Black lives matter.

We stand in solidarity with the Black community.

Racism is unacceptable.

It conflicts with the core values of the Kubernetes project and our community does not tolerate it.

CRD Validation

These markers modify how the CRD validation schema is produced for the types and fields they modify. Each corresponds roughly to an OpenAPI/JSON schema option.

See Generating CRDs for examples.

// +kubebuilder:default
any
sets the default value for this field.

A default value will be accepted as any value valid for the field. Formatting for common types include: boolean: true, string: Cluster, numerical: 1.24, array: {1,2}, object: {policy: "delete"}). Defaults should be defined in pruned form, and only best-effort validation will be performed. Full validation of a default requires submission of the containing CRD to an apiserver.

any
// +kubebuilder:validation:EmbeddedResource
EmbeddedResource marks a fields as an embedded resource with apiVersion, kind and metadata fields.

An embedded resource is a value that has apiVersion, kind and metadata fields. They are validated implicitly according to the semantics of the currently running apiserver. It is not necessary to add any additional schema for these field, yet it is possible. This can be combined with PreserveUnknownFields.

// +kubebuilder:validation:Enum
any
specifies that this (scalar) field is restricted to the *exact* values specified here.
any
// +kubebuilder:validation:Enum
any
specifies that this (scalar) field is restricted to the *exact* values specified here.
any
// +kubebuilder:validation:ExclusiveMaximum
bool
indicates that the maximum is "up to" but not including that value.
bool
// +kubebuilder:validation:ExclusiveMaximum
bool
indicates that the maximum is "up to" but not including that value.
bool
// +kubebuilder:validation:ExclusiveMinimum
bool
indicates that the minimum is "up to" but not including that value.
bool
// +kubebuilder:validation:ExclusiveMinimum
bool
indicates that the minimum is "up to" but not including that value.
bool
// +kubebuilder:validation:Format
string
specifies additional "complex" formatting for this field.

For example, a date-time field would be marked as “type: string“ and “format: date-time“.

string
// +kubebuilder:validation:Format
string
specifies additional "complex" formatting for this field.

For example, a date-time field would be marked as “type: string“ and “format: date-time“.

string
// +kubebuilder:validation:MaxItems
int
specifies the maximum length for this list.
int
// +kubebuilder:validation:MaxItems
int
specifies the maximum length for this list.
int
// +kubebuilder:validation:MaxLength
int
specifies the maximum length for this string.
int
// +kubebuilder:validation:MaxLength
int
specifies the maximum length for this string.
int
// +kubebuilder:validation:MaxProperties
int
restricts the number of keys in an object
int
// +kubebuilder:validation:MaxProperties
int
restricts the number of keys in an object
int
// +kubebuilder:validation:Maximum
int
specifies the maximum numeric value that this field can have.
int
// +kubebuilder:validation:Maximum
int
specifies the maximum numeric value that this field can have.
int
// +kubebuilder:validation:MinItems
int
specifies the minimun length for this list.
int
// +kubebuilder:validation:MinItems
int
specifies the minimun length for this list.
int
// +kubebuilder:validation:MinLength
int
specifies the minimum length for this string.
int
// +kubebuilder:validation:MinLength
int
specifies the minimum length for this string.
int
// +kubebuilder:validation:MinProperties
int
restricts the number of keys in an object
int
// +kubebuilder:validation:MinProperties
int
restricts the number of keys in an object
int
// +kubebuilder:validation:Minimum
int
specifies the minimum numeric value that this field can have. Negative integers are supported.
int
// +kubebuilder:validation:Minimum
int
specifies the minimum numeric value that this field can have. Negative integers are supported.
int
// +kubebuilder:validation:MultipleOf
int
specifies that this field must have a numeric value that's a multiple of this one.
int
// +kubebuilder:validation:MultipleOf
int
specifies that this field must have a numeric value that's a multiple of this one.
int
// +kubebuilder:validation:Optional
specifies that all fields in this package are optional by default.
// +kubebuilder:validation:Optional
specifies that this field is optional, if fields are required by default.
// +kubebuilder:validation:Pattern
string
specifies that this string must match the given regular expression.
string
// +kubebuilder:validation:Pattern
string
specifies that this string must match the given regular expression.
string
// +kubebuilder:validation:Required
specifies that this field is required, if fields are optional by default.
// +kubebuilder:validation:Required
specifies that all fields in this package are required by default.
// +kubebuilder:validation:Schemaless
marks a field as being a schemaless object.

Schemaless objects are not introspected, so you must provide any type and validation information yourself. One use for this tag is for embedding fields that hold JSONSchema typed objects. Because this field disables all type checking, it is recommended to be used only as a last resort.

// +kubebuilder:validation:Type
string
overrides the type for this field (which defaults to the equivalent of the Go type).

This generally must be paired with custom serialization. For example, the metav1.Time field would be marked as “type: string“ and “format: date-time“.

string
// +kubebuilder:validation:Type
string
overrides the type for this field (which defaults to the equivalent of the Go type).

This generally must be paired with custom serialization. For example, the metav1.Time field would be marked as “type: string“ and “format: date-time“.

string
// +kubebuilder:validation:UniqueItems
bool
specifies that all items in this list must be unique.
bool
// +kubebuilder:validation:UniqueItems
bool
specifies that all items in this list must be unique.
bool
// +kubebuilder:validation:XEmbeddedResource
EmbeddedResource marks a fields as an embedded resource with apiVersion, kind and metadata fields.

An embedded resource is a value that has apiVersion, kind and metadata fields. They are validated implicitly according to the semantics of the currently running apiserver. It is not necessary to add any additional schema for these field, yet it is possible. This can be combined with PreserveUnknownFields.

// +kubebuilder:validation:XEmbeddedResource
EmbeddedResource marks a fields as an embedded resource with apiVersion, kind and metadata fields.

An embedded resource is a value that has apiVersion, kind and metadata fields. They are validated implicitly according to the semantics of the currently running apiserver. It is not necessary to add any additional schema for these field, yet it is possible. This can be combined with PreserveUnknownFields.

// +nullable
marks this field as allowing the "null" value.

This is often not necessary, but may be helpful with custom serialization.

// +optional
specifies that this field is optional, if fields are required by default.