add builder

Dockerfile.builder

@@ -0,0 +1,2 @@
+FROM golang:1.26-alpine
+RUN apk add --no-cache gcc musl-dev

Makefile

@@ -12,12 +12,16 @@ generate:
 run:
 	go run ./cmd/pinned_message/main.go
 
+build-builder:
+	docker build -f Dockerfile.builder -t my-go-builder .
+
 build-macos:
 	rm -rf bin
 	CGO_ENABLED=1 GOOS=darwin GOARCH=arm64 go build -o bin/pinned_message_macos_arm64 cmd/pinned_message/main.go
 
 build-linux:
-	rm -rf bin
-	docker run --rm -v "$$PWD":/app -w /app golang:1.22-alpine sh -c \
-  		"apk add --no-cache gcc musl-dev && \
-		CGO_ENABLED=1 GOOS=linux GOARCH=arm64 go build -o bin/pinned_message_linux_arm64 cmd/pinned_message/main.go"
+	docker run --rm \
+		-v "$$PWD":/app \
+		-w /app \
+		my-go-builder sh -c \
+		"CGO_ENABLED=1 GOOS=linux GOARCH=arm64 go build -o bin/pinned_message_linux_arm64 cmd/pinned_message/main.go"

go.mod

@@ -1,6 +1,6 @@
 module pinned_message
 
-go 1.22
+go 1.26
 
 require (
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0