using mapstructure for flexible unmarshalling

cmd/otel-allocator/config/config.go

@@ -21,16 +21,16 @@ import (
 	"fmt"
 	"io/fs"
 	"os"
-	"strings"
+	"reflect"
 	"time"
 
-	"dario.cat/mergo"
 	"github.com/go-logr/logr"
-	yaml "github.com/goccy/go-yaml"
+	"github.com/mitchellh/mapstructure"
 	"github.com/prometheus/common/model"
 	promconfig "github.com/prometheus/prometheus/config"
 	_ "github.com/prometheus/prometheus/discovery/install"
 	"github.com/spf13/pflag"
+	"gopkg.in/yaml.v2"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/clientcmd"
@@ -41,7 +41,7 @@ import (
 
 const (
 	DefaultResyncTime                        = 5 * time.Minute
-	DefaultConfigFilePath     string         = "/conf/targetallocator.yaml"
+	DefaultConfigFilePath     string         = "../../conf/targetallocator.yaml"
 	DefaultCRScrapeInterval   model.Duration = model.Duration(time.Second * 30)
 	DefaultAllocationStrategy                = "consistent-hashing"
 	DefaultFilterStrategy                    = "relabel-config"
@@ -77,11 +77,6 @@ type HTTPSServerConfig struct {
 	TLSKeyFilePath  string `yaml:"tls_key_file_path,omitempty"`
 }
 
-type LabeLSelectorPaths struct {
-	MatchLabelsPath      string
-	MatchExpressionsPath string
-}
-
 func LoadFromFile(file string, target *Config) error {
 	return unmarshal(target, file)
 }
@@ -155,92 +150,55 @@ func LoadFromCLI(target *Config, flagSet *pflag.FlagSet) error {
 	return nil
 }
 
-// readPath extracts value from specific YAMLPath.
-func readPath(p string, yamlFile []byte, f interface{}) error {
-	path, err := yaml.PathString(p)
-	if err != nil {
-		return err
-	}
-	if err := path.Read(strings.NewReader(string(yamlFile)), f); err != nil {
-		return err
-	}
-	return nil
-}
-
-func readLabelSelectorPaths(ps LabeLSelectorPaths, yamlFile []byte, f *metav1.LabelSelector) (bool, error) {
-	founderrs := 0
-
-	if err := readPath(ps.MatchLabelsPath, yamlFile, &f.MatchLabels); err != nil {
-		if !errors.Is(err, yaml.ErrNotFoundNode) {
-			return false, err
+func StringToModelDurationHookFunc() mapstructure.DecodeHookFunc {
+	return func(
+		f reflect.Type,
+		t reflect.Type,
+		data interface{},
+	) (interface{}, error) {
+		if f.Kind() != reflect.String {
+			return data, nil
 		}
-		founderrs += 1
-	}
-	if err := readPath(ps.MatchExpressionsPath, yamlFile, &f.MatchExpressions); err != nil {
-		if !errors.Is(err, yaml.ErrNotFoundNode) {
-			return false, err
-		}
-		founderrs += 1
-	}
-
-	return founderrs < 2, nil
-}
-
-func flexibleLabelSelector(yamlFile []byte, fieldPathsMap map[*metav1.LabelSelector]LabeLSelectorPaths) error {
-	for f, ps := range fieldPathsMap {
-		tmpls := metav1.LabelSelector{}
-
-		found, err := readLabelSelectorPaths(ps, yamlFile, &tmpls)
-		if err != nil {
-			return err
+		if t != reflect.TypeOf(model.Duration(5)) {
+			return data, nil
 		}
 
-		if found {
-			if err := mergo.Merge(f, tmpls, mergo.WithOverride); err != nil {
-				return err
-			}
-		}
+		// Convert it by parsing
+		return time.ParseDuration(data.(string))
 	}
-	return nil
 }
 
-func flexibleCollectorSelector(yamlFile []byte, cfg *Config) error {
-	collectorSelectorFieldPathsMap := map[*metav1.LabelSelector]LabeLSelectorPaths{
-		cfg.CollectorSelector: {
-			MatchLabelsPath:      "$.collector_selector.matchlabels",
-			MatchExpressionsPath: "$.collector_selector.matchexpressions",
-		},
+func decodeSubConfig(t interface{}, dc mapstructure.DecoderConfig) error {
+	dec, decError := mapstructure.NewDecoder(&dc)
+	if decError != nil {
+		return decError
 	}
-
-	if err := flexibleLabelSelector(yamlFile, collectorSelectorFieldPathsMap); err != nil {
+	if err := dec.Decode(t); err != nil {
 		return err
 	}
 	return nil
 }
 
-func flexiblePrometheusCR(yamlFile []byte, cfg *Config) error {
-	prometheusCRFieldPathsMap := map[*metav1.LabelSelector]LabeLSelectorPaths{
-		cfg.PrometheusCR.PodMonitorSelector: {
-			MatchLabelsPath:      "$.prometheus_cr.pod_monitor_selector.matchlabels",
-			MatchExpressionsPath: "$.prometheus_cr.pod_monitor_selector.matchexpressions",
-		},
-		cfg.PrometheusCR.ServiceMonitorSelector: {
-			MatchLabelsPath:      "$.prometheus_cr.service_monitor_selector.matchlabels",
-			MatchExpressionsPath: "$.prometheus_cr.service_monitor_selector.matchexpressions",
-		},
-		cfg.PrometheusCR.ServiceMonitorNamespaceSelector: {
-			MatchLabelsPath:      "$.prometheus_cr.service_monitor_namespace_selector.matchlabels",
-			MatchExpressionsPath: "$.prometheus_cr.service_monitor_namespace_selector.matchexpressions",
-		},
-		cfg.PrometheusCR.PodMonitorNamespaceSelector: {
-			MatchLabelsPath:      "$.prometheus_cr.pod_monitor_namespace_selector.matchlabels",
-			MatchExpressionsPath: "$.prometheus_cr.pod_monitor_namespace_selector.matchexpressions",
-		},
+func flexibleUnmarshal(yamlFile []byte, cfg *Config) error {
+	t := make(map[string]interface{})
+	if err := yaml.Unmarshal(yamlFile, &t); err != nil {
+		return fmt.Errorf("error unmarshaling YAML: %w", err)
 	}
 
-	if err := flexibleLabelSelector(yamlFile, prometheusCRFieldPathsMap); err != nil {
-		return err
+	if t["collector_selector"] != nil {
+		dc := mapstructure.DecoderConfig{TagName: "yaml", Result: cfg.CollectorSelector}
+		if err := decodeSubConfig(t["collector_selector"], dc); err != nil {
+			return err
+		}
+	}
+
+	if t["prometheus_cr"] != nil {
+		dc := mapstructure.DecoderConfig{TagName: "yaml", Result: &cfg.PrometheusCR, DecodeHook: StringToModelDurationHookFunc()}
+		if err := decodeSubConfig(t["prometheus_cr"], dc); err != nil {
+			return err
+		}
 	}
+
 	return nil
 }
 
@@ -249,16 +207,11 @@ func unmarshal(cfg *Config, configFile string) error {
 	if err != nil {
 		return err
 	}
-
 	if err = yaml.Unmarshal(yamlFile, cfg); err != nil {
 		return fmt.Errorf("error unmarshaling YAML: %w", err)
 	}
 
-	if err := flexibleCollectorSelector(yamlFile, cfg); err != nil {
-		return err
-	}
-
-	if err := flexiblePrometheusCR(yamlFile, cfg); err != nil {
+	if err := flexibleUnmarshal(yamlFile, cfg); err != nil {
 		return err
 	}
 

go.mod

@@ -14,7 +14,6 @@ require (
 	github.com/gin-gonic/gin v1.10.0
 	github.com/go-kit/log v0.2.1
 	github.com/go-logr/logr v1.4.2
-	github.com/goccy/go-yaml v1.13.4
 	github.com/google/uuid v1.6.0
 	github.com/json-iterator/go v1.1.12
 	github.com/mitchellh/mapstructure v1.5.0
@@ -94,7 +93,7 @@ require (
 	github.com/envoyproxy/protoc-gen-validate v1.1.0 // indirect
 	github.com/evanphx/json-patch/v5 v5.9.0 // indirect
 	github.com/facette/natsort v0.0.0-20181210072756-2cd4dd1e2dcb // indirect
-	github.com/fatih/color v1.18.0 // indirect
+	github.com/fatih/color v1.16.0 // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/fsnotify/fsnotify v1.7.0 // indirect
 	github.com/fxamacker/cbor/v2 v2.7.0 // indirect
@@ -116,7 +115,7 @@ require (
 	github.com/go-openapi/validate v0.24.0 // indirect
 	github.com/go-playground/locales v0.14.1 // indirect
 	github.com/go-playground/universal-translator v0.18.1 // indirect
-	github.com/go-playground/validator/v10 v10.22.1 // indirect
+	github.com/go-playground/validator/v10 v10.20.0 // indirect
 	github.com/go-resty/resty/v2 v2.13.1 // indirect
 	github.com/go-zookeeper/zk v1.0.3 // indirect
 	github.com/goccy/go-json v0.10.2 // indirect

go.sum

@@ -165,8 +165,8 @@ github.com/facette/natsort v0.0.0-20181210072756-2cd4dd1e2dcb/go.mod h1:bH6Xx7IW
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
 github.com/fatih/color v1.9.0/go.mod h1:eQcE1qtQxscV5RaZvpXrrb8Drkc3/DdQ+uUYCNjL+zU=
 github.com/fatih/color v1.13.0/go.mod h1:kLAiJbzzSOZDVNGyDpeOxJ47H46qBXwg5ILebYFFOfk=
-github.com/fatih/color v1.18.0 h1:S8gINlzdQ840/4pfAwic/ZE0djQEH3wM94VfqLTZcOM=
-github.com/fatih/color v1.18.0/go.mod h1:4FelSpRwEGDpQ12mAdzqdOukCy4u8WUtOY6lkT/6HfU=
+github.com/fatih/color v1.16.0 h1:zmkK9Ngbjj+K0yRhTVONQh1p/HknKYSlNT+vZCzyokM=
+github.com/fatih/color v1.16.0/go.mod h1:fL2Sau1YI5c0pdGEVCbKQbLXB6edEj1ZgiY4NijnWvE=
 github.com/felixge/httpsnoop v1.0.4 h1:NFTV2Zj1bL4mc9sqWACXbQFVBBg2W3GPvqp8/ESS2Wg=
 github.com/felixge/httpsnoop v1.0.4/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nosvA=
@@ -229,8 +229,8 @@ github.com/go-playground/locales v0.14.1 h1:EWaQ/wswjilfKLTECiXz7Rh+3BjFhfDFKv/o
 github.com/go-playground/locales v0.14.1/go.mod h1:hxrqLVvrK65+Rwrd5Fc6F2O76J/NuW9t0sjnWqG1slY=
 github.com/go-playground/universal-translator v0.18.1 h1:Bcnm0ZwsGyWbCzImXv+pAJnYK9S473LQFuzCbDbfSFY=
 github.com/go-playground/universal-translator v0.18.1/go.mod h1:xekY+UJKNuX9WP91TpwSH2VMlDf28Uj24BCp08ZFTUY=
-github.com/go-playground/validator/v10 v10.22.1 h1:40JcKH+bBNGFczGuoBYgX4I6m/i27HYW8P9FDk5PbgA=
-github.com/go-playground/validator/v10 v10.22.1/go.mod h1:dbuPbCMFw/DrkbEynArYaCwl3amGuJotoKCe95atGMM=
+github.com/go-playground/validator/v10 v10.20.0 h1:K9ISHbSaI0lyB2eWMPJo+kOS/FBExVwjEviJTixqxL8=
+github.com/go-playground/validator/v10 v10.20.0/go.mod h1:dbuPbCMFw/DrkbEynArYaCwl3amGuJotoKCe95atGMM=
 github.com/go-resty/resty/v2 v2.13.1 h1:x+LHXBI2nMB1vqndymf26quycC4aggYJ7DECYbiz03g=
 github.com/go-resty/resty/v2 v2.13.1/go.mod h1:GznXlLxkq6Nh4sU59rPmUw3VtgpO3aS96ORAI6Q7d+0=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
@@ -240,8 +240,6 @@ github.com/go-zookeeper/zk v1.0.3 h1:7M2kwOsc//9VeeFiPtf+uSJlVpU66x9Ba5+8XK7/TDg
 github.com/go-zookeeper/zk v1.0.3/go.mod h1:nOB03cncLtlp4t+UAkGSV+9beXP/akpekBwL+UX1Qcw=
 github.com/goccy/go-json v0.10.2 h1:CrxCmQqYDkv1z7lO7Wbh2HN93uovUHgrECaO5ZrCXAU=
 github.com/goccy/go-json v0.10.2/go.mod h1:6MelG93GURQebXPDq3khkgXZkazVtN9CRI+MGFi0w8I=
-github.com/goccy/go-yaml v1.13.4 h1:XOnLX9GqT+kH/gB7YzCMUiDBFU9B7pm3HZz6kyeDPkk=
-github.com/goccy/go-yaml v1.13.4/go.mod h1:IjYwxUiJDoqpx2RmbdjMUceGHZwYLon3sfOGl5Hi9lc=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/gogo/protobuf v1.3.2 h1:Ov1cvc58UF3b5XjBnZv7+opcTcQFZebYjWzi34vdm4Q=
 github.com/gogo/protobuf v1.3.2/go.mod h1:P1XiOD3dCwIKUDQYPy72D8LYyHL2YPYrpS2s69NZV8Q=