controller-gen CLI
Kubebuilder makes use of a tool called controller-gen for generating utility code and Kubernetes YAML. This code and config generation is controlled by the presence of special “marker comments” in Go code.
controller-gen is built out of different “generators” (which specify what to generate) and “output rules” (which specify how and where to write the results).
Both are configured through command line options specified in marker format.
For instance, the following command:
controller-gen paths=./... crd:trivialVersions=true rbac:roleName=controller-perms output:crd:artifacts:config=config/crd/bases
generates CRDs and RBAC, and specifically stores the generated CRD YAML in
config/crd/bases. For the RBAC, it uses the default output rules
(config/rbac). It considers every package in the current directory tree
(as per the normal rules of the go ... wildcard).
Generators
Each different generator is configured through a CLI option. Multiple
generators may be used in a single invocation of controller-gen.
- // +webhook
- headerFile
- string
- year
- string
generates (partial) {Mutating,Validating}WebhookConfiguration objects.
- headerFile
- string
specifies the header text (e.g. license) to prepend to generated files.
- year
- string
specifies the year to substitute for " YEAR" in the header file.
- // +schemapatch
- generateEmbeddedObjectMeta
- bool
- manifests
- string
- maxDescLen
- int
patches existing CRDs with new schemata.
It will generate output for each "CRD Version" (API version of the CRD type itself) , e.g. apiextensions/v1) available.
- generateEmbeddedObjectMeta
- bool
specifies if any embedded ObjectMeta in the CRD should be generated
- manifests
- string
contains the CustomResourceDefinition YAML files.
- maxDescLen
- int
specifies the maximum description length for fields in CRD's OpenAPI schema.
0 indicates drop the description for all fields completely. n indicates limit the description to at most n characters and truncate the description to closest sentence boundary if it exceeds n characters.
- // +rbac
- headerFile
- string
- roleName
- string
- year
- string
generates ClusterRole objects.
- headerFile
- string
specifies the header text (e.g. license) to prepend to generated files.
- roleName
- string
sets the name of the generated ClusterRole.
- year
- string
specifies the year to substitute for " YEAR" in the header file.
- // +object
- headerFile
- string
- year
- string
generates code containing DeepCopy, DeepCopyInto, and
DeepCopyObject method implementations.
- headerFile
- string
specifies the header text (e.g. license) to prepend to generated files.
- year
- string
specifies the year to substitute for " YEAR" in the header file.
- // +crd
- allowDangerousTypes
- bool
- crdVersions
- string
- deprecatedV1beta1CompatibilityPreserveUnknownFields
- bool
- generateEmbeddedObjectMeta
- bool
- headerFile
- string
- ignoreUnexportedFields
- bool
- maxDescLen
- int
- year
- string
generates CustomResourceDefinition objects.
- allowDangerousTypes
- bool
allows types which are usually omitted from CRD generation
because they are not recommended.
Currently the following additional types are allowed when this is true: float32 float64
Left unspecified, the default is false
- crdVersions
- string
specifies the target API versions of the CRD type itself to
generate. Defaults to v1.
Currently, the only supported value is v1.
The first version listed will be assumed to be the "default" version and will not get a version suffix in the output filename.
You'll need to use "v1" to get support for features like defaulting, along with an API server that supports it (Kubernetes 1.16+).
- deprecatedV1beta1CompatibilityPreserveUnknownFields
- bool
indicates whether
or not we should turn off field pruning for this resource.
Specifies spec.preserveUnknownFields value that is false and omitted by default. This value can only be specified for CustomResourceDefinitions that were created with
apiextensions.k8s.io/v1beta1.The field can be set for compatiblity reasons, although strongly discouraged, resource authors should move to a structural OpenAPI schema instead.
See https://kubernetes.io/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/#field-pruning for more information about field pruning and v1beta1 resources compatibility.
- generateEmbeddedObjectMeta
- bool
specifies if any embedded ObjectMeta in the CRD should be generated
- headerFile
- string
specifies the header text (e.g. license) to prepend to generated files.
- ignoreUnexportedFields
- bool
indicates that we should skip unexported fields.
Left unspecified, the default is false.
- maxDescLen
- int
specifies the maximum description length for fields in CRD's OpenAPI schema.
0 indicates drop the description for all fields completely. n indicates limit the description to at most n characters and truncate the description to closest sentence boundary if it exceeds n characters.
- year
- string
specifies the year to substitute for " YEAR" in the header file.
Output Rules
Output rules configure how a given generator outputs its results. There is
always one global “fallback” output rule (specified as output:<rule>),
plus per-generator overrides (specified as output:<generator>:<rule>).
For brevity, the per-generator output rules (output:<generator>:<rule>)
are omitted below. They are equivalent to the global fallback options
listed here.
- // +output:artifacts
- code
- string
- config
- string
outputs artifacts to different locations, depending on
whether they're package-associated or not.
Non-package associated artifacts are output to the Config directory, while package-associated ones are output to their package's source files' directory, unless an alternate path is specified in Code.
- code
- string
overrides the directory in which to write new code (defaults to where the existing code lives).
- config
- string
points to the directory to which to write configuration.
- // +output:dir
- string
outputs each artifact to the given directory, regardless
of if it's package-associated or not.
- string
- // +output:none
skips outputting anything.
- // +output:stdout
outputs everything to standard-out, with no separation.
Generally useful for single-artifact outputs.
Other Options
- // +paths
- string
represents paths and go-style path patterns to use as package roots.
Multiple paths can be specified using "{path1, path2, path3}".
- string