85 lines
3.1 KiB
Python
85 lines
3.1 KiB
Python
"""系统调用监控器的 Flask Web 服务层。
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提供两个页面与一个 JSON 接口：
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- 实时监控页：展示各系统调用的累计调用次数
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- 配置页：增删需要追踪的系统调用名称
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- /api/counts：返回当前计数，供前端轮询
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"""
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import json
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import threading
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from pathlib import Path
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from flask import Flask, jsonify, redirect, render_template, request, url_for
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from collector.syscall_tracer import get_tracer
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# 项目根目录与配置文件路径
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BASE_DIR = Path(__file__).resolve().parent.parent
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CONFIG_PATH = BASE_DIR / "config" / "monitors.json"
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# 配置读写锁：防止多个请求并发修改 monitors.json 时互相覆盖
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_config_lock = threading.Lock()
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def _read_config() -> dict:
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"""读取监控配置；文件不存在时返回空配置。"""
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if not CONFIG_PATH.exists():
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return {"syscalls": []}
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with CONFIG_PATH.open("r", encoding="utf-8") as f:
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return json.load(f)
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def _write_config(data: dict) -> None:
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"""原子化写入配置：先写临时文件再替换，避免写入过程中被读到半个文件。"""
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CONFIG_PATH.parent.mkdir(parents=True, exist_ok=True)
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tmp = CONFIG_PATH.with_suffix(".json.tmp")
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with tmp.open("w", encoding="utf-8") as f:
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# ensure_ascii=False 保留中文注释字段的原始字符
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json.dump(data, f, indent=2, ensure_ascii=False)
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tmp.replace(CONFIG_PATH)
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def create_app() -> Flask:
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"""Flask 应用工厂：创建并返回配置好的 Flask 实例。"""
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app = Flask(__name__, template_folder="templates", static_folder="static")
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# 初始化系统调用追踪器，由其负责挂载 eBPF 探针并维护计数
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tracer = get_tracer(CONFIG_PATH)
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@app.get("/")
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def index():
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# 实时监控首页：渲染当前监控项列表，前端会定时轮询 /api/counts 刷新数据
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cfg = _read_config()
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return render_template("index.html", syscalls=cfg.get("syscalls", []))
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@app.get("/api/counts")
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def api_counts():
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# 返回各系统调用的累计调用次数（dict：syscall 名 -> 次数）
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return jsonify(tracer.get_counts())
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@app.route("/config", methods=["GET", "POST"])
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def config_page():
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# 加锁保护配置文件的读-改-写流程，避免并发请求导致更新丢失
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with _config_lock:
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cfg = _read_config()
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syscalls = list(cfg.get("syscalls", []))
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if request.method == "POST":
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# 处理「添加」/「移除」表单：根据 action 字段决定操作
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action = request.form.get("action", "")
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name = (request.form.get("name") or "").strip()
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if action == "add" and name and name not in syscalls:
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syscalls.append(name)
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elif action == "remove" and name in syscalls:
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syscalls.remove(name)
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cfg["syscalls"] = syscalls
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_write_config(cfg)
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# PRG 模式：提交后重定向到配置页，避免刷新重复提交
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return redirect(url_for("config_page"))
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return render_template("config.html", syscalls=syscalls)
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return app
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