cel

Documentation

Index

• Constants
• func BuildNamespaceType() *apiservercel.DeclType
• func BuildRequestType() *apiservercel.DeclType
• func CreateAdmissionRequest(attr admission.Attributes, equivalentGVR metav1.GroupVersionResource, ...) *admissionv1.AdmissionRequest
• func CreateNamespaceObject(namespace *v1.Namespace) *v1.Namespace
• type CompilationResult
• type Compiler
  • func NewCompiler(env *environment.EnvSet) Compiler
• type CompositedCompiler
  • func NewCompositedCompiler(envSet *environment.EnvSet) (*CompositedCompiler, error)
  • func (c *CompositedCompiler) Compile(expressions []ExpressionAccessor, optionalDecls OptionalVariableDeclarations, ...) Filter
  • func (c *CompositedCompiler) CompileAndStoreVariable(variable NamedExpressionAccessor, options OptionalVariableDeclarations, ...) CompilationResult
  • func (c *CompositedCompiler) CompileAndStoreVariables(variables []NamedExpressionAccessor, options OptionalVariableDeclarations, ...)
• type CompositedFilter
  • func (f *CompositedFilter) ForInput(ctx context.Context, versionedAttr *admission.VersionedAttributes, ...) ([]EvaluationResult, int64, error)
• type CompositionContext
• type CompositionEnv
  • func NewCompositionEnv(typeName string, baseEnvSet *environment.EnvSet) (*CompositionEnv, error)
  • func (c *CompositionEnv) AddField(name string, celType *cel.Type)
  • func (c *CompositionEnv) CreateContext(parent context.Context) CompositionContext
• type EvaluationResult
• type ExpressionAccessor
• type Filter
  • func NewFilter(compilationResults []CompilationResult) Filter
• type FilterCompiler
  • func NewFilterCompiler(env *environment.EnvSet) FilterCompiler
• type NamedExpressionAccessor
• type OptionalVariableBindings
• type OptionalVariableDeclarations

Constants

const (
	ObjectVarName                    = "object"
	OldObjectVarName                 = "oldObject"
	ParamsVarName                    = "params"
	RequestVarName                   = "request"
	NamespaceVarName                 = "namespaceObject"
	AuthorizerVarName                = "authorizer"
	RequestResourceAuthorizerVarName = "authorizer.requestResource"
	VariableVarName                  = "variables"
)

const VariablesTypeName = "kubernetes.variables"

Functions

func BuildNamespaceType

func BuildNamespaceType() *apiservercel.DeclType

BuildNamespaceType generates a DeclType for Namespace. Certain nested fields in Namespace (e.g. managedFields, ownerReferences etc.) are omitted in the generated DeclType by design.

func BuildRequestType

func BuildRequestType() *apiservercel.DeclType

BuildRequestType generates a DeclType for AdmissionRequest. This may be replaced with a utility that converts the native type definition to apiservercel.DeclType once such a utility becomes available. The 'uid' field is omitted since it is not needed for in-process admission review. The 'object' and 'oldObject' fields are omitted since they are exposed as root level CEL variables.

func CreateAdmissionRequest

func CreateAdmissionRequest(attr admission.Attributes, equivalentGVR metav1.GroupVersionResource, equivalentKind metav1.GroupVersionKind) *admissionv1.AdmissionRequest

TODO: to reuse https://github.com/kubernetes/kubernetes/blob/master/staging/src/k8s.io/apiserver/pkg/admission/plugin/webhook/request/admissionreview.go#L154

func CreateNamespaceObject

func CreateNamespaceObject(namespace *v1.Namespace) *v1.Namespace

CreateNamespaceObject creates a Namespace object that is suitable for the CEL evaluation. If the namespace is nil, CreateNamespaceObject returns nil

Types

type CompilationResult

type CompilationResult struct {
	Program            cel.Program
	Error              *apiservercel.Error
	ExpressionAccessor ExpressionAccessor
	OutputType         *cel.Type
}

CompilationResult represents a compiled validations expression.

type Compiler

type Compiler interface {
	CompileCELExpression(expressionAccessor ExpressionAccessor, options OptionalVariableDeclarations, mode environment.Type) CompilationResult
}

Compiler provides a CEL expression compiler configured with the desired admission related CEL variables and environment mode.

func NewCompiler

func NewCompiler(env *environment.EnvSet) Compiler

type CompositedCompiler

type CompositedCompiler struct {
	Compiler
	FilterCompiler

	CompositionEnv *CompositionEnv
}

func NewCompositedCompiler

func NewCompositedCompiler(envSet *environment.EnvSet) (*CompositedCompiler, error)

func (*CompositedCompiler) Compile

func (c *CompositedCompiler) Compile(expressions []ExpressionAccessor, optionalDecls OptionalVariableDeclarations, envType environment.Type) Filter

func (*CompositedCompiler) CompileAndStoreVariable

func (c *CompositedCompiler) CompileAndStoreVariable(variable NamedExpressionAccessor, options OptionalVariableDeclarations, mode environment.Type) CompilationResult

func (*CompositedCompiler) CompileAndStoreVariables

func (c *CompositedCompiler) CompileAndStoreVariables(variables []NamedExpressionAccessor, options OptionalVariableDeclarations, mode environment.Type)

type CompositedFilter

type CompositedFilter struct {
	Filter
	// contains filtered or unexported fields
}

func (*CompositedFilter) ForInput

func (f *CompositedFilter) ForInput(ctx context.Context, versionedAttr *admission.VersionedAttributes, request *v1.AdmissionRequest, optionalVars OptionalVariableBindings, namespace *corev1.Namespace, runtimeCELCostBudget int64) ([]EvaluationResult, int64, error)

type CompositionContext

type CompositionContext interface {
	context.Context
	Variables(activation any) ref.Val
	GetAndResetCost() int64
}

type CompositionEnv

type CompositionEnv struct {
	*environment.EnvSet

	MapType           *apiservercel.DeclType
	CompiledVariables map[string]CompilationResult
}

func NewCompositionEnv

func NewCompositionEnv(typeName string, baseEnvSet *environment.EnvSet) (*CompositionEnv, error)

func (*CompositionEnv) AddField

func (c *CompositionEnv) AddField(name string, celType *cel.Type)

func (*CompositionEnv) CreateContext

func (c *CompositionEnv) CreateContext(parent context.Context) CompositionContext

type EvaluationResult

type EvaluationResult struct {
	EvalResult         ref.Val
	ExpressionAccessor ExpressionAccessor
	Elapsed            time.Duration
	Error              error
}

EvaluationResult contains the minimal required fields and metadata of a cel evaluation

type ExpressionAccessor

type ExpressionAccessor interface {
	GetExpression() string
	ReturnTypes() []*cel.Type
}

type Filter

type Filter interface {
	// ForInput converts compiled CEL-typed values into evaluated CEL-typed value.
	// runtimeCELCostBudget was added for testing purpose only. Callers should always use const RuntimeCELCostBudget from k8s.io/apiserver/pkg/apis/cel/config.go as input.
	// If cost budget is calculated, the filter should return the remaining budget.
	ForInput(ctx context.Context, versionedAttr *admission.VersionedAttributes, request *v1.AdmissionRequest, optionalVars OptionalVariableBindings, namespace *corev1.Namespace, runtimeCELCostBudget int64) ([]EvaluationResult, int64, error)

	// CompilationErrors returns a list of errors from the compilation of the evaluator
	CompilationErrors() []error
}

Filter contains a function to evaluate compiled CEL-typed values It expects the inbound object to already have been converted to the version expected by the underlying CEL code (which is indicated by the match criteria of a policy definition). versionedParams may be nil.

func NewFilter

func NewFilter(compilationResults []CompilationResult) Filter

type FilterCompiler

type FilterCompiler interface {
	// Compile is used for the cel expression compilation
	Compile(expressions []ExpressionAccessor, optionalDecls OptionalVariableDeclarations, envType environment.Type) Filter
}

FilterCompiler contains a function to assist with converting types and values to/from CEL-typed values.

func NewFilterCompiler

func NewFilterCompiler(env *environment.EnvSet) FilterCompiler

type NamedExpressionAccessor

type NamedExpressionAccessor interface {
	ExpressionAccessor

	GetName() string // follows the naming convention of ExpressionAccessor
}

NamedExpressionAccessor extends NamedExpressionAccessor with a name.

type OptionalVariableBindings

type OptionalVariableBindings struct {
	// VersionedParams provides the "params" variable binding. This variable binding may
	// be set to nil even when OptionalVariableDeclarations.HashParams is set to true.
	VersionedParams runtime.Object
	// Authorizer provides the authorizer used for the "authorizer" and
	// "authorizer.requestResource" variable bindings. If the expression was compiled with
	// OptionalVariableDeclarations.HasAuthorizer set to true this must be non-nil.
	Authorizer authorizer.Authorizer
}

OptionalVariableBindings provides expression bindings for optional CEL variables.

type OptionalVariableDeclarations

type OptionalVariableDeclarations struct {
	// HasParams specifies if the "params" variable is declared.
	// The "params" variable may still be bound to "null" when declared.
	HasParams bool
	// HasAuthorizer specifies if the"authorizer" and "authorizer.requestResource"
	// variables are declared. When declared, the authorizer variables are
	// expected to be non-null.
	HasAuthorizer bool
}

OptionalVariableDeclarations declares which optional CEL variables are declared for an expression.