update project structure

- move agent to /agent
- change /beszel to /src
- update workflows and docker builds

agent/agent.go

@@ -0,0 +1,182 @@
+// Package agent handles the agent's SSH server and system stats collection.
+package agent
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"log/slog"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/gliderlabs/ssh"
+	"github.com/henrygd/beszel"
+	"github.com/henrygd/beszel/src/entities/system"
+	"github.com/shirou/gopsutil/v4/host"
+	gossh "golang.org/x/crypto/ssh"
+)
+
+type Agent struct {
+	sync.Mutex                                   // Used to lock agent while collecting data
+	debug             bool                       // true if LOG_LEVEL is set to debug
+	zfs               bool                       // true if system has arcstats
+	memCalc           string                     // Memory calculation formula
+	fsNames           []string                   // List of filesystem device names being monitored
+	fsStats           map[string]*system.FsStats // Keeps track of disk stats for each filesystem
+	netInterfaces     map[string]struct{}        // Stores all valid network interfaces
+	netIoStats        system.NetIoStats          // Keeps track of bandwidth usage
+	dockerManager     *dockerManager             // Manages Docker API requests
+	sensorConfig      *SensorConfig              // Sensors config
+	systemInfo        system.Info                // Host system info
+	gpuManager        *GPUManager                // Manages GPU data
+	cache             *SessionCache              // Cache for system stats based on primary session ID
+	connectionManager *ConnectionManager         // Channel to signal connection events
+	server            *ssh.Server                // SSH server
+	dataDir           string                     // Directory for persisting data
+	keys              []gossh.PublicKey          // SSH public keys
+}
+
+// NewAgent creates a new agent with the given data directory for persisting data.
+// If the data directory is not set, it will attempt to find the optimal directory.
+func NewAgent(dataDir ...string) (agent *Agent, err error) {
+	agent = &Agent{
+		fsStats: make(map[string]*system.FsStats),
+		cache:   NewSessionCache(69 * time.Second),
+	}
+
+	agent.dataDir, err = getDataDir(dataDir...)
+	if err != nil {
+		slog.Warn("Data directory not found")
+	} else {
+		slog.Info("Data directory", "path", agent.dataDir)
+	}
+
+	agent.memCalc, _ = GetEnv("MEM_CALC")
+	agent.sensorConfig = agent.newSensorConfig()
+	// Set up slog with a log level determined by the LOG_LEVEL env var
+	if logLevelStr, exists := GetEnv("LOG_LEVEL"); exists {
+		switch strings.ToLower(logLevelStr) {
+		case "debug":
+			agent.debug = true
+			slog.SetLogLoggerLevel(slog.LevelDebug)
+		case "warn":
+			slog.SetLogLoggerLevel(slog.LevelWarn)
+		case "error":
+			slog.SetLogLoggerLevel(slog.LevelError)
+		}
+	}
+
+	slog.Debug(beszel.Version)
+
+	// initialize system info
+	agent.initializeSystemInfo()
+
+	// initialize connection manager
+	agent.connectionManager = newConnectionManager(agent)
+
+	// initialize disk info
+	agent.initializeDiskInfo()
+
+	// initialize net io stats
+	agent.initializeNetIoStats()
+
+	// initialize docker manager
+	agent.dockerManager = newDockerManager(agent)
+
+	// initialize GPU manager
+	if gm, err := NewGPUManager(); err != nil {
+		slog.Debug("GPU", "err", err)
+	} else {
+		agent.gpuManager = gm
+	}
+
+	// if debugging, print stats
+	if agent.debug {
+		slog.Debug("Stats", "data", agent.gatherStats(""))
+	}
+
+	return agent, nil
+}
+
+// GetEnv retrieves an environment variable with a "BESZEL_AGENT_" prefix, or falls back to the unprefixed key.
+func GetEnv(key string) (value string, exists bool) {
+	if value, exists = os.LookupEnv("BESZEL_AGENT_" + key); exists {
+		return value, exists
+	}
+	// Fallback to the old unprefixed key
+	return os.LookupEnv(key)
+}
+
+func (a *Agent) gatherStats(sessionID string) *system.CombinedData {
+	a.Lock()
+	defer a.Unlock()
+
+	data, isCached := a.cache.Get(sessionID)
+	if isCached {
+		slog.Debug("Cached data", "session", sessionID)
+		return data
+	}
+
+	*data = system.CombinedData{
+		Stats: a.getSystemStats(),
+		Info:  a.systemInfo,
+	}
+	slog.Debug("System data", "data", data)
+
+	if a.dockerManager != nil {
+		if containerStats, err := a.dockerManager.getDockerStats(); err == nil {
+			data.Containers = containerStats
+			slog.Debug("Containers", "data", data.Containers)
+		} else {
+			slog.Debug("Containers", "err", err)
+		}
+	}
+
+	data.Stats.ExtraFs = make(map[string]*system.FsStats)
+	for name, stats := range a.fsStats {
+		if !stats.Root && stats.DiskTotal > 0 {
+			data.Stats.ExtraFs[name] = stats
+		}
+	}
+	slog.Debug("Extra FS", "data", data.Stats.ExtraFs)
+
+	a.cache.Set(sessionID, data)
+	return data
+}
+
+// StartAgent initializes and starts the agent with optional WebSocket connection
+func (a *Agent) Start(serverOptions ServerOptions) error {
+	a.keys = serverOptions.Keys
+	return a.connectionManager.Start(serverOptions)
+}
+
+func (a *Agent) getFingerprint() string {
+	// first look for a fingerprint in the data directory
+	if a.dataDir != "" {
+		if fp, err := os.ReadFile(filepath.Join(a.dataDir, "fingerprint")); err == nil {
+			return string(fp)
+		}
+	}
+
+	// if no fingerprint is found, generate one
+	fingerprint, err := host.HostID()
+	if err != nil || fingerprint == "" {
+		fingerprint = a.systemInfo.Hostname + a.systemInfo.CpuModel
+	}
+
+	// hash fingerprint
+	sum := sha256.Sum256([]byte(fingerprint))
+	fingerprint = hex.EncodeToString(sum[:24])
+
+	// save fingerprint to data directory
+	if a.dataDir != "" {
+		err = os.WriteFile(filepath.Join(a.dataDir, "fingerprint"), []byte(fingerprint), 0644)
+		if err != nil {
+			slog.Warn("Failed to save fingerprint", "err", err)
+		}
+	}
+
+	return fingerprint
+}