fix: migrate old config key

if cfg.Internal.UnixFSShardingSizeThreshold is set and
cfg.Import.UnixFSHAMTDirectorySizeThreshold is not, assign old value
to new field and print ERROR urging user to migrate

this way we wont break any existing CI etc

Author: lidel

core/node/groups.go

@@ -408,31 +408,30 @@ func IPFS(ctx context.Context, bcfg *BuildCfg) fx.Option {
 		return fx.Error(err)
 	}
 
-	// Auto-sharding settings
-	shardingThresholdString := cfg.Import.UnixFSHAMTDirectorySizeThreshold.WithDefault(config.DefaultUnixFSHAMTDirectorySizeThreshold)
-	shardSingThresholdInt, err := humanize.ParseBytes(shardingThresholdString)
-	if err != nil {
-		return fx.Error(err)
-	}
-	shardMaxFanout := cfg.Import.UnixFSHAMTDirectoryMaxFanout.WithDefault(config.DefaultUnixFSHAMTDirectoryMaxFanout)
-	// TODO: avoid overriding this globally, see if we can extend Directory interface like Get/SetMaxLinks from https://github.com/ipfs/boxo/pull/906
-	uio.HAMTShardingSize = int(shardSingThresholdInt)
-	uio.DefaultShardWidth = int(shardMaxFanout)
-
 	// Migrate users of deprecated Experimental.ShardingEnabled flag
 	if cfg.Experimental.ShardingEnabled {
-		logger.Fatal("The `Experimental.ShardingEnabled` field is no longer used, please remove it from the config.\n" +
-			"go-ipfs now automatically shards when directory block is bigger than  `" + shardingThresholdString + "`.\n" +
-			"If you need to restore the old behavior (sharding everything) set `Import.UnixFSHAMTDirectorySizeThreshold` to `1B`.\n")
+		logger.Fatal("The `Experimental.ShardingEnabled` field is no longer used, please remove it from the config. Use Import.UnixFSHAMTDirectorySizeThreshold instead.")
 	}
 	if !cfg.Internal.UnixFSShardingSizeThreshold.IsDefault() {
 		msg := "The `Internal.UnixFSShardingSizeThreshold` field was renamed to `Import.UnixFSHAMTDirectorySizeThreshold`. Please update your config.\n"
 		if !cfg.Import.UnixFSHAMTDirectorySizeThreshold.IsDefault() {
 			logger.Fatal(msg) // conflicting values, hard fail
 		}
 		logger.Error(msg)
+		cfg.Import.UnixFSHAMTDirectorySizeThreshold = *cfg.Internal.UnixFSShardingSizeThreshold
 	}
 
+	// Auto-sharding settings
+	shardingThresholdString := cfg.Import.UnixFSHAMTDirectorySizeThreshold.WithDefault(config.DefaultUnixFSHAMTDirectorySizeThreshold)
+	shardSingThresholdInt, err := humanize.ParseBytes(shardingThresholdString)
+	if err != nil {
+		return fx.Error(err)
+	}
+	shardMaxFanout := cfg.Import.UnixFSHAMTDirectoryMaxFanout.WithDefault(config.DefaultUnixFSHAMTDirectoryMaxFanout)
+	// TODO: avoid overriding this globally, see if we can extend Directory interface like Get/SetMaxLinks from https://github.com/ipfs/boxo/pull/906
+	uio.HAMTShardingSize = int(shardSingThresholdInt)
+	uio.DefaultShardWidth = int(shardMaxFanout)
+
 	return fx.Options(
 		bcfgOpts,