fix: load paramsFromFile as a relative path to the config file location

Signed-off-by: Martin Chodur <[email protected]>

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [2.12.0] - 2024-03-07
+- Fixed resolving of the path in `paramsFromFile`. Formerly it was resolved from the current working directory, now it must be a relative path, that will be resolved from the config file location.
+
 ## [2.11.0] - 2024-03-07
 - :warning: CHANGED: Params of the `hasSourceTenantsForMetrics` validator (again FACEPALM). Now the tenant can have multiple regexp matchers.
   See its [docs](docs/validations.md#hassourcetenantsformetrics).

README.md

@@ -160,6 +160,7 @@ validationRules:
         params:
           labels: [ "severity" ]
         # OPTIONAL If you want to load the parameters from a separate file, you can use this option.
+        # Its value must be a relative path to the file from the location of the config file.
         # The content of the file must be in the exact form as the expected params would be.
         # The option is mutually exclusive with the `params` option.
         # paramsFromFile: /path/to/file.yaml

examples/validation.yaml

@@ -12,7 +12,7 @@ validationRules:
         params:
           labels: ["severity"]
       - type: labelHasAllowedValue
-        paramsFromFile: ./examples/allowed_values_params.yaml
+        paramsFromFile: ./allowed_values_params.yaml
       - type: exclusiveLabels
         params:
           firstLabel: severity

main.go

@@ -14,7 +14,6 @@ import (
 	"github.com/fusakla/promruval/v2/pkg/validationrule"
 	"github.com/fusakla/promruval/v2/pkg/validator"
 	log "github.com/sirupsen/logrus"
-	"gopkg.in/yaml.v3"
 )
 
 var (
@@ -42,17 +41,8 @@ var (
 )
 
 func loadConfigFile(configFilePath string) (*config.Config, error) {
-	configFile, err := os.Open(configFilePath)
-	if err != nil {
-		return nil, fmt.Errorf("open config file: %w", err)
-	}
-	validationConfig := &config.Config{}
-	decoder := yaml.NewDecoder(configFile)
-	decoder.KnownFields(true)
-	if err := decoder.Decode(validationConfig); err != nil {
-		return nil, fmt.Errorf("loading config file: %w", err)
-	}
-	return validationConfig, nil
+	configLoader := config.NewLoader(configFilePath)
+	return configLoader.Load()
 }
 
 func validationRulesFromConfig(validationConfig *config.Config) ([]*validationrule.ValidationRule, error) {

pkg/config/config.go

@@ -3,6 +3,8 @@ package config
 import (
 	"fmt"
 	"os"
+	"path"
+	"sync"
 	"time"
 
 	"gopkg.in/yaml.v3"
@@ -19,6 +21,45 @@ const (
 
 var ValidationScopes = []ValidationScope{Group, AlertScope, RecordingRuleScope, AllRulesScope}
 
+// Ugly hack with a global variable to be able to use it in UnmarshalYAML.
+// Not sure how to better propagate some context to the UnmarshalYAML function.
+var (
+	configDir    string
+	configDirMtx sync.Mutex
+)
+
+func init() {
+	configDirMtx = sync.Mutex{}
+}
+
+func NewLoader(cfgPath string) Loader {
+	return Loader{ConfigPath: cfgPath}
+}
+
+type Loader struct {
+	ConfigPath string
+}
+
+func (l *Loader) Load() (*Config, error) {
+	configFile, err := os.Open(l.ConfigPath)
+	if err != nil {
+		return nil, fmt.Errorf("open config file: %w", err)
+	}
+	configDirMtx.Lock()
+	configDir = path.Dir(l.ConfigPath)
+	defer func() {
+		configDir = ""
+		configDirMtx.Unlock()
+	}()
+	validationConfig := Config{}
+	decoder := yaml.NewDecoder(configFile)
+	decoder.KnownFields(true)
+	if err := decoder.Decode(&validationConfig); err != nil {
+		return nil, fmt.Errorf("loading config file: %w", err)
+	}
+	return &validationConfig, nil
+}
+
 type Config struct {
 	CustomExcludeAnnotation string           `yaml:"customExcludeAnnotation"`
 	CustomDisableComment    string           `yaml:"customDisableComment"`
@@ -71,7 +112,10 @@ func (c *ValidatorConfig) UnmarshalYAML(unmarshal func(interface{}) error) error
 		if !c.Params.IsZero() {
 			return fmt.Errorf("cannot use both `params` and `paramsFromFile`")
 		}
-		fileData, err := os.ReadFile(c.ParamsFromFile)
+		if path.IsAbs(c.ParamsFromFile) {
+			return fmt.Errorf("`paramsFromFile` must be a relative path to the config file")
+		}
+		fileData, err := os.ReadFile(path.Join(configDir, c.ParamsFromFile))
 		if err != nil {
 			return fmt.Errorf("cannot read params from file %s: %w", c.ParamsFromFile, err)
 		}