How can I pass map variable to Azure Devops pipeline job? - azure

Question

I'm learning Azure Devops pipelines, my first project is to create simple vnet with subnet using Terraform. I figured how to pass simple key-value variables, but problem is how to pass for example list of strings or more important, map variable from Terraform.
I'm using it to create subnets using each key - each value loop.
There are files that I'm using, I'm getting error about syntax in pipeline.yaml for VirtualNetworkAddressSpace and VirtualNetworkSubnets values.
Can you please help me with this one?
variables.tf
variable RG_Name {
type = string
#default = "TESTMS"
}
variable RG_Location {
type = string
#default = "West Europe"
}
variable VirtualNetworkName {
type = string
#default = "TESTSS"
}
variable VirtualNetworkAddressSpace {
type = list(string)
#default = ["10.0.0.0/16"]
}
variable VirtualNetworkSubnets {
type = map
#default = {
#"GatewaySubnet" = "10.0.255.0/27"
#}
}
dev.tfvars
RG_Name = __rgNAME__
RG_Location = __rgLOCATION__
VirtualNetworkName = __VirtualNetworkName__
VirtualNetworkAddressSpace = __VirtualNetworkAddressSpace__
VirtualNetworkSubnets = __VirtualNetworkSubnets__
pipeline.yaml
resources:
repositories:
- repository: self
trigger:
- feature/learning
stages:
- stage: DEV
jobs:
- deployment: TERRAFORM
displayName: 'Terraform deployment'
pool:
nvmImage: 'ubuntu-latest'
workspace:
clean: all
variables:
- name: 'rgNAME'
value: 'skwiera-rg'
- name: 'rgLOCATION'
value: 'West Europe'
- name: 'VirtualNetworkName'
value: 'SkwieraVNET'
- name: 'VirtualNetworkAddressSpace'
value: ['10.0.0.0/16']
- name: 'VirtualNetworkSubnets'
value: {'GatewaySubnet' : '10.0.255.0/27'}
environment: 'DEV'
strategy:
runOnce:
deploy:
steps:
- checkout: self
- task: qetza.replacetokens.replacetokens-task.replacetokens#3
displayName: 'Replace Terraform variables'
inputs:
targetFiles: '**/*.tfvars'
tokenPrefix: '__'
tokenSuffix: '__'
- task: TerraformInstaller#0
displayName: "Install Terraform"
inputs:
terraformVersion: '1.0.8'
- task: TerraformTaskV2#2
displayName: 'Terraform Init'
inputs:
provider: 'azurerm'
command: 'init'
backendServiceArm: 'skwieralearning'
backendAzureRmResourceGroupName: 'skwiera-learning-rg'
backendAzureRmStorageAccountName: 'skwieralearningtfstate'
backendAzureRmContainerName: 'tfstate'
backendAzureRmKey: 'dev.tfstate'
- task: TerraformTaskV2#2
displayName: 'Terraform Validate'
inputs:
provider: 'azurerm'
command: 'validate'
- task: TerraformTaskV2#2
displayName: "Terraform Plan"
inputs:
provider: 'azurerm'
command: 'plan'
environmentServiceNameAzureRM: 'skwieralearning'
- task: TerraformTaskV2#2
displayName: 'Terraform Apply'
inputs:
provider: 'azurerm'
command: 'apply'
environmentServiceNameAzureRM: 'skwieralearning'

Answer 1

The Azure Devops pipeline.yaml file is expecting the job variable's value to be a string but if you use:
- name: 'VirtualNetworkSubnets'
value: {'GatewaySubnet' : '10.0.255.0/27'}
Then the YAML parser sees that as a nested mapping under the value key as YAML supports both key1: value and {key: value} syntax for mappings.
You can avoid it being read as a mapping by wrapping it in quotes so that it's read as a string literal:
- name: 'VirtualNetworkSubnets'
value: "{'GatewaySubnet' : '10.0.255.0/27'}"
Separately you can avoid the qetza.replacetokens.replacetokens-task.replacetokens#3 step and the tokenised values in dev.tfvars by prefixing the environment variables with TF_VAR_:
stages:
- stage: DEV
jobs:
- deployment: TERRAFORM
displayName: 'Terraform deployment'
pool:
nvmImage: 'ubuntu-latest'
workspace:
clean: all
variables:
- name: 'TF_VAR_rgNAME'
value: 'skwiera-rg'
- name: 'TF_VAR_rgLOCATION'
value: 'West Europe'
- name: 'TF_VAR_VirtualNetworkName'
value: 'SkwieraVNET'
- name: 'TF_VAR_VirtualNetworkAddressSpace'
value: "['10.0.0.0/16']"
- name: 'TF_VAR_VirtualNetworkSubnets'
value: "{'GatewaySubnet' : '10.0.255.0/27'}"