I have a pretty complex setup of my Pipelines in Azure DevOps for various reasons but I'm kind of stuck in a special scenario now. Let me explain a bit.
There is a Stage_A with Job_A setting a Variable_A. Now there is a Stage_B with Job_B, need to use the Variable_A from Stage_A.Job_A.
The variable in Job_A is set by this:
echo ##vso[task.setvariable variable=Variable_A;isOutput=true]$value
Now, Job_B in Stage_B can access the variable in a condition with
variables:
Variable_A_FromStageA: $[stageDependencies.Stage_A.Job_A.outputs['task_A.Variable_A']]
I can also do an echo on the variable by using
echo $(Variable_A_FromStageA)
the Question is now, how can I use this in an if-statement? I tried different approaches:
- ${{ if eq($(Variable_A_FromStageA), 'True') }}:
- ${{ if eq(variables.Variable_A_FromStageA, 'True') }}:
- ${{ if eq(variables['Variable_A_FromStageA'], 'True') }}:
- ${{ if eq(stageDependencies.Stage_A.Job_A.outputs['task_A.Variable_A'], "True") }}:
Nothing actually works. Either the system complains about syntax issues or it doesn't evaluate it correctly. I don't really know how to use the information in my if statement in the yaml file. The documentation is not really clear about it. It only mentions the usage of a stage dependency in a condition and that's it.
Hope anyone can help me here!
Cheers,
Frank
use stageDependencies in if-statements in Azure DevOps yaml
If you mean you want to use conditional insertion to use the variables output from the logging command, then answer is NO.
The reason is the conditional insertion needs compile time value(you must provide them before pipeline run.), but the variable that the logging command output is runtime. Conditional Insertion will be unable to get it.
The right way is to use "condition" instead of "Conditional Insertion". Using condition can achieve your situation.
I write a demo for you as below:
trigger:
- none
pool:
vmImage: ubuntu-latest
stages:
- stage: A
jobs:
- job: A1
steps:
- bash: echo "##vso[task.setvariable variable=shouldrun;isOutput=true]true"
# or on Windows:
# - script: echo ##vso[task.setvariable variable=shouldrun;isOutput=true]true
name: printvar
- stage: B
condition: and(succeeded(), eq(dependencies.A.outputs['A1.printvar.shouldrun'], 'true'))
variables:
myStageAVar: $[stageDependencies.A.A1.outputs['printvar.shouldrun']]
dependsOn: A
jobs:
- job: B1
steps:
- script: echo $(myStageAVar)
Related
I have set up a pipeline with variables users can enter using the UI like this:
UI for userinput of variable called 'forceRelease'
I now want to use this variable in the pipeline yaml inside an if-statement like this:
jobs:
- job: Demo
steps:
- ${{ if eq(variables['forceRelease'], 'true') }}:
...some more stuff...
This does'nt work. I've tried different approaches but could not find the right syntax.
If I use the variable inside a condition, it works fine. Like this:
jobs:
- job: MAVEN_Build
- task: Bash#3
condition: eq(variables['forceRelease'], 'true')
I also tried to map the variable inside the variables block to a new pipeline variable like this:
variables:
isReleaseBranch: ${{ startsWith(variables['build.sourcebranch'],'refs/heads/pipelines-playground') }}
isForceRelease: $(forceRelease)
The first variable using 'build.sourcebranch' works fine. My approach using forceRelease doesnt work :(
Any ideas would be appreciated!
Cheers,
Dirk
AFAIK this is working as intended. User set variables are not expanded during parsing of the template.
You can read more on pipeline processing here:
https://learn.microsoft.com/en-us/azure/devops/pipelines/process/runs?view=azure-devops
You should instead use parameters.
parameters:
- name: "forceRelease"
type: boolean
default: "false"
- name: "someOtherParameter"
type: string
default: "someValue"
stages:
- ${{ if eq(parameters['forceRelease'], true)}}:
- stage: build
jobs:
- job: bash_job
steps:
- task: Bash#3
inputs:
targetType: 'inline'
script: |
# Write your commands here
And then when you run the pipeline you have the option to enable the parameter forceRelease or add someOtherParameter string.
Am working on Azure DevOps templates lately. And came across this double curly braces syntax. Just want to know how to use double curly braces in Azure DevOps.
Have seen some posts regarding the same.
Assign conditional value to variables in Azure DevOps
Curly braces in Yaml files
If else in Azure DevOps
Conditional Variable Assignment in Azure DevOps
So lets say, I have a variable defined in a group as follows.
Also we can define variables as follows in a yaml file.
variables:
- name: BuildConfiguration
value: 'Release'
- name: finalBuildArtifactName
value: 'TempFolderName'
When should we use the double curly brace syntax?
I have idea about and using the following ways to reference variables.
variables['MyVar']
variables.MyVar
What can we accomplish with double curly braces in contrast to the above two?
Its very difficult to get things working in a yaml pipeline. Do the change, checkin, run the pipeline, see the result and circle back again. This is highly time consuming, and not smooth to say the least.
${{}} syntax is used for expressions. What's more there is another $[ <expression> ]. And here is the difference:
# Two examples of expressions used to define variables
# The first one, a, is evaluated when the YAML file is compiled into a plan.
# The second one, b, is evaluated at runtime.
# Note the syntax ${{}} for compile time and $[] for runtime expressions.
variables:
a: ${{ <expression> }}
b: $[ <expression> ]
Please check documentation here.
And as you may see here
steps:
- task: PublishPipelineArtifact#1
inputs:
targetPath: '$(Pipeline.Workspace)'
${{ if eq(variables['Build.SourceBranchName'], 'main') }}:
artifact: 'prod'
${{ else }}:
artifact: 'dev'
publishLocation: 'pipeline'
you can use variables['Build.SourceBranchName'] syntax for accessing variables. But,
variables:
- name: foo
value: fabrikam # triggers else condition
pool:
vmImage: 'ubuntu-latest'
steps:
- script: echo "start"
- ${{ if eq(variables.foo, 'adaptum') }}:
- script: echo "this is adaptum"
- ${{ elseif eq(variables.foo, 'contoso') }}:
- script: echo "this is contoso"
- ${{ else }}:
- script: echo "the value is not adaptum or contoso"
You may also use variables.foo.
Expressons are often used for conditional evaluation, dynamic steps/jobs/stages configuration etc.
I am trying to use if else conditions in Azure Devops yml pipeline with variable groups. I am trying to implement it as per latest Azure Devops yaml pipeline build.
Following is the sample code for the if else condition in my scenario. test is a variable inside my-global variable group.
variables:
- group: my-global
- name: fileName
${{ if eq(variables['test'], 'true') }}:
value: 'product.js'
${{ elseif eq(variables['test'], false) }}:
value: 'productCost.js'
jobs:
- job:
steps:
- bash:
echo test variable value $(fileName)
When the above code is executed, in echo statement we don't see any value for filename, i.e. it empty, meaning none of the above if else condition was executed, however when I test the if else condition with the following condition.
- name: fileName
${{ if eq('true', 'true') }}:
value: 'product.js'
Filename did echo the correct value, i.e. product.js. So my conclusion is that I am not able to refer the variables from the variable group correctly. So any suggestion will be helpful and appreciated.
Thanks!
Unfortunately there is no ternary operator in Azure DevOps Pipelines. And it seems unlikely considering the state of https://github.com/microsoft/azure-pipelines-yaml/issues/256 and https://github.com/microsoft/azure-pipelines-yaml/issues/278. So for the time being the only choices are :
conditional insertion : it works with parameters, and should work with variables according to the documentation (but it is difficult to use properly),
or the hacks you can find in this Stack Overflow question.
Another work-around has been posted by Simon Alling on GitHub (https://github.com/microsoft/azure-pipelines-yaml/issues/256#issuecomment-1077684972) :
format(
replace(replace(condition, True, '{0}'), False, '{1}'),
valueIfTrue,
valueIfFalse
)
It is similar to the solution provided by Tejas Nagchandi, but I find it a little bit better because the syntax looks closer to what it would be if there was a ternary operator.
I was able to achieve the goal using some dirty work-around, but I do agree that using parameters would be much better way unless ternary operators are available for Azure DevOps YAML pipeline.
The issue is that ${{ if condition }}: is compile time expression, thus the variables under variable group are not available.
I was able to use runtime expressions $[<expression>]
Reference: https://learn.microsoft.com/en-us/azure/devops/pipelines/process/expressions?view=azure-devops
My pipeline:
trigger:
- none
variables:
- group: Temp-group-for-testing
- name: fileName
value: $[replace(replace('True',eq(variables['test'], 'True'), 'value1'),'True','value2')]
stages:
- stage: test
jobs:
- job: testvar
continueOnError: false
steps:
- bash: echo $(fileName)
displayName: "echo variable"
Results are available on github
After detailed investigation I realized that if else doesnt work with variables in Az Devop yaml pipelines, it only works with parameters. However the solution posted by #Tejas Nagchandi is a workaround and might be able to accomplish the same logic of if else setting variable value with replace commands. Hats off to TN.
I know that it is possible to conditionally set a variable in azure pipelines yml.
See https://learn.microsoft.com/en-us/azure/devops/pipelines/process/expressions?view=azure-devops#conditional-insertion
Is it also somehow possible to conditionally use a variable group?
Let's say if a pipeline run variable is set or has a certain value then the pipeline shall use a variable group. If not then the group shall not be used.
Thank you
Is it possible like here for instance:
trigger: none
pr: none
variables:
isProd: true
stages:
- stage: Test
displayName: Build and restore
variables:
- ${{ if eq(variables['isProd'], 'false') }}:
- group: QA
- ${{ if eq(variables['isProd'], 'true') }}:
- group: PROD
jobs:
- job: A
steps:
- bash: echo $(name)
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