Fix crash observed in OPA initialization (#7990)

Related to #7982, this PR refactors the code
such that we validate the OPA or JWKS in a
common place.

This is also a refactor which is already done
in the new config migration change. Attempt
to avoid any network I/O during Unmarshal of
JSON from disk, instead do it later when
updating the in-memory data structure.

cmd/config-current.go

@@ -281,28 +281,27 @@ func (s *serverConfig) loadFromEnvs() {
 	}
 
 	if jwksURL, ok := os.LookupEnv("MINIO_IAM_JWKS_URL"); ok {
-		if u, err := xnet.ParseURL(jwksURL); err == nil {
+		u, err := xnet.ParseURL(jwksURL)
-			s.OpenID.JWKS.URL = u
+		if err != nil {
-			logger.FatalIf(s.OpenID.JWKS.PopulatePublicKey(), "Unable to populate public key from JWKS URL")
-		} else {
 			logger.FatalIf(err, "Unable to parse MINIO_IAM_JWKS_URL %s", jwksURL)
 		}
+		s.OpenID.JWKS.URL = u
 	}
 
 	if opaURL, ok := os.LookupEnv("MINIO_IAM_OPA_URL"); ok {
-		if u, err := xnet.ParseURL(opaURL); err == nil {
+		u, err := xnet.ParseURL(opaURL)
+		if err != nil {
+			logger.FatalIf(err, "Unable to parse MINIO_IAM_OPA_URL %s", opaURL)
+		}
 		opaArgs := iampolicy.OpaArgs{
 			URL:         u,
 			AuthToken:   os.Getenv("MINIO_IAM_OPA_AUTHTOKEN"),
 			Transport:   NewCustomHTTPTransport(),
 			CloseRespFn: xhttp.DrainBody,
 		}
+		logger.FatalIf(opaArgs.Validate(), "Unable to reach MINIO_IAM_OPA_URL %s", opaURL)
 		s.Policy.OPA.URL = opaArgs.URL
 		s.Policy.OPA.AuthToken = opaArgs.AuthToken
-			logger.FatalIf(opaArgs.Validate(), "Unable to reach MINIO_IAM_OPA_URL %s", opaURL)
-		} else {
-			logger.FatalIf(err, "Unable to parse MINIO_IAM_OPA_URL %s", opaURL)
-		}
 	}
 }
 
@@ -547,7 +546,7 @@ func (s *serverConfig) loadToCachedConfigs() {
 		globalCacheMaxUse = cacheConf.MaxUse
 	}
 	if err := Environment.LookupKMSConfig(s.KMS); err != nil {
-		logger.FatalIf(err, "Unable to setup the KMS")
+		logger.FatalIf(err, "Unable to setup the KMS %s", s.KMS.Vault.Endpoint)
 	}
 
 	if !globalIsCompressionEnabled {
@@ -557,15 +556,22 @@ func (s *serverConfig) loadToCachedConfigs() {
 		globalIsCompressionEnabled = compressionConf.Enabled
 	}
 
+	if s.OpenID.JWKS.URL != nil && s.OpenID.JWKS.URL.String() != "" {
+		logger.FatalIf(s.OpenID.JWKS.PopulatePublicKey(),
+			"Unable to populate public key from JWKS URL %s", s.OpenID.JWKS.URL)
+	}
+
 	globalIAMValidators = getAuthValidators(s)
 
 	if s.Policy.OPA.URL != nil && s.Policy.OPA.URL.String() != "" {
-		globalPolicyOPA = iampolicy.NewOpa(iampolicy.OpaArgs{
+		opaArgs := iampolicy.OpaArgs{
 			URL:         s.Policy.OPA.URL,
 			AuthToken:   s.Policy.OPA.AuthToken,
 			Transport:   NewCustomHTTPTransport(),
 			CloseRespFn: xhttp.DrainBody,
-		})
+		}
+		logger.FatalIf(opaArgs.Validate(), "Unable to reach OPA URL %s", s.Policy.OPA.URL)
+		globalPolicyOPA = iampolicy.NewOpa(opaArgs)
 	}
 }
 

pkg/iam/policy/opa.go

@@ -22,7 +22,6 @@ import (
 	"io"
 	"io/ioutil"
 	"net/http"
-	"os"
 
 	xnet "github.com/minio/minio/pkg/net"
 )
@@ -63,18 +62,9 @@ func (a *OpaArgs) UnmarshalJSON(data []byte) error {
 	type subOpaArgs OpaArgs
 	var so subOpaArgs
 
-	if opaURL, ok := os.LookupEnv("MINIO_IAM_OPA_URL"); ok {
-		u, err := xnet.ParseURL(opaURL)
-		if err != nil {
-			return err
-		}
-		so.URL = u
-		so.AuthToken = os.Getenv("MINIO_IAM_OPA_AUTHTOKEN")
-	} else {
 	if err := json.Unmarshal(data, &so); err != nil {
 		return err
 	}
-	}
 
 	oa := OpaArgs(so)
 	if oa.URL == nil || oa.URL.String() == "" {
@@ -82,10 +72,6 @@ func (a *OpaArgs) UnmarshalJSON(data []byte) error {
 		return nil
 	}
 
-	if err := oa.Validate(); err != nil {
-		return err
-	}
-
 	*a = oa
 	return nil
 }

pkg/iam/validator/jwt.go

@@ -24,7 +24,6 @@ import (
 	"fmt"
 	"net"
 	"net/http"
-	"os"
 	"strconv"
 	"time"
 
@@ -38,11 +37,6 @@ type JWKSArgs struct {
 	publicKeys map[string]crypto.PublicKey
 }
 
-// Validate JWT authentication target arguments
-func (r *JWKSArgs) Validate() error {
-	return nil
-}
-
 // PopulatePublicKey - populates a new publickey from the JWKS URL.
 func (r *JWKSArgs) PopulatePublicKey() error {
 	insecureClient := &http.Client{Transport: newCustomHTTPTransport(true)}
@@ -83,31 +77,15 @@ func (r *JWKSArgs) UnmarshalJSON(data []byte) error {
 	type subJWKSArgs JWKSArgs
 	var sr subJWKSArgs
 
-	// IAM related envs.
-	if jwksURL, ok := os.LookupEnv("MINIO_IAM_JWKS_URL"); ok {
-		u, err := xnet.ParseURL(jwksURL)
-		if err != nil {
-			return err
-		}
-		sr.URL = u
-	} else {
 	if err := json.Unmarshal(data, &sr); err != nil {
 		return err
 	}
-	}
 
 	ar := JWKSArgs(sr)
 	if ar.URL == nil || ar.URL.String() == "" {
 		*r = ar
 		return nil
 	}
-	if err := ar.Validate(); err != nil {
-		return err
-	}
-
-	if err := ar.PopulatePublicKey(); err != nil {
-		return err
-	}
 
 	*r = ar
 	return nil