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Unit test forhelm chart in YAML to keep your chart consistent and robust!

Feature:

• write test file in pure YAML
• render locally
• createnothing on your cluster
• wildcard selection for templates
• define values and release options
• snapshot testing
• test suite code completion and validation

If you are ready for writing tests, check theDOCUMENT for the test API in YAML.

• Install
• Docker Usage
• Get Started
• Test Suite File
  • Templated Test Suites
• Usage
  • Flags
  • Yaml JsonPath Support
  • DocumentSelector
• Example
  • Open Source Community Examples
• Snapshot Testing
• Dependent subchart Testing
• Tests within subchart
• Test suite code completion and validation
• Frequently Asked Questions
• Related Projects / Commands
• Contributing

$ helm plugin install https://github.com/helm-unittest/helm-unittest.git

It will install the latest version of binary into helm plugin directory.

# run help of latest helm with latest helm unittest plugindocker run -ti --rm -v $(pwd):/apps helmunittest/helm-unittest# run help of specific helm version with specific helm unittest plugin versiondocker run -ti --rm -v $(pwd):/apps helmunittest/helm-unittest:3.11.1-0.3.0# run unittests of a helm 3 chart# make sure to mount local folder to /apps in containerdocker run -ti --rm -v $(pwd):/apps helmunittest/helm-unittest:3.11.1-0.3.0 .# run unittests of a helm 3 chart with Junit output for CI validation# make sure to mount local folder to /apps in container# the test-output.xml will be available in the local folder.docker run -ti --rm -v $(pwd):/apps helmunittest/helm-unittest:3.11.1-0.3.0 -o test-output.xml -t junit .

The docker container contains the fully installed helm client, including the helm-unittest plugin.

Addtests in.helmignore of your chart, and create the following test file at$YOUR_CHART/tests/deployment_test.yaml:

suite:test deploymenttemplates:  -deployment.yamltests:  -it:should workset:image.tag:latestasserts:      -isKind:of:Deployment      -matchRegex:path:metadata.namepattern:-my-chart$      -equal:path:spec.template.spec.containers[0].imagevalue:nginx:latest

and run:

$ helm unittest $YOUR_CHART

Now there is your first test! ;)

The test suite file is written in pure YAML, and default placed under thetests/ directory of the chart with suffix_test.yaml. You can also have your own suite files arrangement with-f, --file option of cli set as the glob patterns of test suite files related to chart directory, like:

$ helm unittest -f'my-tests/*.yaml' -f'more-tests/**/*.yaml' my-chart

CheckDOCUMENT for more details about writing tests.

You may find yourself needing to set up a lots o tests that are a parameterization of a single test. For instance, let's say that you deploy to 3 environmentsenv = dev | staging | prod.

In order to do this, you can actually write your tests as a helm chart as well. If you go about this route, youmust set the--chart-tests-path option. Once you have done so, helm unittest will run a standard helm renderagainst the values.yaml in your specified directory.

/my-chart  /tests-chart    /Chart.yaml    /values.yaml    /templates      /per_env_snapshots.yaml  /Chart.yaml  /values.yaml  /.helmignore  /templates    /actual_template.yaml

In the above example file structure, you would maintain a helm chart that will render out against the Chart.yamlthat as provided and the values.yaml. With rendered charts, any test suite that is generated is automatically ranwe do not look for a file postfix or glob.

Note: since you can create multiple suites in a single template file, you must provide the suite name, since we can no longer use the test suite file name meaningfully.

Note 2: since you can be running against subcharts and multiple charts, you need to make sure that you do not designate your--chart-tests-path to be the same folder as your other tests. This is because we will try to render those non-helm test folders and fail during the unit test.

Note 3: for snapshot tests, you will need to provide a helm ignore that ignores*/__snapshot__/*. Otherwise, subsequent runs will try to render those snapshots.

The command for the above chart and test configuration would be:

helm unittest --chart-tests-path tests-chart my-chart

$ helm unittest [flags] CHART [...]

This renders your charts locally (without tiller) and runs testsdefined in test suite files.

      --color                  enforce printing colored output even stdout is not a tty. Set to false to disable color      --strict                 strict parse the testsuites (default false)  -d  --debugPlugin            enable debug logging (default false)  -v, --values stringArray     absolute or glob paths of values files location to override helmchart values  -f, --file stringArray       glob paths of test files location, default to tests\*_test.yaml (default [tests\*_test.yaml])  -q, --failfast               direct quit testing, when a test is failed (default false)  -h, --help                   help for unittest  -t, --output-type string     the file-format where testresults are written in, accepted types are (JUnit, NUnit, XUnit) (default XUnit)  -o, --output-file string     the file where testresults are written in format specified, defaults no output is written to file  -u, --update-snapshot        update the snapshot cached if needed, make sure you review the change before update  -s, --with-subchart charts   include tests of the subcharts within charts folder (default true)      --chart-tests-path string the folder location relative to the chart where a helm chart to render test suites is located

Now JsonPath is supported for mappings and arrays.This makes it possible to find items in an array, based on JsonPath.For more detail on thejsonPath syntax.

Due to the change to JsonPath, the map keys inpath containing periods (.) or special characters (/) are now supported with the use of"":

-equal:path:metadata.annotations["kubernetes.io/ingress.class"]value:nginx

The next releases it will be possible to validate multiple paths when JsonPath result into multiple results.

The test job or assertion can also specify a documentSelector rather than a documentIndex. Note that the documentSelector will always override a documentIndex if a match is found. This field is particularly useful when helm produces multiple templates and the order is not always guaranteed.

Thepath in the documentSelector has Yaml JsonPath Support, using JsonPath expressions it is possible to filter on multiple fields.

Thevalue in the documentSelector can validate complete yaml objects and is optional.

...tests:  -it:should passvalues:      -./values/staging.yamlset:image.pullPolicy:Alwaysresources:limits:memory:128Mitemplate:deployment.yamldocumentSelector:path:metadata.namevalue:my-service-nameasserts:      -equal:path:metadata.namevalue:my-deploy

Checktest/data/v3/basic/ for some basic use cases of a simple chart.

Open-source solutions that uses helm-unittest to improve helm and kubernetes experience

• Traefik: kubernetes ingress
• Prometheus: community charts
• Grafana: kubernetes monitoring
• HiveMQ: mqtt platform
• Gitlab runner
• External DNS: kubernetes-sigs/external-dns

Sometimes you may just want to keep the rendered manifest not changed between changes without every details asserted. That's the reason for snapshot testing! Check the tests below:

templates:  -templates/deployment.yamltests:  -it:pod spec should match snapshotasserts:      -matchSnapshot:path:spec.template.spec# or you can snapshot the whole manifest  -it:manifest should match snapshotasserts:      -matchSnapshot:{}  -it:manifest should match snapshot and pattern and not match another patternasserts:      -matchSnapshot:matchRegex:pattern:.*app.*notMatchRegex:pattern:.*bcde.*

ThematchSnapshot assertion validate the content rendered the same as cached last time. It fails if the content changed, and you should check and update the cache with-u, --update-snapshot option of cli.

$ helm unittest -u my-chart

The cache files is stored as__snapshot__/*_test.yaml.snap at the directory your test file placed, you should add them in version control with your chart.

If you have hard dependency subcharts (installed viahelm dependency) existed incharts directory (they don't need to be extracted), it is possible to unittest these from the root chart. This feature can be helpful to validate if good default values are accidentally overwritten within your default helm chart.

# $YOUR_CHART/tests/xxx_test.yamltemplates:  -charts/postgresql/templates/xxx.yamltests:  -it:set:# this time required to prefix with "postgresql."postgresql.somevalue:should_be_scopedasserts:      -...

Note 1: if dependent subcharts uses an alias, use the alias name in the templates.Note 2: using the folder structure in templates can also be used to unittest templates which are placed in subfolders or unittest subcharts from the rootchart.

Checktest/data/v3/with-subchart/ as an example.

If you have customized hard dependency subchart (not installed viahelm dependency, but added manually) existed incharts directory, tests inside would also be executed by default. You can disable this behavior by setting--with-subchart=false flag in cli, thus only the tests in root chart will be executed. Notice that the values defined in subchart tests will be automatically scoped, you don't have to add dependency scope yourself:

# with-subchart/charts/child-chart/tests/xxx_test.yamltemplates:  -templates/xxx.yamltests:  -it:set:# no need to prefix with "child-chart."somevalue:should_be_scopedasserts:      -...

Checktest/data/v3/with-subchart/ as an example.

Most popular IDEs (IntelliJ, Visual Studio Code, etc.) support applying schemas to YAML files using a JSON Schema. This provides comprehensive documentation as well as code completion while editing the test-suite file:

In addition, test-suite files can be validated while editing so wrongfully added additional properties or incorrect data types can be detected while editing:

When developing with VSCode, the very popular YAML plug-in (created by RedHat) allows adding references to schemas by adding a comment line on top of the file:

# yaml-language-server: $schema=https://raw.githubusercontent.com/helm-unittest/helm-unittest/main/schema/helm-testsuite.jsonsuite:http-service.configmap_test.yamltemplates:[configmap.yaml]release:name:test-releasenamespace:TEST_NAMESPACE

Alternatively, you can add the schema globally to the IDE, using a well defined pattern:

"yaml.schemas": {"https://raw.githubusercontent.com/helm-unittest/helm-unittest/main/schema/helm-testsuite.json": ["charts/*/tests/*_test.yaml"]}

Similar to VSCode, IntelliJ allows mapping file patterns to schemas via preferences: Languages & Frameworks -> Schemas and DTDs -> JSON Schema Mappings

As more people use the unittest plugin, more questions will come. Therefore aFrequently Asked Question page is created to answer the most common questions.

If you are missing an answer to a question, feel free to raise a ticket.

This plugin is inspired byhelm-template, and the idea of snapshot testing and some printing format comes fromjest.

And there are some other helm commands you might want to use:

• helm template: render the chart and print the output.

• helm lint: examines a chart for possible issues, useful to validate chart dependencies.

• helm test: test a release with testing pod defined in chart. Note this does create resources on your cluster to verify if your release is correct. Check thedoc.

Alternatively, you can also use generic tests frameworks:

• Python -pytest-helm-charts

• Go -terratest

MIT

Issues and PRs are welcome!To start developing this plugin please follow theContribution guidelines.