correct alpine update command

Author: chaptersix

Makefile

@@ -10,5 +10,22 @@ internal/commands.gen.go: internal/commandsgen/commands.yml
 build:
 	go build ./cmd/temporal
 
-update-alpine:
-	$(MAKE) -C .github/docker update-alpine
+update-alpine: ## Update Alpine base image to latest version and digest (usage: make update-alpine [ALPINE_TAG=3.22])
+	@if [ -n "$(ALPINE_TAG)" ]; then \
+		LATEST_TAG=$(ALPINE_TAG); \
+	else \
+		echo "Fetching latest Alpine version from Docker Hub..."; \
+		LATEST_TAG=$$(curl -s https://registry.hub.docker.com/v2/repositories/library/alpine/tags\?page_size=100 | \
+			jq -r '.results[].name' | grep -E '^3\.[0-9]+$$' | sort -V | tail -1); \
+	fi && \
+	echo "Alpine version: $$LATEST_TAG" && \
+	DIGEST=$$(docker buildx imagetools inspect alpine:$$LATEST_TAG 2>/dev/null | grep "Digest:" | head -1 | awk '{print $$2}') && \
+	DIGEST_HASH=$${DIGEST#sha256:} && \
+	echo "Digest: sha256:$$DIGEST_HASH" && \
+	ALPINE_FULL="alpine:$$LATEST_TAG@sha256:$$DIGEST_HASH" && \
+	if sed --version 2>&1 | grep -q GNU; then \
+		sed -i "s|default = \"alpine:[^\"]*\"|default = \"$$ALPINE_FULL\"|" .github/docker/docker-bake.hcl; \
+	else \
+		sed -i '' "s|default = \"alpine:[^\"]*\"|default = \"$$ALPINE_FULL\"|" .github/docker/docker-bake.hcl; \
+	fi && \
+	echo "Updated .github/docker/docker-bake.hcl with $$ALPINE_FULL"