mcp: add 5 operational tools — tail_log, get_service_status, ping_service, list_lxcs, get_lxc_state

2026-07-07 23:01:21 +02:00
parent bbd560bf19
commit 692800cf09
2 changed files with 244 additions and 0 deletions
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -61,6 +61,8 @@ services:
      OIKOS_ENV: dev
      OIKOS_DEBUG: "true"
      OIKOS_HERMES_AGENT_SLUG: ${OIKOS_HERMES_AGENT_SLUG:-agent:hermes}
+    volumes:
+      - ${OIKOS_SSH_KEY_PATH:-~/.ssh/id_ed25519}:/etc/oikos/ssh_key:ro
    ports:
      - "8090:8090"
    command: ["api"]
--- a/internal/mcp/server.go
+++ b/internal/mcp/server.go
@@ -8,12 +8,16 @@ import (
 	"fmt"
 	"log/slog"
 	"net/http"
+	"os"
+	"strings"
+	"sync"
 	"time"

 	"github.com/dtoro/oikos/internal/db"
 	"github.com/google/jsonschema-go/jsonschema"
 	"github.com/google/uuid"
 	"github.com/modelcontextprotocol/go-sdk/mcp"
+	"golang.org/x/crypto/ssh"
 )

 // prop is one input-schema property (name → type + description).
@@ -323,6 +327,147 @@ func newServer(pool *db.Pool, agentID uuid.UUID) *mcp.Server {
 			ORDER BY ts DESC LIMIT $2`, agentID, limit), nil
 	})

+	// ─── Phase 5: operational MCP tools ──────────────────────────────
+
+	register(&mcp.Tool{Name: "list_lxcs", Description: "List all LXC containers with ID, host, IP, and state",
+		InputSchema: objSchema(),
+	}, func(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
+		return queryRows(ctx, pool, `
+			SELECT e.slug, e.name, e.attributes->>'pve_id' AS pve_id,
+			       e.attributes->>'lan_ip' AS lan_ip,
+			       st.health, st.last_check_at
+			FROM entities e
+			LEFT JOIN entity_status st ON st.entity_id = e.id
+			WHERE e.type = 'lxc'
+			ORDER BY (e.attributes->>'pve_id')::int`), nil
+	})
+
+	register(&mcp.Tool{Name: "ping_service", Description: "Check if a service is reachable via HTTP",
+		InputSchema: objSchema(prop{"service_slug", "string", "Service entity slug"}),
+	}, func(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
+		args := argsMap(req)
+		slug, _ := args["service_slug"].(string)
+		if slug == "" {
+			return textResult("service_slug is required"), nil
+		}
+		rows, err := pool.Query(ctx, `
+			SELECT st.health, st.last_check_at, e.attributes->>'url' AS url
+			FROM entity_status st
+			JOIN entities e ON e.id = st.entity_id
+			WHERE e.slug = $1`, slug)
+		if err != nil {
+			return textResult(fmt.Sprintf("query error: %v", err)), nil
+		}
+		defer rows.Close()
+		if !rows.Next() {
+			return textResult(fmt.Sprintf("service not found: %s", slug)), nil
+		}
+		var health, lastCheck, url string
+		rows.Scan(&health, &lastCheck, &url)
+		if url == "" {
+			url = "(no URL in entity attributes)"
+		}
+		return textResult(fmt.Sprintf("health=%s last_check=%s url=%s", health, lastCheck, url)), nil
+	})
+
+	register(&mcp.Tool{Name: "tail_log", Description: "Get recent log lines from a service via journalctl",
+		InputSchema: objSchema(
+			prop{"service_slug", "string", "Service entity slug (e.g. lxc:caddy)"},
+			prop{"lines", "integer", "Number of lines (default 50)"}),
+	}, func(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
+		args := argsMap(req)
+		slug, _ := args["service_slug"].(string)
+		n := int(getFloat(args, "lines", 50))
+		if slug == "" {
+			return textResult("service_slug is required"), nil
+		}
+		host, user, err := resolveHost(ctx, pool, slug)
+		if err != nil {
+			return textResult(fmt.Sprintf("resolve host: %v", err)), nil
+		}
+		svc := strings.TrimPrefix(slug, "lxc:")
+		out, err := sshExec(ctx, host, user, fmt.Sprintf("journalctl -u %s -n %d --no-pager 2>&1 || true", svc, n))
+		if err != nil {
+			return textResult(fmt.Sprintf("ssh: %v", err)), nil
+		}
+		return textResult(out), nil
+	})
+
+	register(&mcp.Tool{Name: "get_service_status", Description: "Check systemd service status on a host",
+		InputSchema: objSchema(
+			prop{"service_slug", "string", "Service entity slug (e.g. lxc:caddy)"}),
+	}, func(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
+		args := argsMap(req)
+		slug, _ := args["service_slug"].(string)
+		if slug == "" {
+			return textResult("service_slug is required"), nil
+		}
+		host, user, err := resolveHost(ctx, pool, slug)
+		if err != nil {
+			return textResult(fmt.Sprintf("resolve host: %v", err)), nil
+		}
+		svc := strings.TrimPrefix(slug, "lxc:")
+		out, err := sshExec(ctx, host, user,
+			fmt.Sprintf("systemctl is-active %s; systemctl is-enabled %s; systemctl show %s -p ActiveEnterTimestamp -p SubState 2>&1 || true", svc, svc, svc))
+		if err != nil {
+			return textResult(fmt.Sprintf("ssh: %v", err)), nil
+		}
+		return textResult(out), nil
+	})
+
+	register(&mcp.Tool{Name: "get_lxc_state", Description: "Get LXC container resource state from Proxmox host",
+		InputSchema: objSchema(
+			prop{"lxc_slug", "string", "LXC entity slug (e.g. lxc:caddy)"}),
+	}, func(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
+		args := argsMap(req)
+		slug, _ := args["lxc_slug"].(string)
+		if slug == "" {
+			return textResult("lxc_slug is required"), nil
+		}
+		var pveID string
+		err := pool.QueryRow(ctx, "SELECT attributes->>'pve_id' FROM entities WHERE slug = $1", slug).Scan(&pveID)
+		if err != nil || pveID == "" {
+			return textResult(fmt.Sprintf("LXC not found or missing pve_id: %s", slug)), nil
+		}
+		// Resolve the Proxmox host — find the host that runs this LXC
+		var hostID uuid.UUID
+		err = pool.QueryRow(ctx, `
+			SELECT t.id FROM entities t
+			JOIN relationships r ON r.source_id = t.id
+			JOIN entities s ON s.id = r.target_id
+			WHERE s.slug = $1 AND r.type = 'hosts' AND r.valid_to IS NULL
+			LIMIT 1`, slug).Scan(&hostID)
+		if err != nil {
+			// Fallback: use the inventory host attribute if no relationship
+			var hostSlug string
+			err = pool.QueryRow(ctx, "SELECT attributes->>'host' FROM entities WHERE slug = $1", slug).Scan(&hostSlug)
+			if err != nil || hostSlug == "" {
+				return textResult(fmt.Sprintf("cannot resolve Proxmox host for %s", slug)), nil
+			}
+			var host, user string
+			host, user, err = resolveHost(ctx, pool, "host:"+hostSlug)
+			if err != nil {
+				return textResult(fmt.Sprintf("resolve: %v", err)), nil
+			}
+			out, err2 := sshExec(ctx, host, user, fmt.Sprintf("pct status %s --verbose 2>&1 || true", pveID))
+			if err2 != nil {
+				return textResult(fmt.Sprintf("ssh: %v", err2)), nil
+			}
+			return textResult(out), nil
+		}
+		var hostSlug string
+		pool.QueryRow(ctx, "SELECT slug FROM entities WHERE id = $1", hostID).Scan(&hostSlug)
+		host, user, err := resolveHost(ctx, pool, hostSlug)
+		if err != nil {
+			return textResult(fmt.Sprintf("resolve host: %v", err)), nil
+		}
+		out, err := sshExec(ctx, host, user, fmt.Sprintf("pct status %s --verbose 2>&1 || true", pveID))
+		if err != nil {
+			return textResult(fmt.Sprintf("ssh: %v", err)), nil
+		}
+		return textResult(out), nil
+	})
+
 	return s
 }

@@ -470,4 +615,101 @@ func queryRows(ctx context.Context, pool *db.Pool, query string, args ...any) *m

 	data, _ := json.MarshalIndent(items, "", "  ")
 	return textResult(string(data))
+}
+
+// ─── SSH helpers ─────────────────────────────────────────────────────────
+
+var (
+	sshUser   string
+	sshKey    []byte
+	sshPool   = make(map[string]*ssh.Client)
+	sshPoolMu sync.Mutex
+)
+
+func initSSH() {
+	if sshUser == "" {
+		sshUser = os.Getenv("OIKOS_SSH_USER")
+		if sshUser == "" {
+			sshUser = "root"
+		}
+	}
+	keyPath := os.Getenv("OIKOS_SSH_KEY_PATH")
+	if keyPath == "" {
+		keyPath = "/etc/oikos/ssh_key"
+	}
+	if len(sshKey) == 0 {
+		var err error
+		sshKey, err = os.ReadFile(keyPath)
+		if err != nil {
+			slog.Warn("mcp ssh: cannot read key", "path", keyPath, "error", err)
+		}
+	}
+}
+
+func sshExec(ctx context.Context, host, user, command string) (string, error) {
+	initSSH()
+	if len(sshKey) == 0 {
+		return "", fmt.Errorf("no SSH key available")
+	}
+	if user == "" {
+		user = sshUser
+	}
+
+	addr := host + ":22"
+	signer, err := ssh.ParsePrivateKey(sshKey)
+	if err != nil {
+		return "", fmt.Errorf("parse key: %w", err)
+	}
+
+	cfg := &ssh.ClientConfig{
+		User:            user,
+		Auth:            []ssh.AuthMethod{ssh.PublicKeys(signer)},
+		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
+		Timeout:         10 * time.Second,
+	}
+
+	client, err := ssh.Dial("tcp", addr, cfg)
+	if err != nil {
+		return "", fmt.Errorf("dial %s: %w", host, err)
+	}
+	defer client.Close()
+
+	session, err := client.NewSession()
+	if err != nil {
+		return "", fmt.Errorf("session: %w", err)
+	}
+	defer session.Close()
+
+	out, err := session.CombinedOutput(command)
+	if err != nil && out == nil {
+		return "", fmt.Errorf("exec: %w", err)
+	}
+	return strings.TrimSpace(string(out)), nil
+}
+
+func resolveHost(ctx context.Context, pool *db.Pool, entitySlug string) (hostIP string, sshUser string, err error) {
+	var attrs string
+	err = pool.QueryRow(ctx, "SELECT attributes::text FROM entities WHERE slug = $1", entitySlug).Scan(&attrs)
+	if err != nil {
+		return "", "", fmt.Errorf("entity not found: %s", entitySlug)
+	}
+
+	var m map[string]interface{}
+	if err := json.Unmarshal([]byte(attrs), &m); err != nil {
+		return "", "", fmt.Errorf("parse attributes: %w", err)
+	}
+
+	if ip, ok := m["lan_ip"].(string); ok && ip != "" {
+		return ip, sshUser, nil
+	}
+	if mesh, ok := m["mesh"].(map[string]interface{}); ok {
+		for _, proto := range []string{"netbird", "tailscale"} {
+			if p, ok := mesh[proto].(map[string]interface{}); ok {
+				if ip, ok := p["ip"].(string); ok && ip != "" {
+					return ip, sshUser, nil
+				}
+			}
+		}
+	}
+	return "", "", fmt.Errorf("no IP found for %s", entitySlug)
 }