chore: cleanup the usage of rctx.getenv (bazel-contrib#3640)

Remove most of the usage of os.environ.get and use getenv instead.
The question is if we should just replace all usages blindly?

Author: aignas

python/private/auth.bzl

@@ -95,11 +95,7 @@ def get_auth(ctx, urls, ctx_attr = None):
     if ctx_attr.netrc:
         netrc = read_netrc(ctx, ctx_attr.netrc)
     elif "NETRC" in ctx.os.environ:
-        # This can be used on newer bazel versions
-        if hasattr(ctx, "getenv"):
-            netrc = read_netrc(ctx, ctx.getenv("NETRC"))
-        else:
-            netrc = read_netrc(ctx, ctx.os.environ["NETRC"])
+        netrc = read_netrc(ctx, ctx.getenv("NETRC"))
     else:
         netrc = read_user_netrc(ctx)
 

python/private/envsubst.bzl

@@ -20,9 +20,7 @@ def envsubst(template_string, varnames, getenv):
     Supports `$VARNAME`, `${VARNAME}` and `${VARNAME:-default}`
     syntaxes in the `template_string`, looking up each `VARNAME`
     listed in the `varnames` list in the environment defined by the
-    `getenv` function. Typically called with `getenv = rctx.getenv`
-    (if it is available) or `getenv = rctx.os.environ.get` (on e.g.
-    Bazel 6 or Bazel 7, which don't have `rctx.getenv` yet).
+    `getenv` function. Typically called with `getenv = rctx.getenv`.
 
     Limitations: Unlike the shell, we don't support `${VARNAME}` and
     `${VARNAME:-default}` in the default expression for a different

python/private/internal_config_repo.bzl

@@ -147,4 +147,4 @@ internal_config_repo = repository_rule(
 )
 
 def _bool_from_environ(rctx, key, default):
-    return bool(int(repo_utils.getenv(rctx, key, default)))
+    return bool(int(rctx.getenv(key, default)))

python/private/local_runtime_repo.bzl

@@ -359,7 +359,7 @@ def _resolve_interpreter_path(rctx):
         if "/" not in interpreter_path and "\\" not in interpreter_path:
             # Provide a bit nicer integration with pyenv: recalculate the runtime if the
             # user changes the python version using e.g. `pyenv shell`
-            repo_utils.getenv(rctx, "PYENV_VERSION")
+            rctx.getenv("PYENV_VERSION")
             result = repo_utils.which_unchecked(rctx, interpreter_path)
             resolved_path = result.binary
             describe_failure = result.describe_failure

python/private/pypi/attrs.bzl

@@ -240,7 +240,7 @@ def use_isolated(ctx, attr):
     use_isolated = attr.isolated
 
     # The environment variable will take precedence over the attribute
-    isolated_env = ctx.os.environ.get("RULES_PYTHON_PIP_ISOLATED", None)
+    isolated_env = ctx.getenv("RULES_PYTHON_PIP_ISOLATED", None)
     if isolated_env != None:
         if isolated_env.lower() in ("0", "false"):
             use_isolated = False

python/private/pypi/pip_repository.bzl

@@ -65,7 +65,7 @@ def use_isolated(ctx, attr):
     use_isolated = attr.isolated
 
     # The environment variable will take precedence over the attribute
-    isolated_env = ctx.os.environ.get("RULES_PYTHON_PIP_ISOLATED", None)
+    isolated_env = ctx.getenv("RULES_PYTHON_PIP_ISOLATED", None)
     if isolated_env != None:
         if isolated_env.lower() in ("0", "false"):
             use_isolated = False

python/private/pypi/simpleapi_download.bzl

@@ -189,11 +189,7 @@ def _read_simpleapi(ctx, url, attr, cache, get_auth = None, **download_kwargs):
     # them to ctx.download if we want to correctly handle the relative URLs.
     # TODO: Add a test that env subbed index urls do not leak into the lock file.
 
-    real_url = strip_empty_path_segments(envsubst(
-        url,
-        attr.envsubst,
-        ctx.getenv if hasattr(ctx, "getenv") else ctx.os.environ.get,
-    ))
+    real_url = strip_empty_path_segments(envsubst(url, attr.envsubst, ctx.getenv))
 
     cache_key = real_url
     cached_result = cache.get(cache_key)

python/private/pypi/whl_library.bzl

@@ -151,21 +151,13 @@ def _parse_optional_attrs(rctx, args, extra_pip_args = None):
     if use_isolated(rctx, rctx.attr):
         args.append("--isolated")
 
-    # Bazel version 7.1.0 and later (and rolling releases from version 8.0.0-pre.20240128.3)
-    # support rctx.getenv(name, default): When building incrementally, any change to the value of
-    # the variable named by name will cause this repository to be re-fetched.
-    if "getenv" in dir(rctx):
-        getenv = rctx.getenv
-    else:
-        getenv = rctx.os.environ.get
-
     # Check for None so we use empty default types from our attrs.
     # Some args want to be list, and some want to be dict.
     if extra_pip_args != None:
         args += [
             "--extra_pip_args",
             json.encode(struct(arg = [
-                envsubst(pip_arg, rctx.attr.envsubst, getenv)
+                envsubst(pip_arg, rctx.attr.envsubst, rctx.getenv)
                 for pip_arg in extra_pip_args
             ])),
         ]

python/private/python.bzl

@@ -56,7 +56,7 @@ def parse_modules(*, module_ctx, logger, _fail = fail):
               platform suffix.
             * register_coverage_tool: bool
     """
-    if module_ctx.os.environ.get("RULES_PYTHON_BZLMOD_DEBUG", "0") == "1":
+    if module_ctx.getenv("RULES_PYTHON_BZLMOD_DEBUG", "0") == "1":
         debug_info = {
             "toolchains_registered": [],
         }

python/private/repo_utils.bzl

@@ -29,7 +29,7 @@ def _is_repo_debug_enabled(mrctx):
     Returns:
         True if enabled, False if not.
     """
-    return _getenv(mrctx, REPO_DEBUG_ENV_VAR) == "1"
+    return mrctx.getenv(REPO_DEBUG_ENV_VAR) == "1"
 
 def _logger(mrctx = None, name = None, verbosity_level = None, printer = None):
     """Creates a logger instance for printing messages.
@@ -56,7 +56,7 @@ def _logger(mrctx = None, name = None, verbosity_level = None, printer = None):
         else:
             verbosity_level = "WARN"
 
-        env_var_verbosity = _getenv(mrctx, REPO_VERBOSITY_ENV_VAR)
+        env_var_verbosity = mrctx.getenv(REPO_VERBOSITY_ENV_VAR)
         verbosity_level = env_var_verbosity or verbosity_level
 
     verbosity = {
@@ -302,7 +302,7 @@ def _which_unchecked(mrctx, binary_name):
         mrctx.watch(binary)
         describe_failure = None
     else:
-        path = _getenv(mrctx, "PATH", "")
+        path = mrctx.getenv("PATH", "")
         describe_failure = lambda: _which_describe_failure(binary_name, path)
 
     return struct(
@@ -319,10 +319,6 @@ def _which_describe_failure(binary_name, path):
         path = path,
     )
 
-def _getenv(mrctx, name, default = None):
-    # Bazel 7+ API has (repository|module)_ctx.getenv
-    return getattr(mrctx, "getenv", mrctx.os.environ.get)(name, default)
-
 def _args_to_str(arguments):
     return " ".join([_arg_repr(a) for a in arguments])
 
@@ -467,7 +463,6 @@ repo_utils = struct(
     extract = _extract,
     get_platforms_cpu_name = _get_platforms_cpu_name,
     get_platforms_os_name = _get_platforms_os_name,
-    getenv = _getenv,
     is_repo_debug_enabled = _is_repo_debug_enabled,
     logger = _logger,
     which_checked = _which_checked,