feat: v0 — glpi-go client, mglpi CLI, mglpi-mcp, fake-GLPI test suite [#767]

https://projects.knownelement.com/issues/767#note-4191
2026-09-04 08:41:25 -05:00
commit 5da1eee08f
26 changed files with 4956 additions and 0 deletions
@@ -0,0 +1,287 @@
+// Package mcp implements a minimal stdio JSON-RPC MCP (Model Context
+// Protocol) server over the glpi library — stdlib only, no third-party
+// modules. Transport is newline-delimited JSON on the reader/writer
+// pair. Tools: change_create, change_list, change_transition,
+// change_followup, ci_search, ci_show. An optional agent profile id
+// (e.g. 5 = Hotliner) is applied on the first tool call.
+package mcp
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"strconv"
+	"sync"
+
+	"git.knownelement.com/ukrrs/mopac-glpi-go/glpi"
+)
+
+// protocolVersionDefault answers initialize when the client does not
+// name one.
+const protocolVersionDefault = "2025-06-18"
+
+// Server is the MCP server over one glpi.Client.
+type Server struct {
+	client  *glpi.Client
+	profile int
+
+	once       sync.Once
+	profileErr error
+}
+
+// New builds a Server. profileID > 0 switches the session's active
+// profile (agent mode) on first use.
+func New(c *glpi.Client, profileID int) *Server {
+	return &Server{client: c, profile: profileID}
+}
+
+// Serve reads newline-delimited JSON-RPC requests until EOF, writing
+// one response line per request that carries an id (notifications are
+// acknowledged by silence).
+func (s *Server) Serve(in io.Reader, out io.Writer) error {
+	sc := bufio.NewScanner(in)
+	sc.Buffer(make([]byte, 0, 64*1024), 4<<20)
+	for sc.Scan() {
+		line := bytes.TrimSpace(sc.Bytes())
+		if len(line) == 0 {
+			continue
+		}
+		if err := s.handle(line, out); err != nil {
+			return err
+		}
+	}
+	return sc.Err()
+}
+
+// request is one inbound JSON-RPC message.
+type request struct {
+	JSONRPC string          `json:"jsonrpc"`
+	ID      json.RawMessage `json:"id"`
+	Method  string          `json:"method"`
+	Params  struct {
+		ProtocolVersion string          `json:"protocolVersion"`
+		Name            string          `json:"name"`
+		Arguments       json.RawMessage `json:"arguments"`
+	} `json:"params"`
+}
+
+// response is one outbound JSON-RPC message (result XOR error).
+type response struct {
+	JSONRPC string          `json:"jsonrpc"`
+	ID      json.RawMessage `json:"id"`
+	Result  any             `json:"result,omitempty"`
+	Error   *rpcError       `json:"error,omitempty"`
+}
+
+type rpcError struct {
+	Code    int    `json:"code"`
+	Message string `json:"message"`
+}
+
+func (s *Server) handle(line []byte, out io.Writer) error {
+	var req request
+	if err := json.Unmarshal(line, &req); err != nil || req.Method == "" {
+		return nil // cannot route a malformed line; never guess an id
+	}
+	if len(req.ID) == 0 || string(req.ID) == "null" {
+		return nil // notification: no response per JSON-RPC
+	}
+
+	resp := response{JSONRPC: "2.0", ID: req.ID}
+	switch req.Method {
+	case "initialize":
+		pv := req.Params.ProtocolVersion
+		if pv == "" {
+			pv = protocolVersionDefault
+		}
+		resp.Result = map[string]any{
+			"protocolVersion": pv,
+			"capabilities":    map[string]any{"tools": map[string]any{}},
+			"serverInfo":      map[string]any{"name": "mglpi-mcp", "version": "0.1.0"},
+		}
+	case "ping":
+		resp.Result = map[string]any{}
+	case "tools/list":
+		resp.Result = map[string]any{"tools": toolDefs()}
+	case "tools/call":
+		resp.Result = s.callTool(req.Params.Name, req.Params.Arguments)
+	default:
+		resp.Result = nil
+		resp.Error = &rpcError{Code: -32601, Message: fmt.Sprintf("method not found: %s", req.Method)}
+	}
+	return writeLine(out, resp)
+}
+
+// ensureProfile applies the agent profile once per server lifetime (an
+// API op; it also warms the session).
+func (s *Server) ensureProfile() error {
+	s.once.Do(func() {
+		if s.profile > 0 {
+			s.profileErr = s.client.ChangeActiveProfile(context.Background(), s.profile)
+		}
+	})
+	return s.profileErr
+}
+
+// callTool dispatches one tools/call. Tool failures are RESULTS with
+// isError=true (protocol errors are the -32601 path only).
+func (s *Server) callTool(name string, args json.RawMessage) map[string]any {
+	if err := s.ensureProfile(); err != nil {
+		return toolError(err)
+	}
+	var a map[string]any
+	if len(args) > 0 {
+		if err := json.Unmarshal(args, &a); err != nil {
+			return toolError(fmt.Errorf("arguments are not an object"))
+		}
+	}
+	ctx := context.Background()
+	var payload any
+	switch name {
+	case "change_create":
+		title, _ := a["title"].(string)
+		if title == "" {
+			return toolError(fmt.Errorf("change_create requires title"))
+		}
+		content, _ := a["content"].(string)
+		id, err := s.client.CreateChange(ctx, title, content, argInt(a, "urgency", 3), argInt(a, "impact", 3))
+		if err != nil {
+			return toolError(err)
+		}
+		payload = map[string]any{"change": map[string]any{"id": id}}
+	case "change_list":
+		rows, err := s.client.ListChanges(ctx, argInt(a, "status", 0))
+		if err != nil {
+			return toolError(err)
+		}
+		payload = map[string]any{"changes": rows}
+	case "change_transition":
+		id := argInt(a, "id", 0)
+		status, ok := glpi.StatusID(argString(a, "status"))
+		if !ok {
+			status = argInt(a, "status", 0)
+		}
+		if id == 0 || status == 0 {
+			return toolError(fmt.Errorf("change_transition requires id and status"))
+		}
+		if err := s.client.TransitionChange(ctx, id, status); err != nil {
+			return toolError(err)
+		}
+		payload = map[string]any{"transitioned": map[string]any{"id": id, "status": glpi.StatusName(status)}}
+	case "change_followup":
+		id := argInt(a, "id", 0)
+		content, _ := a["content"].(string)
+		if id == 0 || content == "" {
+			return toolError(fmt.Errorf("change_followup requires id and content"))
+		}
+		if err := s.client.AddFollowup(ctx, id, content); err != nil {
+			return toolError(err)
+		}
+		payload = map[string]any{"followup": map[string]any{"items_id": id}}
+	case "ci_search":
+		rows, err := s.client.SearchCI(ctx, argString(a, "itemtype"), argString(a, "term"))
+		if err != nil {
+			return toolError(err)
+		}
+		type result struct {
+			ID   int    `json:"id"`
+			Name string `json:"name"`
+		}
+		results := make([]result, 0, len(rows))
+		for _, r := range rows {
+			results = append(results, result{ID: r.ID, Name: r.Name})
+		}
+		payload = map[string]any{"results": results}
+	case "ci_show":
+		id := argInt(a, "id", 0)
+		obj, err := s.client.GetItem(ctx, argString(a, "itemtype"), id)
+		if err != nil {
+			return toolError(err)
+		}
+		payload = obj
+	default:
+		return toolError(fmt.Errorf("unknown tool: %s", name))
+	}
+	b, err := json.Marshal(payload)
+	if err != nil {
+		return toolError(fmt.Errorf("cannot encode tool result"))
+	}
+	return map[string]any{
+		"content": []map[string]any{{"type": "text", "text": string(b)}},
+		"isError": false,
+	}
+}
+
+func toolError(err error) map[string]any {
+	return map[string]any{
+		"content": []map[string]any{{"type": "text", "text": err.Error()}},
+		"isError": true,
+	}
+}
+
+func argString(a map[string]any, key string) string {
+	s, _ := a[key].(string)
+	return s
+}
+
+func argInt(a map[string]any, key string, def int) int {
+	switch v := a[key].(type) {
+	case float64:
+		return int(v)
+	case string:
+		if n, err := strconv.Atoi(v); err == nil {
+			return n
+		}
+	}
+	return def
+}
+
+// toolDefs is the advertised tool surface (stable order).
+func toolDefs() []map[string]any {
+	schema := func(required ...string) map[string]any {
+		props := map[string]any{}
+		for _, p := range required {
+			props[p] = map[string]any{"type": "string"}
+		}
+		return map[string]any{
+			"type":       "object",
+			"properties": props,
+			"required":   required,
+		}
+	}
+	full := func(req []string, opt map[string]string) map[string]any {
+		props := map[string]any{}
+		for _, p := range req {
+			props[p] = map[string]any{"type": "string"}
+		}
+		for p, t := range opt {
+			props[p] = map[string]any{"type": t}
+		}
+		return map[string]any{
+			"type":       "object",
+			"properties": props,
+			"required":   req,
+		}
+	}
+	return []map[string]any{
+		{"name": "change_create", "description": "Create a GLPI change (urgency/impact 1-5, 3=medium)", "inputSchema": full([]string{"title"}, map[string]string{"content": "string", "urgency": "integer", "impact": "integer"})},
+		{"name": "change_list", "description": "List GLPI changes (optional status filter)", "inputSchema": schema()},
+		{"name": "change_transition", "description": "Move a change to a status (name or numeric id)", "inputSchema": schema("id", "status")},
+		{"name": "change_followup", "description": "Append a followup note to a change", "inputSchema": schema("id", "content")},
+		{"name": "ci_search", "description": "Search CIs of an itemtype by name substring", "inputSchema": schema("itemtype", "term")},
+		{"name": "ci_show", "description": "Fetch one CI raw by itemtype and id", "inputSchema": schema("itemtype", "id")},
+	}
+}
+
+// writeLine emits one compact JSON response line.
+func writeLine(out io.Writer, v any) error {
+	b, err := json.Marshal(v)
+	if err != nil {
+		return err
+	}
+	_, err = out.Write(append(b, '\n'))
+	return err
+}