Added name validation scheme as a config field and flag as well

docs/configuration/config-file-reference.md

@@ -68,6 +68,11 @@ Where default_value is the value to use if the environment variable is undefined
 # CLI flag: -http.prefix
 [http_prefix: <string> | default = "/api/prom"]
 
+# NameValidationScheme for prometheus
+# Set to legacy as default
+# CLI flag: -name.validation.scheme
+[name_validation_scheme: <string> | default = "legacy"]
+
 # Comma-separated list of resources to monitor. Supported values are cpu and
 # heap, which tracks metrics from github.com/prometheus/procfs and
 # runtime/metrics that are close estimates. Empty string to disable.

pkg/cortex/configinit/init.go

@@ -1,7 +1,7 @@
 package configinit
 
-import "github.com/prometheus/common/model"
+// import "github.com/prometheus/common/model"
 
-func init() {
-	model.NameValidationScheme = model.LegacyValidation
-}
+// func init() {
+// 	model.NameValidationScheme = model.LegacyValidation
+// }

pkg/cortex/cortex.go

@@ -14,6 +14,7 @@ import (
 	"github.com/go-kit/log/level"
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/model"
 	"github.com/prometheus/prometheus/promql"
 	prom_storage "github.com/prometheus/prometheus/storage"
 	"github.com/weaveworks/common/server"
@@ -90,11 +91,12 @@ var (
 
 // Config is the root config for Cortex.
 type Config struct {
-	Target             flagext.StringSliceCSV `yaml:"target"`
-	AuthEnabled        bool                   `yaml:"auth_enabled"`
-	PrintConfig        bool                   `yaml:"-"`
-	HTTPPrefix         string                 `yaml:"http_prefix"`
-	MonitoredResources flagext.StringSliceCSV `yaml:"monitored_resources"`
+	Target               flagext.StringSliceCSV `yaml:"target"`
+	AuthEnabled          bool                   `yaml:"auth_enabled"`
+	PrintConfig          bool                   `yaml:"-"`
+	HTTPPrefix           string                 `yaml:"http_prefix"`
+	NameValidationScheme string                 `yaml:"name_validation_scheme"`
+	MonitoredResources   flagext.StringSliceCSV `yaml:"monitored_resources"`
 
 	ExternalQueryable prom_storage.Queryable `yaml:"-"`
 	ExternalPusher    ruler.Pusher           `yaml:"-"`
@@ -146,6 +148,7 @@ func (c *Config) RegisterFlags(f *flag.FlagSet) {
 	f.BoolVar(&c.AuthEnabled, "auth.enabled", true, "Set to false to disable auth.")
 	f.BoolVar(&c.PrintConfig, "print.config", false, "Print the config and exit.")
 	f.StringVar(&c.HTTPPrefix, "http.prefix", "/api/prom", "HTTP path prefix for Cortex API.")
+	f.StringVar(&c.NameValidationScheme, "name.validation.scheme", "strict", "Used to set name validation scheme in prometheus common. legacy by default")
 
 	c.MonitoredResources = []string{}
 	f.Var(&c.MonitoredResources, "monitored.resources", "Comma-separated list of resources to monitor. "+
@@ -193,6 +196,10 @@ func (c *Config) Validate(log log.Logger) error {
 		return errInvalidHTTPPrefix
 	}
 
+	if c.NameValidationScheme != "" && c.NameValidationScheme != "legacy" && c.NameValidationScheme != "utf-8" {
+		return fmt.Errorf("invalid name validation scheme")
+	}
+
 	if err := c.API.Validate(); err != nil {
 		return errors.Wrap(err, "invalid api config")
 	}
@@ -361,6 +368,13 @@ func New(cfg Config) (*Cortex, error) {
 		os.Exit(0)
 	}
 
+	// Sets the NameValidationScheme in prometheus/common
+	if cfg.NameValidationScheme != "legacy" {
+		model.NameValidationScheme = model.LegacyValidation
+	} else {
+		model.NameValidationScheme = model.UTF8Validation
+	}
+
 	// Swap out the default resolver to support multiple tenant IDs separated by a '|'
 	if cfg.TenantFederation.Enabled {
 		util_log.WarnExperimentalUse("tenant-federation")

pkg/cortex/cortex_test.go

@@ -184,6 +184,42 @@ func TestConfigValidation(t *testing.T) {
 			},
 			expectedError: nil,
 		},
+		// NameValidationScheme tests 
+		{
+			name: "should not fail validation for empty name validation scheme",
+			getTestConfig: func() *Config {
+				configuration := newDefaultConfig()
+				return configuration
+			},
+			expectedError: nil,
+		},
+		{
+			name: "should not fail validation for legacy name validation scheme",
+			getTestConfig: func() *Config {
+				configuration := newDefaultConfig()
+				configuration.NameValidationScheme = "legacy"
+				return configuration
+			},
+			expectedError: nil,
+		},
+		{
+			name: "should not fail validation for utf-8 name validation scheme",
+			getTestConfig: func() *Config {
+				configuration := newDefaultConfig()
+				configuration.NameValidationScheme = "utf-8"
+				return configuration
+			},
+			expectedError: nil,
+		},
+		{
+			name: "should fail validation for invalid(anything other than legacy and utf-8) name validation scheme",
+			getTestConfig: func() *Config {
+				configuration := newDefaultConfig()
+				configuration.NameValidationScheme = "invalid"
+				return configuration
+			},
+			expectedError: fmt.Errorf("invalid name validation scheme"),
+		},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
 			err := tc.getTestConfig().Validate(nil)