Error retrieving ID of template: json: cannot unmarshal object into Go struct field alias.childtemplates of type []interface {} #15

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1. yadvr

   assigned

   Pearl1594

   on Oct 12, 2021
2. yadvr

   assigned

   davidjumani

   on Nov 19, 2021
3. synergiator commented on Nov 28, 2021

   

   synergiator

   on Nov 28, 2021

   More actions

   Strange enough, VM deployment using a unit test works, can't reproduce this error with this SDK itself.
   Based on the mock test kindly provided by @Pearl1594 (just removed the HTTP mock server and hardcoded required params/values) I've tried the following against an instance with API level 4.11:

   func TestVirtualMachineService_DeployVirtualMachineReal(t *testing.T) {
   	
   	var URL="https://<DOMAIN>/client/api"
   	var APIKEY =  ...
   	var SECRETKEY = ...
   
   	var zoneid = "23ec4069-ede9-46b4-9236-d8e373a4ef59"
   	var templateid = "450ec62f-16b1-4d04-a00b-a6fd4933e429"
   	var networkids = []string{"690ef536-3996-4aaf-b45d-5501f079d6eb"}
   	var serviceofferingid = "171aa1ff-3c93-4030-946a-d16e34774a76"
   
   	client := NewAsyncClient(URL, APIKEY, SECRETKEY, true)
   	params := client.VirtualMachine.NewDeployVirtualMachineParams(serviceofferingid, templateid, zoneid)
   	params.SetName("testDummyVM")
   	params.SetNetworkids(networkids)
   	resp, err := client.VirtualMachine.DeployVirtualMachine(params)
   	if err != nil {
   		t.Errorf("Failed to deploy VM with given specs due to %v", err)
   		return
   	}
   
   	if resp == nil || resp.Name != "testDummyVM" {
   		t.Errorf("Failed to deploy VM with given specs")
   	}
   }
   
   

   Run single unit test:

   go test -v -run TestVirtualMachineService_DeployVirtualMachineReal
   

   Result: VM appears in the management UI and the test reports success.

   === RUN   TestVirtualMachineService_DeployVirtualMachineReal
   --- PASS: TestVirtualMachineService_DeployVirtualMachineReal (79.34s)
   
4. yadvr commented on Nov 29, 2021

   

   yadvr

   on Nov 29, 2021

   Member

   More actions

   Perhaps this is no longer an issue now, can you check and confirm @nishiokay @synergiator ? Thanks.
5. davidjumani commented on Nov 29, 2021

   

   davidjumani

   on Nov 29, 2021

   Last edited by davidjumani

   Contributor

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   This appears to be an issue with parsing the listTemplate API response, @nishiokay could you :

   • List the template (which has child templates) via the sdk
   • Provide the response to the listTemplate response with the templateid 450ec62f-16b1-4d04-a00b-a6fd4933e429 (or whichever one you're having issues with on terraform)
6. synergiator commented on Dec 27, 2021

   

   synergiator

   on Dec 27, 2021

   More actions

   In the test asset, there is no method to test listing templates.
7. yadvr

   assigned

   shwstppr

   and unassigned

   davidjumani

   and

   Pearl1594

   on Feb 9, 2024
8. DaanHoogland

   added this to Apache CloudStack BugFest - Issueson May 15, 2026
9. DaanHoogland

   moved this to Todo in Apache CloudStack BugFest - Issueson May 15, 2026
10. DaanHoogland

    added this to the 2.20.0 milestone on May 19, 2026
11. jmsperu commented on Jun 20, 2026

    

    jmsperu

    on Jun 20, 2026

    Contributor

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    Still reproduces on current main (2026). Minimal repro:

    body := `{"id":"t1","name":"tmpl","childtemplates":{"foo":"bar"}}`
    var tmpl cloudstack.Template
    err := json.Unmarshal([]byte(body), &tmpl)
    // json: cannot unmarshal object into Go struct field alias.childtemplates of type []interface {}

    Root cause: childtemplates is declared "type": "set" in listApis.json, and the generator maps set → []interface{} (mapType, generate.go). But some CloudStack/CloudPlatform versions return childtemplates as a JSON object, not an array, so json.Unmarshal fails — and because it is hit through the struct’s custom UnmarshalJSON (type alias Template), the whole template (and thus listTemplates / GetTemplateID) fails. The field appears as []interface{} in 7 template structs (Template, CopyTemplateResponse, CreateTemplateResponse, PrepareTemplateResponse, RegisterTemplate, UpdateTemplateResponse, …).

    Suggested fix: narrowly special-case this field — make childtemplates interface{} instead of []interface{} (interface{} accepts an object, an array, or null). It must be a field-level special-case, not a change to the set→[]interface{} mapping, which would touch ~100 unrelated fields. It is a small type change (slice → interface{}) on a field that is already opaque and currently unusable on the affected versions, so net it restores functionality.

    I have this fix + a regression test ready (the repro above passes after the change, fails before). Happy to open a PR if a maintainer is OK with the interface{} approach — flagging the minor type change for visibility before I do.
12. abh1sar

    modified the milestones: 2.20.0, 2.19.1 on Jul 12, 2026