: Post
{
"parameters":[
14121207
]
}
Replace: $user, $apiKey, 22892000(vsiId) and 14121207(diskImageId) with your own information
Updated
According to the exception that you got, it seems that you are not sending a diskImageId valid, if you wish to get the diskImageId from your image template, try the following:
Python Command Line (SLCLI)
slcli call-api Virtual_Guest_Block_Device_Template_Group getChildren
--id $templateGroupId --mask=blockDevices.diskImageId
to get more details about disk images from the image template:
> slcli call-api Virtual_Guest_Block_Device_Template_Group getChildren
> --id $templateGroupId --mask=blockDevices.diskImage
Replace $templateGroupId with your image id
Rest:
https://$user:$apiKey@api.softlayer.com/rest/v3.1/SoftLayer_Virtual_Guest_Block_Device_Template_Group/$templateGroupId/getChildren?objectMask=mask[blockDevices[diskImage]]
Method: Get
References: