add substreams tools extract-wasm

docs/release-notes/change-log.md

@@ -14,6 +14,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 * Changed `substreams run`: the two positional parameters now align with `gui`: `[package [module_name]]`. Before, it was using fuzzy heuristics to see if a single param was a module name or a package name. You need to be more explicit now, like `gui`.
 * Added `substreams publish` to `publish` a package on the substreams registry (check on `https://substreams.dev`).
 * Added `substreams registry` to `login` and `publish` on the substreams registry (check on `https://substreams.dev`).
+* Added `substreams tools extract-wasm` to extract a wasm file from a substreams package.
 
 ## v1.10.11
 

tools/extract-wasm.go

@@ -0,0 +1,84 @@
+package tools
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"github.com/streamingfast/cli/sflags"
+	"github.com/streamingfast/substreams/manifest"
+	pbsubstreams "github.com/streamingfast/substreams/pb/sf/substreams/v1"
+)
+
+var extractWASMCmd = &cobra.Command{
+	Use:   "extract-wasm <spkg-url> [dest-wasm-file]",
+	Short: "extract a wasm binary from a substreams package, useful when publishing a new release of a substreams package without changing the hashes",
+	Args:  cobra.RangeArgs(1, 2),
+	RunE:  extractWASME,
+}
+
+func init() {
+	extractWASMCmd.Flags().String("module", "", "module name to extract")
+	Cmd.AddCommand(extractWASMCmd)
+}
+
+func extractWASME(cmd *cobra.Command, args []string) error {
+	src := args[0]
+	dest := "extracted.wasm"
+	if len(args) == 2 {
+		dest = args[1]
+	}
+
+	module := sflags.MustGetString(cmd, "module")
+
+	manifestReader, err := manifest.NewReader(src)
+	if err != nil {
+		return fmt.Errorf("manifest reader: %w", err)
+	}
+
+	pkgBundle, err := manifestReader.Read()
+	if err != nil {
+		return fmt.Errorf("read manifest %q: %w", src, err)
+	}
+
+	if pkgBundle == nil {
+		return fmt.Errorf("no package found")
+	}
+
+	var bin *pbsubstreams.Binary
+	switch {
+	case module != "":
+		for _, mod := range pkgBundle.Package.Modules.Modules {
+			if mod.Name == module {
+				bin = pkgBundle.Package.Modules.Binaries[mod.BinaryIndex]
+				break
+			}
+		}
+		if bin == nil {
+			return fmt.Errorf("module %q not found", module)
+		}
+	case len(pkgBundle.Package.Modules.Binaries) == 1:
+		bin = pkgBundle.Package.Modules.Binaries[0]
+	default:
+		return fmt.Errorf("multiple binaries found, please specify a module name")
+	}
+
+	if err := os.WriteFile(dest, bin.Content, 0644); err != nil {
+		return fmt.Errorf("write file %q: %w", dest, err)
+	}
+	fmt.Printf("WASM extracted to file %s (%s) (%d bytes)\n", dest, bin.Type, len(bin.Content))
+
+	fmt.Println("\nTo use in all your modules, replace the file that is set as 'default' under 'binaries' in your substreams.yaml file.")
+	fmt.Println("To use only on some of your modules, add the following:")
+	fmt.Printf(`
+binaries:
+  extracted:
+    type: %s
+    file: %s
+`,
+		bin.Type, dest)
+	fmt.Printf("\nand set the `binary` field in each module to the name of the binary, e.g. `extracted`\n\n")
+
+	return nil
+}