fix(apex): preserve environments and restore secure standalone operations

actions/configure/base.py

@@ -1,13 +1,85 @@
 # actions/configure/base.py
 """Port of configure/base — base packages + ufw + ufw-docker helper."""
+import hashlib
 import os
-import shutil
-import tempfile
+from pathlib import Path
+import re
+import stat
 import urllib.request
 from engine.descriptor import Meta
 
 METADATA = Meta(summary="Configure base system packages (curl, wget, git, rsyslog, ufw, ufw-docker).")
-UFW_DOCKER_URL = "https://github.com/chaifeng/ufw-docker/raw/master/ufw-docker"
+UFW_DOCKER_REVISION = "020a8699f95592561f254d8d4ad1bb40d401dfc7"
+UFW_DOCKER_SHA256 = "643e56b080567c567b4aa28650196849b2a2da5dd0473fd3e5216b0886035ab0"
+UFW_DOCKER_URL = (
+    "https://raw.githubusercontent.com/chaifeng/ufw-docker/"
+    + UFW_DOCKER_REVISION + "/ufw-docker"
+)
+UFW_DOCKER_PATH = Path("/usr/local/bin/ufw-docker")
+BASE_PACKAGES = ("curl", "wget", "git", "rsyslog", "ufw")
+
+
+def _install_missing(s, packages):
+    missing = []
+    for package in packages:
+        result = s.run(["dpkg-query", "-W", "-f=${Status}", package],
+                       check=False, capture=True)
+        if result.returncode or result.stdout.split()[1:] != ["ok", "installed"]:
+            missing.append(package)
+    if not missing:
+        return
+    apt = ["env", "LC_ALL=C", "DEBIAN_FRONTEND=noninteractive", "apt-get",
+           "-o", "DPkg::Lock::Timeout=60", "-o", "Acquire::Retries=2",
+           "-o", "Acquire::http::Timeout=30", "-o", "Acquire::https::Timeout=30"]
+    s.sudo([*apt, "update", "--error-on=any"])
+    command = [*apt, "install", "-y", "--no-install-recommends", "--no-upgrade",
+               "--no-remove", *missing]
+    plan = s.sudo([*command, "--simulate"], capture=True)
+    if any(line.startswith("Remv ") or re.match(r"^Inst \S+ \[", line)
+           for line in plan.stdout.splitlines()):
+        raise RuntimeError("Missing packages require upgrades/removals; reconcile packages first.")
+    s.sudo(command)
+
+
+def _check_helper_path(path):
+    for parent in reversed(path.parents):
+        info = parent.lstat()
+        if (not stat.S_ISDIR(info.st_mode) or info.st_uid != 0 or
+                info.st_mode & 0o022):
+            raise RuntimeError(f"Unsafe ufw-docker ancestor: {parent}")
+    try:
+        info = path.lstat()
+    except FileNotFoundError:
+        return False
+    if (not stat.S_ISREG(info.st_mode) or info.st_uid != 0 or info.st_gid != 0 or
+            info.st_mode & 0o022 or info.st_nlink != 1):
+        raise RuntimeError(f"Unsafe ufw-docker target: {path}")
+    return True
+
+
+def _install_helper(ctx):
+    path = UFW_DOCKER_PATH
+    exists = _check_helper_path(path)
+    payload = path.read_bytes() if exists else None
+    if payload is None or hashlib.sha256(payload).hexdigest() != UFW_DOCKER_SHA256:
+        ctx.log.info(f"Downloading pinned ufw-docker helper to {path}...")
+        # The immutable HTTPS URL is authenticated by the digest below.
+        with urllib.request.urlopen(UFW_DOCKER_URL, timeout=30) as response:  # noqa: S310
+            payload = response.read(1024 * 1024 + 1)
+        if len(payload) > 1024 * 1024 or hashlib.sha256(payload).hexdigest() != UFW_DOCKER_SHA256:
+            raise RuntimeError("ufw-docker checksum mismatch; refusing installation.")
+        _check_helper_path(path)
+        ctx.host.write_file(str(path), payload.decode("utf-8"), mode="0755",
+                            backup=False, sudo=True)
+    elif stat.S_IMODE(path.stat().st_mode) != 0o755:
+        ctx.host.write_file(str(path), payload.decode("utf-8"), mode="0755",
+                            backup=False, sudo=True)
+    if (not _check_helper_path(path) or
+            hashlib.sha256(path.read_bytes()).hexdigest() != UFW_DOCKER_SHA256 or
+            stat.S_IMODE(path.stat().st_mode) != 0o755):
+        raise RuntimeError("ufw-docker verification failed; refusing execution.")
+    ctx.log.info("Ensuring ufw-docker routing rules are installed in UFW...")
+    ctx.sys.sudo([str(path), "install"])
 
 
 def run(ctx, args):
@@ -16,14 +88,8 @@ def run(ctx, args):
     if not os.path.isfile("/etc/debian_version"):
         log.error("Requires a Debian-based system (Debian/Ubuntu).")
         raise SystemExit(1)
-    needed = [p for p in ["curl", "wget", "git", "rsyslog"] if not shutil.which(p)]
-    if needed:
-        log.info("Updating package lists...")
-        s.sudo(["apt-get", "update", "-y"])
-        log.info(f"Installing missing essential packages: {', '.join(needed)}...")
-        s.sudo(["apt-get", "install", "-y", "-o", "DPkg::Lock::Timeout=60", *needed])
-    else:
-        log.info("Essential packages already installed.")
+    _check_helper_path(UFW_DOCKER_PATH)
+    _install_missing(s, BASE_PACKAGES)
     s.ensure_running("rsyslog")
 
     # Configure APT to discard downloaded archives
@@ -61,29 +127,5 @@ def run(ctx, args):
         s.sudo(["tee", journal_conf], input=journal_content)
         s.sudo(["systemctl", "restart", "systemd-journald"])
 
-    if not shutil.which("ufw"):
-        log.info("Installing UFW...")
-        s.sudo(["apt-get", "install", "-y", "-o", "DPkg::Lock::Timeout=60", "ufw"])
-    else:
-        log.info("UFW already installed.")
-
-    target_bin = "/usr/local/bin/ufw-docker"
-    if not (os.path.isfile(target_bin) and os.access(target_bin, os.X_OK)):
-        log.info("Downloading ufw-docker helper to /usr/local/bin/ufw-docker...")
-        with tempfile.NamedTemporaryFile(delete=False) as tf:
-            tmp_name = tf.name
-        try:
-            urllib.request.urlretrieve(UFW_DOCKER_URL, tmp_name)
-            s.sudo(["cp", tmp_name, target_bin])
-            s.sudo(["chown", "root:root", target_bin])
-            s.sudo(["chmod", "0755", target_bin])
-            log.success(f"ufw-docker installed to {target_bin}.")
-        finally:
-            if os.path.exists(tmp_name):
-                os.unlink(tmp_name)
-    else:
-        log.info(f"ufw-docker already exists at {target_bin}.")
-
-    log.info("Ensuring ufw-docker routing rules are installed in UFW...")
-    s.sudo([target_bin, "install"])
+    _install_helper(ctx)
     log.success("Base system initialization completed.")