2 files changed, 36 insertions, 28 deletions

diff --git a/docker/configure_workers_and_start.py b/docker/configure_workers_and_start.py
index 23cac18e8d..3bda6c300b 100755
--- a/docker/configure_workers_and_start.py
+++ b/docker/configure_workers_and_start.py
@@ -29,7 +29,7 @@
 import os
 import subprocess
 import sys
-from typing import Any, Dict, Mapping, Set
+from typing import Any, Dict, List, Mapping, MutableMapping, NoReturn, Set
 
 import jinja2
 import yaml
@@ -201,7 +201,7 @@ upstream {upstream_worker_type} {{
 
 
 # Utility functions
-def log(txt: str):
+def log(txt: str) -> None:
     """Log something to the stdout.
 
     Args:
@@ -210,7 +210,7 @@ def log(txt: str):
     print(txt)
 
 
-def error(txt: str):
+def error(txt: str) -> NoReturn:
     """Log something and exit with an error code.
 
     Args:
@@ -220,7 +220,7 @@ def error(txt: str):
     sys.exit(2)
 
 
-def convert(src: str, dst: str, **template_vars):
+def convert(src: str, dst: str, **template_vars: object) -> None:
     """Generate a file from a template
 
     Args:
@@ -290,7 +290,7 @@ def add_sharding_to_shared_config(
         shared_config.setdefault("media_instance_running_background_jobs", worker_name)
 
 
-def generate_base_homeserver_config():
+def generate_base_homeserver_config() -> None:
     """Starts Synapse and generates a basic homeserver config, which will later be
     modified for worker support.
 
@@ -302,12 +302,14 @@ def generate_base_homeserver_config():
     subprocess.check_output(["/usr/local/bin/python", "/start.py", "migrate_config"])
 
 
-def generate_worker_files(environ, config_path: str, data_dir: str):
+def generate_worker_files(
+    environ: Mapping[str, str], config_path: str, data_dir: str
+) -> None:
     """Read the desired list of workers from environment variables and generate
     shared homeserver, nginx and supervisord configs.
 
     Args:
-        environ: _Environ[str]
+        environ: os.environ instance.
         config_path: The location of the generated Synapse main worker config file.
         data_dir: The location of the synapse data directory. Where log and
             user-facing config files live.
@@ -369,13 +371,13 @@ def generate_worker_files(environ, config_path: str, data_dir: str):
     nginx_locations = {}
 
     # Read the desired worker configuration from the environment
-    worker_types = environ.get("SYNAPSE_WORKER_TYPES")
-    if worker_types is None:
+    worker_types_env = environ.get("SYNAPSE_WORKER_TYPES")
+    if worker_types_env is None:
         # No workers, just the main process
         worker_types = []
     else:
         # Split type names by comma
-        worker_types = worker_types.split(",")
+        worker_types = worker_types_env.split(",")
 
     # Create the worker configuration directory if it doesn't already exist
     os.makedirs("/conf/workers", exist_ok=True)
@@ -547,7 +549,7 @@ def generate_worker_log_config(
     return log_config_filepath
 
 
-def main(args, environ):
+def main(args: List[str], environ: MutableMapping[str, str]) -> None:
     config_dir = environ.get("SYNAPSE_CONFIG_DIR", "/data")
     config_path = environ.get("SYNAPSE_CONFIG_PATH", config_dir + "/homeserver.yaml")
     data_dir = environ.get("SYNAPSE_DATA_DIR", "/data")
diff --git a/docker/start.py b/docker/start.py
index ac62bbc8ba..4ac8f03477 100755
--- a/docker/start.py
+++ b/docker/start.py
@@ -6,27 +6,28 @@ import os
 import platform
 import subprocess
 import sys
+from typing import Any, Dict, List, Mapping, MutableMapping, NoReturn, Optional
 
 import jinja2
 
 
 # Utility functions
-def log(txt):
+def log(txt: str) -> None:
     print(txt, file=sys.stderr)
 
 
-def error(txt):
+def error(txt: str) -> NoReturn:
     log(txt)
     sys.exit(2)
 
 
-def convert(src, dst, environ):
+def convert(src: str, dst: str, environ: Mapping[str, object]) -> None:
     """Generate a file from a template
 
     Args:
-        src (str): path to input file
-        dst (str): path to file to write
-        environ (dict): environment dictionary, for replacement mappings.
+        src: path to input file
+        dst: path to file to write
+        environ: environment dictionary, for replacement mappings.
     """
     with open(src) as infile:
         template = infile.read()
@@ -35,25 +36,30 @@ def convert(src, dst, environ):
         outfile.write(rendered)
 
 
-def generate_config_from_template(config_dir, config_path, environ, ownership):
+def generate_config_from_template(
+    config_dir: str,
+    config_path: str,
+    os_environ: Mapping[str, str],
+    ownership: Optional[str],
+) -> None:
     """Generate a homeserver.yaml from environment variables
 
     Args:
-        config_dir (str): where to put generated config files
-        config_path (str): where to put the main config file
-        environ (dict): environment dictionary
-        ownership (str|None): "<user>:<group>" string which will be used to set
+        config_dir: where to put generated config files
+        config_path: where to put the main config file
+        os_environ: environment mapping
+        ownership: "<user>:<group>" string which will be used to set
             ownership of the generated configs. If None, ownership will not change.
     """
     for v in ("SYNAPSE_SERVER_NAME", "SYNAPSE_REPORT_STATS"):
-        if v not in environ:
+        if v not in os_environ:
             error(
                 "Environment variable '%s' is mandatory when generating a config file."
                 % (v,)
             )
 
     # populate some params from data files (if they exist, else create new ones)
-    environ = environ.copy()
+    environ: Dict[str, Any] = dict(os_environ)
     secrets = {
         "registration": "SYNAPSE_REGISTRATION_SHARED_SECRET",
         "macaroon": "SYNAPSE_MACAROON_SECRET_KEY",
@@ -127,12 +133,12 @@ def generate_config_from_template(config_dir, config_path, environ, ownership):
     subprocess.check_output(args)
 
 
-def run_generate_config(environ, ownership):
+def run_generate_config(environ: Mapping[str, str], ownership: Optional[str]) -> None:
     """Run synapse with a --generate-config param to generate a template config file
 
     Args:
-        environ (dict): env var dict
-        ownership (str|None): "userid:groupid" arg for chmod. If None, ownership will not change.
+        environ: env vars from `os.enrivon`.
+        ownership: "userid:groupid" arg for chmod. If None, ownership will not change.
 
     Never returns.
     """
@@ -178,7 +184,7 @@ def run_generate_config(environ, ownership):
     os.execv(sys.executable, args)
 
 
-def main(args, environ):
+def main(args: List[str], environ: MutableMapping[str, str]) -> None:
     mode = args[1] if len(args) > 1 else "run"
 
     # if we were given an explicit user to switch to, do so