build: move build metadata preparation to a standalone script

- Extracted `build_info` preparation logic to `script/prepare-build-info`.
- Updated Dockerfile and GitHub workflows to use the new script.
- Simplified metadata injection process for better reusability.

Author: SchulteDev

.github/workflows/go.yml

@@ -29,16 +29,7 @@ jobs:
         run: script/test
 
       - name: Prepare build_info files
-        shell: bash
-        run: |
-          BUILD_DATE=$(date -u +%Y-%m-%dT%H:%M:%SZ)
-          mkdir -p cmd/github-mcp-server/build_info
-          echo "${{ github.sha }}" > cmd/github-mcp-server/build_info/commit.txt
-          echo "$BUILD_DATE" > cmd/github-mcp-server/build_info/date.txt
-          if [ "${{ github.event_name }}" = "push" ]; then
-            echo "${{ github.ref_name }}" > cmd/github-mcp-server/build_info/version.txt
-          else
-            echo "pr-${{ github.event.pull_request.number }}" > cmd/github-mcp-server/build_info/version.txt
-          fi
+        run: script/prepare-build-info
+
       - name: Build
         run: go build -v ./cmd/github-mcp-server

Dockerfile

@@ -1,5 +1,4 @@
 FROM golang:1.24.4-alpine AS build
-ARG VERSION="dev"
 
 # Set the working directory
 WORKDIR /build
@@ -8,18 +7,12 @@ WORKDIR /build
 RUN --mount=type=cache,target=/var/cache/apk \
     apk add git
 
-# Prepare build_info files
-RUN --mount=type=bind,target=. \
-    mkdir -p cmd/github-mcp-server/build_info && \
-    git rev-parse HEAD > cmd/github-mcp-server/build_info/commit.txt && \
-    date -u +%Y-%m-%dT%H:%M:%SZ > cmd/github-mcp-server/build_info/date.txt && \
-    echo "${VERSION}" > cmd/github-mcp-server/build_info/version.txt
-
 # Build the server
 # go build automatically download required module dependencies to /go/pkg/mod
 RUN --mount=type=cache,target=/go/pkg/mod \
     --mount=type=cache,target=/root/.cache/go-build \
     --mount=type=bind,target=. \
+    script/prepare-build-info && \
     CGO_ENABLED=0 go build -ldflags="-s -w" \
     -o /bin/github-mcp-server cmd/github-mcp-server/main.go
 

script/prepare-build-info

@@ -0,0 +1,29 @@
+
+#!/bin/sh
+set -eu
+
+mkdir -p cmd/github-mcp-server/build_info
+
+BUILD_DATE=$(date -u +%Y-%m-%dT%H:%M:%SZ)
+
+if [ -n "${GITHUB_ACTIONS:-}" ]; then
+  # GitHub Actions context
+  COMMIT="${GITHUB_SHA}"
+
+  if [ "${GITHUB_EVENT_NAME}" = "push" ] && [ "${GITHUB_REF_TYPE}" = "tag" ]; then
+    VERSION="${GITHUB_REF_NAME}"
+  elif [ "${GITHUB_EVENT_NAME}" = "push" ]; then
+    VERSION="${GITHUB_REF_NAME}-${GITHUB_SHA}"
+  else
+    VERSION="pr-${GITHUB_EVENT_PULL_REQUEST_NUMBER}"
+  fi
+else
+  # Local/Docker context
+  COMMIT=$(git rev-parse HEAD 2>/dev/null || echo 'unknown')
+  VERSION="dev"
+fi
+
+# Write build info files
+echo "${COMMIT}" > cmd/github-mcp-server/build_info/commit.txt
+echo "${BUILD_DATE}" > cmd/github-mcp-server/build_info/date.txt
+echo "${VERSION}" > cmd/github-mcp-server/build_info/version.txt