/
arangodb_scaler.go
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/
arangodb_scaler.go
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package scalers
import (
"context"
"fmt"
"strconv"
"strings"
driver "github.com/arangodb/go-driver"
"github.com/arangodb/go-driver/http"
"github.com/arangodb/go-driver/jwt"
"github.com/go-logr/logr"
v2 "k8s.io/api/autoscaling/v2"
"k8s.io/metrics/pkg/apis/external_metrics"
"github.com/kedacore/keda/v2/pkg/scalers/authentication"
"github.com/kedacore/keda/v2/pkg/scalers/scalersconfig"
"github.com/kedacore/keda/v2/pkg/util"
)
type arangoDBScaler struct {
metricType v2.MetricTargetType
metadata *arangoDBMetadata
client driver.Client
logger logr.Logger
}
type dbResult struct {
Value float64 `json:"value"`
}
// arangoDBMetadata specify arangoDB scaler params.
type arangoDBMetadata struct {
// Specify arangoDB server endpoint URL or comma separated URL endpoints of all the coordinators.
// +required
endpoints string
// Authentication parameters for connecting to the database
// +required
arangoDBAuth *authentication.AuthMeta
// Specify the unique arangoDB server ID. Only required if bearer JWT is being used.
// +optional
serverID string
// The name of the database to be queried.
// +required
dbName string
// The name of the collection to be queried.
// +required
collection string
// The arangoDB query to be executed.
// +required
query string
// A threshold that is used as targetAverageValue in HPA.
// +required
queryValue float64
// A threshold that is used to check if scaler is active.
// +optional
activationQueryValue float64
// Specify whether to verify the server's certificate chain and host name.
// +optional
unsafeSsl bool
// Specify the max size of the active connection pool.
// +optional
connectionLimit int64
// The index of the scaler inside the ScaledObject
// +internal
triggerIndex int
}
// NewArangoDBScaler creates a new arangodbScaler
func NewArangoDBScaler(config *scalersconfig.ScalerConfig) (Scaler, error) {
metricType, err := GetMetricTargetType(config)
if err != nil {
return nil, fmt.Errorf("error getting scaler metric type: %w", err)
}
meta, err := parseArangoDBMetadata(config)
if err != nil {
return nil, fmt.Errorf("error parsing arangoDB metadata: %w", err)
}
client, err := getNewArangoDBClient(meta)
if err != nil {
return nil, err
}
return &arangoDBScaler{
metricType: metricType,
metadata: meta,
client: client,
logger: InitializeLogger(config, "arangodb_scaler"),
}, nil
}
func getNewArangoDBClient(meta *arangoDBMetadata) (driver.Client, error) {
var auth driver.Authentication
conn, err := http.NewConnection(http.ConnectionConfig{
Endpoints: strings.Split(meta.endpoints, ","),
TLSConfig: util.CreateTLSClientConfig(meta.unsafeSsl),
})
if err != nil {
return nil, fmt.Errorf("failed to create a new http connection, %w", err)
}
if meta.arangoDBAuth.EnableBasicAuth {
auth = driver.BasicAuthentication(meta.arangoDBAuth.Username, meta.arangoDBAuth.Password)
} else if meta.arangoDBAuth.EnableBearerAuth {
hdr, err := jwt.CreateArangodJwtAuthorizationHeader(meta.arangoDBAuth.BearerToken, meta.serverID)
if err != nil {
return nil, fmt.Errorf("failed to create bearer token authorization header, %w", err)
}
auth = driver.RawAuthentication(hdr)
}
client, err := driver.NewClient(driver.ClientConfig{
Connection: conn,
Authentication: auth,
})
if err != nil {
return nil, fmt.Errorf("failed to initialize a new client, %w", err)
}
return client, nil
}
func parseArangoDBMetadata(config *scalersconfig.ScalerConfig) (*arangoDBMetadata, error) {
// setting default metadata
meta := arangoDBMetadata{}
// parse metaData from ScaledJob config
endpoints, err := GetFromAuthOrMeta(config, "endpoints")
if err != nil {
return nil, err
}
meta.endpoints = endpoints
if val, ok := config.TriggerMetadata["collection"]; ok {
meta.collection = val
} else {
return nil, fmt.Errorf("no collection given")
}
if val, ok := config.TriggerMetadata["query"]; ok {
meta.query = val
} else {
return nil, fmt.Errorf("no query given")
}
if val, ok := config.TriggerMetadata["queryValue"]; ok {
queryValue, err := strconv.ParseFloat(val, 64)
if err != nil {
return nil, fmt.Errorf("failed to convert queryValue to int, %w", err)
}
meta.queryValue = queryValue
} else {
if config.AsMetricSource {
meta.queryValue = 0
} else {
return nil, fmt.Errorf("no queryValue given")
}
}
meta.activationQueryValue = 0
if val, ok := config.TriggerMetadata["activationQueryValue"]; ok {
activationQueryValue, err := strconv.ParseFloat(val, 64)
if err != nil {
return nil, fmt.Errorf("failed to convert activationQueryValue to int, %w", err)
}
meta.activationQueryValue = activationQueryValue
}
dbName, err := GetFromAuthOrMeta(config, "dbName")
if err != nil {
return nil, err
}
meta.dbName = dbName
meta.unsafeSsl = false
if val, ok := config.TriggerMetadata["unsafeSsl"]; ok && val != "" {
unsafeSslValue, err := strconv.ParseBool(val)
if err != nil {
return nil, fmt.Errorf("failed to parse unsafeSsl, %w", err)
}
meta.unsafeSsl = unsafeSslValue
}
if val, ok := config.TriggerMetadata["connectionLimit"]; ok {
connectionLimit, err := strconv.ParseInt(val, 10, 64)
if err != nil {
return nil, fmt.Errorf("failed to convert connectionLimit to int, %w", err)
}
meta.connectionLimit = connectionLimit
}
// parse auth configs from ScalerConfig
arangoDBAuth, err := authentication.GetAuthConfigs(config.TriggerMetadata, config.AuthParams)
if err != nil {
return nil, err
}
meta.arangoDBAuth = arangoDBAuth
meta.triggerIndex = config.TriggerIndex
return &meta, nil
}
// Close disposes of arangoDB connections
func (s *arangoDBScaler) Close(_ context.Context) error {
return nil
}
func (s *arangoDBScaler) getQueryResult(ctx context.Context) (float64, error) {
dbExists, err := s.client.DatabaseExists(ctx, s.metadata.dbName)
if err != nil {
return -1, fmt.Errorf("failed to check if %s database exists, %w", s.metadata.dbName, err)
}
if !dbExists {
return -1, fmt.Errorf("%s database not found", s.metadata.dbName)
}
db, err := s.client.Database(ctx, s.metadata.dbName)
if err != nil {
return -1, fmt.Errorf("failed to connect to %s db, %w", s.metadata.dbName, err)
}
collectionExists, err := db.CollectionExists(ctx, s.metadata.collection)
if err != nil {
return -1, fmt.Errorf("failed to check if %s collection exists, %w", s.metadata.collection, err)
}
if !collectionExists {
return -1, fmt.Errorf("%s collection not found in %s database", s.metadata.collection, s.metadata.dbName)
}
ctx = driver.WithQueryCount(ctx)
cursor, err := db.Query(ctx, s.metadata.query, nil)
if err != nil {
return -1, fmt.Errorf("failed to execute the query, %w", err)
}
defer cursor.Close()
if cursor.Count() != 1 {
return -1, fmt.Errorf("more than one values received, please check the query, %w", err)
}
var result dbResult
if _, err = cursor.ReadDocument(ctx, &result); err != nil {
return -1, fmt.Errorf("query result is not in the specified format, pleast check the query, %w", err)
}
return result.Value, nil
}
// GetMetricsAndActivity query from arangoDB, and return to external metrics and activity
func (s *arangoDBScaler) GetMetricsAndActivity(ctx context.Context, metricName string) ([]external_metrics.ExternalMetricValue, bool, error) {
num, err := s.getQueryResult(ctx)
if err != nil {
return []external_metrics.ExternalMetricValue{}, false, fmt.Errorf("failed to inspect arangoDB, %w", err)
}
metric := GenerateMetricInMili(metricName, num)
return append([]external_metrics.ExternalMetricValue{}, metric), num > s.metadata.activationQueryValue, nil
}
// GetMetricSpecForScaling get the query value for scaling
func (s *arangoDBScaler) GetMetricSpecForScaling(context.Context) []v2.MetricSpec {
externalMetric := &v2.ExternalMetricSource{
Metric: v2.MetricIdentifier{
Name: GenerateMetricNameWithIndex(s.metadata.triggerIndex, "arangodb"),
},
Target: GetMetricTargetMili(s.metricType, s.metadata.queryValue),
}
metricSpec := v2.MetricSpec{
External: externalMetric, Type: externalMetricType,
}
return []v2.MetricSpec{metricSpec}
}