loadTextContent() - support variable or parameter as input

[slavizh]

Is your feature request related to a problem? Please describe.

I would like for loadTextContent() to support variable or parameter as input parameter. What I would like to offer is for the end user to specify text from file or to use the default file available. Currently if I use the below syntax I get error:
The value must be a compile-time constant.bicep(BCP032)

I know that function is being used at compile time so this will probably require some other approach and even changes in template spec for supporting it there as well.

var alertRules = {
  memoryLow: {
    description: empty(bastionHostMonitoring.alertRules.memoryLow.descriptionFilePath) ? loadTextContent('alert-descriptions/memory-low.txt') : loadTextContent(bastionHostMonitoring.alertRules.memoryLow.descriptionFilePath)
  }
}

[alex-frankel]

We cannot do this with a param since we won't know the value at compile time. In other words, if you were to run bicep build with a param argument, we'd have no idea which file to "load".

In theory, this should be possible with variables, but my understanding is it requires more of #444 implemented

[mblant]

Very interested in this thread.

The ability to load another file inside a var would open a load of options around not hardcoded 10s or 100s are variables to reference existing file to load data

var manifest = json(loadTextContent('./data/manifest.json'))

var itemsArray = [ for item in manifest : {
  data: json(loadTextContent('./data/${item.dataFile}'))
  parameters: json(loadTextContent('./data/${item.parametersFile}'))
}

In theory, this should all be available at compile time as all files are static and nothing is dynamically generated.
The manifest object is be generated. So, the itemsArray should be compiled off manifest as well at compile time. Depending on how the complier interrupts order of operation, right?

[alex-frankel]

#3607 seems related to this @mblant, but it is not the same ask

[mblant]

I removed the string interpellation and just put the file path in the manifest file and it worked. So, I then assumed it is the interpellation causing the compile time error.

But then, after three or four runs in my test environment, it’s back to the compile time error “The value must be a compile-time constant. bicep(BCP032)”
Not sure what is up in the compiler that it let it run several times (and it actually worked!!) only to go back to throwing the error with no changes?
Happy to get some more data, if someone can give a pointer on where to start.

az bicep version
Bicep CLI version 0.4.1124 (66c84c8)

[mblant]

Interesting. No errors if there is only a single element in the manifest.json. Add additional elements and back to failure.

[leechan-bicep]

Hi, I have the same error when providing more than one file location getting the "The value must be a compile-time constant." error.Please let us know how to fix this issue

var stringArray = [
'./policies/policy_1.json'
]

var policies = [for i in range(0, length(stringArray)): json(loadTextContent(stringArray[i]))]

[alex-frankel]

Repro for triage:

works:

var stringArray = [
  './policies/policy_1.json'
]
  
var policies = [for i in range(0, length(stringArray)): json(loadTextContent(stringArray[i]))]

doesn't work:

var stringArray = [
  './policies/policy_1.json'
  './policies/policy_2.json'
]
  
var policies = [for i in range(0, length(stringArray)): json(loadTextContent(stringArray[i]))]

[alex-frankel]

The reason this works is because the type of a single-item string array gets simplified down to a string literal, which the function can handle. It's not something we intentionally designed and in fact we should probably block this scenario. We are going to take a look at validating this better.

[alex-frankel]

@miqm will break out this last comment and track the fix with a separate issue

[miqm]

Anyway, back to the original proposal - using parameters as arguments for loadTextContent is not possible. Parameters are evaluated during the deployment (runtime), while file loading in loadTextContent is done during compilation (bicep build command). the azure cli does the compilation on the fly before the actual deployment occurs, hence the impression that it could be done.

The only way I can think of to provide this functionality is to introduce a compile-time parameters (similar to C# symbols - https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/preprocessor-directives#conditional-compilation).
AFAIR there are some other issues that refers to introducing similar functionality (i.e. #3109, #1761). It might be worth to think about it. but IMHO it will not be as fast as you would like :)

[cpinotossi]

Hello, would be great if we would support this and make it more general. So it will also support similar functions like loadFileAsBase64.
It would give more flexibility when working with modules.

[miqm]

Would having function that loads json from file be a solution? Mind, that vars can be runtime values, while load* functions can accept only compile-time values as arguments.

[wsucoug69]

We have the same requirement\need, we are creating role definitions and looking to pass in the json file containing the permissions.

[garrettsingletary]

+1 to this. Have the same need for populating permissions from json.

[charotAmine]

Hello @leechan-bicep , @alex-frankel

A workaround for this :

Hi, I have the same error when providing more than one file location getting the "The value must be a compile-time constant." error.Please let us know how to fix this issue

var stringArray = [ './policies/policy_1.json' ]

var policies = [for i in range(0, length(stringArray)): json(loadTextContent(stringArray[i]))]

May be :
var stringArray = [
loadTextContent('./policy-1.json')
loadTextContent('./policy-2.json')
loadTextContent('./policy-3.json')
]

var policies = [for i in range(0, length(stringArray)): json(stringArray[i])]
Since in anyways, we should put a constant path.

[SeSeicht]

hey, I tried @charotAmine code, but it didn't worked for me. But I created a similar way to solve this:
@alex-frankel goes in the same direction like your code snippet

var stringArray = [
  json(loadTextContent('./file1.json'))
  json(loadTextContent('./file2json'))
  json(loadTextContent('./file3.json'))
  ]

module m_pol_def 'br/modules:microsoft.authorization.policydefinitions:1.0' = [for onePol in stringArray: { 
  name: onePol.name
    params: {...}
}]

[calebherbison]

+1 for using this to load local files for openapi specs

[krowlandson]

@alex-frankel

I have a similar situation which appears to be a cross between this issue and #3607.

In my case, I am looking to load multiple "resource configuration" files. These files may vary from deployment to deployment but will be re-usable. Depending on the specific scenario, I would like to point my Bicep configuration at a single JSON file containing a list of required "resource configuration" files, and then loop over that to load in the "resource configuration" files.

I will always know the location of the first file, and the point of this is to abstract the list of other sources from the template to simplify code maintenance and D.R.Y.

Take an example such as the following:

configLocations.Scenario1.json example

[
    "config/resource1settings.json",
    "config/resource2settings.json",
    "config/resource3settings.json",
    "config/resource4settings.json",
    "config/resource5settings.json",
    "config/resource6settings.json"
]

config/resource1settings.json example

{
  "setting1": "value",
  "setting2": 100,
  "setting3": true,
  "setting4": []
}

sample.bicep example

// The following var is used to load the list of resource configs to import
var listResourceConfigs = loadJsonContent('configLocations.Scenario1.json')

// The following var is used to load the resource configs
var resourceConfigs = [for config in listResourceConfigs: loadJsonContent(config)]

This results in the error The value must be a compile-time constant.bicep(BCP032):

As such, it would be really useful to have a way to do the following for compile-time operations:

1. Declare constants (only visible in Bicep, maybe using a decorator format such as @constant(key='value'))
2. Support for loops (again, possibly using a different format to declare the loops so they are explicitly identified as used at compile-time)

In my scenario, explicitly declaring the list of "resource configuration" files into the bicep file as proposed in the above "work-arounds" would defeat the point of this abstraction.

Thank you

[brwilkinson]

Adding comment for support.

• Currently a custom PowerShell deployment Script is required to pass in metadata for deployment.
  • I would like to remove the requirement for this custom deploy script.

I currently pull in 3 files with Global or Regional metadata.

1. Global metadata
2. Regional metadata
3. Custom role definition lookups

• E.g. For 3, exported lists for role assignments for a specific subscription, to do friendly name lookups for role assignments. This is required because different custom role assignments are available in different subscriptions.

    # Read in the Rolegroups Lookup.
    $RolesGroupsLookup = Get-Content -Path $Artifacts/tenants/$App/Global-Config.json | ConvertFrom-Json -Depth 10 | ForEach-Object RolesGroupsLookup
    $Global.Add('RolesGroupsLookup', ($RolesGroupsLookup | ConvertTo-Json -Compress -Depth 10))

I would like to move this into the Bicep template file itself.

param App string = 'LAB'
var computeGlobal = json(loadTextContent('../tenants/${App}/Global-Config.json'))

Since the project can deploy to multiple subscriptions, I need to pass in the App to differentiate which Role lookup file to use,

The value must be a compile-time constant.

• Since this is unsupported, I still depend on the custom deployment PowerShell script.

The deployment script that I currently use for ALL deployments.

• https://github.com/brwilkinson/AzureDeploymentFramework/blob/main/ADF/release-az/Start-AzDeploy.psm1#L66

Examples of the metadata files that I have-to pass in at runtime (per tenant/App) in the above script.

• https://github.com/brwilkinson/AzureDeploymentFramework/blob/main/ADF/tenants/LAB/Global-Config.json (Role lookups)
• https://github.com/brwilkinson/AzureDeploymentFramework/blob/main/ADF/tenants/LAB/Global-Global.json (Global)
• https://github.com/brwilkinson/AzureDeploymentFramework/blob/main/ADF/tenants/LAB/Global-ACU1.json (Region)

[UmairSyed]

+1 please

[Kielar-Peter]

+1

[AshutoshNirkhe]

This will be really a value addition!

[jimSampica]

This is something Terraform supports so Bicep should too. It is not possible to download and deploy a certificate resource unless the path is known at deploy time. Only workaround is using a keyvault instead.

Terraform:

resource "azurerm_app_service_certificate" "webapp_certificate" {
    ...
    pfx_blob = filebase64(var.certificate_path) // Works
}

Bicep:

resource certificate 'Microsoft.Web/certificates@2022-09-01' = {
    ...
    properties: {
        pfx_blob: loadFileAsBase64(certificate_path) // Compile error
    }
}

[brwilkinson]

An additional comment on this... If you test out bicepparam you can create a parameter that uses loadtextcontent() or other loadX() to read the file. By having this in the parameter file instead of the template, you get some degree in flexibility to read different files based on the parameter file you are using.

[jimSampica]

Good to know. I dont think a parameter file will work in my case because I want to download a secure file from Azure DevOps and read the contents in.

[brwilkinson]

@jamesSampica

Bicep functions are supported in bicepparam.

https://learn.microsoft.com/en-us/azure/azure-resource-manager/bicep/bicep-functions-string#base64tostring

https://learn.microsoft.com/en-us/azure/azure-resource-manager/bicep/bicep-functions-files#loadfileasbase64

[brwilkinson]

Still exploring bicepparam

I like that you can reference other parameters in bicepparam file. E.g. Prefix below.

using '../../bicep/00-ALL-SUB.bicep'

param Global = union(
  loadJsonContent('Global-${Prefix}.json'), // Can reference this file based on the region I am in... clone the file, update the Prefix
  loadJsonContent('Global-Global.json'),
  loadJsonContent('Global-Config.json')
  )

param Prefix = 'AWU3'
param Environment = 'P'
param DeploymentID = '0'

I haven't completed testing all scenarios, however I believe this covers my needs from my previous comment in this thread, where I achieved the above union with PowerShell custom code.

• loadTextContent() - support variable or parameter as input #3816 (comment)

[sohirani]

+1

[gscorrea]

+1
I am in the middle of defining variables that need to ready yaml/json/text contents from files to build AOSM NFDV for a bicep publisher file.
The thing is that besides these variables the bicep publisher is common to several of my NFs to be published, so I do not want to have to make copies of same files several times to build the NFDV for my NFs, but I want to use params/variables to build the load(Yaml/Json/Text)Content filePath and use same bicep to publish my NFs NFDVs.
Commented out below is how I tried to implement with params on the filePath and did not work, but this is needed.
I understand that at this time the bicep build process happens before the params are read, but I have a need to have the params available at bicep build time.

param aksClusterGroup string
param aksClusterName string
param aosmParametersLocation string
param aosmSchemaLocation string
param aosmSetSetFilesParametersLocation string
param artifactManifestName string
param artifactStore string
param cgsName string
param cgvName string
param cnfName string
param helmPackageName string
param helmPackageVersion string
param helmReleaseName string
param location string = resourceGroup().location
param nfdgroupName string
param nfdvNfName string
param nfdversion string
param nsdGroup string
param nsdvName string
param publisherName string
param releaseNamespace string
param resourceExists bool = false
param siteName string
param snsName string
param valuesLocation string
param valuesParam object
param yamlLocation string
//********************************************
//LOADING ALL VALUES ON allTogether
//********************************************
//var mval = loadYamlContent(valuesLocation'/'cnfName'-values.yaml') //parameters passed to helm chart
//var svals = loadJsonContent(aosmSetSetFilesParametersLocation'/'cnfName'_nf_deployment_set_parameters.json') //file with --set parameters for helm
var mval = loadYamlContent('../values.final/my_cnf-values.yaml') //parameters passed to helm chart
var svals = loadJsonContent('../aosmSetSetFilesParameters.final/my_cnf_nf_deployment_set_parameters.json') //file with --set parameters for helm
var allTogether= union(mval, svals) //joining parameters. change order of list to use correct precedence.

[Afsalmc]

I am facing the same issue while loading a script for deploymentscript bicep module.

[obriankevin11]

same here

[lesca]

+1

[thisispr]

+1

[hybridtechie]

+1

[Saulopv]

+1

[SvenRelijveld1995]

+1

[dewolfs]

Running into the error

Error BCP032: The value must be a compile-time constant.

when trying to import an API into Azure API Management based on the OpenAPI specification.
Our API is private so we need to use format openapi+json.

• openapi+json: The contents are inline and Content Type is a OpenAPI 3.0 JSON Document.
• openapi-link: The OpenAPI 3.0 YAML document is hosted on a publicly accessible internet address.

Ref: https://learn.microsoft.com/en-us/javascript/api/@azure/arm-apimanagement/contentformat?view=azure-node-latest

param openApiSpecJSON string

resource apis 'Microsoft.ApiManagement/service/apis@2022-08-01' = {
    ...
    description: api.apiDescription
    format: 'openapi+json'
    value: loadTextContent('${openApiSpecJSON}')
  }
}

[nayanshah]

Repro for triage:

works:

var stringArray = [
  './policies/policy_1.json'
]
  
var policies = [for i in range(0, length(stringArray)): json(loadTextContent(stringArray[i]))]

doesn't work:

var stringArray = [
  './policies/policy_1.json'
  './policies/policy_2.json'
]
  
var policies = [for i in range(0, length(stringArray)): json(loadTextContent(stringArray[i]))]

The currently supported way for making this work involves duplicating loadTextContent calls which gets annoying if additional logic is needed like in #10112. This violates Goal-4 i.e. "Code re-use should not require any 'copy/paste'-ing".

P.S: my workaround for this issue is generating a .bicep file before compilation which isn't ideal but gets the job done - Example: https://gist.github.com/nayanshah/7c86cfe6c9882c9e8133cee6ce17c9bb

[woeterman94]

Any update on this?
I'd love to be able to do:
value: loadTextContent('policies/${environmentName}.xml')

[corwestermaniddink]

+3 .. really Microsoft, fix this.

Almost can't believe I ran into this limitation. It's really a bugger, because this means redundancy in my Bicep modules. Bicepparam is also not working for my use-case.

The use-case based upon Microsoft his own example for Azure Search setup, found here: https://github.com/Azure-Samples/azure-search-deployment-template/blob/main/bicep/setup-search-service.bicep (row 50)

[bpwc]

+1
seriously? this is a deal breaking limitation

[mennolaan]

Please lets get bicep finally mature and workable, this is one of the many things IaC like bicep should support. And while at it, make sure to get it working in bicep and bicep param files.

The thing is, this has been asked three years ago. Sometimes I wonder how big the team of bicep is. Very big shortcomings like this, or the extend param feature that has been butchered or even creating a static var is not supported. We're talking about Microsoft, we're talking about bicep. Does Microsoft even care about proper DevOps? Im sure the few people working in the bicep team care a lot, but it's just insane how bad Bicep still is after all these years. the progress is so slow, and what has been put out isn't even the biggest issues we DevOps engineers face.

[alex-frankel]

The reality is the team is relatively small and age of an issue is not determinant of what gets prioritized. We would love to be able to do every feature request that has been accepted once enough time has progressed, but we don't have that luxury. I know these are not the answers people want to hear, but always want to be as transparent with you all as possible.

what has been put out isn't even the biggest issues we DevOps engineers face.

If we are getting our priorities wrong, we want to know that as that's what we have the power to change. Is there something we are working on now that you feel should be de-prioritized? On our Community Call tomorrow, we will be discussing what our plans are for the remainder of the semester (through 3/31). That will be a great forum to share these concerns.

Regarding bicepparam, have you filed an issue to help us understand what has been "buchered"? We would definitely want to understand that better. I imagine @stephaniezyen / @polatengin would also be happy to jump on a call as they were researching the work remaining for bicepparam that must be urgently completed.

[mennolaan]

Hi Alex,

There was a bit frustration in my message after trying for days to get something simple working in bicep (just a constant value to be shared across bicepparam files). With every possible solution we come across Open reports in GitHub that have been reported years ago.

This is one of them, #14656 is another regarding extended bicepparams,. In relation we have #14135 although not open for long. I did comment on the pr's we saw on extended and others as well, and seeying what was actually released felt more like a hello world example that missed the biggest requests we had with it. But not being able to actually UDT is the biggest, this is something we should be using as much as possible as it prevents run time errors.

Bicep has been out for a long time. If it was a small shop that tried something new, it would have been understandable. But it just amazes me that the company who created the best developer environment with visual studio and c#/.Net, bicep seems to not get that much love.

Its a shame because there is real potential, but to be honest. The more I use it the more I question if its really a smart move regarding getting a stable production ready IaC. The features like sharing vars across bicepparam files, or declaring statics, even updating keys in keyvaults Azure/bicep-types-az#1906 should be long hanging fruit. Some functions are possible in bicep files, some in bicepparam files, but to be honest why not both? For example why can i not do read environment var in bicep files but i can in bicepparam files?

I'm always eagerly awaiting the community calls because i do care, but to be honest, for two years we see the date being pushed back for alpha release. Eveyr time i ask myself, what the new release date? That does make you wonder. Nothing but the best towards the team and you guys, like I said, they must care. But Microsoft also needs to start caring more about this.

I'll have a look at your referred page regarding features for the community call.

[alex-frankel]

@mennolaan would you be up for having an extended call with the product group? I think you are touching on a lot of good points that we'd love to unpack with you further. Then, if you think it's a good idea, we can share the notes and any action items from the call with the community.

If you're interested, send me an email at [email protected] and we will set it up.