websearch: MCP env 写进租户 config，不只靠 docker -e

2026-10-30 实测：Codex bash 里有 SEARXNG_URL + proxy，
MCP 链却只有 duckduckgo、DNS 瞬间失败——Codex 的 MCP
子进程不继承 Codex 进程 env；给租户 config 加
[mcp_servers.websearch.env] 后同一任务立刻返回真实
SearXNG 结果。修法：worker 在 _docker_task_context
算出网关后、容器启动前，用 ensure_websearch_mcp_env
把 proxy + 搜索 env 写进租户 config（网关此时才已知，
播种时写不死；写失败只记日志不阻塞）。
测试：新增 test_websearch_mcp_env 4 项，相关共 33 项全过。

cloud/tests/test_websearch_mcp_env.py

@@ -0,0 +1,71 @@
+"""ensure_websearch_mcp_env: MCP env lives in config.toml, because
+Codex's MCP subprocess does not inherit the Codex process env
+(2026-10-30: Codex bash had SEARXNG_URL + proxy, MCP chain was
+still ["duckduckgo"] only; adding the config env section made
+the same task return real SearXNG results)."""
+
+import os
+import sys
+import tempfile
+import unittest
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", ".."))
+from cloud.websearch import ensure_websearch_mcp_env  # noqa: E402
+
+
+BASE = ("model = \"gpt-6.1-sol\"\n\n"
+        "[mcp_servers.websearch]\n"
+        "command = \"python3\"\n"
+        "args = [\"/var/lib/codex-app-server/codex-home/"
+        "websearch_mcp.py\"]\n")
+
+
+class TestMcpEnv(unittest.TestCase):
+    def _home(self, text):
+        tmp = tempfile.mkdtemp()
+        with open(os.path.join(tmp, "config.toml"), "w") as fh:
+            fh.write(text)
+        return tmp
+
+    def _read(self, home):
+        with open(os.path.join(home, "config.toml")) as fh:
+            return fh.read()
+
+    def test_insert_env_after_websearch_section(self):
+        home = self._home(BASE)
+        self.assertTrue(ensure_websearch_mcp_env(
+            home, {"SEARXNG_URL": "http://searx.test",
+                   "http_proxy": "http://10.0.0.1:8888"}))
+        text = self._read(home)
+        self.assertIn("[mcp_servers.websearch.env]", text)
+        self.assertIn('SEARXNG_URL = "http://searx.test"', text)
+        self.assertIn('http_proxy = "http://10.0.0.1:8888"', text)
+        self.assertIn('command = "python3"', text)
+
+    def test_replace_existing_env_preserves_other_sections(self):
+        home = self._home(BASE + "[mcp_servers.websearch.env]\n"
+                          "SEARXNG_URL = \"http://old.test\"\n\n"
+                          "[other]\nfoo = 1\n")
+        self.assertTrue(ensure_websearch_mcp_env(
+            home, {"SEARXNG_URL": "http://new.test"}))
+        text = self._read(home)
+        self.assertIn('SEARXNG_URL = "http://new.test"', text)
+        self.assertNotIn("old.test", text)
+        self.assertIn("[other]\nfoo = 1", text)
+
+    def test_empty_env_writes_nothing(self):
+        home = self._home(BASE)
+        self.assertFalse(ensure_websearch_mcp_env(home, {}))
+        self.assertEqual(self._read(home), BASE)
+
+    def test_idempotent_second_write(self):
+        home = self._home(BASE)
+        env = {"SEARXNG_URL": "http://searx.test"}
+        self.assertTrue(ensure_websearch_mcp_env(home, env))
+        self.assertFalse(ensure_websearch_mcp_env(home, env))
+        self.assertEqual(self._read(home).count(
+            "[mcp_servers.websearch.env]"), 1)
+
+
+if __name__ == "__main__":
+    unittest.main()

cloud/websearch.py

@@ -647,3 +647,79 @@ def ensure_codex_home_websearch(codex_home_dir, command_args=None,
             "config_changed": config_changed,
             "script_changed": script_changed,
             "script_differs": script_differs}
+
+
+def ensure_websearch_mcp_env(codex_home_dir, env):
+    """Write [mcp_servers.websearch.env] into a tenant config.toml.
+
+    Why this exists (measured 2026-10-30, not guessed): Codex's
+    MCP server subprocess does NOT inherit the Codex process env.
+    A Docker task whose Codex bash env contained SEARXNG_URL and
+    http_proxy still ran web_search with chain ["duckduckgo"]
+    only, failing instantly with "Temporary failure in name
+    resolution" -- SEARXNG_URL never reached the MCP process, and
+    without a proxy the container has no direct DNS. Adding an
+    explicit ``env`` table to the MCP config made the same task
+    return real SearXNG results. Container env (docker -e) is
+    therefore NOT sufficient for MCP tools; the env must live in
+    config.toml, where Codex actually reads it for MCP servers.
+
+    Idempotent: an existing env subsection is replaced in place,
+    other sections are left untouched, and a missing websearch
+    section is created first (command/args only, no env values
+    invented). Values are written as TOML basic strings via
+    json.dumps (safe for URLs and proxy URLs). Returns True when
+    the file was written, False when env is empty or the file
+    could not be written (caller logs, never crashes the task).
+    """
+    if not env:
+        return False
+    home = os.path.abspath(codex_home_dir)
+    config_path = os.path.join(home, "config.toml")
+    try:
+        existing = ""
+        if os.path.exists(config_path):
+            with open(config_path, encoding="utf-8") as fh:
+                existing = fh.read()
+        if "[mcp_servers.websearch]" not in existing:
+            existing += ("\n[mcp_servers.websearch]\n"
+                         "command = \"python3\"\n"
+                         "args = [\"/var/lib/codex-app-server/"
+                         "codex-home/websearch_mcp.py\"]\n")
+        env_lines = ["[mcp_servers.websearch.env]"]
+        for key in sorted(env):
+            env_lines.append("%s = %s" % (key, json.dumps(env[key])))
+        env_block = "\n".join(env_lines) + "\n"
+        lines = existing.splitlines(keepends=True)
+        start = end = None
+        for i, line in enumerate(lines):
+            if line.strip() == "[mcp_servers.websearch.env]":
+                start = i
+            elif start is not None and line.startswith("["):
+                end = i
+                break
+        if start is not None:
+            if end is None:
+                end = len(lines)
+            lines[start:end] = [env_block]
+            new_text = "".join(lines)
+        else:
+            insert_at = None
+            in_section = False
+            for i, line in enumerate(lines):
+                if line.strip() == "[mcp_servers.websearch]":
+                    in_section = True
+                elif in_section and line.startswith("["):
+                    insert_at = i
+                    break
+            if insert_at is None:
+                insert_at = len(lines)
+            lines.insert(insert_at, env_block)
+            new_text = "".join(lines)
+        if new_text == existing:
+            return False
+        with open(config_path, "w", encoding="utf-8") as fh:
+            fh.write(new_text)
+        return True
+    except Exception:
+        return False

cloud/worker.py

@@ -166,6 +166,7 @@ from cloud.peer_messages import peer_message_prefix as _peer_prefix
 from cloud.peer_messages import row_get as _row_get
 from cloud.sub2api import ensure_user_gateway_key as _ensure_sub2api_key
 from cloud.websearch import ensure_codex_home_websearch as _ensure_websearch_mcp
+from cloud.websearch import ensure_websearch_mcp_env as _ensure_websearch_mcp_env
 from cloud.skill_seed import ensure_codex_home_skills as _ensure_skills
 from cloud.sub2api import gateway_name as _gateway_name
 from cloud.sub2api import gateway_origin as _gateway_origin
@@ -2823,6 +2824,22 @@ class Worker:
         }
         if search_env:
             proxy_env = _merge_env(proxy_env, search_env)
+        # MCP env must live in config.toml, not just docker -e:
+        # Codex's MCP subprocess does not inherit the Codex
+        # process env (2026-10-30实测：Codex bash 里有
+        # SEARXNG_URL + proxy，MCP 链却只有 duckduckgo，
+        # DNS 瞬间失败；给 config 加 [mcp_servers.websearch.env]
+        # 后同一任务立刻返回真实 SearXNG 结果）。网关在此时
+        # 才已知，所以这里、容器启动前写租户 config，绝不
+        # 在播种时写死一个网关。写失败只记日志，不阻塞任务。
+        if self.tenant_isolation and proxy_env:
+            try:
+                home = self._tenant_dirs(
+                    task.get("project_id"))["codex_home"]
+                _ensure_websearch_mcp_env(home, proxy_env)
+            except Exception as exc:
+                self.logger.warning(
+                    "websearch MCP env write failed: %s" % exc)
         return (True, tenant_mounts, tenant_network, proxy_env, None)
 
     def _run_fork(self, task, quota_check=None):