Use f-strings in many places in acme and certbot. (#9225)

13 files changed, 45 insertions, 61 deletions

diff --git a/acme/acme/challenges.py b/acme/acme/challenges.py
index ce0cf2ed4..9000b370a 100644
--- a/acme/acme/challenges.py
+++ b/acme/acme/challenges.py
@@ -279,7 +279,7 @@ class DNS01(KeyAuthorizationChallenge):
         :rtype: str
 
         """
-        return "{0}.{1}".format(self.LABEL, name)
+        return f"{self.LABEL}.{name}"
 
 
 @ChallengeResponse.register
diff --git a/acme/acme/client.py b/acme/acme/client.py
index aacbbc263..2e86ce549 100644
--- a/acme/acme/client.py
+++ b/acme/acme/client.py
@@ -1142,8 +1142,7 @@ class ClientNetwork:
                     'response', response_ct)
 
             if content_type == cls.JSON_CONTENT_TYPE and jobj is None:
-                raise errors.ClientError(
-                    'Unexpected response Content-Type: {0}'.format(response_ct))
+                raise errors.ClientError(f'Unexpected response Content-Type: {response_ct}')
 
         return response
 
@@ -1196,7 +1195,7 @@ class ClientNetwork:
             if m is None:
                 raise  # pragma: no cover
             host, path, _err_no, err_msg = m.groups()
-            raise ValueError("Requesting {0}{1}:{2}".format(host, path, err_msg))
+            raise ValueError(f"Requesting {host}{path}:{err_msg}")
 
         # If the Content-Type is DER or an Accept header was sent in the
         # request, the response may not be UTF-8 encoded. In this case, we
diff --git a/acme/acme/messages.py b/acme/acme/messages.py
index c9704d537..299da68d7 100644
--- a/acme/acme/messages.py
+++ b/acme/acme/messages.py
@@ -157,12 +157,11 @@ class _Constant(jose.JSONDeSerializable, Hashable):
     @classmethod
     def from_json(cls, jobj: str) -> '_Constant':
         if jobj not in cls.POSSIBLE_NAMES:  # pylint: disable=unsupported-membership-test
-            raise jose.DeserializationError(
-                '{0} not recognized'.format(cls.__name__))
+            raise jose.DeserializationError(f'{cls.__name__} not recognized')
         return cls.POSSIBLE_NAMES[jobj]
 
     def __repr__(self) -> str:
-        return '{0}({1})'.format(self.__class__.__name__, self.name)
+        return f'{self.__class__.__name__}({self.name})'
 
     def __eq__(self, other: Any) -> bool:
         return isinstance(other, type(self)) and other.name == self.name
diff --git a/acme/acme/mixins.py b/acme/acme/mixins.py
index 38551d550..e6e678d60 100644
--- a/acme/acme/mixins.py
+++ b/acme/acme/mixins.py
@@ -65,4 +65,4 @@ def _safe_jobj_compliance(instance: Any, jobj_method: str,
             jobj.pop(uncompliant_field, None)
         return jobj
 
-    raise AttributeError('Method {0}() is not implemented.'.format(jobj_method))  # pragma: no cover
+    raise AttributeError(f'Method {jobj_method}() is not implemented.')  # pragma: no cover
diff --git a/certbot/certbot/_internal/account.py b/certbot/certbot/_internal/account.py
index 8c45efe21..6097ee038 100644
--- a/certbot/certbot/_internal/account.py
+++ b/certbot/certbot/_internal/account.py
@@ -226,8 +226,7 @@ class AccountFileStorage(interfaces.AccountStorage):
                 else:
                     self._symlink_to_accounts_dir(prev_server_path, server_path)
                 return prev_loaded_account
-            raise errors.AccountNotFound(
-                "Account at %s does not exist" % account_dir_path)
+            raise errors.AccountNotFound(f"Account at {account_dir_path} does not exist")
 
         try:
             with open(self._regr_path(account_dir_path)) as regr_file:
@@ -296,8 +295,7 @@ class AccountFileStorage(interfaces.AccountStorage):
         """
         account_dir_path = self._account_dir_path(account_id)
         if not os.path.isdir(account_dir_path):
-            raise errors.AccountNotFound(
-                "Account at %s does not exist" % account_dir_path)
+            raise errors.AccountNotFound(f"Account at {account_dir_path} does not exist")
         # Step 1: Delete account specific links and the directory
         self._delete_account_dir_for_server_path(account_id, self.config.server_path)
 
diff --git a/certbot/certbot/_internal/auth_handler.py b/certbot/certbot/_internal/auth_handler.py
index e7e059656..979ef0220 100644
--- a/certbot/certbot/_internal/auth_handler.py
+++ b/certbot/certbot/_internal/auth_handler.py
@@ -383,8 +383,7 @@ def challb_to_achall(challb: messages.ChallengeBody, account_key: josepy.JWK,
             challb=challb, domain=domain, account_key=account_key)
     elif isinstance(chall, challenges.DNS):
         return achallenges.DNS(challb=challb, domain=domain)
-    raise errors.Error(
-        "Received unsupported challenge of type: {0}".format(chall.typ))
+    raise errors.Error(f"Received unsupported challenge of type: {chall.typ}")
 
 
 def gen_challenge_path(challbs: List[messages.ChallengeBody],
diff --git a/certbot/certbot/_internal/cert_manager.py b/certbot/certbot/_internal/cert_manager.py
index 7eeddfa1a..c7205c304 100644
--- a/certbot/certbot/_internal/cert_manager.py
+++ b/certbot/certbot/_internal/cert_manager.py
@@ -285,7 +285,7 @@ def match_and_check_overlaps(cli_config: configuration.NamespaceConfig,
 
     matched: List[str] = _search_lineages(cli_config, find_matches, [], acceptable_matches)
     if not matched:
-        raise errors.Error("No match found for cert-path {0}!".format(cli_config.cert_path))
+        raise errors.Error(f"No match found for cert-path {cli_config.cert_path}!")
     elif len(matched) > 1:
         raise errors.OverlappingMatchFound()
     return matched
@@ -318,26 +318,19 @@ def human_readable_cert_info(config: configuration.NamespaceConfig, cert: storag
         if diff.days == 1:
             status = "VALID: 1 day"
         elif diff.days < 1:
-            status = "VALID: {0} hour(s)".format(diff.seconds // 3600)
+            status = f"VALID: {diff.seconds // 3600} hour(s)"
         else:
-            status = "VALID: {0} days".format(diff.days)
+            status = f"VALID: {diff.days} days"
 
     valid_string = "{0} ({1})".format(cert.target_expiry, status)
     serial = format(crypto_util.get_serial_from_cert(cert.cert_path), 'x')
-    certinfo.append("  Certificate Name: {}\n"
-                    "    Serial Number: {}\n"
-                    "    Key Type: {}\n"
-                    "    Domains: {}\n"
-                    "    Expiry Date: {}\n"
-                    "    Certificate Path: {}\n"
-                    "    Private Key Path: {}".format(
-                         cert.lineagename,
-                         serial,
-                         cert.private_key_type,
-                         " ".join(cert.names()),
-                         valid_string,
-                         cert.fullchain,
-                         cert.privkey))
+    certinfo.append(f"  Certificate Name: {cert.lineagename}\n"
+                    f"    Serial Number: {serial}\n"
+                    f"    Key Type: {cert.private_key_type}\n"
+                    f'    Domains: {" ".join(cert.names())}\n'
+                    f"    Expiry Date: {valid_string}\n"
+                    f"    Certificate Path: {cert.fullchain}\n"
+                    f"    Private Key Path: {cert.privkey}")
     return "".join(certinfo)
 
 
diff --git a/certbot/certbot/_internal/client.py b/certbot/certbot/_internal/client.py
index 9688918cd..057b4f059 100644
--- a/certbot/certbot/_internal/client.py
+++ b/certbot/certbot/_internal/client.py
@@ -271,9 +271,9 @@ def perform_registration(acme: acme_client.ClientV2, config: configuration.Names
     except messages.Error as e:
         if e.code in ("invalidEmail", "invalidContact"):
             if config.noninteractive_mode:
-                msg = ("The ACME server believes %s is an invalid email address. "
+                msg = (f"The ACME server believes {config.email} is an invalid email address. "
                        "Please ensure it is a valid email and attempt "
-                       "registration again." % config.email)
+                       "registration again.")
                 raise errors.Error(msg)
             config.email = display_ops.get_email(invalid=True)
             return perform_registration(acme, config, tos_cb)
diff --git a/certbot/certbot/_internal/display/obj.py b/certbot/certbot/_internal/display/obj.py
index 39b737e80..c5c2e388b 100644
--- a/certbot/certbot/_internal/display/obj.py
+++ b/certbot/certbot/_internal/display/obj.py
@@ -356,16 +356,15 @@ class FileDisplay:
         """
         # Can take either tuples or single items in choices list
         if choices and isinstance(choices[0], tuple):
-            choices = ["%s - %s" % (c[0], c[1]) for c in choices]
+            choices = [f"{c[0]} - {c[1]}" for c in choices]
 
         # Write out the message to the user
-        self.outfile.write(
-            "{new}{msg}{new}".format(new=os.linesep, msg=message))
+        self.outfile.write(f"{os.linesep}{message}{os.linesep}")
         self.outfile.write(SIDE_FRAME + os.linesep)
 
         # Write out the menu choices
         for i, desc in enumerate(choices, 1):
-            msg = "{num}: {desc}".format(num=i, desc=desc)
+            msg = f"{i}: {desc}"
             self.outfile.write(util.wrap_lines(msg))
 
             # Keep this outside of the textwrap
diff --git a/certbot/certbot/_internal/hooks.py b/certbot/certbot/_internal/hooks.py
index 813f7f6bd..76cda466a 100644
--- a/certbot/certbot/_internal/hooks.py
+++ b/certbot/certbot/_internal/hooks.py
@@ -52,10 +52,11 @@ def validate_hook(shell_cmd: str, hook_name: str) -> None:
         if not _prog(cmd):
             path = os.environ["PATH"]
             if os.path.exists(cmd):
-                msg = "{1}-hook command {0} exists, but is not executable.".format(cmd, hook_name)
+                msg = f"{cmd}-hook command {hook_name} exists, but is not executable."
             else:
-                msg = "Unable to find {2}-hook command {0} in the PATH.\n(PATH is {1})".format(
-                    cmd, path, hook_name)
+                msg = (
+                    f"Unable to find {hook_name}-hook command {cmd} in the PATH.\n(PATH is {path})"
+                )
 
             raise errors.HookCommandNotFound(msg)
 
diff --git a/certbot/certbot/_internal/renewal.py b/certbot/certbot/_internal/renewal.py
index 91a38b11f..4fb2ca00a 100644
--- a/certbot/certbot/_internal/renewal.py
+++ b/certbot/certbot/_internal/renewal.py
@@ -247,8 +247,7 @@ def _restore_bool(name: str, value: str) -> bool:
     """
     lowercase_value = value.lower()
     if lowercase_value not in ("true", "false"):
-        raise errors.Error(
-            "Expected True or False for {0} but found {1}".format(name, value))
+        raise errors.Error(f"Expected True or False for {name} but found {value}")
     return lowercase_value == "true"
 
 
@@ -271,7 +270,7 @@ def _restore_int(name: str, value: str) -> int:
     try:
         return int(value)
     except ValueError:
-        raise errors.Error("Expected a numeric value for {0}".format(name))
+        raise errors.Error(f"Expected a numeric value for {name}")
 
 
 def _restore_str(name: str, value: str) -> Optional[str]:
@@ -323,8 +322,8 @@ def _avoid_invalidating_lineage(config: configuration.NamespaceConfig,
                 names = ", ".join(lineage.names())
                 raise errors.Error(
                     "You've asked to renew/replace a seemingly valid certificate with "
-                    "a test certificate (domains: {0}). We will not do that "
-                    "unless you use the --break-my-certs flag!".format(names))
+                    f"a test certificate (domains: {names}). We will not do that "
+                    "unless you use the --break-my-certs flag!")
 
 
 def renew_cert(config: configuration.NamespaceConfig, domains: Optional[List[str]],
@@ -375,7 +374,7 @@ def _renew_describe_results(config: configuration.NamespaceConfig, renew_success
     notify = display_util.notify
     notify_error = logger.error
 
-    notify('\n{}'.format(display_obj.SIDE_FRAME))
+    notify(f'\n{display_obj.SIDE_FRAME}')
 
     renewal_noun = "simulated renewal" if config.dry_run else "renewal"
 
@@ -383,19 +382,19 @@ def _renew_describe_results(config: configuration.NamespaceConfig, renew_success
         notify("The following certificates are not due for renewal yet:")
         notify(report(renew_skipped, "skipped"))
     if not renew_successes and not renew_failures:
-        notify("No {renewal}s were attempted.".format(renewal=renewal_noun))
+        notify(f"No {renewal_noun}s were attempted.")
         if (config.pre_hook is not None or
                 config.renew_hook is not None or config.post_hook is not None):
             notify("No hooks were run.")
     elif renew_successes and not renew_failures:
-        notify("Congratulations, all {renewal}s succeeded: ".format(renewal=renewal_noun))
+        notify(f"Congratulations, all {renewal_noun}s succeeded: ")
         notify(report(renew_successes, "success"))
     elif renew_failures and not renew_successes:
         notify_error("All %ss failed. The following certificates could "
                "not be renewed:", renewal_noun)
         notify_error(report(renew_failures, "failure"))
     elif renew_failures and renew_successes:
-        notify("The following {renewal}s succeeded:".format(renewal=renewal_noun))
+        notify(f"The following {renewal_noun}s succeeded:")
         notify(report(renew_successes, "success") + "\n")
         notify_error("The following %ss failed:", renewal_noun)
         notify_error(report(renew_failures, "failure"))
@@ -508,8 +507,8 @@ def handle_renewal_request(config: configuration.NamespaceConfig) -> None:
                             renew_skipped, parse_failures)
 
     if renew_failures or parse_failures:
-        raise errors.Error("{0} renew failure(s), {1} parse failure(s)".format(
-            len(renew_failures), len(parse_failures)))
+        raise errors.Error(
+            f"{len(renew_failures)} renew failure(s), {len(parse_failures)} parse failure(s)")
 
     # Windows installer integration tests rely on handle_renewal_request behavior here.
     # If the text below changes, these tests will need to be updated accordingly.
@@ -526,4 +525,4 @@ def _update_renewal_params_from_key(key_path: str, config: configuration.Namespa
         config.key_type = 'ecdsa'
         config.elliptic_curve = key.curve.name
     else:
-        raise errors.Error('Key at {0} is of an unsupported type: {1}.'.format(key_path, type(key)))
+        raise errors.Error(f'Key at {key_path} is of an unsupported type: {type(key)}.')
diff --git a/certbot/certbot/_internal/storage.py b/certbot/certbot/_internal/storage.py
index 9bdbe2731..567073acf 100644
--- a/certbot/certbot/_internal/storage.py
+++ b/certbot/certbot/_internal/storage.py
@@ -60,10 +60,10 @@ def renewal_conf_files(config: configuration.NamespaceConfig) -> List[str]:
 
 def renewal_file_for_certname(config: configuration.NamespaceConfig, certname: str) -> str:
     """Return /path/to/certname.conf in the renewal conf directory"""
-    path = os.path.join(config.renewal_configs_dir, "{0}.conf".format(certname))
+    path = os.path.join(config.renewal_configs_dir, f"{certname}.conf")
     if not os.path.exists(path):
-        raise errors.CertStorageError("No certificate found with name {0} (expected "
-            "{1}).".format(certname, path))
+        raise errors.CertStorageError(
+            f"No certificate found with name {certname} (expected {path}).")
     return path
 
 
@@ -1179,7 +1179,7 @@ class RenewableCert(interfaces.RenewableCert):
             if os.path.islink(old_privkey):
                 old_privkey = filesystem.readlink(old_privkey)
             else:
-                old_privkey = "privkey{0}.pem".format(prior_version)
+                old_privkey = f"privkey{prior_version}.pem"
             logger.debug("Writing symlink to old private key, %s.", old_privkey)
             os.symlink(old_privkey, target["privkey"])
         else:
diff --git a/certbot/certbot/reverter.py b/certbot/certbot/reverter.py
index 69a8ac83f..0c22b3e49 100644
--- a/certbot/certbot/reverter.py
+++ b/certbot/certbot/reverter.py
@@ -241,8 +241,7 @@ class Reverter:
             except (IOError, OSError):
                 # This file is required in all checkpoints.
                 logger.error("Unable to recover files from %s", cp_dir)
-                raise errors.ReverterError(
-                    "Unable to recover files from %s" % cp_dir)
+                raise errors.ReverterError(f"Unable to recover files from {cp_dir}")
 
         # Remove any newly added files if they exist
         self._remove_contained_files(os.path.join(cp_dir, "NEW_FILES"))
@@ -295,9 +294,7 @@ class Reverter:
         # Verify no save_file is in protected_files
         for filename in protected_files:
             if filename in save_files:
-                raise errors.ReverterError(
-                    "Attempting to overwrite challenge "
-                    "file - %s" % filename)
+                raise errors.ReverterError(f"Attempting to overwrite challenge file - {filename}")
 
     def register_file_creation(self, temporary: bool, *files: str) -> None:
         r"""Register the creation of all files during certbot execution.