feat: add async SSH ping for all hosts with status indicator

internal/connectivity/ping.go

@@ -0,0 +1,212 @@
+package connectivity
+
+import (
+	"context"
+	"net"
+	"sshm/internal/config"
+	"strings"
+	"sync"
+	"time"
+
+	"golang.org/x/crypto/ssh"
+)
+
+// PingStatus represents the connectivity status of an SSH host
+type PingStatus int
+
+const (
+	StatusUnknown PingStatus = iota
+	StatusConnecting
+	StatusOnline
+	StatusOffline
+)
+
+func (s PingStatus) String() string {
+	switch s {
+	case StatusUnknown:
+		return "unknown"
+	case StatusConnecting:
+		return "connecting"
+	case StatusOnline:
+		return "online"
+	case StatusOffline:
+		return "offline"
+	}
+	return "unknown"
+}
+
+// HostPingResult represents the result of pinging a host
+type HostPingResult struct {
+	HostName string
+	Status   PingStatus
+	Error    error
+	Duration time.Duration
+}
+
+// PingManager manages SSH connectivity checks for multiple hosts
+type PingManager struct {
+	results map[string]*HostPingResult
+	mutex   sync.RWMutex
+	timeout time.Duration
+}
+
+// NewPingManager creates a new ping manager with the specified timeout
+func NewPingManager(timeout time.Duration) *PingManager {
+	return &PingManager{
+		results: make(map[string]*HostPingResult),
+		timeout: timeout,
+	}
+}
+
+// GetStatus returns the current status for a host
+func (pm *PingManager) GetStatus(hostName string) PingStatus {
+	pm.mutex.RLock()
+	defer pm.mutex.RUnlock()
+
+	if result, exists := pm.results[hostName]; exists {
+		return result.Status
+	}
+	return StatusUnknown
+}
+
+// GetResult returns the complete result for a host
+func (pm *PingManager) GetResult(hostName string) (*HostPingResult, bool) {
+	pm.mutex.RLock()
+	defer pm.mutex.RUnlock()
+
+	result, exists := pm.results[hostName]
+	return result, exists
+}
+
+// updateStatus updates the status for a host
+func (pm *PingManager) updateStatus(hostName string, status PingStatus, err error, duration time.Duration) {
+	pm.mutex.Lock()
+	defer pm.mutex.Unlock()
+
+	pm.results[hostName] = &HostPingResult{
+		HostName: hostName,
+		Status:   status,
+		Error:    err,
+		Duration: duration,
+	}
+}
+
+// PingHost performs an SSH connectivity check for a single host
+func (pm *PingManager) PingHost(ctx context.Context, host config.SSHHost) *HostPingResult {
+	start := time.Now()
+
+	// Mark as connecting
+	pm.updateStatus(host.Name, StatusConnecting, nil, 0)
+
+	// Determine the actual hostname and port
+	hostname := host.Hostname
+	if hostname == "" {
+		hostname = host.Name
+	}
+
+	port := host.Port
+	if port == "" {
+		port = "22"
+	}
+
+	// Create context with timeout
+	pingCtx, cancel := context.WithTimeout(ctx, pm.timeout)
+	defer cancel()
+
+	// Try to establish a TCP connection first (faster than SSH handshake)
+	dialer := &net.Dialer{}
+	conn, err := dialer.DialContext(pingCtx, "tcp", net.JoinHostPort(hostname, port))
+	if err != nil {
+		duration := time.Since(start)
+		pm.updateStatus(host.Name, StatusOffline, err, duration)
+		return &HostPingResult{
+			HostName: host.Name,
+			Status:   StatusOffline,
+			Error:    err,
+			Duration: duration,
+		}
+	}
+	defer conn.Close()
+
+	// If TCP connection succeeds, try SSH handshake
+	sshConfig := &ssh.ClientConfig{
+		User:            host.User,
+		HostKeyCallback: ssh.InsecureIgnoreHostKey(), // For ping purposes only
+		Timeout:         time.Second * 2,             // Short timeout for handshake
+	}
+
+	// We don't need to authenticate, just check if SSH is responding
+	sshConn, _, _, err := ssh.NewClientConn(conn, net.JoinHostPort(hostname, port), sshConfig)
+	if sshConn != nil {
+		sshConn.Close()
+	}
+
+	duration := time.Since(start)
+
+	// Even if SSH handshake fails, if we got a TCP connection, consider it online
+	// This handles cases where authentication fails but the host is reachable
+	status := StatusOnline
+	if err != nil && isConnectionError(err) {
+		status = StatusOffline
+	}
+
+	pm.updateStatus(host.Name, status, err, duration)
+	return &HostPingResult{
+		HostName: host.Name,
+		Status:   status,
+		Error:    err,
+		Duration: duration,
+	}
+}
+
+// PingAllHosts pings all hosts concurrently and returns a channel of results
+func (pm *PingManager) PingAllHosts(ctx context.Context, hosts []config.SSHHost) <-chan *HostPingResult {
+	resultChan := make(chan *HostPingResult, len(hosts))
+
+	var wg sync.WaitGroup
+
+	for _, host := range hosts {
+		wg.Add(1)
+		go func(h config.SSHHost) {
+			defer wg.Done()
+			result := pm.PingHost(ctx, h)
+			select {
+			case resultChan <- result:
+			case <-ctx.Done():
+				return
+			}
+		}(host)
+	}
+
+	// Close the channel when all goroutines are done
+	go func() {
+		wg.Wait()
+		close(resultChan)
+	}()
+
+	return resultChan
+}
+
+// isConnectionError determines if an error is a connection-related error
+func isConnectionError(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	errStr := err.Error()
+	connectionErrors := []string{
+		"connection refused",
+		"no route to host",
+		"network is unreachable",
+		"timeout",
+		"connection timed out",
+	}
+
+	for _, connErr := range connectionErrors {
+		if strings.Contains(strings.ToLower(errStr), connErr) {
+			return true
+		}
+	}
+
+	return false
+}