CI: Create darwin universal binary and arm64 binary

.github/workflows/build.yml

@@ -3,21 +3,70 @@ on:
   push:
     branches: [ master ]
   pull_request:
+
 jobs:
   build:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-22.04, macos-13, macos-14] # linux-x86_64, darwin-x86_64, darwin-arm64
+        os: [ubuntu-24.04, ubuntu-24.04-arm, macos-13, macos-14] # linux-x86_64, linux-arm64, darwin-x86_64, darwin-arm64
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-go@v4
         with:
-          go-version: '1.23.6'
+          go-version: '1.23.11'
       - run: make test
       - run: make package
-      - run: shasum -a 256 node_exporter node_exporter*.tar.gz
+      - run: shasum -a 256 node_exporter node_exporter*.tar.gz | tee checksums-${{ matrix.os }}.txt
       - uses: actions/upload-artifact@v4
         with:
           name: package-${{ matrix.os }}
           path: "*.tar.gz"
+      - uses: actions/upload-artifact@v4
+        with:
+          name: checksums-${{ matrix.os }}
+          path: "checksums-${{ matrix.os }}.txt"
+
+  create-universal-binary:
+    runs-on: macos-14
+    needs: build
+    steps:
+      - uses: actions/checkout@v4
+      - name: Download macOS x86_64 artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: package-macos-13
+          path: ./macos-x86_64
+      - name: Download macOS arm64 artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: package-macos-14
+          path: ./macos-arm64
+      - name: Extract binaries
+        run: |
+          cd macos-x86_64 && tar -xzf *.tar.gz
+          cd ../macos-arm64 && tar -xzf *.tar.gz
+      - name: Create universal binary
+        run: |
+          lipo -create -output node_exporter_universal \
+            macos-x86_64/node_exporter \
+            macos-arm64/node_exporter
+      - name: Verify universal binary
+        run: |
+          file node_exporter_universal
+          lipo -info node_exporter_universal
+      - name: Package universal binary
+        run: |
+          mv node_exporter_universal node_exporter
+          PACKAGE_NAME=node_exporter-stable-darwin-universal.tar.gz
+          tar -czvf ${PACKAGE_NAME} node_exporter
+      - name: Generate checksum
+        run: shasum -a 256 node_exporter node_exporter*.tar.gz | tee checksums-darwin-universal.txt
+      - uses: actions/upload-artifact@v4
+        with:
+          name: package-darwin-universal
+          path: "*.tar.gz"
+      - uses: actions/upload-artifact@v4
+        with:
+          name: checksums-darwin-universal
+          path: "checksums-darwin-universal.txt"

CLAUDE.md

@@ -0,0 +1,98 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+This is a fork of the Prometheus Node Exporter that includes an additional **gateway collector** for Algod with buffering and other features. The Node Exporter is a Prometheus exporter for hardware and OS metrics exposed by *NIX kernels, written in Go with pluggable metric collectors.
+
+The key distinguishing feature of this fork is the `gateway.go` collector in the `collector/` directory, which provides enhanced functionality for Algorand's needs.
+
+## Development Commands
+
+### Building
+```bash
+make                    # Build with all checks (style, vet, staticcheck, checkmetrics, build, package, test)
+make build              # Build binaries only
+make package            # Create tarball package
+```
+
+### Testing
+```bash
+make test               # Run all tests
+make test-short         # Run short tests only
+make test-e2e           # Run end-to-end tests (Linux only)
+make test-32bit         # Cross-architecture testing (when supported)
+```
+
+### Code Quality
+```bash
+make style              # Check code formatting
+make vet                # Run go vet
+make staticcheck        # Run staticcheck linter
+make checkmetrics       # Validate metrics with promtool
+make format             # Format code
+```
+
+### Docker
+```bash
+make docker             # Build Docker image
+make test-docker        # Test Docker image
+```
+
+## Code Architecture
+
+### Core Components
+
+1. **Main Entry Point** (`node_exporter.go`): HTTP server that exposes metrics at `/metrics` endpoint
+2. **Collector Framework** (`collector/collector.go`): Plugin architecture for metric collectors
+3. **Gateway Collector** (`collector/gateway.go`): Algorand-specific collector with buffering and POST handling
+4. **Individual Collectors** (`collector/*_*.go`): Platform-specific metric collectors
+
+### Collector System
+
+The Node Exporter uses a plugin-based collector system:
+- Collectors are registered via `registerCollector()` with default enabled/disabled state
+- Each collector implements the `Collector` interface with `Update(ch chan<- prometheus.Metric) error`
+- Collectors can be enabled/disabled via `--collector.<name>` and `--no-collector.<name>` flags
+- The main collector orchestrates concurrent collection from all enabled collectors
+
+### Gateway Collector Architecture
+
+The gateway collector (`collector/gateway.go`) provides unique functionality:
+- Acts as HTTP middleware, intercepting POST requests to `/metrics`
+- Parses Prometheus format metrics from POST body
+- Maintains internal counters and gauges with automatic expiration
+- Implements buffering with configurable sample intervals
+- Provides metric lifecycle management (creation, updating, expiration)
+
+## Platform Support
+
+Collectors have varying support across operating systems:
+- **Linux**: Full support for most collectors
+- **Darwin/macOS**: Limited support for core metrics
+- **BSD variants**: Platform-specific implementations
+- **Windows**: Use WMI exporter instead
+
+## Build System
+
+- Uses Go modules (`go.mod`) with Go 1.23+
+- Makefile-based build system with `Makefile.common` for shared rules
+- Cross-compilation support via `GOOS`/`GOARCH` environment variables
+- CGO usage controlled by `.promu-cgo.yml` vs `.promu-no-cgo.yml`
+- CI/CD via GitHub Actions (`.github/workflows/build.yml`)
+
+## Testing Infrastructure
+
+- Extensive fixture-based testing in `collector/fixtures/`
+- Mock `/proc` and `/sys` filesystem data for reproducible tests
+- End-to-end testing with expected output validation
+- Platform-specific test execution based on build environment
+
+## Key Design Principles
+
+1. **Machine Metrics Only**: Focus on hardware/OS metrics, not application metrics
+2. **No External Commands**: Use only system calls, proc/sys files, and local sockets
+3. **No Root Privileges**: All metrics must be accessible without elevated permissions
+4. **Hardware Agnostic**: Expose raw values without vendor-specific transformations
+5. **Performance First**: Concurrent collection with minimal overhead