open-nomad/helper/funcs.go
2023-04-10 15:36:59 +00:00

501 lines
12 KiB
Go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0
package helper
import (
"crypto/sha512"
"fmt"
"math"
"net/http"
"path/filepath"
"reflect"
"regexp"
"strings"
"sync"
"time"
multierror "github.com/hashicorp/go-multierror"
"github.com/hashicorp/go-set"
"github.com/hashicorp/hcl/hcl/ast"
"golang.org/x/exp/constraints"
"golang.org/x/exp/maps"
"golang.org/x/exp/slices"
)
// validUUID is used to check if a given string looks like a UUID
var validUUID = regexp.MustCompile(`(?i)^[\da-f]{8}-[\da-f]{4}-[\da-f]{4}-[\da-f]{4}-[\da-f]{12}$`)
// validInterpVarKey matches valid dotted variable names for interpolation. The
// string must begin with one or more non-dot characters which may be followed
// by sequences containing a dot followed by a one or more non-dot characters.
var validInterpVarKey = regexp.MustCompile(`^[^.]+(\.[^.]+)*$`)
// invalidFilename is the minimum set of characters which must be removed or
// replaced to produce a valid filename
var invalidFilename = regexp.MustCompile(`[/\\<>:"|?*]`)
// invalidFilenameNonASCII = invalidFilename plus all non-ASCII characters
var invalidFilenameNonASCII = regexp.MustCompile(`[[:^ascii:]/\\<>:"|?*]`)
// invalidFilenameStrict = invalidFilename plus additional punctuation
var invalidFilenameStrict = regexp.MustCompile(`[/\\<>:"|?*$()+=[\];#@~,&']`)
type Copyable[T any] interface {
Copy() T
}
// IsUUID returns true if the given string is a valid UUID.
func IsUUID(str string) bool {
const uuidLen = 36
if len(str) != uuidLen {
return false
}
return validUUID.MatchString(str)
}
// IsValidInterpVariable returns true if a valid dotted variable names for
// interpolation. The string must begin with one or more non-dot characters
// which may be followed by sequences containing a dot followed by a one or more
// non-dot characters.
func IsValidInterpVariable(str string) bool {
return validInterpVarKey.MatchString(str)
}
// HashUUID takes an input UUID and returns a hashed version of the UUID to
// ensure it is well distributed.
func HashUUID(input string) (output string, hashed bool) {
if !IsUUID(input) {
return "", false
}
// Hash the input
buf := sha512.Sum512([]byte(input))
output = fmt.Sprintf("%08x-%04x-%04x-%04x-%12x",
buf[0:4],
buf[4:6],
buf[6:8],
buf[8:10],
buf[10:16])
return output, true
}
// Min returns the minimum of a and b.
func Min[T constraints.Ordered](a, b T) T {
if a < b {
return a
}
return b
}
// Max returns the maximum of a and b.
func Max[T constraints.Ordered](a, b T) T {
if a > b {
return a
}
return b
}
// UniqueMapSliceValues returns the union of values from each slice in a map[K][]V.
func UniqueMapSliceValues[K, V comparable](m map[K][]V) []V {
s := set.New[V](0)
for _, slice := range m {
s.InsertAll(slice)
}
return s.List()
}
// IsSubset returns whether the smaller set of items is a subset of
// the larger. If the smaller set is not a subset, the offending elements are
// returned.
func IsSubset[T comparable](larger, smaller []T) (bool, []T) {
l := set.From(larger)
if l.ContainsAll(smaller) {
return true, nil
}
s := set.From(smaller)
return false, s.Difference(l).List()
}
// StringHasPrefixInSlice returns true if s starts with any prefix in list.
func StringHasPrefixInSlice(s string, prefixes []string) bool {
for _, prefix := range prefixes {
if strings.HasPrefix(s, prefix) {
return true
}
}
return false
}
// IsDisjoint returns whether first and second are disjoint sets, and the set of
// offending elements if not.
func IsDisjoint[T comparable](first, second []T) (bool, []T) {
f, s := set.From(first), set.From(second)
intersection := f.Intersect(s)
if intersection.Size() > 0 {
return false, intersection.List()
}
return true, nil
}
// DeepCopyMap creates a copy of m by calling Copy() on each value.
//
// If m is nil the return value is nil.
func DeepCopyMap[M ~map[K]V, K comparable, V Copyable[V]](m M) M {
if m == nil {
return nil
}
result := make(M, len(m))
for k, v := range m {
result[k] = v.Copy()
}
return result
}
// CopySlice creates a deep copy of s. For slices with elements that do not
// implement Copy(), use slices.Clone.
func CopySlice[S ~[]E, E Copyable[E]](s S) S {
if s == nil {
return nil
}
result := make(S, len(s))
for i, v := range s {
result[i] = v.Copy()
}
return result
}
// MergeMapStringString will merge two maps into one. If a duplicate key exists
// the value in the second map will replace the value in the first map. If both
// maps are empty or nil this returns an empty map.
func MergeMapStringString(m map[string]string, n map[string]string) map[string]string {
if len(m) == 0 && len(n) == 0 {
return map[string]string{}
}
if len(m) == 0 {
return n
}
if len(n) == 0 {
return m
}
result := maps.Clone(m)
for k, v := range n {
result[k] = v
}
return result
}
// CopyMapOfSlice creates a copy of m, making copies of each []V.
func CopyMapOfSlice[K comparable, V any](m map[K][]V) map[K][]V {
l := len(m)
if l == 0 {
return nil
}
c := make(map[K][]V, l)
for k, v := range m {
c[k] = slices.Clone(v)
}
return c
}
// CleanEnvVar replaces all occurrences of illegal characters in an environment
// variable with the specified byte.
func CleanEnvVar(s string, r byte) string {
b := []byte(s)
for i, c := range b {
switch {
case c == '_':
case c == '.':
case c >= 'a' && c <= 'z':
case c >= 'A' && c <= 'Z':
case i > 0 && c >= '0' && c <= '9':
default:
// Replace!
b[i] = r
}
}
return string(b)
}
// CleanFilename replaces invalid characters in filename
func CleanFilename(filename string, replace string) string {
clean := invalidFilename.ReplaceAllLiteralString(filename, replace)
return clean
}
// CleanFilenameASCIIOnly replaces invalid and non-ASCII characters in filename
func CleanFilenameASCIIOnly(filename string, replace string) string {
clean := invalidFilenameNonASCII.ReplaceAllLiteralString(filename, replace)
return clean
}
// CleanFilenameStrict replaces invalid and punctuation characters in filename
func CleanFilenameStrict(filename string, replace string) string {
clean := invalidFilenameStrict.ReplaceAllLiteralString(filename, replace)
return clean
}
func CheckHCLKeys(node ast.Node, valid []string) error {
var list *ast.ObjectList
switch n := node.(type) {
case *ast.ObjectList:
list = n
case *ast.ObjectType:
list = n.List
default:
return fmt.Errorf("cannot check HCL keys of type %T", n)
}
validMap := make(map[string]struct{}, len(valid))
for _, v := range valid {
validMap[v] = struct{}{}
}
var result error
for _, item := range list.Items {
key := item.Keys[0].Token.Value().(string)
if _, ok := validMap[key]; !ok {
result = multierror.Append(result, fmt.Errorf(
"invalid key: %s", key))
}
}
return result
}
// UnusedKeys returns a pretty-printed error if any `hcl:",unusedKeys"` is not empty
func UnusedKeys(obj interface{}) error {
val := reflect.ValueOf(obj)
if val.Kind() == reflect.Ptr {
val = reflect.Indirect(val)
}
return unusedKeysImpl([]string{}, val)
}
func unusedKeysImpl(path []string, val reflect.Value) error {
stype := val.Type()
for i := 0; i < stype.NumField(); i++ {
ftype := stype.Field(i)
fval := val.Field(i)
tags := strings.Split(ftype.Tag.Get("hcl"), ",")
name := tags[0]
tags = tags[1:]
if fval.Kind() == reflect.Ptr {
fval = reflect.Indirect(fval)
}
// struct? recurse. Add the struct's key to the path
if fval.Kind() == reflect.Struct {
err := unusedKeysImpl(append([]string{name}, path...), fval)
if err != nil {
return err
}
continue
}
// Search the hcl tags for "unusedKeys"
unusedKeys := false
for _, p := range tags {
if p == "unusedKeys" {
unusedKeys = true
break
}
}
if unusedKeys {
ks, ok := fval.Interface().([]string)
if ok && len(ks) != 0 {
ps := ""
if len(path) > 0 {
ps = strings.Join(path, ".") + " "
}
return fmt.Errorf("%sunexpected keys %s",
ps,
strings.Join(ks, ", "))
}
}
}
return nil
}
// RemoveEqualFold removes the first string that EqualFold matches. It updates xs in place
func RemoveEqualFold(xs *[]string, search string) {
sl := *xs
for i, x := range sl {
if strings.EqualFold(x, search) {
sl = append(sl[:i], sl[i+1:]...)
if len(sl) == 0 {
*xs = nil
} else {
*xs = sl
}
return
}
}
}
// CheckNamespaceScope ensures that the provided namespace is equal to
// or a parent of the requested namespaces. Returns requested namespaces
// which are not equal to or a child of the provided namespace.
func CheckNamespaceScope(provided string, requested []string) []string {
var offending []string
for _, ns := range requested {
rel, err := filepath.Rel(provided, ns)
if err != nil {
offending = append(offending, ns)
// If relative path requires ".." it's not a child
} else if strings.Contains(rel, "..") {
offending = append(offending, ns)
}
}
if len(offending) > 0 {
return offending
}
return nil
}
// StopFunc is used to stop a time.Timer created with NewSafeTimer
type StopFunc func()
// NewSafeTimer creates a time.Timer but does not panic if duration is <= 0.
//
// Using a time.Timer is recommended instead of time.After when it is necessary
// to avoid leaking goroutines (e.g. in a select inside a loop).
//
// Returns the time.Timer and also a StopFunc, forcing the caller to deal
// with stopping the time.Timer to avoid leaking a goroutine.
//
// Note: If creating a Timer that should do nothing until Reset is called, use
// NewStoppedTimer instead for safely creating the timer in a stopped state.
func NewSafeTimer(duration time.Duration) (*time.Timer, StopFunc) {
if duration <= 0 {
// Avoid panic by using the smallest positive value. This is close enough
// to the behavior of time.After(0), which this helper is intended to
// replace.
// https://go.dev/play/p/EIkm9MsPbHY
duration = 1
}
t := time.NewTimer(duration)
cancel := func() {
t.Stop()
}
return t, cancel
}
// NewStoppedTimer creates a time.Timer in a stopped state. This is useful when
// the actual wait time will computed and set later via Reset.
func NewStoppedTimer() (*time.Timer, StopFunc) {
t, f := NewSafeTimer(math.MaxInt64)
t.Stop()
return t, f
}
// ConvertSlice takes the input slice and generates a new one using the
// supplied conversion function to covert the element. This is useful when
// converting a slice of strings to a slice of structs which wraps the string.
func ConvertSlice[A, B any](original []A, conversion func(a A) B) []B {
result := make([]B, len(original))
for i, element := range original {
result[i] = conversion(element)
}
return result
}
// IsMethodHTTP returns whether s is a known HTTP method, ignoring case.
func IsMethodHTTP(s string) bool {
switch strings.ToUpper(s) {
case http.MethodGet:
case http.MethodHead:
case http.MethodPost:
case http.MethodPut:
case http.MethodPatch:
case http.MethodDelete:
case http.MethodConnect:
case http.MethodOptions:
case http.MethodTrace:
default:
return false
}
return true
}
// EqualFunc represents a type implementing the Equal method.
type EqualFunc[A any] interface {
Equal(A) bool
}
// ElementsEqual returns true if slices a and b contain the same elements (in
// no particular order) using the Equal function defined on their type for
// comparison.
func ElementsEqual[T EqualFunc[T]](a, b []T) bool {
if len(a) != len(b) {
return false
}
OUTER:
for _, item := range a {
for _, other := range b {
if item.Equal(other) {
continue OUTER
}
}
return false
}
return true
}
// SliceSetEq returns true if slices a and b contain the same elements (in no
// particular order), using '==' for comparison.
//
// Note: for pointers, consider implementing an Equal method and using
// ElementsEqual instead.
func SliceSetEq[T comparable](a, b []T) bool {
lenA, lenB := len(a), len(b)
if lenA != lenB {
return false
}
if lenA > 10 {
// avoid quadratic comparisons over large input
return set.From(a).EqualSlice(b)
}
OUTER:
for _, item := range a {
for _, other := range b {
if item == other {
continue OUTER
}
}
return false
}
return true
}
// WithLock executes a function while holding a lock.
func WithLock(lock sync.Locker, f func()) {
lock.Lock()
defer lock.Unlock()
f()
}
// Merge takes two variables and returns variable b in case a has zero value.
// For pointer values please use pointer.Merge.
func Merge[T comparable](a, b T) T {
var zero T
if a == zero {
return b
}
return a
}