fix: resolve all ruff lint errors and SQLite UNIQUE constraint issue

Ruff fixes (20 errors → 0):
- F401: Remove unused imports (DeckyConfig, random_hostname, IniConfig,
  COMPOSE_FILE, sys, patch) across cli.py, mutator/engine.py,
  templates/ftp, templates/rdp, test_mysql.py, test_postgres.py
- F541: Remove extraneous f-prefixes on strings with no placeholders
  in templates/imap, test_ftp_live, test_http_live
- E741: Rename ambiguous variable 'l' to descriptive names (line, entry,
  part) across conftest.py, test_ftp_live, test_http_live,
  test_mongodb_live, test_pop3, test_ssh

SQLite fix:
- Change _initialize_sync() admin seeding from SELECT-then-INSERT to
  INSERT OR IGNORE, preventing IntegrityError when admin user already
  exists from a previous run

decnet/cli.py

@@ -24,13 +24,11 @@ from decnet.env import (
 )
 from decnet.archetypes import Archetype, all_archetypes, get_archetype
 from decnet.config import (
-    DeckyConfig,
     DecnetConfig,
-    random_hostname,
 )
 from decnet.distros import all_distros, get_distro
 from decnet.fleet import all_service_names, build_deckies, build_deckies_from_ini
-from decnet.ini_loader import IniConfig, load_ini
+from decnet.ini_loader import load_ini
 from decnet.network import detect_interface, detect_subnet, allocate_ips, get_host_ip
 from decnet.services.registry import all_services
 

decnet/mutator/engine.py

@@ -13,7 +13,7 @@ from decnet.archetypes import get_archetype
 from decnet.fleet import all_service_names
 from decnet.composer import write_compose
 from decnet.config import DeckyConfig, load_state, save_state
-from decnet.engine import COMPOSE_FILE, _compose_with_retry
+from decnet.engine import _compose_with_retry
 
 import subprocess  # nosec B404
 

decnet/web/db/sqlite/repository.py

@@ -33,14 +33,9 @@ class SQLiteRepository(BaseRepository):
         from decnet.web.db.sqlite.database import get_sync_engine
         engine = get_sync_engine(self.db_path)
         with engine.connect() as conn:
-            result = conn.execute(
-                text("SELECT uuid FROM users WHERE username = :u"),
-                {"u": DECNET_ADMIN_USER},
-            )
-            if not result.fetchone():
             conn.execute(
                 text(
-                        "INSERT INTO users (uuid, username, password_hash, role, must_change_password) "
+                    "INSERT OR IGNORE INTO users (uuid, username, password_hash, role, must_change_password) "
                     "VALUES (:uuid, :u, :p, :r, :m)"
                 ),
                 {

templates/ftp/server.py

@@ -6,7 +6,6 @@ forwards events as JSON to LOG_TARGET if set.
 """
 
 import os
-import sys
 from pathlib import Path
 
 from twisted.internet import defer, reactor

templates/imap/server.py

@@ -18,7 +18,7 @@ NODE_NAME   = os.environ.get("NODE_NAME", "mailserver")
 SERVICE_NAME = "imap"
 LOG_TARGET  = os.environ.get("LOG_TARGET", "")
 PORT        = int(os.environ.get("PORT", "143"))
-IMAP_BANNER = os.environ.get("IMAP_BANNER", f"* OK Dovecot ready.\r\n")
+IMAP_BANNER = os.environ.get("IMAP_BANNER", "* OK Dovecot ready.\r\n")
 _RAW_USERS  = os.environ.get("IMAP_USERS", "admin:admin123,root:toor,mail:mail,user:user")
 
 VALID_USERS: dict[str, str] = {

templates/rdp/server.py

@@ -7,7 +7,6 @@ LOG_TARGET if set.
 """
 
 import os
-import sys
 
 from twisted.internet import protocol, reactor
 from twisted.python import log as twisted_log

tests/live/conftest.py

@@ -83,7 +83,7 @@ def assert_rfc5424(
     criteria = {"service": service, "event_type": event_type, **fields}
     raise AssertionError(
         f"No RFC 5424 line matching {criteria!r} found among {len(lines)} lines:\n"
-        + "\n".join(f"  {l!r}" for l in lines[:20])
+        + "\n".join(f"  {line!r}" for line in lines[:20])
     )
 
 

tests/live/test_ftp_live.py

@@ -35,5 +35,5 @@ class TestFTPLive:
         ftp.close()
         lines = drain()
         # At least one RFC 5424 line from the ftp service
-        rfc_lines = [l for l in lines if "<" in l and ">1 " in l and "ftp" in l]
-        assert rfc_lines, f"No ftp RFC 5424 lines found. stdout:\n" + "\n".join(lines[:15])
+        rfc_lines = [line for line in lines if "<" in line and ">1 " in line and "ftp" in line]
+        assert rfc_lines, "No ftp RFC 5424 lines found. stdout:\n" + "\n".join(lines[:15])

tests/live/test_http_live.py

@@ -28,8 +28,8 @@ class TestHTTPLive:
         )
         lines = drain()
         # body field present in log line
-        assert any("body=" in l for l in lines if "request" in l), (
-            f"Expected 'body=' in request log line. Got:\n" + "\n".join(lines[:10])
+        assert any("body=" in line for line in lines if "request" in line), (
+            "Expected 'body=' in request log line. Got:\n" + "\n".join(lines[:10])
         )
 
     def test_method_and_path_in_log(self, live_service):

tests/live/test_mongodb_live.py

@@ -65,6 +65,6 @@ class TestMongoDBLive:
             client.close()
         lines = drain()
         # At least one message was exchanged
-        assert any("mongodb" in l for l in lines), (
+        assert any("mongodb" in line for line in lines), (
             "Expected at least one mongodb log line"
         )

tests/service_testing/test_mysql.py

@@ -8,7 +8,7 @@ length fields that could cause huge buffer allocations.
 import importlib.util
 import struct
 import sys
-from unittest.mock import MagicMock, patch
+from unittest.mock import MagicMock
 
 import pytest
 from hypothesis import given, settings

tests/service_testing/test_pop3.py

@@ -176,7 +176,7 @@ def test_pop3_list_returns_10_entries(pop3_mod):
     resp = _replies(written).decode()
     assert resp.startswith("+OK 10")
     # Count individual message lines: "N size\r\n"
-    entries = [l for l in resp.split("\r\n") if l and l[0].isdigit()]
+    entries = [entry for entry in resp.split("\r\n") if entry and entry[0].isdigit()]
     assert len(entries) == 10
 
 
@@ -225,7 +225,7 @@ def test_pop3_top_3_body_lines_count(pop3_mod):
     parts = resp.split("\r\n\r\n", 1)
     assert len(parts) == 2
     body_section = parts[1].rstrip("\r\n.")
-    body_lines = [l for l in body_section.split("\r\n") if l != "."]
+    body_lines = [part for part in body_section.split("\r\n") if part != "."]
     assert len(body_lines) <= 3
 
 
@@ -235,7 +235,7 @@ def test_pop3_uidl_returns_10_entries(pop3_mod):
     _send(proto, "UIDL")
     resp = _replies(written).decode()
     assert resp.startswith("+OK")
-    entries = [l for l in resp.split("\r\n") if l and l[0].isdigit()]
+    entries = [entry for entry in resp.split("\r\n") if entry and entry[0].isdigit()]
     assert len(entries) == 10
 
 

tests/service_testing/test_postgres.py

@@ -8,7 +8,7 @@ tests for zero/tiny/huge msg_len in both the startup and auth states.
 import importlib.util
 import struct
 import sys
-from unittest.mock import MagicMock, patch
+from unittest.mock import MagicMock
 
 import pytest
 from hypothesis import given, settings

tests/test_ssh.py

@@ -112,8 +112,8 @@ def test_dockerfile_has_rsyslog():
 
 
 def test_dockerfile_runs_as_root():
-    lines = [l.strip() for l in _dockerfile_text().splitlines()]
-    user_lines = [l for l in lines if l.startswith("USER ")]
+    lines = [line.strip() for line in _dockerfile_text().splitlines()]
+    user_lines = [line for line in lines if line.startswith("USER ")]
     assert user_lines == [], f"Unexpected USER directive(s): {user_lines}"