HTTP/500 error when re-running a job from History which has a blank/empty template variables

[jimbobmcgee]

I have an Otter job template for which I have defined a number of custom variables, some of which are marked as Required and some are not.

If I view previous executions of that job in /jobs/history, there is a small (play) button icon against each execution, for which I believe the intention is to re-run any one particular execution with the variable prompts pre-populated with the previously-entered values for that execution.

If there were no custom variables defined on the template or, for that execution, if all the custom variables were populated with a value, clicking that button works as intended.

If, however, I did not set a value for one of the properties (i.e. it was left as an empty text box), clicking that button results in an HTTP/500 server error. The Diagnostic Centre page yields the following:

An error occurred in the web application: The given key 'MyCustomVariableName' was not present in the dictionary.

URL: http://xxxx:8626/jobs/from-template?jobTemplateId=Default%3A%3AJobTemplate%3A%3AMyTemplateFolder%2FMyTemplateName&jobId=140
Referrer: http://xxxx:8626/jobs/history
User: Admin
User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:132.0) Gecko/20100101 Firefox/132.0
Stack trace:    at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
   at Inedo.Otter.WebApplication.Pages.Jobs.CreateJobFromTemplatePage.VariablePrompts..ctor(IEnumerable`1 variables, Dictionary`2 selectedValues, VariableTemplateContext context)
   at Inedo.Otter.WebApplication.Pages.Jobs.CreateJobFromTemplatePage.CreateChildControls()
   at Inedo.Otter.WebApplication.Pages.OtterSimplePageBase.InitializeAsync()
   at Inedo.Web.PageFree.SimplePageBase.ExecutePageLifeCycleAsync()
   at Inedo.Web.PageFree.SimplePageBase.ProcessRequestAsync(AhHttpContext context)
   at Inedo.Web.AhWebMiddleware.InvokeAsync(HttpContext context)

::HTTP Error on 19/12/2024 18:55:42::

I'm fairly certain it boils down to a simple null-ref check in the CreateJobFromTemplatePage class (decompiled from Otter.WebApplication.dll):

public VariablePrompts(IEnumerable<TemplateVariable> variables, Dictionary<string, string> selectedValues, VariableTemplateContext context)
{
    object item;
    CreateJobFromTemplatePage.VariablePrompts variablePrompt = this;
    foreach (TemplateVariable variable in variables)
    {
        if (this.variableValues.ContainsKey(variable.Name))
        {
            continue;
        }
        TemplateVariable templateVariable = variable;
        if (selectedValues != null)
        {
            item = selectedValues[variable.Name];    // <-- here
        }
        else
        {
            item = null;
        }
        if (item == null)
        {
            item = variable.InitialValue;
        }
        templateVariable.InitialValue = (string)item;
        VariableTemplateInput variableTemplateInput = variable.Type.CreateInput(variable, context);
        variablePrompt.get_Controls().Add(variableTemplateInput);
        this.variableValues.Add(variable.Name, variableTemplateInput);
    }
}

My guess is that you are not serializing unset/empty values or that they are not being deserialized correctly to the selectedValues dictionary by the caller. Whether or not that is a larger problem is unknown, but you can probably bandage it here by simply changing to...

if (selectedValues != null || !selectedValues.ContainsKey(variable.Name))
{
    item = selectedValues[variable.Name];
}

...without affecting the surrounding logic.

[dean-houston]

@jimbobmcgee thanks for the detailed analysis! This is on my list, but haven't had time to properly reproduce and test this.... but as you noted, the code fix looks so easy.

I just made a quick change (OT-513) and prerelease (2024.2-rc.1). Can you give it a shot?

https://docs.inedo.com/docs/installation/windows/howto-install-prerelease-product-versions

[jimbobmcgee]

@dean-houston This might be a really silly question, but what is the URL for the Pre-Release package source feed?

The linked documentation suggests that Package source should be a drop-down list in InedoHub (from which I should select Inedo's Prerelease Feed); mine is a free text field containing https://proget.inedo.com/upack/Products.

[atripp]

@jimbobmcgee

I think you might have an old version of Inedo Hub; you can just download a new version and the dropdown will be there. I guess the old version should work, I just worry about some bugfix/change that might cause newer versions to not work.

The feed is https://proget.inedo.com/upack/PrereleaseProducts

[jimbobmcgee]

Can confirm 2024.2-rc.1 fixes this specific HTTP/500 error. Thanks for looking.

(@atripp - as soon as I manually changed the feed URL in InedoHub to the one you gave, it offered to update itself from 1.3.12 to 1.4.4, so I did that first. Ironically, 1.3.12 is the version in the documentation page's screenshot, so I didn't consider it might be out of date.)

[atripp]

@jimbobmcgee excellent thanks!! Release has been published then :)