agent: add separate glibc build with NVML support (#1618)

purego requires dynamic linking, so split the agent builds:
- Default: static binary without NVML (works on musl/alpine)
- Glibc: dynamic binary with NVML support via purego

Changes:
- Add glibc build tag to conditionally include NVML code
- Add beszel-agent-linux-amd64-glibc build/archive in goreleaser
- Update ghupdate to use glibc binary on glibc systems
- Switch nvidia dockerfile to golang:bookworm with -tags glibc

.goreleaser.yml

@@ -76,6 +76,18 @@ builds:
       - goos: windows
         goarch: riscv64
 
+  - id: beszel-agent-linux-amd64-glibc
+    binary: beszel-agent
+    main: internal/cmd/agent/agent.go
+    env:
+      - CGO_ENABLED=0
+    flags:
+      - -tags=glibc
+    goos:
+      - linux
+    goarch:
+      - amd64
+
 archives:
   - id: beszel-agent
     formats: [tar.gz]
@@ -89,6 +101,15 @@ archives:
       - goos: windows
         formats: [zip]
 
+  - id: beszel-agent-linux-amd64-glibc
+    formats: [tar.gz]
+    ids:
+      - beszel-agent-linux-amd64-glibc
+    name_template: >-
+      {{ .Binary }}_
+      {{- .Os }}_
+      {{- .Arch }}_glibc
+
   - id: beszel
     formats: [tar.gz]
     ids:

agent/gpu.go

@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
+	"log/slog"
 	"maps"
 	"os/exec"
 	"regexp"
@@ -14,8 +15,6 @@ import (
 	"time"
 
 	"github.com/henrygd/beszel/internal/entities/system"
-
-	"log/slog"
 )
 
 const (

agent/gpu_nvml.go

@@ -1,4 +1,4 @@
-//go:build (linux || windows) && amd64
+//go:build amd64 && (windows || (linux && glibc))
 
 package agent
 

agent/gpu_nvml_linux.go

@@ -1,4 +1,4 @@
-//go:build linux && amd64
+//go:build glibc && linux && amd64
 
 package agent
 

agent/gpu_nvml_unsupported.go

@@ -1,4 +1,4 @@
-//go:build (!linux && !windows) || !amd64
+//go:build (!linux && !windows) || !amd64 || (linux && !glibc)
 
 package agent
 

agent/systemd_nonlinux_test.go

@@ -19,11 +19,11 @@ func TestSystemdManagerGetServiceStats(t *testing.T) {
 	assert.NoError(t, err)
 
 	// Test with refresh = true
-	result := manager.getServiceStats(true)
+	result := manager.getServiceStats("any-service", true)
 	assert.Nil(t, result)
 
 	// Test with refresh = false
-	result = manager.getServiceStats(false)
+	result = manager.getServiceStats("any-service", false)
 	assert.Nil(t, result)
 }
 

internal/dockerfile_agent_nvidia

@@ -1,4 +1,4 @@
-FROM --platform=$BUILDPLATFORM golang:alpine AS builder
+FROM --platform=$BUILDPLATFORM golang:bookworm AS builder
 
 WORKDIR /app
 
@@ -10,7 +10,7 @@ COPY . ./
 
 # Build
 ARG TARGETOS TARGETARCH
-RUN CGO_ENABLED=0 GOGC=75 GOOS=$TARGETOS GOARCH=$TARGETARCH go build -ldflags "-w -s" -o /agent ./internal/cmd/agent
+RUN CGO_ENABLED=0 GOGC=75 GOOS=$TARGETOS GOARCH=$TARGETARCH go build -tags glibc -ldflags "-w -s" -o /agent ./internal/cmd/agent
 
 # --------------------------
 # Smartmontools builder stage

internal/ghupdate/ghupdate.go

@@ -11,6 +11,7 @@ import (
 	"log/slog"
 	"net/http"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"runtime"
 	"strings"
@@ -345,5 +346,32 @@ func archiveSuffix(binaryName, goos, goarch string) string {
 	if goos == "windows" {
 		return fmt.Sprintf("%s_%s_%s.zip", binaryName, goos, goarch)
 	}
+	// Use glibc build for agent on glibc systems (includes NVML support via purego)
+	if binaryName == "beszel-agent" && goos == "linux" && goarch == "amd64" && isGlibc() {
+		return fmt.Sprintf("%s_%s_%s_glibc.tar.gz", binaryName, goos, goarch)
+	}
 	return fmt.Sprintf("%s_%s_%s.tar.gz", binaryName, goos, goarch)
 }
+
+func isGlibc() bool {
+	for _, path := range []string{
+		"/lib64/ld-linux-x86-64.so.2",                // common on many distros
+		"/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2", // Debian/Ubuntu
+		"/lib/ld-linux-x86-64.so.2",                  // alternate
+	} {
+		if _, err := os.Stat(path); err == nil {
+			return true
+		}
+	}
+	// Fallback to ldd output when present (musl ldd reports musl, glibc reports GNU libc/glibc).
+	if lddPath, err := exec.LookPath("ldd"); err == nil {
+		out, err := exec.Command(lddPath, "--version").CombinedOutput()
+		if err == nil {
+			s := strings.ToLower(string(out))
+			if strings.Contains(s, "gnu libc") || strings.Contains(s, "glibc") {
+				return true
+			}
+		}
+	}
+	return false
+}