E2E tests confirm the functionality of the system end-to-end from the perspective of a user employing the Functions CLI func, either standalone or as a plugin to kn (kn func).

E2E tests are designed in a way that they can be easily runnable (and thus debuggable) locally by a developer, in addition to remotely in CI as acceptance criteria for pull requests.

• ./hack/binaries.sh Fetch binaries into ./hack/bin
• ./hack/registry.sh (once) Configure insecure local registry
• ./hack/cluster.sh Create a cluster and kubeconfig in ./hack/bin
• make test-full Run all tests using these binaries and cluster
• ./hack/delete.sh Remove the cluster

Tests themselves are separated into categories: Core, Metadata, Remote, Podman, Matrix, and Config CI.

Core tests include checking the basic CRUDL operations; Create, Read, Update, Delete and List. Creation is implemented as func init, running the function locally with func run, and running the cluster with func deploy. Reading is implemented as func describe. Updating, which ensures that an updated function replaces the old, is implemented as func deploy. Finally, func list implements a standard listing operation. Tests also confirm the core features function when referring to a remote repository, using templates (repositories) and other core variants.

Metadata tests ensure that manipulation of a Function's metadata is correctly carried to the final Function. Metadata includes environment variables, labels, volumes, secrets and event subscriptions.

Remote tests confirm features related to building and deploying remotely via in-cluster builds, etc.

Podman tests ensure that the Podman container engine is also supported. Note that these tests require that 'podman' and 'ssh' are available in your path.

Matrix tests is a larger set which checks operations which differ in implementation between language runtimes. The primary operations which differ and must be checked for each runtime are creation and running locally. Therefore, the runtime tests execute for each language, for each template, for each builder. As a side-effect of the test implementation, "func invoke" is also tested.

Config CI tests verify that GitHub Actions workflows generated by func config ci deploy a function successfully. They use nektos/act to execute the generated workflow YAML against a real cluster, iterating over supported runtimes. Requires act (installed via hack/binaries.sh). Since act runs with -self-hosted, the host machine must have the runtime toolchains installed:

• Go: go on PATH
• Node / TypeScript: node and npm on PATH
• Python: python and pip on PATH
• Quarkus: Full JDK 17+ (not just JRE) with javac on PATH

These tests expect a compiled binary, which will be executed utilizing a cluster configured to run Functions, as well as an available and authenticated container registry. These can be configured locally for testing by using scripts in ../hack:

• binaries.sh: Installs executables needed for cluster setup and configuration into hack/bin.

• registry.sh: Configures the local Podman or Docker to allow unencrypted communication with local registries.

• cluster.sh: Creates a local Function-ready cluster with Knative, Tekton, and GitLab support. Includes DNS configuration for localtest.me domains.

• delete.sh: Removes the cluster and registry. Using this to recreate the cluster between test runs will ensure the cluster is in a clean state.

• gitlab.sh: Sets up GitLab instance for testing Git-based deployments. Only required if gitlab tests are enabled.

The suite accepts environment variables which alter the default behavior:

FUNC_E2E_BIN: sets the path to the binary to use for the E2E tests. This is by default the binary created when make is run in the repository root. Note that if providing a relative path, this path is relative to this test package, not the directory from which go test was run.

FUNC_E2E_PLUGIN: if set, the command run by the tests will be ${FUNC_E2E_BIN} ${FUNC_E2E_PLUGIN}, allowing for running all tests when func is installed as a plugin; such as when used as a plugin for the Knative cluster admin tool kn. The value should be set to the name of the subcommand for the func plugin (usually func). For example to run E2E tests on kn with the kn-func plugged in use FUNC_E2E_BIN=/path/to/kn FUNC_E2E_PLUGIN=func.

FUNC_E2E_REGISTRY: if provided, tests will use this registry (in form registry.example.com/user) instead of the test suite default of registry.localtest.me/func. This is used for local builds that push from the developer's machine to the registry.

FUNC_E2E_CLUSTER_REGISTRY: specifies the cluster-internal registry URL used for in-cluster (remote) builds with Tekton. This registry must be accessible from within the cluster. Format: registry.namespace.svc.cluster.local:port/path. Defaults to registry.localtest.me/func.

FUNC_E2E_MATRIX_RUNTIMES: Sets which runtimes will be tested during the matrix tests. By default matrix test are not enabled unless this value is passed. Note that the core tests always use the go runtime.

FUNC_E2E_MATRIX_BUILDERS: Sets which builders will be tested during the matrix tests. By default matrix tests are not enabled unless this value is passed. Note that core tests always use the host builder.

FUNC_E2E_KUBECONFIG: The path to the kubeconfig to be used by tests. This defaults to ../hack/bin/kubeconfig.yaml, which is created when using the ../hack/cluster.sh script to set up a test cluster.

FUNC_E2E_GOCOVERDIR: The path to use for Go coverage data reported by these tests. This defaults to ../.coverage.

FUNC_E2E_GO: the path to the go binary tests should use when running outside of a container (host builder). This can be used to test against specific go versions. Defaults to the go binary found in the current session's PATH.

FUNC_E2E_GIT: the path to the git binary tests should provide to the commands being tested for git-related activities. Defaults to the git binary found in the current session's PATH.

FUNC_E2E_VERBOSE: instructs the test suite to run all commands in verbose mode. When set to "true", the -v flag is automatically added to all func commands executed during tests. Defaults to "false".

FUNC_E2E_CLEAN: controls whether tests clean up deployed functions after completion. When set to "true" (default), functions are deleted after each test. Set to "false" to leave functions deployed for debugging. This speeds up test execution when the same cluster is reused across multiple test runs.

FUNC_E2E_DOCKER_HOST: sets the DOCKER_HOST environment variable for container operations during tests. This is useful when using a remote Docker daemon or when the Docker socket is not at the default location.

FUNC_E2E_HOME: sets a custom home directory path for test execution. By default, tests create a temporary .func_e2e_home directory within each test's clean environment. Use this to debug tests with a persistent home directory, but note that all tests in the invocation will share this home.

FUNC_E2E_KUBECTL: specifies the path to the kubectl binary used during tests. Defaults to the kubectl found in PATH. Tests use kubectl to manipulate cluster state as necessary, such as creating secrets and configmaps.

FUNC_E2E_MATRIX: enables comprehensive matrix testing across different combinations of runtimes, builders, and templates. When set to "true", the test suite will run tests for all supported permutations. Defaults to "false" for faster test execution.

FUNC_E2E_MATRIX_TEMPLATES: sets which templates will be tested during matrix tests. Accepts a comma-separated list (e.g., "http,cloudevents"). By default, both "http" and "cloudevents" templates are tested when matrix tests are enabled.

FUNC_E2E_DOMAIN: specifies the DNS domain suffix used for function URLs during tests. Defaults to "localtest.me". When using a custom domain, ensure it is configured in both the cluster's CoreDNS setup and Knative serving config-domain ConfigMap. The URL pattern is http://{function}.{namespace}.{domain}. For local development, "localtest.me" is recommended as it automatically resolves to 127.0.0.1 without additional DNS configuration.

FUNC_E2E_NAMESPACE: specifies the Kubernetes namespace where functions will be deployed during tests. Defaults to "default". When using a custom namespace, ensure DNS is configured for {function}.{namespace}.{domain} patterns. This requires corresponding DNS or ingress configuration in your cluster.

FUNC_E2E_PODMAN: enables tests specifically for the Podman container engine. When set to "true", tests will verify that functions can be built and deployed using Podman with both Pack and S2I builders. Requires FUNC_E2E_PODMAN_HOST to be set.

FUNC_E2E_PODMAN_HOST: specifies the Podman socket path for Podman-specific tests. This is required when FUNC_E2E_PODMAN is enabled. Example: "unix:///run/user/1000/podman/podman.sock" for rootless Podman.

FUNC_E2E_CONFIG_CI: enables Config CI tests that deploy functions via generated GitHub Actions workflows using act. Requires act to be installed (via hack/binaries.sh). Defaults to "false".

FUNC_CLUSTER_RETRIES: controls the number of retry attempts for cluster allocation. Defaults to "1" (no retries). Set to a higher value (e.g., "5") for environments with flaky cluster setup. Used by the cluster.sh script.

FUNC_INT_TEKTON_ENABLED: enables Tekton-specific tests. Set to "1" to include tests that verify Tekton pipeline functionality. Defaults to disabled.

FUNC_INT_GITLAB_ENABLED: enables GitLab-specific tests. Set to "1" to include tests that verify GitLab integration. Requires gitlab.sh to be run. Defaults to disabled.

FUNC_E2E_TOOLS: specifies the path to supporting tools. Defaults to "../hack/bin" relative to the e2e directory.

FUNC_E2E_TESTDATA: specifies the path to supporting testdata. Defaults to "./testdata" relative to the e2e directory.

From the root of the repository, run make test-full. This will compile the current source, creating the binary ./func if it does not already exist, or is out of date. It will then run go test -tags e2e ./e2e. By default the tests will use the locally compiled func binary unless FUNC_E2E_BIN is provided.

The test cache is cleaned before running the tests when using the make targets to eliminate situations where changes to the environment or system can result in invalid results due to caching. Caching can be utilized by running tests directly (eg go test -tags e2e ./e2e).

Tests follow a naming convention to allow for manually testing subsets. For example, To run only "core" tests, run make to update the binary to test, then go test -tags e2e -run TestCore ./e2e. Subsets include:

• TestCore
• TestMetadata
• TestRemote
• TestMatrix
• TestConfigCI

The tests do attempt to clean up after themselves, but since a test failure is definitionally the entering of an unknown state, it is suggested to delete the cluster between full test runs. To remove the local cluster, use the delete.sh script described above. If you do plan to remove the cluster, tests can be sped up by disabling cleanup with FUNC_E2E_CLEAN=false

Replace script executions with "make test-full" (backwards compatibility for environment variables is implemented).

The binary is compiled automatically via the make target.