traefik/vendor/gopkg.in/ns1/ns1-go.v2/rest/model/data/meta.go
2018-05-31 09:30:04 +02:00

492 lines
14 KiB
Go

package data
import (
"bytes"
"encoding/json"
"fmt"
"net"
"reflect"
"sort"
"strconv"
"strings"
)
// FeedPtr represents the dynamic metadata value in which a feed is providing the value.
type FeedPtr struct {
FeedID string `json:"feed,omitempty"`
}
// Meta contains information on an entity's metadata table. Metadata key/value
// pairs are used by a record's filter pipeline during a dns query.
// All values can be a feed id as well, indicating real-time updates of these values.
// Structure/Precendence of metadata tables:
// - Record
// - Meta <- lowest precendence in filter
// - Region(s)
// - Meta <- middle precedence in filter chain
// - ...
// - Answer(s)
// - Meta <- highest precedence in filter chain
// - ...
// - ...
type Meta struct {
// STATUS
// Indicates whether or not entity is considered 'up'
// bool or FeedPtr.
Up interface{} `json:"up,omitempty"`
// Indicates the number of active connections.
// Values must be positive.
// int or FeedPtr.
Connections interface{} `json:"connections,omitempty"`
// Indicates the number of active requests (HTTP or otherwise).
// Values must be positive.
// int or FeedPtr.
Requests interface{} `json:"requests,omitempty"`
// Indicates the "load average".
// Values must be positive, and will be rounded to the nearest tenth.
// float64 or FeedPtr.
LoadAvg interface{} `json:"loadavg,omitempty"`
// The Job ID of a Pulsar telemetry gathering job and routing granularities
// to associate with.
// string or FeedPtr.
Pulsar interface{} `json:"pulsar,omitempty"`
// GEOGRAPHICAL
// Must be between -180.0 and +180.0 where negative
// indicates South and positive indicates North.
// e.g., the longitude of the datacenter where a server resides.
// float64 or FeedPtr.
Latitude interface{} `json:"latitude,omitempty"`
// Must be between -180.0 and +180.0 where negative
// indicates West and positive indicates East.
// e.g., the longitude of the datacenter where a server resides.
// float64 or FeedPtr.
Longitude interface{} `json:"longitude,omitempty"`
// Valid geographic regions are: 'US-EAST', 'US-CENTRAL', 'US-WEST',
// 'EUROPE', 'ASIAPAC', 'SOUTH-AMERICA', 'AFRICA'.
// e.g., the rough geographic location of the Datacenter where a server resides.
// []string or FeedPtr.
Georegion interface{} `json:"georegion,omitempty"`
// Countr(ies) must be specified as ISO3166 2-character country code(s).
// []string or FeedPtr.
Country interface{} `json:"country,omitempty"`
// State(s) must be specified as standard 2-character state code(s).
// []string or FeedPtr.
USState interface{} `json:"us_state,omitempty"`
// Canadian Province(s) must be specified as standard 2-character province
// code(s).
// []string or FeedPtr.
CAProvince interface{} `json:"ca_province,omitempty"`
// INFORMATIONAL
// Notes to indicate any necessary details for operators.
// Up to 256 characters in length.
// string or FeedPtr.
Note interface{} `json:"note,omitempty"`
// NETWORK
// IP (v4 and v6) prefixes in CIDR format ("a.b.c.d/mask").
// May include up to 1000 prefixes.
// e.g., "1.2.3.4/24"
// []string or FeedPtr.
IPPrefixes interface{} `json:"ip_prefixes,omitempty"`
// Autonomous System (AS) number(s).
// May include up to 1000 AS numbers.
// []string or FeedPtr.
ASN interface{} `json:"asn,omitempty"`
// TRAFFIC
// Indicates the "priority tier".
// Lower values indicate higher priority.
// Values must be positive.
// int or FeedPtr.
Priority interface{} `json:"priority,omitempty"`
// Indicates a weight.
// Filters that use weights normalize them.
// Any positive values are allowed.
// Values between 0 and 100 are recommended for simplicity's sake.
// float64 or FeedPtr.
Weight interface{} `json:"weight,omitempty"`
// Indicates a "low watermark" to use for load shedding.
// The value should depend on the metric used to determine
// load (e.g., loadavg, connections, etc).
// int or FeedPtr.
LowWatermark interface{} `json:"low_watermark,omitempty"`
// Indicates a "high watermark" to use for load shedding.
// The value should depend on the metric used to determine
// load (e.g., loadavg, connections, etc).
// int or FeedPtr.
HighWatermark interface{} `json:"high_watermark,omitempty"`
}
// StringMap returns a map[string]interface{} representation of metadata (for use with terraform in nested structures)
func (meta *Meta) StringMap() map[string]interface{} {
m := make(map[string]interface{})
v := reflect.Indirect(reflect.ValueOf(meta))
t := v.Type()
for i := 0; i < t.NumField(); i++ {
f := t.Field(i)
fv := v.Field(i)
if fv.IsNil() {
continue
}
tag := f.Tag.Get("json")
tag = strings.Split(tag, ",")[0]
m[tag] = FormatInterface(fv.Interface())
}
return m
}
// FormatInterface takes an interface of types: string, bool, int, float64, []string, and FeedPtr, and returns a string representation of said interface
func FormatInterface(i interface{}) string {
switch v := i.(type) {
case string:
return v
case bool:
if v {
return "1"
}
return "0"
case int:
return strconv.FormatInt(int64(v), 10)
case float64:
return strconv.FormatFloat(v, 'f', -1, 64)
case []string:
return strings.Join(v, ",")
case []interface{}:
slc := make([]string, 0)
for _, s := range v {
slc = append(slc, s.(string))
}
return strings.Join(slc, ",")
case FeedPtr:
data, _ := json.Marshal(v)
return string(data)
default:
panic(fmt.Sprintf("expected v to be convertible to a string, got: %+v, %T", v, v))
}
}
// ParseType returns an interface containing a string, bool, int, float64, []string, or FeedPtr
// float64 values with no decimal may be returned as integers, but that should be ok because the api won't know the difference
// when it's json encoded
func ParseType(s string) interface{} {
slc := strings.Split(s, ",")
if len(slc) > 1 {
sort.Strings(slc)
return slc
}
feedptr := FeedPtr{}
err := json.Unmarshal([]byte(s), &feedptr)
if err == nil {
return feedptr
}
f, err := strconv.ParseFloat(s, 64)
if err == nil {
if !isIntegral(f) {
return f
}
return int(f)
}
return s
}
func isIntegral(f float64) bool {
return f == float64(int(f))
}
// MetaFromMap creates a *Meta and uses reflection to set fields from a map. This will panic if a value for a key is not a string.
// This it to ensure compatibility with terraform
func MetaFromMap(m map[string]interface{}) *Meta {
meta := &Meta{}
mv := reflect.Indirect(reflect.ValueOf(meta))
mt := mv.Type()
for k, v := range m {
name := ToCamel(k)
if _, ok := mt.FieldByName(name); ok {
fv := mv.FieldByName(name)
if name == "Up" {
if v.(string) == "1" {
fv.Set(reflect.ValueOf(true))
} else {
fv.Set(reflect.ValueOf(false))
}
} else {
fv.Set(reflect.ValueOf(ParseType(v.(string))))
}
}
}
return meta
}
// metaValidation is a validation struct for a metadata field.
// It contains the kinds of types that the field can be, and a list of check functions that will run on the field
type metaValidation struct {
kinds []reflect.Kind
checkFuncs []func(v reflect.Value) error
}
// validateLatLong makes sure that the given lat/long is within the range 180.0 to -180.0
func validateLatLong(v reflect.Value) error {
if v.Kind() == reflect.Float64 {
f := v.Interface().(float64)
if f < -180.0 || f > 180.0 {
return fmt.Errorf("latitude/longitude values must be between -180.0 and 180.0, got %f", f)
}
}
return nil
}
// validateCidr makes sure that the given string is a valid cidr
func validateCidr(v reflect.Value) error {
if v.Kind() == reflect.String {
s := v.Interface().(string)
_, _, err := net.ParseCIDR(s)
if err != nil {
return err
}
}
var last error
if v.Kind() == reflect.Slice {
slc := v.Interface().([]interface{})
for _, s := range slc {
_, _, err := net.ParseCIDR(s.(string))
last = err
}
}
return last
}
// validatePositiveNumber makes sure that the given number (float or int) is positive
func validatePositiveNumber(fieldName string, v reflect.Value) error {
i := 0
if v.Kind() == reflect.Int {
i = v.Interface().(int)
}
if v.Kind() == reflect.Float64 {
i = int(v.Interface().(float64))
}
if i < 0 {
return fmt.Errorf("%s must be a positive number, was %+v", fieldName, v.Interface())
}
return nil
}
// geoMap is a map of all of the georegions
var geoMap = map[string]struct{}{
"US-EAST": {}, "US-CENTRAL": {}, "US-WEST": {},
"EUROPE": {}, "ASIAPAC": {}, "SOUTH-AMERICA": {}, "AFRICA": {},
}
// geoKeyString returns a string representation of all of the georegions
func geoKeyString() string {
length := 0
slc := make([]string, 0)
for k := range geoMap {
slc = append(slc, k)
length += len(k) + 1
}
sort.Strings(slc)
b := bytes.NewBuffer(make([]byte, 0, length-1))
for _, k := range slc {
b.WriteString(k + ",")
}
return strings.TrimRight(b.String(), ",")
}
// validateGeoregion makes sure that the given georegion is correct
func validateGeoregion(v reflect.Value) error {
if v.Kind() == reflect.String {
s := v.String()
if _, ok := geoMap[s]; !ok {
return fmt.Errorf("georegion must be one or more of %s, found %s", geoKeyString(), s)
}
}
if v.Kind() == reflect.Slice {
if slc, ok := v.Interface().([]string); ok {
for _, s := range slc {
if _, ok := geoMap[s]; !ok {
return fmt.Errorf("georegion must be one or more of %s, found %s", geoKeyString(), s)
}
}
return nil
}
slc := v.Interface().([]interface{})
for _, s := range slc {
if _, ok := geoMap[s.(string)]; !ok {
return fmt.Errorf("georegion must be one or more of %s, found %s", geoKeyString(), s)
}
}
}
return nil
}
// validateCountryStateProvince makes sure that the given field only has two characters
func validateCountryStateProvince(v reflect.Value) error {
if v.Kind() == reflect.String {
s := v.String()
if len(s) != 2 {
return fmt.Errorf("country/state/province codes must be 2 digits as specified in ISO3166/ISO3166-2, got: %s", s)
}
}
if v.Kind() == reflect.Slice {
if slc, ok := v.Interface().([]string); ok {
for _, s := range slc {
if len(s) != 2 {
return fmt.Errorf("country/state/province codes must be 2 digits as specified in ISO3166/ISO3166-2, got: %s", s)
}
}
return nil
}
slc := v.Interface().([]interface{})
for _, s := range slc {
if len(s.(string)) != 2 {
return fmt.Errorf("country/state/province codes must be 2 digits as specified in ISO3166/ISO3166-2, got: %s", s)
}
}
}
return nil
}
// validateNoteLength validates that a note's length is less than 256 characters
func validateNoteLength(v reflect.Value) error {
if v.Kind() == reflect.String {
s := v.String()
if len(s) > 256 {
return fmt.Errorf("note length must be less than 256 characters, was %d", len(s))
}
}
return nil
}
// checkFuncs is shorthand for returning a slice of functions that take a reflect.Value and return an error
func checkFuncs(f ...func(v reflect.Value) error) []func(v reflect.Value) error {
return f
}
// kinds is shorthand for returning a slice of reflect.Kind
func kinds(k ...reflect.Kind) []reflect.Kind {
return k
}
// validationMap is a map of meta fields to validation types and functions
var validationMap = map[string]metaValidation{
"Up": {kinds(reflect.Bool), nil},
"Connections": {kinds(reflect.Int), checkFuncs(
func(v reflect.Value) error {
return validatePositiveNumber("Connections", v)
})},
"Requests": {kinds(reflect.Int), checkFuncs(
func(v reflect.Value) error {
return validatePositiveNumber("Requests", v)
})},
"LoadAvg": {kinds(reflect.Float64, reflect.Int), checkFuncs(
func(v reflect.Value) error {
return validatePositiveNumber("LoadAvg", v)
})},
"Pulsar": {kinds(reflect.String), nil},
"Latitude": {kinds(reflect.Float64, reflect.Int), checkFuncs(validateLatLong)},
"Longitude": {kinds(reflect.Float64, reflect.Int), checkFuncs(validateLatLong)},
"Georegion": {kinds(reflect.String, reflect.Slice), checkFuncs(validateGeoregion)},
"Country": {kinds(reflect.String, reflect.Slice), checkFuncs(validateCountryStateProvince)},
"USState": {kinds(reflect.String, reflect.Slice), checkFuncs(validateCountryStateProvince)},
"CAProvince": {kinds(reflect.String, reflect.Slice), checkFuncs(validateCountryStateProvince)},
"Note": {kinds(reflect.String), checkFuncs(validateNoteLength)},
"IPPrefixes": {kinds(reflect.String, reflect.Slice), checkFuncs(validateCidr)},
"ASN": {kinds(reflect.String, reflect.Slice), nil},
"Priority": {kinds(reflect.Int), checkFuncs(
func(v reflect.Value) error {
return validatePositiveNumber("Priority", v)
})},
"Weight": {kinds(reflect.Float64, reflect.Int), checkFuncs(
func(v reflect.Value) error {
return validatePositiveNumber("Weight", v)
})},
"LowWatermark": {kinds(reflect.Int), nil},
"HighWatermark": {kinds(reflect.Int), nil},
}
// validate takes a field name, a reflect value, and metaValidation and validates the given field
func validate(name string, v reflect.Value, m metaValidation) (errs []error) {
check := true
// if this is a FeedPtr or a *FeedPtr then we're ok, skip checking the rest of the types
if v.Kind() == reflect.Struct || v.Kind() == reflect.Invalid {
check = false
}
if check {
match := false
for _, k := range m.kinds {
if k == v.Kind() {
match = true
}
}
if !match {
errs = append(errs, fmt.Errorf("found type mismatch for meta field '%s'. expected %+v, got: %+v", name, m.kinds, v.Kind()))
}
for _, f := range m.checkFuncs {
err := f(v)
if err != nil {
errs = append(errs, err)
}
}
}
if v.Kind() == reflect.Struct {
if _, ok := v.Interface().(FeedPtr); !ok {
errs = append(errs, fmt.Errorf("if a meta field is a struct, it must be a FeedPtr, got: %s", v.Type()))
}
}
return
}
// Validate validates metadata fields and returns a list of errors if any are found
func (meta *Meta) Validate() (errs []error) {
mv := reflect.Indirect(reflect.ValueOf(meta))
mt := mv.Type()
for i := 0; i < mt.NumField(); i++ {
fv := mt.Field(i)
err := validate(fv.Name, mv.Field(i).Elem(), validationMap[fv.Name])
if err != nil {
errs = append(errs, err...)
}
}
return errs
}