style: apply ruff and django-upgrade

mdb/__init__.py

@@ -1 +0,0 @@
-default_app_config = "mdb.apps.MdbAppConfig"

mdb/admin.py

@@ -54,9 +54,10 @@ class InterfaceInline(admin.TabularInline):
     form = InterfaceForm
 
     def get_queryset(self, request):
-        return super(InterfaceInline, self).get_queryset(request).select_related()
+        return super().get_queryset(request).select_related()
 
 
+@admin.register(Host)
 class HostAdmin(admin.ModelAdmin):
     ordering = ("hostname",)
     inlines = [InterfaceInline]
@@ -114,28 +115,26 @@ class HostAdmin(admin.ModelAdmin):
         )
         return ", ".join(addresses)
 
+    @admin.display(description="in domains")
     def in_domain(self, host):
         domains = host.interface_set.values_list("domain__domain_name", flat=True)
         return ",".join(domains)
 
-    in_domain.short_description = "in domains"
-
+    @admin.display(boolean=True)
     def ipv6_enabled(self, host):
         ipv6_ifs = host.interface_set.annotate(num_ipv6=Count("ip6address")).filter(
             num_ipv6__gt=0
         )
         return ipv6_ifs.exists()
 
-    ipv6_enabled.boolean = True
     # FIXME: custom filter to sort custom field
 
     @staticmethod
     def _get_host_warning_message(host, ifs):
         ifs_str = ", ".join([_if.name for _if in ifs])
-        return "Host {} might not be installable since interface(s) {} has no IP set.".format(
-            host, ifs_str
-        )
+        return f"Host {host} might not be installable since interface(s) {ifs_str} has no IP set."
 
+    @admin.action(description="Mark selected hosts as PXE installable")
     def set_installable(self, request, queryset):
         invalid_ifs_per_host = []
 
@@ -153,10 +152,8 @@ class HostAdmin(admin.ModelAdmin):
                 request, message="\n".join(invalid_ifs_per_host), level=messages.WARNING
             )
 
-    set_installable.short_description = "Mark selected hosts as PXE installable"
-
     def get_queryset(self, request):
-        return super(HostAdmin, self).get_queryset(request).select_related()
+        return super().get_queryset(request).select_related()
 
 
 class Ip4AddressInline(admin.TabularInline):
@@ -164,11 +161,10 @@ class Ip4AddressInline(admin.TabularInline):
     extra = 0
     readonly_fields = ["address", "assigned_to_host"]
 
+    @admin.display(description="Assigned to Host")
     def assigned_to_host(self, addr):
         return addr.interface.host
 
-    assigned_to_host.short_description = "Assigned to Host"
-
 
 class DhcpOptionInline(admin.TabularInline):
     model = DhcpOption
@@ -180,6 +176,7 @@ class DhcpCustomFieldInline(admin.TabularInline):
     extra = 0
 
 
+@admin.register(Ip4Subnet)
 class Ip4SubnetAdmin(SerialFieldAdminMixin, admin.ModelAdmin):
     list_display = [
         "name",
@@ -194,32 +191,32 @@ class Ip4SubnetAdmin(SerialFieldAdminMixin, admin.ModelAdmin):
     readonly_fields = ["domain_name"]
     inlines = [DhcpOptionInline, DhcpCustomFieldInline, Ip4AddressInline]
 
+    @admin.display(description="# addresses")
     def num_addresses(self, ip4subnet):
         subnet = ipaddress.IPv4Network(ip4subnet.network + "/" + ip4subnet.netmask)
         return subnet.num_addresses
 
+    @admin.display(description="broadcast")
     def broadcast_address(self, ip4subnet):
         subnet = ipaddress.IPv4Network(ip4subnet.network + "/" + ip4subnet.netmask)
         return subnet.broadcast_address
 
+    @admin.display(description="first address")
     def first_address(self, ip4subnet):
         subnet = ipaddress.IPv4Network(ip4subnet.network + "/" + ip4subnet.netmask)
         return next(subnet.hosts())
 
+    @admin.display(description="last address")
     def last_address(self, ip4subnet):
         subnet = ipaddress.IPv4Network(ip4subnet.network + "/" + ip4subnet.netmask)
         return list(subnet.hosts())[-1]
 
-    broadcast_address.short_description = "broadcast"
-    num_addresses.short_description = "# addresses"
-    first_address.short_description = "first address"
-    last_address.short_description = "last address"
-
     def get_queryset(self, request):
         # TODO: optimize
-        return super(Ip4SubnetAdmin, self).get_queryset(request)
+        return super().get_queryset(request)
 
 
+@admin.register(Ip6Subnet)
 class Ip6SubnetAdmin(SerialFieldAdminMixin, admin.ModelAdmin):
     list_display = [
         "name",
@@ -234,23 +231,22 @@ class Ip6SubnetAdmin(SerialFieldAdminMixin, admin.ModelAdmin):
 
     def _network(self, ip6subnet):
         return ipaddress.IPv6Network(
-            "%s::/%d" % (ip6subnet.network, ip6subnet.netmask), strict=False
+            f"{ip6subnet.network}::/{ip6subnet.netmask:d}", strict=False
         )
 
+    @admin.display(description="# addresses")
     def num_addresses(self, ip6subnet):
         return self._network(ip6subnet).num_addresses
 
+    @admin.display(description="first address")
     def first_address(self, ip6subnet):
         return self._network(ip6subnet).network_address
 
+    @admin.display(description="last address")
     def last_address(self, ip6subnet):
         # subnet[-1] is O(1); never materialize hosts() for a /64.
         return self._network(ip6subnet)[-1]
 
-    num_addresses.short_description = "# addresses"
-    first_address.short_description = "first address"
-    last_address.short_description = "last address"
-
 
 class DomainSrvRecordInline(admin.TabularInline):
     model = DomainSrvRecord
@@ -277,6 +273,7 @@ class DomainAAAARecordInline(admin.TabularInline):
     extra = 0
 
 
+@admin.register(Domain)
 class DomainAdmin(SerialFieldAdminMixin, admin.ModelAdmin):
     inlines = [
         DomainSrvRecordInline,
@@ -298,6 +295,7 @@ class DomainAdmin(SerialFieldAdminMixin, admin.ModelAdmin):
         models.IntegerField: {"widget": NumberInput(attrs={"style": "width: 10em"})},
     }
 
+    @admin.display(description="Num Records")
     def num_records(self, domain):
         host_a_records = Host.objects.filter(interface__domain=domain).count()
         size = {
@@ -306,15 +304,15 @@ class DomainAdmin(SerialFieldAdminMixin, admin.ModelAdmin):
             "TXT": domain.domaintxtrecord_set.count(),
             "A": domain.domainarecord_set.count() + host_a_records,
         }
-        return ", ".join(["{}: {}".format(k, v) for k, v in size.items()])
-
-    num_records.short_description = "Num Records"
+        return ", ".join([f"{k}: {v}" for k, v in size.items()])
 
 
+@admin.register(HostType)
 class HostTypeAdmin(admin.ModelAdmin):
     list_display = ["host_type", "description", "num_members"]
 
 
+@admin.register(OperatingSystem)
 class OperatingSystemAdmin(admin.ModelAdmin):
     list_display = [
         "name",
@@ -326,14 +324,8 @@ class OperatingSystemAdmin(admin.ModelAdmin):
     ]
 
 
-admin.site.register(Domain, DomainAdmin)
-admin.site.register(Host, HostAdmin)
-admin.site.register(Ip4Subnet, Ip4SubnetAdmin)
-admin.site.register(Ip6Subnet, Ip6SubnetAdmin)
 admin.site.register(Ip6Address)
 admin.site.register(Nameserver)
 admin.site.register(MailExchange)
-admin.site.register(OperatingSystem, OperatingSystemAdmin)
-admin.site.register(HostType, HostTypeAdmin)
 admin.site.register(DhcpConfig)
 admin.site.register(DhcpOption)

mdb/forms.py

@@ -22,7 +22,7 @@ class SerialNumberInput(NumberInput):
 
     def render(self, name, value, attrs=None, renderer=None):
         field = super().render(name, value, attrs, renderer)
-        field_id = (attrs or {}).get("id", "id_%s" % name)
+        field_id = (attrs or {}).get("id", f"id_{name}")
         extra = """
 <button type="button" class="button" style="margin-left: 0.5em;"
         onclick="mdbBumpSerial('__ID__')">Today + next serial</button>
@@ -44,9 +44,7 @@ if (typeof window.mdbBumpSerial === 'undefined') {
     };
 }
 </script>
-""".replace(
-            "__ID__", field_id
-        )
+""".replace("__ID__", field_id)
         return mark_safe(field + extra)
 
 
@@ -55,7 +53,7 @@ class Ip4ModelChoiceField(ModelChoiceField):
         if not hasattr(obj, "interface"):
             return obj.address
 
-        return "{} ({})".format(obj.address, obj.interface.host.hostname)
+        return f"{obj.address} ({obj.interface.host.hostname})"
 
 
 class InterfaceForm(forms.ModelForm):
@@ -71,7 +69,7 @@ class InterfaceForm(forms.ModelForm):
                 raise ValidationError("Macaddr already in this subnet")
 
     def __init__(self, *args, **kwargs):
-        super(InterfaceForm, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
         # Join Ip4Address with tables interface and host,
         # before printing the select labels that walk those two relations.

mdb/management/commands/dhcp_sync.py

@@ -42,7 +42,7 @@ class Command(BaseCommand):
         config = service.get_config()
 
         if not service.needs_update(config):
-            self.stdout.write("Nothing to do, serial is the same: %s\n" % config.serial)
+            self.stdout.write(f"Nothing to do, serial is the same: {config.serial}\n")
             return
 
         if output is None:
@@ -64,20 +64,19 @@ class Command(BaseCommand):
             self.stdout.write("fail\n")
             message = (
                 "Failed to restart isc-dhcp-server, please inspect...\n\n"
-                "%s@%s$ %s\n%s"
-                % (os.getlogin(), os.uname()[1], service.restart_command, output)
+                f"{os.getlogin()}@{os.uname()[1]}$ {service.restart_command}\n{output}"
             )
             discord.notify(
-                subject="⚠️ FAIL: dhcpd %s -> %s" % (old_serial, config.active_serial),
+                subject=f"⚠️ FAIL: dhcpd {old_serial} -> {config.active_serial}",
                 message=message,
                 preformatted=diff or None,
             )
             raise SystemExit(1)
 
         self.stdout.write("ok\n")
-        message = "Updated dhcpd configuration to serial %d" % config.active_serial
+        message = f"Updated dhcpd configuration to serial {config.active_serial:d}"
         discord.notify(
-            subject="✅ Success: dhcpd %s -> %s" % (old_serial, config.active_serial),
+            subject=f"✅ Success: dhcpd {old_serial} -> {config.active_serial}",
             message=message,
             preformatted=diff or None,
         )

mdb/management/commands/zone_sync.py

@@ -48,7 +48,7 @@ class Command(BaseCommand):
         if zone_name:
             zone = service.find_zone(zone_name)
             if zone is None:
-                self.stderr.write("error: zone '%s' not found\n" % zone_name)
+                self.stderr.write(f"error: zone '{zone_name}' not found\n")
                 raise SystemExit(1)
             zones = [zone]
         else:
@@ -107,7 +107,7 @@ class Command(BaseCommand):
 
         self.stdout.write("ok\n")
         for zone, info in changes.items():
-            message = "Successfully updated bind zone file for `%s`" % zone
+            message = f"Successfully updated bind zone file for `{zone}`"
             if info["errors"]:
                 message += "\n\n" + info["errors"]
             discord.notify(
@@ -120,14 +120,7 @@ class Command(BaseCommand):
         self, summary, failed_command, output, zones, errors="", diffs=""
     ):
         zone_list = "\n".join("- " + z for z in zones)
-        message = "%s, please inspect...\n\n%s@%s$ %s\n%s\n%s" % (
-            summary,
-            os.getlogin(),
-            os.uname()[1],
-            failed_command,
-            output,
-            zone_list,
-        )
+        message = f"{summary}, please inspect...\n\n{os.getlogin()}@{os.uname()[1]}$ {failed_command}\n{output}\n{zone_list}"
         if errors:
             message += "\n\n" + errors
         discord.notify(

mdb/models.py

@@ -54,33 +54,33 @@ class Domain(models.Model):
         return self.domain_name == other.domain_name
 
     def zone_file_contents(self):
-        content = "; serial:%d\n" % self.domain_serial
-        content += "; zone file for %s\n" % self.domain_name
-        content += "; %s\n" % datetime.datetime.now()
-        content += "; filename: %s\n" % self.domain_filename
-        content += "$TTL %s\n" % self.domain_ttl
-        content += "@ IN SOA %s. %s. (\n" % (
+        content = f"; serial:{self.domain_serial:d}\n"
+        content += f"; zone file for {self.domain_name}\n"
+        content += f"; {datetime.datetime.now()}\n"
+        content += f"; filename: {self.domain_filename}\n"
+        content += f"$TTL {self.domain_ttl}\n"
+        content += "@ IN SOA {}. {}. (\n".format(
             self.domain_soa,
             self.domain_admin.replace("@", "."),
         )
-        content += "\t%d\t; serial\n" % self.domain_serial
-        content += "\t%d\t; refresh\n" % self.domain_refresh
-        content += "\t%d\t; retry\n" % self.domain_retry
-        content += "\t%d\t; expire\n" % self.domain_expire
-        content += "\t%d )\t; minimum ttl\n" % self.domain_minimum_ttl
+        content += f"\t{self.domain_serial:d}\t; serial\n"
+        content += f"\t{self.domain_refresh:d}\t; refresh\n"
+        content += f"\t{self.domain_retry:d}\t; retry\n"
+        content += f"\t{self.domain_expire:d}\t; expire\n"
+        content += f"\t{self.domain_minimum_ttl:d} )\t; minimum ttl\n"
         content += ";\n"
 
         for nameserver in self.domain_nameservers.all():
-            content += "@\tIN\tNS\t%s.\n" % nameserver.hostname
+            content += f"@\tIN\tNS\t{nameserver.hostname}.\n"
 
         for mx in self.domain_mailexchanges.all():
-            content += "@\t\tMX\t%d %s.\n" % (mx.priority, mx.hostname)
+            content += f"@\t\tMX\t{mx.priority:d} {mx.hostname}.\n"
 
         if self.domain_ipaddr is not None:
-            content += "@\tIN\tA\t%s\n" % self.domain_ipaddr
+            content += f"@\tIN\tA\t{self.domain_ipaddr}\n"
 
         if self.domain_ip6addr:
-            content += "@\tIN\tAAAA\t%s\n" % self.domain_ip6addr
+            content += f"@\tIN\tAAAA\t{self.domain_ip6addr}\n"
 
         content += "; SRV records\n"
 
@@ -100,7 +100,7 @@ class Domain(models.Model):
         content += "; CNAME records \n"
 
         for cname in self.domaincnamerecord_set.all():
-            content += "%s\tIN\tCNAME\t%s\n" % (cname.name, cname.target)
+            content += f"{cname.name}\tIN\tCNAME\t{cname.target}\n"
 
         content += "; TXT records \n"
 
@@ -112,16 +112,12 @@ class Domain(models.Model):
         for interface in self.interface_set.all():
             host = interface.host
             if interface.ip4address:
-                content += "%-20s\tIN\tA\t%s\n" % (
-                    host.hostname,
-                    interface.ip4address.address,
+                content += (
+                    f"{host.hostname:<20}\tIN\tA\t{interface.ip4address.address}\n"
                 )
 
             for ipv6addr in interface.ip6address_set.all():
-                content += "%-20s\tIN\tAAAA\t%s\n" % (
-                    host.hostname,
-                    ipv6addr.full_address(),
-                )
+                content += f"{host.hostname:<20}\tIN\tAAAA\t{ipv6addr.full_address()}\n"
 
             if host.allow_email and interface.ip4address:
                 content += f'{host.hostname}\tTXT\t"v=spf1 mx ip4:{interface.ip4address.address} -all"\n'
@@ -143,15 +139,7 @@ class DomainSrvRecord(models.Model):
     created_date = models.DateTimeField(auto_now_add=True)
 
     def as_record(self):
-        return "{}.{}.{}. IN SRV {} {} {} {}.".format(
-            self.srvce,
-            self.prot,
-            self.name,
-            self.priority,
-            self.weight,
-            self.port,
-            self.target,
-        )
+        return f"{self.srvce}.{self.prot}.{self.name}. IN SRV {self.priority} {self.weight} {self.port} {self.target}."
 
     def __str__(self):
         return self.as_record()
@@ -167,7 +155,7 @@ class DomainTxtRecord(models.Model):
     created_date = models.DateTimeField(auto_now_add=True)
 
     def as_record(self):
-        return "{} TXT {}".format(self.name, self.target)
+        return f"{self.name} TXT {self.target}"
 
     def __str__(self):
         return self.as_record()
@@ -180,7 +168,7 @@ class DomainCnameRecord(models.Model):
     created_date = models.DateTimeField(auto_now_add=True)
 
     def as_record(self):
-        return "{} IN CNAME {}".format(self.name, self.target)
+        return f"{self.name} IN CNAME {self.target}"
 
     def __str__(self):
         return self.as_record()
@@ -193,7 +181,7 @@ class DomainARecord(models.Model):
     created_date = models.DateTimeField(auto_now_add=True)
 
     def as_record(self):
-        return "{} IN A {}".format(self.name, self.target)
+        return f"{self.name} IN A {self.target}"
 
     def __str__(self):
         return self.as_record()
@@ -206,7 +194,7 @@ class DomainAAAARecord(models.Model):
     created_date = models.DateTimeField(auto_now_add=True)
 
     def as_record(self):
-        return "{} IN AAAA {}".format(self.name, self.target)
+        return f"{self.name} IN AAAA {self.target}"
 
     def __str__(self):
         return self.as_record()
@@ -223,29 +211,28 @@ class DhcpConfig(models.Model):
     log_facility = models.CharField(max_length=255)
 
     def dhcpd_configuration(self):
-        content = "# Autogenerated configuration %s\n" % datetime.datetime.now()
+        content = f"# Autogenerated configuration {datetime.datetime.now()}\n"
         if self.authoritative:
             content += "authoritative;\n"
-        content += "default-lease-time %d;\n" % self.default_lease_time
-        content += "max-lease-time %d;\n" % self.max_lease_time
-        content += "log-facility %s;\n" % self.log_facility
-        content += "ddns-update-style %s;\n" % self.ddns_update_style
+        content += f"default-lease-time {self.default_lease_time:d};\n"
+        content += f"max-lease-time {self.max_lease_time:d};\n"
+        content += f"log-facility {self.log_facility};\n"
+        content += f"ddns-update-style {self.ddns_update_style};\n"
 
         # time to write the subnet definitions
         for subnet in self.ip4subnet_set.all():
-            content += "\n# %s\n" % subnet.name
-            content += "subnet %s netmask %s {\n" % (subnet.network, subnet.netmask)
+            content += f"\n# {subnet.name}\n"
+            content += f"subnet {subnet.network} netmask {subnet.netmask} {{\n"
 
             for option in subnet.dhcpoption_set.all():
-                content += "\toption %s %s;\n" % (option.key, option.value)
+                content += f"\toption {option.key} {option.value};\n"
 
             for option in subnet.dhcpcustomfield_set.all():
-                content += "\t%s;\n" % option.value
+                content += f"\t{option.value};\n"
 
             if subnet.dhcp_dynamic:
-                content += "\trange %s %s;\n" % (
-                    subnet.dhcp_dynamic_start,
-                    subnet.dhcp_dynamic_end,
+                content += (
+                    f"\trange {subnet.dhcp_dynamic_start} {subnet.dhcp_dynamic_end};\n"
                 )
 
             content += "}\n"
@@ -259,14 +246,13 @@ class DhcpConfig(models.Model):
                 ):
                     continue
                 _if = ip4address.interface
-                content += "\nhost %s {\n" % _if.host.hostname
-                content += "\thardware ethernet %s;\n" % _if.macaddr
-                content += "\tfixed-address %s.%s;\n" % (
-                    _if.host.hostname,
-                    _if.domain.domain_name,
+                content += f"\nhost {_if.host.hostname} {{\n"
+                content += f"\thardware ethernet {_if.macaddr};\n"
+                content += (
+                    f"\tfixed-address {_if.host.hostname}.{_if.domain.domain_name};\n"
                 )
                 if len(_if.pxe_filename) > 0:
-                    content += '\tfilename "%s";\n' % _if.pxe_filename
+                    content += f'\tfilename "{_if.pxe_filename}";\n'
                 content += "}\n"
 
         return content
@@ -307,30 +293,30 @@ class Ip6Subnet(models.Model):
         Delegation in ip6.arpa happens on nibble (4-bit) boundaries, so the
         prefix is truncated down to whole nibbles.
         """
-        network = ipaddress.IPv6Address("%s::" % self.network)
+        network = ipaddress.IPv6Address(f"{self.network}::")
         nibbles = self.netmask // 4
         return ".".join(network.exploded.replace(":", "")[:nibbles])[::-1] + ".ip6.arpa"
 
     def zone_file_contents(self, generate_unassigned=False):
         content = ""
-        content += "; zone file for %s\n" % self.domain_name
-        content += "; %s\n" % datetime.datetime.now()
-        content += "; filename: %s\n" % self.domain_filename
-        content += "$TTL %s\n" % self.domain_ttl
-        content += "@ IN SOA %s. %s. (\n" % (
+        content += f"; zone file for {self.domain_name}\n"
+        content += f"; {datetime.datetime.now()}\n"
+        content += f"; filename: {self.domain_filename}\n"
+        content += f"$TTL {self.domain_ttl}\n"
+        content += "@ IN SOA {}. {}. (\n".format(
             self.domain_soa,
             self.domain_admin.replace("@", "."),
         )
-        content += "\t%d\t; serial\n" % self.domain_serial
-        content += "\t%d\t; refresh\n" % self.domain_refresh
-        content += "\t%d\t; retry\n" % self.domain_retry
-        content += "\t%d\t; expire\n" % self.domain_expire
-        content += "\t%d )\t; minimum ttl\n" % self.domain_minimum_ttl
+        content += f"\t{self.domain_serial:d}\t; serial\n"
+        content += f"\t{self.domain_refresh:d}\t; refresh\n"
+        content += f"\t{self.domain_retry:d}\t; retry\n"
+        content += f"\t{self.domain_expire:d}\t; expire\n"
+        content += f"\t{self.domain_minimum_ttl:d} )\t; minimum ttl\n"
         content += ";\n"
         content += ";\n"
 
         for nameserver in self.domain_nameservers.all():
-            content += "@\tIN\tNS\t%s.\n" % nameserver.hostname
+            content += f"@\tIN\tNS\t{nameserver.hostname}.\n"
 
         content += ";\n"
 
@@ -343,14 +329,13 @@ class Ip6Subnet(models.Model):
 
             if addr.interface.domain is None:
                 continue
-            hostname = "%s.%s" % (
-                addr.interface.host.hostname,
-                addr.interface.domain.domain_name,
+            hostname = (
+                f"{addr.interface.host.hostname}.{addr.interface.domain.domain_name}"
             )
 
             ip = ipaddress.IPv6Address(self.network + addr.address)
             ip = ".".join(ip.exploded.replace(":", "")[16:])[::-1]
-            content += "%s\tPTR\t%s.\n" % (ip, hostname)
+            content += f"{ip}\tPTR\t{hostname}.\n"
 
             # addr = ipaddr.IPv6Address("%s%s" % (interface.
             # content += "%20s\tIN\tPTR\t%s.\n" % (addr.address.split(".")[3], hostname)
@@ -401,51 +386,43 @@ class Ip4Subnet(models.Model):
         This is the apex BIND expects -- it must match the zone name in
         named.conf or rndc refuses to load the file.
         """
-        net = ipaddress.IPv4Network(
-            "%s/%s" % (self.network, self.netmask), strict=False
-        )
+        net = ipaddress.IPv4Network(f"{self.network}/{self.netmask}", strict=False)
         o1, o2, o3, o4 = str(net.network_address).split(".")
-        rev = "%s.%s.%s" % (o3, o2, o1)
+        rev = f"{o3}.{o2}.{o1}"
         if net.prefixlen > 24:
-            return "%s-%d.%s.in-addr.arpa" % (o4, net.prefixlen, rev)
-        return "%s.in-addr.arpa" % rev
+            return f"{o4}-{net.prefixlen:d}.{rev}.in-addr.arpa"
+        return f"{rev}.in-addr.arpa"
 
     def zone_file_contents(self, generate_unassigned=False):
         content = ""
-        content += "; zone file for %s\n" % self.domain_name
-        content += "; %s\n" % datetime.datetime.now()
-        content += "; filename: %s\n" % self.domain_filename
-        content += "$TTL %s\n" % self.domain_ttl
-        content += "@ IN SOA %s. %s. (\n" % (
+        content += f"; zone file for {self.domain_name}\n"
+        content += f"; {datetime.datetime.now()}\n"
+        content += f"; filename: {self.domain_filename}\n"
+        content += f"$TTL {self.domain_ttl}\n"
+        content += "@ IN SOA {}. {}. (\n".format(
             self.domain_soa,
             self.domain_admin.replace("@", "."),
         )
-        content += "\t%d\t; serial\n" % self.domain_serial
-        content += "\t%d\t; refresh\n" % self.domain_refresh
-        content += "\t%d\t; retry\n" % self.domain_retry
-        content += "\t%d\t; expire\n" % self.domain_expire
-        content += "\t%d )\t; minimum ttl\n" % self.domain_minimum_ttl
+        content += f"\t{self.domain_serial:d}\t; serial\n"
+        content += f"\t{self.domain_refresh:d}\t; refresh\n"
+        content += f"\t{self.domain_retry:d}\t; retry\n"
+        content += f"\t{self.domain_expire:d}\t; expire\n"
+        content += f"\t{self.domain_minimum_ttl:d} )\t; minimum ttl\n"
         content += ";\n"
         content += ";\n"
 
         for nameserver in self.domain_nameservers.all():
-            content += "@\tIN\tNS\t%s.\n" % nameserver.hostname
+            content += f"@\tIN\tNS\t{nameserver.hostname}.\n"
 
         content += ";\n"
 
         for addr in self.ip4address_set.all():
             """ Get PTR records for each v4 address in subnet """
             if hasattr(addr, "interface") and addr.interface.domain:
-                hostname = "%s.%s" % (
-                    addr.interface.host.hostname,
-                    addr.interface.domain.domain_name,
-                )
-                content += "%-20s\tIN\tPTR\t%s.\n" % (
-                    addr.address.split(".")[3],
-                    hostname,
-                )
+                hostname = f"{addr.interface.host.hostname}.{addr.interface.domain.domain_name}"
+                content += f"{addr.address.split('.')[3]:<20}\tIN\tPTR\t{hostname}.\n"
             elif not hasattr(addr, "interface") and generate_unassigned:
-                content += "%s\tIN\tPTR\t%s.%s\n" % (
+                content += "{}\tIN\tPTR\t{}.{}\n".format(
                     addr.address,
                     addr.address.split(".")[3],
                     "dhcp.neuf.no.",
@@ -580,7 +557,7 @@ class Interface(models.Model):
     domain = models.ForeignKey(Domain, models.CASCADE)
 
     def __str__(self):
-        return "%s (%s on %s)" % (self.macaddr, self.name, self.host.hostname)
+        return f"{self.macaddr} ({self.name} on {self.host.hostname})"
 
     def ipv6_enabled(self):
         return self.ip6address_set.exists()
@@ -595,11 +572,7 @@ class Ip6Address(models.Model):
         return self.subnet.network + self.address
 
     def __str__(self):
-        return "%s (%s on %s)" % (
-            self.full_address(),
-            self.interface.name,
-            self.interface.host.hostname,
-        )
+        return f"{self.full_address()} ({self.interface.name} on {self.interface.host.hostname})"
 
     class Meta:
         verbose_name = "IPv6 address"

mdb/pxe.py

@@ -1,6 +1,7 @@
+import ipaddress
+
 from django.conf import settings
 from django.template.loader import render_to_string
-import ipaddress
 
 
 def render_pxelinux_cfg(_if, host):
@@ -35,9 +36,7 @@ def get_pxe_filename(interface, filename_format="mac_addr"):
     Mac or IP address based PXE filename
     Ref: http://www.syslinux.org/wiki/index.php/PXELINUX#Examples
     """
-    ip_addr_in_hex = "{:02X}".format(
-        int(ipaddress.IPv4Address(interface.ip4address.address))
-    )
+    ip_addr_in_hex = f"{int(ipaddress.IPv4Address(interface.ip4address.address)):02X}"
     formats = {
         "ip_addr": ip_addr_in_hex,
         "mac_addr": "01-{}".format(interface.macaddr.lower().replace(":", "-")),

mdb/services/dhcp_sync.py

@@ -33,9 +33,9 @@ class DhcpSyncService:
         Returns (old_serial, diff).
         """
         try:
-            with open(output_path, "r") as f:
+            with open(output_path) as f:
                 old = f.read()
-        except IOError:
+        except OSError:
             old = ""
 
         new = config.dhcpd_configuration()

mdb/services/zone_sync.py

@@ -12,9 +12,9 @@ from mdb.models import Domain, Ip4Subnet, Ip6Subnet
 
 class ZoneSyncService:
     rndc_bin = shutil.which("rndc") or "/usr/sbin/rndc"
-    freeze_command = "%s freeze" % rndc_bin
-    reload_command = "%s reload" % rndc_bin
-    thaw_command = "%s thaw" % rndc_bin
+    freeze_command = f"{rndc_bin} freeze"
+    reload_command = f"{rndc_bin} reload"
+    thaw_command = f"{rndc_bin} thaw"
     checkzone_bin = shutil.which("named-checkzone") or "/usr/sbin/named-checkzone"
     compilezone_bin = shutil.which("named-compilezone") or "/usr/sbin/named-compilezone"
     checkzone_dir = "/tmp/mdb-checkzone"
@@ -28,7 +28,7 @@ class ZoneSyncService:
     def validate_binaries_exist(self):
         for f in (self.checkzone_bin, self.compilezone_bin, self.rndc_bin):
             if not os.path.isfile(f) and not self.debug:
-                print("ERROR: no such file %s, exiting..." % f)
+                print(f"ERROR: no such file {f}, exiting...")
                 sys.exit(1)
 
     def run_commands(self, commands):
@@ -76,9 +76,9 @@ class ZoneSyncService:
         zonetype = getattr(zone._meta, "verbose_name", None) or zone._meta.model_name
 
         try:
-            with open(zone.domain_filename, "r") as f:
+            with open(zone.domain_filename) as f:
                 old = f.read()
-        except IOError:
+        except OSError:
             old = ""
 
         # Dynamic updates (ACME dns-01 challenges) raise the serial in the
@@ -97,13 +97,8 @@ class ZoneSyncService:
         }
 
         print(
-            "updating %s %s [%d -> %d]"
-            % (
-                zonetype,
-                zone.domain_name,
-                zone.domain_active_serial,
-                zone.domain_serial,
-            )
+            f"updating {zonetype} {zone.domain_name} "
+            f"[{zone.domain_active_serial:d} -> {zone.domain_serial:d}]"
         )
 
         # Normalize to BIND's canonical format so the on-disk file and our
@@ -161,11 +156,7 @@ class ZoneSyncService:
             tmpfile = f.name
 
         try:
-            cmd = "%s -f text -F text -s relative -i none -o - %s %s" % (
-                self.compilezone_bin,
-                zone.domain_name,
-                tmpfile,
-            )
+            cmd = f"{self.compilezone_bin} -f text -F text -s relative -i none -o - {zone.domain_name} {tmpfile}"
             status, output = getstatusoutput(cmd + " 2>/dev/null")
             if status == 0:
                 return output
@@ -189,6 +180,4 @@ class ZoneSyncService:
         with open(zonefile, "w") as f:
             f.write(contents)
 
-        return getstatusoutput(
-            "%s %s %s" % (self.checkzone_bin, zone.domain_name, zonefile)
-        )
+        return getstatusoutput(f"{self.checkzone_bin} {zone.domain_name} {zonefile}")

mdb/signals.py

@@ -1,12 +1,13 @@
+import ipaddress
 import logging
 import os
 import uuid
-from django.conf import settings
-from django.db.models.signals import pre_delete, post_save, pre_save
-from django.dispatch import receiver
-import ipaddress
 
-from mdb.models import Interface, Host, Ip6Subnet, Ip4Subnet, Ip4Address
+from django.conf import settings
+from django.db.models.signals import post_save, pre_delete, pre_save
+from django.dispatch import receiver
+
+from mdb.models import Host, Interface, Ip4Address, Ip4Subnet, Ip6Subnet
 from mdb.utils import format_domain_serial_and_add_one
 
 logger = logging.getLogger(__name__)
@@ -106,7 +107,7 @@ def create_pxe_key_and_write_pxe_files_when_host_changes(
             # Write pxeconfig file to disk
             with open(path, "w+") as f:
                 f.write(pxe_file)
-                logger.info("Created or updated {}".format(path))
+                logger.info(f"Created or updated {path}")
             os.chmod(path, 0o644)  # Not writeable for all
 
             # Also set necessary fields for pxe installation
@@ -128,7 +129,7 @@ def create_pxe_key_and_write_pxe_files_when_host_changes(
             if os.path.exists(path):
                 # Delete pxeconfig file from disk
                 os.unlink(path)
-                logger.info("deleted {}".format(path))
+                logger.info(f"deleted {path}")
 
 
 @receiver(pre_delete, sender=Interface)

mdb/templates/pxelinux.cfg

@@ -4,4 +4,4 @@ timeout 0
 
 label ninja
   kernel {{kernel}}
-  append ramdisk_size=14984 locale=en_US console-setup/ask_detect=false keyboard-configuration/layoutcode=no netcfg/wireless_wep= netcfg_choose_interface=eth0 netcfg/get_hostname= preseed/url={{preseed_config_url}} vga=normal snop={{host.pxe_key}} initrd={{initrd}} -- quiet
+  append ramdisk_size=14984 locale=en_US console-setup/ask_detect=false keyboard-configuration/layoutcode=no netcfg/wireless_wep= netcfg_choose_interface=eth0 netcfg/get_hostname= preseed/url={{preseed_config_url}} vga=normal snop={{host.pxe_key}} initrd={{initrd}} -- quiet

mdb/utils.py

@@ -5,7 +5,7 @@ import re
 def format_domain_serial_and_add_one(serial):
     today = datetime.datetime.now()
     res = re.findall(
-        r"^%4d%02d%02d(\d\d)$" % (today.year, today.month, today.day),
+        rf"^{today.year:4d}{today.month:02d}{today.day:02d}(\d\d)$",
         str(serial),
         re.DOTALL,
     )
@@ -14,7 +14,7 @@ def format_domain_serial_and_add_one(serial):
         """ This probably means that the serial is malformed
         or the date is wrong. We assume that if the date is wrong,
         it is in the past. Just create a new serial starting from 1."""
-        return "%4d%02d%02d%02d" % (today.year, today.month, today.day, 1)
+        return f"{today.year:4d}{today.month:02d}{today.day:02d}01"
     elif len(res) == 1:
         """ The serial contains todays date, just update it. """
         try:
@@ -28,7 +28,7 @@ def format_domain_serial_and_add_one(serial):
 
         else:
             number += 1
-        return "%4d%02d%02d%02d" % (today.year, today.month, today.day, number)
+        return f"{today.year:4d}{today.month:02d}{today.day:02d}{number:02d}"
     else:
         """ Just return the first serial for today. """
-        return "%4d%02d%02d%02d" % (today.year, today.month, today.day, 1)
+        return f"{today.year:4d}{today.month:02d}{today.day:02d}01"

mdb/validators.py

@@ -1,6 +1,7 @@
-from django.core.validators import RegexValidator
 import re
 
+from django.core.validators import RegexValidator
+
 # http://en.wikipedia.org/wiki/Hostname#Restrictions_on_valid_host_names
 hostname_re = re.compile(r"^(?!-)[-a-z0-9]+(?<!-)$", re.IGNORECASE)
 validate_hostname = RegexValidator(

mdbsite/urls.py

@@ -1,13 +1,14 @@
 from django.contrib import admin
 from django.contrib.staticfiles.urls import staticfiles_urlpatterns
-from django.urls import re_path, path
+from django.urls import path
 from django.views.generic.base import RedirectView
+
 from mdb.api.views import HostPXEValidate
 
 admin.autodiscover()
 
 urlpatterns = [
-    re_path(r"^$", RedirectView.as_view(url="admin/", permanent=True)),
+    path("", RedirectView.as_view(url="admin/", permanent=True)),
     path("admin/", admin.site.urls),
     path(
         "api/validate-host-secret/",

mdbsite/wsgi.py

@@ -1,6 +1,7 @@
-from django.core.wsgi import get_wsgi_application
 import os
 
+from django.core.wsgi import get_wsgi_application
+
 os.environ.setdefault("DJANGO_SETTINGS_MODULE", "mdbsite.settings")
 
 application = get_wsgi_application()

tests/conftest.py

@@ -53,11 +53,3 @@ def db_domain(db, tmp_path):
     )
     DomainTxtRecord.objects.create(domain=domain, name="@", target='"v=spf1 mx ~all"')
     return domain
-
-
-def load_command_class():
-    path = pathlib.Path(__file__).parent.parent / "mdb/management/commands/zone-sync.py"
-    spec = importlib.util.spec_from_file_location("zone_sync_command", path)
-    mod = importlib.util.module_from_spec(spec)
-    spec.loader.exec_module(mod)
-    return mod.Command

tests/test_api.py

@@ -35,11 +35,9 @@ def test_validate_puppet_host_by_secret(api_client, user_with_token, host):
     _, token = user_with_token
     data = {
         "pxe_key": host.pxe_key,
-        "certname": "{}.{}".format(
-            host.hostname, host.interface_set.first().domain.domain_name
-        ),
+        "certname": f"{host.hostname}.{host.interface_set.first().domain.domain_name}",
     }
-    api_client.credentials(HTTP_AUTHORIZATION="Token {}".format(token.key))
+    api_client.credentials(HTTP_AUTHORIZATION=f"Token {token.key}")
     res = api_client.post(reverse("api-validate-host-secret"), data, format="json")
     assert res.status_code == 200, res.content
     assert not Host.objects.get(pk=host.pk).pxe_installable

tests/test_zone_sync_command.py

@@ -3,6 +3,7 @@ from io import StringIO
 from unittest.mock import MagicMock, patch
 
 import pytest
+
 from mdb.management.commands.zone_sync import Command as CommandClass
 from mdb.services.zone_sync import ZoneSyncService