From da532ab93ddb8a58f8fd4ace7e547f44587b140a Mon Sep 17 00:00:00 2001
From: WGH <wgh@torlan.ru>
Date: Sat, 6 Sep 2025 20:37:10 +0300
Subject: [PATCH] Fix support for legacy compression env variables (#21533)

Commit b6eb8dff649b0f46c12d24e89aa11254fb0132fa renamed compression
setting environment variables to follow consistent style.

Although it preserved backward compatibility for the most part (i.e. it
handled MINIO_COMPRESS_ALLOW_ENCRYPTION, MINIO_COMPRESS_EXTENSIONS, and
MINIO_COMPRESS_MIME_TYPES), MINIO_COMPRESS_ENABLE was left behind.

Additionally, due to incorrect fallback ordering, and DefaultKVS
containing enable=off allow_encryption=off (so kvs.Get should've been
tried last), that commit broke MINIO_COMPRESS_ALLOW_ENCRYPTION (even
though it appeared to be handled), and even older MINIO_COMPRESS, too.

The legacy MIME types and extensions variables take precedence over both
config and new variables, so they don't need fixing.
---
 internal/config/compress/compress.go | 11 +++++++----
 internal/config/compress/legacy.go   |  1 +
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/internal/config/compress/compress.go b/internal/config/compress/compress.go
index ce393bc55..dc050e3ba 100644
--- a/internal/config/compress/compress.go
+++ b/internal/config/compress/compress.go
@@ -93,9 +93,12 @@ func LookupConfig(kvs config.KVS) (Config, error) {
 		return cfg, err
 	}
 
-	compress := env.Get(EnvCompressState, kvs.Get(config.Enable))
+	compress := env.Get(EnvCompressState, "")
 	if compress == "" {
-		compress = env.Get(EnvCompress, "")
+		compress = env.Get(EnvCompressEnableLegacy, "")
+		if compress == "" {
+			compress = env.Get(EnvCompress, kvs.Get(config.Enable))
+		}
 	}
 	cfg.Enabled, err = config.ParseBool(compress)
 	if err != nil {
@@ -109,9 +112,9 @@ func LookupConfig(kvs config.KVS) (Config, error) {
 		return cfg, nil
 	}
 
-	allowEnc := env.Get(EnvCompressAllowEncryption, kvs.Get(AllowEncrypted))
+	allowEnc := env.Get(EnvCompressAllowEncryption, "")
 	if allowEnc == "" {
-		allowEnc = env.Get(EnvCompressAllowEncryptionLegacy, "")
+		allowEnc = env.Get(EnvCompressAllowEncryptionLegacy, kvs.Get(AllowEncrypted))
 	}
 
 	cfg.AllowEncrypted, err = config.ParseBool(allowEnc)
diff --git a/internal/config/compress/legacy.go b/internal/config/compress/legacy.go
index 13be9069a..034df304f 100644
--- a/internal/config/compress/legacy.go
+++ b/internal/config/compress/legacy.go
@@ -30,6 +30,7 @@ const (
 
 	// These envs were wrong but we supported them for a long time
 	// so keep them here to support existing deployments.
+	EnvCompressEnableLegacy          = "MINIO_COMPRESS_ENABLE"
 	EnvCompressAllowEncryptionLegacy = "MINIO_COMPRESS_ALLOW_ENCRYPTION"
 	EnvCompressExtensionsLegacy      = "MINIO_COMPRESS_EXTENSIONS"
 	EnvCompressMimeTypesLegacy2      = "MINIO_COMPRESS_MIME_TYPES"