package library

import "k8s.io/apiserver/pkg/cel/library"

Index ¶

• Variables
• func Lists() cel.EnvOption
• func Regex() cel.EnvOption
• func URLs() cel.EnvOption
• type CostEstimator
• func (l *CostEstimator) CallCost(function, overloadId string, args []ref.Val, result ref.Val) *uint64
• func (l *CostEstimator) EstimateCallCost(function, overloadId string, target *checker.AstNode, args []checker.AstNode) *checker.CallEstimate
• func (l *CostEstimator) EstimateSize(element checker.AstNode) *checker.SizeEstimate

Variables ¶

var ExtensionLibRegexOptimizations = []*interpreter.RegexOptimization{FindRegexOptimization, FindAllRegexOptimization}

var ExtensionLibs = append(k8sExtensionLibs, ext.Strings())

ExtensionLibs declares the set of CEL extension libraries available everywhere CEL is used in Kubernetes.

var FindAllRegexOptimization = &interpreter.RegexOptimization{
	Function:   "findAll",
	RegexIndex: 1,
	Factory: func(call interpreter.InterpretableCall, regexPattern string) (interpreter.InterpretableCall, error) {
		compiledRegex, err := regexp.Compile(regexPattern)
		if err != nil {
			return nil, err
		}
		return interpreter.NewCall(call.ID(), call.Function(), call.OverloadID(), call.Args(), func(args ...ref.Val) ref.Val {
			argn := len(args)
			if argn < 2 || argn > 3 {
				return types.NoSuchOverloadErr()
			}
			str, ok := args[0].Value().(string)
			if !ok {
				return types.MaybeNoSuchOverloadErr(args[0])
			}
			n := int64(-1)
			if argn == 3 {
				n, ok = args[2].Value().(int64)
				if !ok {
					return types.MaybeNoSuchOverloadErr(args[2])
				}
			}

			result := compiledRegex.FindAllString(str, int(n))
			return types.NewStringList(types.DefaultTypeAdapter, result)
		}), nil
	},
}

FindAllRegexOptimization optimizes the 'findAll' function by compiling the regex pattern and reporting any compilation errors at program creation time, and using the compiled regex pattern for all function call invocations.

var FindRegexOptimization = &interpreter.RegexOptimization{
	Function:   "find",
	RegexIndex: 1,
	Factory: func(call interpreter.InterpretableCall, regexPattern string) (interpreter.InterpretableCall, error) {
		compiledRegex, err := regexp.Compile(regexPattern)
		if err != nil {
			return nil, err
		}
		return interpreter.NewCall(call.ID(), call.Function(), call.OverloadID(), call.Args(), func(args ...ref.Val) ref.Val {
			if len(args) != 2 {
				return types.NoSuchOverloadErr()
			}
			in, ok := args[0].Value().(string)
			if !ok {
				return types.MaybeNoSuchOverloadErr(args[0])
			}
			return types.String(compiledRegex.FindString(in))
		}), nil
	},
}

FindRegexOptimization optimizes the 'find' function by compiling the regex pattern and reporting any compilation errors at program creation time, and using the compiled regex pattern for all function call invocations.

Functions ¶

func Lists ¶

func Lists() cel.EnvOption

Lists provides a CEL function library extension of list utility functions.

isSorted

Returns true if the provided list of comparable elements is sorted, else returns false.

<list<T>>.isSorted() <bool>, T must be a comparable type

Examples:

[1, 2, 3].isSorted()  // return true
['a', 'b', 'b', 'c'].isSorted()  // return true
[2.0, 1.0].isSorted()  // return false
[1].isSorted()  // return true
[].isSorted()  // return true

sum

Returns the sum of the elements of the provided list. Supports CEL number (int, uint, double) and duration types.

<list<T>>.sum() <T>, T must be a numeric type or a duration

Examples:

[1, 3].sum() // returns 4
[1.0, 3.0].sum() // returns 4.0
['1m', '1s'].sum() // returns '1m1s'
emptyIntList.sum() // returns 0
emptyDoubleList.sum() // returns 0.0
[].sum() // returns 0

min / max

Returns the minimum/maximum valued element of the provided list. Supports all comparable types. If the list is empty, an error is returned.

<list<T>>.min() <T>, T must be a comparable type
<list<T>>.max() <T>, T must be a comparable type

Examples:

[1, 3].min() // returns 1
[1, 3].max() // returns 3
[].min() // error
[1].min() // returns 1
([0] + emptyList).min() // returns 0

indexOf / lastIndexOf

Returns either the first or last positional index of the provided element in the list. If the element is not found, -1 is returned. Supports all equatable types.

<list<T>>.indexOf(<T>) <int>, T must be an equatable type
<list<T>>.lastIndexOf(<T>) <int>, T must be an equatable type

Examples:

[1, 2, 2, 3].indexOf(2) // returns 1
['a', 'b', 'b', 'c'].lastIndexOf('b') // returns 2
[1.0].indexOf(1.1) // returns -1
[].indexOf('string') // returns -1

func Regex ¶

func Regex() cel.EnvOption

Regex provides a CEL function library extension of regex utility functions.

find / findAll

Returns substrings that match the provided regular expression. find returns the first match. findAll may optionally be provided a limit. If the limit is set and >= 0, no more than the limit number of matches are returned.

<string>.find(<string>) <string>
<string>.findAll(<string>) <list <string>>
<string>.findAll(<string>, <int>) <list <string>>

Examples:

"abc 123".find('[0-9]*') // returns '123'
"abc 123".find('xyz') // returns ''
"123 abc 456".findAll('[0-9]*') // returns ['123', '456']
"123 abc 456".findAll('[0-9]*', 1) // returns ['123']
"123 abc 456".findAll('xyz') // returns []

func URLs ¶

func URLs() cel.EnvOption

URLs provides a CEL function library extension of URL parsing functions.

url

Converts a string to a URL or results in an error if the string is not a valid URL. The URL must be an absolute URI or an absolute path.

url(<string>) <URL>

Examples:

url('https://user:pass@example.com:80/path?query=val#fragment') // returns a URL
url('/absolute-path') // returns a URL
url('https://a:b:c/') // error
url('../relative-path') // error

isURL

Returns true if a string is a valid URL. The URL must be an absolute URI or an absolute path.

isURL( <string>) <bool>

Examples:

isURL('https://user:pass@example.com:80/path?query=val#fragment') // returns true
isURL('/absolute-path') // returns true
isURL('https://a:b:c/') // returns false
isURL('../relative-path') // returns false

getScheme / getHost / getHostname / getPort / getEscapedPath / getQuery

Return the parsed components of a URL.

• getScheme: If absent in the URL, returns an empty string.

• getHostname: IPv6 addresses are returned with braces, e.g. "[::1]". If absent in the URL, returns an empty string.

• getHost: IPv6 addresses are returned without braces, e.g. "::1". If absent in the URL, returns an empty string.

• getEscapedPath: The string returned by getEscapedPath is URL escaped, e.g. "with space" becomes "with%20space". If absent in the URL, returns an empty string.

• getPort: If absent in the URL, returns an empty string.

• getQuery: Returns the query parameters in "matrix" form where a repeated query key is interpreted to mean that there are multiple values for that key. The keys and values are returned unescaped. If absent in the URL, returns an empty map.

  <URL>.getScheme() <string> <URL>.getHost() <string> <URL>.getHostname() <string> <URL>.getPort() <string> <URL>.getEscapedPath() <string> <URL>.getQuery() <map <string>, <list <string>>

Examples:

url('/path').getScheme() // returns ''
url('https://example.com/').getScheme() // returns 'https'
url('https://example.com:80/').getHost() // returns 'example.com:80'
url('https://example.com/').getHost() // returns 'example.com'
url('https://[::1]:80/').getHost() // returns '[::1]:80'
url('https://[::1]/').getHost() // returns '[::1]'
url('/path').getHost() // returns ''
url('https://example.com:80/').getHostname() // returns 'example.com'
url('https://127.0.0.1:80/').getHostname() // returns '127.0.0.1'
url('https://[::1]:80/').getHostname() // returns '::1'
url('/path').getHostname() // returns ''
url('https://example.com:80/').getPort() // returns '80'
url('https://example.com/').getPort() // returns ''
url('/path').getPort() // returns ''
url('https://example.com/path').getEscapedPath() // returns '/path'
url('https://example.com/path with spaces/').getEscapedPath() // returns '/path%20with%20spaces/'
url('https://example.com').getEscapedPath() // returns ''
url('https://example.com/path?k1=a&k2=b&k2=c').getQuery() // returns { 'k1': ['a'], 'k2': ['b', 'c']}
url('https://example.com/path?key with spaces=value with spaces').getQuery() // returns { 'key with spaces': ['value with spaces']}
url('https://example.com/path?').getQuery() // returns {}
url('https://example.com/path').getQuery() // returns {}

Types ¶

type CostEstimator ¶

type CostEstimator struct {
	// SizeEstimator provides a CostEstimator.EstimateSize that this CostEstimator will delegate size estimation
	// calculations to if the size is not well known (i.e. a constant).
	SizeEstimator checker.CostEstimator
}

CostEstimator implements CEL's interpretable.ActualCostEstimator and checker.CostEstimator.

func (*CostEstimator) CallCost ¶

func (l *CostEstimator) CallCost(function, overloadId string, args []ref.Val, result ref.Val) *uint64

func (*CostEstimator) EstimateCallCost ¶

func (l *CostEstimator) EstimateCallCost(function, overloadId string, target *checker.AstNode, args []checker.AstNode) *checker.CallEstimate

func (*CostEstimator) EstimateSize ¶

func (l *CostEstimator) EstimateSize(element checker.AstNode) *checker.SizeEstimate

Source Files ¶

cost.go libraries.go lists.go regex.go urls.go