I am trying to do something like this
variables:
${{ if eq(variables['abc'], 'dev') }}:
someOtherVariable: '123'
with a variable defined via UI here:
It doesn't work. someOtherVariable is not defined after this.
Is there a way to use this variable in conditions? What should be the syntax?
thanks
The syntax is correct but doesn't seem to work for conditions that rely on variables within the block where variables are defined for custom variables.
It is one of the (many) quirks of the Azure Pipelines YAML processing pipeline. Some conditions, variables, templates, syntax is only available at specific stages of the YAML processing and it depends on whether you are in a pipeline, template, or decorator.
Simplest solution is to use a script step to set the variable and optionally make that step conditional:
${{ if eq(variables['condition'], 'true') }}:
script: echo '##vso[task.setvariable variable=someOtherVariable]123'
or rely on one of my tasks to do that on your behalf:
- task: SetVariable#1
inputs:
name: 'someOtherVariable'
value: '123'
condition: eq(variables['condition'], 'true')
or:
${{ if eq(variables['condition'], 'true') }}:
- task: SetVariable#1
inputs:
name: 'someOtherVariable'
value: '123'
I have a YAML file which forms an Azure DevOps pipeline. The pipeline itself defines four variables which are needed in the variables section of the YAML...
variables:
environmentIdentifier: "$(environmentIdentifier)"
keyVaultSourceName: "$(keyVaultSourceName)"
location: "$(location)"
locationIdentifier: "$(locationIdentifier)"
The variables are definitely set for each run of the pipeline, but when it runs I encounter errors further down in my script which indicate that these variables were not populated correctly...
ERROR: (InvalidResourceGroup) The provided resource group name 'rg-main-$(locationIdentifier)' has these invalid characters: '$:'. The name can only be a letter, digit, '-', '.', '(', ')' or '_'.
I've also tried...
$env:location
${{variables['location']}}
...but incurred the same error.
How should I correctly declare vars in the variables section of the pipeline definition, where their values are retrieved from the pipeline's variables?
You need to define as:
variables:
- name: location
value: 'Australia Southeast'
If you want them at a later stage as a template expression use:
${{ variables.location }}
and if you want to use them inside a script:
steps:
- bash: echo $(location)
- powershell: echo $(location)
- script: echo $(location)
Check this Link and the below extracted sample for more information.
variables:
- name: one
value: initialValue
steps:
- script: |
echo ${{ variables.one }} # outputs initialValue
echo $(one)
displayName: First variable pass
- bash: echo '##vso[task.setvariable variable=one]secondValue'
displayName: Set new variable value
- script: |
echo ${{ variables.one }} # outputs initialValue
echo $(one) # outputs secondValue
displayName: Second variable pass
It seems that name is a special magic variable that somehow gets used for my output directory.
(Is this behavior documented anywhere?)
I'm trying to set it.
Given the extraordinary difficulty of writing Azure pipeline yml, it's highly unlikely that I'll get it right. In the absence of any form of debugging I want to add a print statement so that I can see the value.
How?
${{ if eq(variables['Build.SourceBranchName'], 'master') }}:
buildConfiguration: 'Release'
tag: ''
${{ if ne(variables['Build.SourceBranchName'], 'master') }}:
buildConfiguration: 'Debug'
tag: ${{ format('-{0}', variables['Build.SourceBranchName']) }}
# How do you do string concatenation in yml? Do I need to do `format` like above?
name: $(Build.BuildId)$(tag)
steps:
- script: echo "name is $(name)"
But the output is
Generating script.
Script contents:
echo "name is $(name)"
...
name is $(name)"
Is it possible to make this work? How?
The name variable is for the Build.BuildNumber value (see here).
So just print it:
- script: echo "name is $(Build.BuildNumber)"
I am quite new in Yaml and AzureDevOps and I am trying to initialize variable based on condition
variables:
- name: DisplayName
${{ if eq('$(env)', 'wh') }}:
value: 'DisplayNAME-WH'
${{ if eq('$(env)', 'lw') }}:
value: 'DisplayNAME-LW'
Where my 'env' is variable passed via UI in Azure DevOps
Issue what I am getting that "DisplayName" stays still empty (is not initialized).
Can you help me out?
Thanks.
Azure DevOps conditional initialization of variables is not working
According to the Understand variable syntax:
In a pipeline, template expression variables (${{ variables.var }})
get processed at compile time, before runtime starts. Macro syntax
variables ($(var)) get processed during runtime before a task runs.
So, we could not use the $(env) in the ${{ if eq('$(env)', 'wh') }}. That because the syntax of ${{ if eq('$(env)', 'wh') }} is parsed before the syntax of $(env).
To resolve this issue, we could to defined the variable as Runtime parameters:
parameters:
- name: 'env'
default: 'wh'
type: string
values:
- wh
- lw
variables:
${{ if eq(parameters.env, 'wh') }}:
DisplayName: 'DisplayNAME-WH'
${{ if eq(parameters.env, 'lw') }}:
DisplayName: 'DisplayNAME-LW'
steps:
- script:
echo $(DisplayName)
The test result:
I'm trying to assign one of 2 values to a variable in addition to variable group and can't find the reference that how to use IF ELSE.
Basically I need to convert this jerkins logic to azure DevOps.
Jenkins
if (branch = 'master') {
env = 'a'
} else if (branch = 'dev'){
env ='b'
}
I found 1 reference from the following one, but this one seems to work if the variables section doesn't have variable groups.
https://stackoverflow.com/a/57532526/5862540
But in my pipeline, I already have a variable group for secrets, so I have to use name/value convention and the example doesn't work with the errors like expected a mapping or A mapping was not expected or Unexpected value 'env'
variables:
- group: my-global
- name: env
value:
${{ if eq(variables['Build.SourceBranchName'], 'master') }}:
env: a
${{ if eq(variables['Build.SourceBranchName'], 'dev') }}:
env: b
or
variables:
- group: my-global
- name: env
value:
${{ if eq(variables['Build.SourceBranchName'], 'master') }}: a
${{ if eq(variables['Build.SourceBranchName'], 'dev') }}: b
This code works.
I'm doing similar with parameters.
variables:
- name: var1
${{ if eq(parameters.var1, 'custom') }}:
value: $(var1.manual.custom)
${{ if ne(parameters.var1, 'custom') }}:
value: ${{ parameters.var1 }}
Update 09/09/2021
We have now natively if else expression and we can write it like
variables:
- group: PROD
- name: env
${{ if eq(variables['Build.SourceBranchName'], 'master') }}:
value: a
${{ else }}:
value: b
steps:
- script: |
echo '$(name)'
echo '$(env)'
Original reply
Syntax with template expressions ${{ if ...... }} is not limited only to job/stage level. Both below pipeline does the same and produce the same output:
stages:
- stage: One
displayName: Build and restore
variables:
- group: PROD
- name: env
${{ if eq(variables['Build.SourceBranchName'], 'master') }}:
value: a
${{ if eq(variables['Build.SourceBranchName'], 'dev') }}:
value: b
jobs:
- job: A
steps:
- script: |
echo '$(name)'
echo '$(env)'
variables:
- group: PROD
- name: env
${{ if eq(variables['Build.SourceBranchName'], 'master') }}:
value: a
${{ if eq(variables['Build.SourceBranchName'], 'dev') }}:
value: b
steps:
- script: |
echo '$(name)'
echo '$(env)'
Microsoft a few weeks ago released a new feature for YAML pipeliens that just lets you do that: IF ELSE notation.
https://learn.microsoft.com/en-us/azure/devops/release-notes/2021/sprint-192-update#new-yaml-conditional-expressions
Writing conditional expressions in YAML files just got easier with the use of ${{ else }} and ${{ elseif }} expressions. Below are examples of how to use these expressions in YAML pipelines files.
steps:
- script: tool
env:
${{ if parameters.debug }}:
TOOL_DEBUG: true
TOOL_DEBUG_DIR: _dbg
${{ else }}:
TOOL_DEBUG: false
TOOL_DEBUG_DIR: _dbg
variables:
${{ if eq(parameters.os, 'win') }}:
testsFolder: windows
${{ elseif eq(parameters.os, 'linux' }}:
testsFolder: linux
${{ else }}:
testsFolder: mac
I wanted to have runtime condition evaluation, something similar to compile time:
variables:
VERBOSE_FLAG:
${{if variables['System.Debug']}}:
value: '--verbose'
${{else}}:
value: ''
but unfortunately Azure devops does not supports special kind of functions like if(condition, then case, else case) - so I've played around and find out that it's possible do double string replacement using replace function. It does looks bit hacky of course.
For example, one may want to tweak task inputs depending on whether system debugging is enabled or not. This cannot be done using "standard conditional insertion" (${{ if … }}:), because System.Debug isn't in scope in template expressions. So, runtime expressions to the rescue:
- job:
variables:
VERBOSE_FLAG: $[
replace(
replace(
eq(lower(variables['System.Debug']), 'true'),
True,
'--verbose'
),
False,
''
)
]
steps:
- task: cURLUploader#2
inputs:
# …
options: --fail --more-curl-flags $(VERBOSE_FLAG)
Note that using eq to check the value of System.Debug before calling replace is not redundant: Since eq always returns either True or False, we can then safely use replace to map those values to '--verbose' and '', respectively.
In general, I highly recommend sticking to boolean expressions (for example the application of a boolean-valued function like eq, gt or in) as the first argument of the inner replace application. Had we not done so and instead just written for example
replace(
replace(
lower(variables['System.Debug']),
'true',
'--verbose'
),
'false',
''
)
then, if System.Debug were set to e.g. footruebar, the value of VERBOSE_FLAG would have become foo--verbosebar.
I think for now you're going to need to use a task to customize with name/value syntax variables and conditional variable values. It looks like the object structure for name/value syntax breaks the parsing of expressions, as you have pointed out.
For me, the following is a reasonably clean implementation, and if you want to abstract it away from the pipeline, it seems that a simple template for your many pipelines to use should satisfy the desire for a central "global" location.
variables:
- group: FakeVarGroup
- name: env
value: dev
steps:
- powershell: |
if ($env:Build_SourceBranchName -eq 'master') {
Write-Host ##vso[task.setvariable variable=env;isOutput=true]a
return
} else {
Write-Host ##vso[task.setvariable variable=env;isOutput=true]b
}
displayName: "Set Env Value"
As far as I know, the best way to have conditional branch build is using "trigger" in your YAML, instead of implementing complex "if-else". It is also much safer, and you have more explicit controls on the branch triggers instead of relying on CI variables.
Example:
# specific branch build
jobs:
- job: buildmaster
pool:
vmImage: 'vs2017-win2016'
trigger:
- master
steps:
- script: |
echo "trigger for master branch"
- job: buildfeature
pool:
vmImage: 'vs2017-win2016'
trigger:
- feature
steps:
- script: |
echo "trigger for feature branch"
To have trigger with branches inclusion and exclusion, you could use more complex syntax of trigger with branches include and exclude.
Example:
# specific branch build
trigger:
branches:
include:
- master
- releases/*
exclude:
- releases/1.*
The official documentation of Azure DevOps Pipelines trigger in YAML is:
Azure Pipelines YAML trigger documentation
UPDATE 1:
I repost my comment here with additional notes:
I was thinking to have different pipelines because having the complexity of juggling between CI variables is not more maintainable than having multi jobs in one YAML with triggers. Having multijobs with triggers is also enforcing us to have clear distinction and provision on branch management. Triggers and conditional branches inclusions have been used for a year by my team because of these maintainability advantages.
Feel free to disagree, but to me having an embedded logic in any scripted in any steps to check which branch is currently in session and then does any further actions, are more like ad-hoc solutions. And this has given my team and me maintenance problems before.
Especially if the embedded logic tends to grow by checking other branches, the complexity is more complex later than having clear separations between branches. Also if the YAML file is going to be maintained for long time, it should have clear provisions and roadmaps across different branches. Redundancy is unavoidable, but the intention to separate specific logic will pay more in the long run for maintainability.
This is why I also emphasize branches inclusions and exclusions in my answer :)
Azure YAML if-else solution (when you have a group defined which required name/value notation use thereafter.
variables:
- group: my-global
- name: env
value: a # set by default
- name: env
${{ if eq(variables['Build.SourceBranchName'], 'master') }}:
value: b # will override default
Of if you don't have a group defined:
variables:
env: a # set by default
${{ if eq(variables['Build.SourceBranchName'], 'master') }}:
env: b # will override default