From 337947f50c044500b1cfca230911e304cc7cef85 Mon Sep 17 00:00:00 2001
From: Jan Dittberner <jan@dittberner.info>
Date: Sat, 7 Nov 2015 22:17:43 +0100
Subject: [PATCH] Update documentation

This commit adds documentation how to setup PowerDNS to use the
gnuviechadmin DNS schema. The queries are provided in a PowerDNS
configuration file.

Addresses #17
---
 docs/conf.py                     |   2 +-
 docs/install.rst                 |  14 +++
 docs/pdns.local.gva_queries.conf | 198 +++++++++++++++++++++++++++++++
 gnuviechadmin/domains/models.py  | 171 ++++++++++++++------------
 4 files changed, 307 insertions(+), 78 deletions(-)
 create mode 100644 docs/pdns.local.gva_queries.conf

diff --git a/docs/conf.py b/docs/conf.py
index a1cec22..5fdf12e 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -104,7 +104,7 @@ pygments_style = 'sphinx'
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
-html_theme = 'default'
+html_theme = 'alabaster'
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
diff --git a/docs/install.rst b/docs/install.rst
index 9e08482..2ac2b6e 100644
--- a/docs/install.rst
+++ b/docs/install.rst
@@ -43,3 +43,17 @@ In development::
 For production::
 
     $ pip install -r requirements.txt
+
+PowerDNS setup
+==============
+
+The models in :py:mod:`domains.models` are meant to be used together with a
+PowerDNS setup with the generic PostgreSQL backend
+(https://doc.powerdns.com/md/authoritative/backend-generic-mypgsql/). The
+database schema differs a bit from the original schema to fit the Django model
+conventions. To make PowerDNS work you have to redefine the SQL statements by
+copying the following content to
+:file:`/etc/powerdns/pdns.d/pdns.local.gva_queries.conf`.
+
+.. literalinclude:: pdns.local.gva_queries.conf
+   :language: properties
diff --git a/docs/pdns.local.gva_queries.conf b/docs/pdns.local.gva_queries.conf
new file mode 100644
index 0000000..392b43b
--- /dev/null
+++ b/docs/pdns.local.gva_queries.conf
@@ -0,0 +1,198 @@
+# Regular queries
+gpgsql-basic-query=SELECT content, ttl, prio, type, domain_id, disabled::int, name, auth::int \
+    FROM domains_dnsrecord \
+    WHERE disabled=false AND type='%s' AND name=E'%s'
+gpgsql-id-query=SELECT content, ttl, prio, type, domain_id, disabled::int, name, auth::int \
+    FROM domains_dnsrecord \
+    WHERE disabled=false AND type='%s' AND name=E'%s' AND domain_id=%d
+gpgsql-any-query=SELECT content, ttl, prio, type, domain_id, disabled::int, name, auth::int \
+    FROM domains_dnsrecord \
+    WHERE disabled=false AND name=E'%s'
+gpgsql-any-id-query=SELECT content, ttl, prio, type, domain_id, disabled::int, name, auth::int \
+    FROM domains_dnsrecord \
+    WHERE disabled=false AND name=E'%s' AND domain_id=%d
+gpgsql-list-query=SELECT content, ttl, prio, type, domain_id, disabled::int, name, auth::int \
+    FROM domains_dnsrecord \
+    WHERE (disabled=false OR %d::bool) AND domain_id='%d' \
+    ORDER BY name, type
+
+# Master/slave queries
+gpgsql-master-zone-query=SELECT master \
+    FROM domains_dnsdomain \
+    WHERE domain=E'%s' AND type='SLAVE'
+gpgsql-info-zone-query=SELECT id, domain, master, last_check, notified_serial, type \
+    FROM domains_dnsdomain \
+    WHERE domain=E'%s'
+gpgsql-info-all-slaves-query=SELECT id, domain, master, last_check, type \
+    FROM domains_dnsdomain \
+    WHERE type='SLAVE'
+gpgsql-supermaster-query=SELECT customer \
+    FROM domains_dnssupermaster \
+    WHERE ip='%s' AND nameserver=E'%s'
+gpgsql-insert-slave-query=INSERT INTO domains_dnsdomain \
+    (type, domain, master, account) \
+    VALUES ('SLAVE', E'%s', E'%s', E'%s')
+gpgsql-insert-record-query=INSERT INTO domains_dnsrecord \
+    (content, ttl, prio, type, domain_id, disabled, name, auth) \
+    VALUES (E'%s', %d, %d, '%s', %d, %d::bool, E'%s', '%d')
+gpgsql-update-serial-query=UPDATE domains_dnsdomain \
+    SET notified_serial=%d \
+    WHERE id=%d
+gpgsql-update-lastcheck-query=UPDATE domains_dnsdomain \
+    SET last_check=%d \
+    WHERE id=%d
+gpgsql-info-all-master-query=SELECT id, domain, master, last_check, notified_serial, type \
+    FROM domains_dnsdomain \
+    WHERE type='MASTER'
+gpgsql-delete-zone-query=DELETE FROM domains_dnsrecord \
+    WHERE domain_id=%d
+
+# Comment queries
+gpgsql-list-comments-query=SELECT domain_id, name, type, modified_at, customer, comment \
+    FROM domains_dnscomment \
+    WHERE domain_id=%d
+gpgsql-insert-comment-query=INSERT INTO domains_dnscomment \
+    (domain_id, name, type, modified_at, customer, comment) \
+    VALUES (%d, E'%s', E'%s', %d, E'%s', E'%s')
+gpgsql-delete-comment-rrset-query=DELETE FROM domains_dnscomment \
+    WHERE domain_id=%d AND name=E'%s' AND type=E'%s'
+gpgsql-delete-comments-query=DELETE FROM domains_dnscomment \
+    WHERE domain_id=%d
+
+# Crypto key queries
+gpgsql-activate-domain-key-query=UPDATE domains_dnscryptokey \
+    SET active=true \
+    WHERE domain_id=( \
+        SELECT id \
+        FROM domains_dnsdomain \
+        WHERE domain=E'%s' \
+    ) AND domains_dnscryptokey.id=%d
+gpgsql-add-domain-key-query=INSERT INTO domains_dnscryptokey \
+    (domain_id, flags, active, content) \
+    SELECT id, %d, (%d = 1), '%s' FROM domains_dnsdomain \
+    WHERE domain=E'%s'
+gpgsql-clear-domain-all-keys-query=DELETE FROM domains_dnscryptokey \
+    WHERE domain_id=( \
+        SELECT id FROM domains_dnsdomain \
+        WHERE domain=E'%s' \
+    )
+gpgsql-deactivate-domain-key-query=UPDATE domains_dnscryptokey \
+    SET active=false \
+    WHERE domain_id=( \
+        SELECT id FROM domains_dnsdomain \
+        WHERE domain=E'%s' \
+    ) AND domains_dnscryptokey.id=%d
+gpgsql-list-domain-keys-query=SELECT domains_dnscryptokey.id, flags, CASE WHEN active THEN 1 ELSE 0 END AS active, content \
+    FROM domains_dnsdomain, domains_cryptokey \
+    WHERE domains_dnscryptokey.domain_id=domains_dnsdomain.id AND domain=E'%s'
+gpgsql-remove-domain-key-query=DELETE FROM domains_dnscryptokey \
+    WHERE domain_id=( \
+        SELECT id FROM domains_dnsdomain \
+        WHERE domain=E'%s' \
+    ) AND domains_dnscryptokey.id=%d
+
+# TSIG key queries
+gpgsql-delete-tsig-key-query=DELETE FROM domains_dnstsigkey \
+    WHERE name='%s'
+gpgsql-get-tsig-key-query=SELECT algorithm, secret \
+    FROM domains_dnstsigkey \
+    WHERE name=E'%s'
+gpgsql-get-tsig-keys-query=SELECT name, algorithm, secret \
+    FROM domains_dnstsigkey
+gpgsql-set-tsig-key-query=INSERT INTO domains_dnstsigkey \
+    (name, algorithm, secret) \
+    VALUES ('%s', '%s', '%s')
+
+# Metadata queries
+gpgsql-clear-domain-all-metadata-query=DELETE FROM domains_dnsdomainmetadata \
+    WHERE domain_id=( \
+        SELECT id FROM domains_dnsdomain \
+        WHERE domain=E'%s' \
+    )
+gpgsql-clear-domain-metadata-query=DELETE FROM domains_dnsdomainmetadata \
+    WHERE domain_id=( \
+        SELECT id FROM domains_dnsdomain \
+        WHERE domain=E'%s' \
+    ) AND domains_dnsdomainmetadata.kind=E'%s'
+gpgsql-get-all-domain-metadata-query=SELECT kind, content \
+    FROM domains_dnsdomain, domains_dnsdomainmetadata \
+    WHERE domains_dnsdomainmetadata.domain_id=domains_dnsdomain.id AND domain=E'%s'
+gpgsql-get-domain-metadata-query=SELECT content \
+    FROM domains_dnsdomain, domains_dnsdomainmetadata \
+    WHERE domains_dnsdomainmetadata.domain_id=domains_dnsdomain.id AND domain=E'%s' AND domains_dnsdomainmetadata.kind=E'%s'
+gpgsql-set-domain-metadata-query=INSERT INTO domains_dnsdomainmetadata \
+    (domain_id, kind, content) \
+    SELECT id, '%s', '%s' FROM domains_dnsdomain \
+    WHERE domain=E'%s'
+
+# Record queries
+gpgsql-delete-empty-non-terminal-query=DELETE FROM domains_dnsrecord \
+    WHERE domain_id='%d' AND name='%s' AND type IS NULL
+gpgsql-delete-names-query=DELETE FROM domains_dnsrecord \
+    WHERE domain_id=%d AND name=E'%s'
+gpgsql-delete-rrset-query=DELETE FROM domains_dnsrecord \
+    WHERE domain_id=%d AND name=E'%s' AND type=E'%s'
+gpgsql-get-order-after-query=SELECT ordername FROM domains_dnsrecord \
+    WHERE disabled=false AND ordername ~>~ E'%s' AND domain_id=%d AND ordername IS NOT NULL \
+    ORDER BY 1 USING ~<~ LIMIT 1
+gpgsql-get-order-before-query=SELECT ordername, name FROM domains_dnsrecord \
+    WHERE disabled=false AND ordername ~<=~ E'%s' AND domain_id=%d AND ordername IS NOT NULL \
+    ORDER BY 1 USING ~>~ LIMIT 1
+gpgsql-get-order-first-query=SELECT ordername, name FROM domains_dnsrecord \
+    WHERE disabled=false AND domain_id=%d AND ordername IS NOT NULL \
+    ORDER BY 1 USING ~<~ LIMIT 1
+gpgsql-get-order-last-query=SELECT ordername, name FROM domains_dnsrecord \
+    WHERE disabled=false AND ordername != '' AND domain_id=%d AND ordername IS NOT NULL \
+    ORDER BY 1 USING ~>~ LIMIT 1
+gpgsql-insert-empty-non-terminal-query=INSERT INTO domains_dnsrecord \
+    (domain_id, name, type, disabled, auth) \
+    VALUES ('%d', '%s', null, false, true)
+    gpgsql-insert-ent-order-query=INSERT INTO domains_dnsrecord \
+    (type, domain_id, disabled, name, ordername, auth) \
+    VALUES (null, '%d', false, E'%s', E'%s', '%d')
+gpgsql-insert-ent-query=INSERT INTO domains_dnsrecord \
+    (type, domain_id, disabled, name, auth) \
+    VALUES (null, '%d', false, E'%s', '%d')
+gpgsql-insert-record-order-query=INSERT INTO domains_dnsrecord \
+    (content, ttl, prio, type, domain_id, disabled, name, ordername, auth) \
+    VALUES (E'%s', %d, %d, '%s', %d, %d::bool, E'%s', E'%s', '%d')
+gpgsql-list-subzone-query=SELECT content, ttl, prio, type, domain_id, disabled::int, name, auth::int \
+    FROM domains_dnsrecord \
+    WHERE disabled=false AND (name=E'%s' OR name like E'%s') AND domain_id='%d'
+gpgsql-nullify-ordername-and-auth-query=UPDATE domains_dnsrecord \
+    SET ordername=NULL, auth=false \
+    WHERE name=E'%s' AND type=E'%s' AND domain_id='%d' AND disabled=false
+gpgsql-nullify-ordername-and-update-auth-query=UPDATE domains_dnsrecord \
+    SET ordername=NULL, auth=%d::bool \
+    WHERE domain_id='%d' AND name='%s' AND disabled=false
+gpgsql-remove-empty-non-terminals-from-zone-query=DELETE FROM domains_dnsrecord \
+    WHERE domain_id='%d' AND type IS NULL
+gpgsql-set-auth-on-ds-record-query=UPDATE domains_dnsrecord \
+    SET auth=true \
+    WHERE domain_id='%d' AND name='%s' AND type='DS' AND disabled=false
+gpgsql-set-order-and-auth-query=UPDATE domains_dnsrecord \
+    SET ordername=E'%s', auth=%d::bool \
+    WHERE name=E'%s' AND domain_id='%d' AND disabled=false
+gpgsql-zone-lastchange-query=SELECT MAX(change_date) FROM domains_dnsrecord \
+    WHERE domain_id=%d
+
+# Domain queries
+gpgsql-delete-domain-query=DELETE FROM domains_dnsdomain \
+    WHERE domain=E'%s'
+gpgsql-insert-zone-query=INSERT INTO domains_dnsdomain \
+    (type, domain) \
+    VALUES ('NATIVE', E'%s')
+gpgsql-update-kind-query=UPDATE domains_dnsdomain \
+    SET type='%s' \
+    WHERE domain='%s'
+gpgsql-update-master-query=UPDATE domains_dnsdomain \
+    SET master='%s' \
+    WHERE domain='%s'
+
+# Mixed queries
+gpgsql-get-all-domains-query=SELECT domains_dnsdomain.id, domains_dnsdomain.domain, domains_dnsrecord.content, \
+    domains_dnsdomain.type, domains_dnsdomain.master, domains_dnsdomain.notified_serial, domains_dnsdomain.last_check \
+    FROM domains_dnsdomain \
+    LEFT JOIN domains_dnsrecord \
+    ON domains_dnsrecord.domain_id=domains_dnsdomain.id AND domains_dnsrecord.type='SOA' AND domains_dnsrecord.name=domains_dnsdomain.domain \
+    WHERE domains_dnsrecord.disabled=false OR %d::bool
diff --git a/gnuviechadmin/domains/models.py b/gnuviechadmin/domains/models.py
index ed6640a..405b2b5 100644
--- a/gnuviechadmin/domains/models.py
+++ b/gnuviechadmin/domains/models.py
@@ -143,18 +143,20 @@ class DNSDomain(DomainBase):
     in the PowerDNS schema specified in
     https://doc.powerdns.com/md/authoritative/backend-generic-mypgsql/.
 
-    CREATE TABLE domains (
-      id                    SERIAL PRIMARY KEY,
-      name                  VARCHAR(255) NOT NULL,
-      master                VARCHAR(128) DEFAULT NULL,
-      last_check            INT DEFAULT NULL,
-      type                  VARCHAR(6) NOT NULL,
-      notified_serial       INT DEFAULT NULL,
-      account               VARCHAR(40) DEFAULT NULL,
-      CONSTRAINT c_lowercase_name CHECK (((name)::TEXT = LOWER((name)::TEXT)))
-    );
+    .. code-block:: sql
 
-    CREATE UNIQUE INDEX name_index ON domains(name);
+       CREATE TABLE domains (
+         id                    SERIAL PRIMARY KEY,
+         name                  VARCHAR(255) NOT NULL,
+         master                VARCHAR(128) DEFAULT NULL,
+         last_check            INT DEFAULT NULL,
+         type                  VARCHAR(6) NOT NULL,
+         notified_serial       INT DEFAULT NULL,
+         account               VARCHAR(40) DEFAULT NULL,
+         CONSTRAINT c_lowercase_name CHECK (((name)::TEXT = LOWER((name)::TEXT)))
+       );
+
+       CREATE UNIQUE INDEX name_index ON domains(name);
 
     """
     # name is represented by domain
@@ -181,28 +183,30 @@ class DNSRecord(models.Model):
     table in the PowerDNS schema specified in
     https://doc.powerdns.com/md/authoritative/backend-generic-mypgsql/.
 
-    CREATE TABLE records (
-      id                    SERIAL PRIMARY KEY,
-      domain_id             INT DEFAULT NULL,
-      name                  VARCHAR(255) DEFAULT NULL,
-      type                  VARCHAR(10) DEFAULT NULL,
-      content               VARCHAR(65535) DEFAULT NULL,
-      ttl                   INT DEFAULT NULL,
-      prio                  INT DEFAULT NULL,
-      change_date           INT DEFAULT NULL,
-      disabled              BOOL DEFAULT 'f',
-      ordername             VARCHAR(255),
-      auth                  BOOL DEFAULT 't',
-      CONSTRAINT domain_exists
-      FOREIGN KEY(domain_id) REFERENCES domains(id)
-      ON DELETE CASCADE,
-      CONSTRAINT c_lowercase_name CHECK (((name)::TEXT = LOWER((name)::TEXT)))
-    );
+    .. code-block:: sql
 
-    CREATE INDEX rec_name_index ON records(name);
-    CREATE INDEX nametype_index ON records(name,type);
-    CREATE INDEX domain_id ON records(domain_id);
-    CREATE INDEX recordorder ON records (domain_id, ordername text_pattern_ops);
+       CREATE TABLE records (
+         id                    SERIAL PRIMARY KEY,
+         domain_id             INT DEFAULT NULL,
+         name                  VARCHAR(255) DEFAULT NULL,
+         type                  VARCHAR(10) DEFAULT NULL,
+         content               VARCHAR(65535) DEFAULT NULL,
+         ttl                   INT DEFAULT NULL,
+         prio                  INT DEFAULT NULL,
+         change_date           INT DEFAULT NULL,
+         disabled              BOOL DEFAULT 'f',
+         ordername             VARCHAR(255),
+         auth                  BOOL DEFAULT 't',
+         CONSTRAINT domain_exists
+         FOREIGN KEY(domain_id) REFERENCES domains(id)
+         ON DELETE CASCADE,
+         CONSTRAINT c_lowercase_name CHECK (((name)::TEXT = LOWER((name)::TEXT)))
+       );
+
+       CREATE INDEX rec_name_index ON records(name);
+       CREATE INDEX nametype_index ON records(name,type);
+       CREATE INDEX domain_id ON records(domain_id);
+       CREATE INDEX recordorder ON records (domain_id, ordername text_pattern_ops);
 
     """
     domain = models.ForeignKey('DNSDomain')
@@ -238,12 +242,14 @@ class DNSSupermaster(models.Model):
     specified in
     https://doc.powerdns.com/md/authoritative/backend-generic-mypgsql/.
 
-    CREATE TABLE supermasters (
-      ip                    INET NOT NULL,
-      nameserver            VARCHAR(255) NOT NULL,
-      account               VARCHAR(40) NOT NULL,
-      PRIMARY KEY(ip, nameserver)
-    );
+    .. code-block:: sql
+
+       CREATE TABLE supermasters (
+         ip                    INET NOT NULL,
+         nameserver            VARCHAR(255) NOT NULL,
+         account               VARCHAR(40) NOT NULL,
+         PRIMARY KEY(ip, nameserver)
+       );
 
     """
     ip = models.GenericIPAddressField()
@@ -272,23 +278,25 @@ class DNSComment(models.Model):
     comments table is used to store user comments related to individual DNS
     records.
 
-    CREATE TABLE comments (
-      id                    SERIAL PRIMARY KEY,
-      domain_id             INT NOT NULL,
-      name                  VARCHAR(255) NOT NULL,
-      type                  VARCHAR(10) NOT NULL,
-      modified_at           INT NOT NULL,
-      account               VARCHAR(40) DEFAULT NULL,
-      comment               VARCHAR(65535) NOT NULL,
-      CONSTRAINT domain_exists
-      FOREIGN KEY(domain_id) REFERENCES domains(id)
-      ON DELETE CASCADE,
-      CONSTRAINT c_lowercase_name CHECK (((name)::TEXT = LOWER((name)::TEXT)))
-    );
+    .. code-block:: sql
 
-    CREATE INDEX comments_domain_id_idx ON comments (domain_id);
-    CREATE INDEX comments_name_type_idx ON comments (name, type);
-    CREATE INDEX comments_order_idx ON comments (domain_id, modified_at);
+       CREATE TABLE comments (
+         id                    SERIAL PRIMARY KEY,
+         domain_id             INT NOT NULL,
+         name                  VARCHAR(255) NOT NULL,
+         type                  VARCHAR(10) NOT NULL,
+         modified_at           INT NOT NULL,
+         account               VARCHAR(40) DEFAULT NULL,
+         comment               VARCHAR(65535) NOT NULL,
+         CONSTRAINT domain_exists
+         FOREIGN KEY(domain_id) REFERENCES domains(id)
+         ON DELETE CASCADE,
+         CONSTRAINT c_lowercase_name CHECK (((name)::TEXT = LOWER((name)::TEXT)))
+       );
+
+       CREATE INDEX comments_domain_id_idx ON comments (domain_id);
+       CREATE INDEX comments_name_type_idx ON comments (name, type);
+       CREATE INDEX comments_order_idx ON comments (domain_id, modified_at);
 
     """
     domain = models.ForeignKey('DNSDomain')
@@ -323,14 +331,17 @@ class DNSDomainMetadata(models.Model):
     The domainmetadata table is used to store domain meta data as described in
     https://doc.powerdns.com/md/authoritative/domainmetadata/.
 
-    CREATE TABLE domainmetadata (
-      id                    SERIAL PRIMARY KEY,
-      domain_id             INT REFERENCES domains(id) ON DELETE CASCADE,
-      kind                  VARCHAR(32),
-      content               TEXT
-    );
+    .. code-block:: sql
+
+       CREATE TABLE domainmetadata (
+         id                    SERIAL PRIMARY KEY,
+         domain_id             INT REFERENCES domains(id) ON DELETE CASCADE,
+         kind                  VARCHAR(32),
+         content               TEXT
+       );
+
+       CREATE INDEX domainidmetaindex ON domainmetadata(domain_id);
 
-    CREATE INDEX domainidmetaindex ON domainmetadata(domain_id);
     """
     domain = models.ForeignKey('DNSDomain')
     kind = models.CharField(max_length=32, choices=DNS_DOMAIN_METADATA_KINDS)
@@ -352,15 +363,18 @@ class DNSCryptoKey(models.Model):
     specified in
     https://doc.powerdns.com/md/authoritative/backend-generic-mypgsql/.
 
-    CREATE TABLE cryptokeys (
-      id                    SERIAL PRIMARY KEY,
-      domain_id             INT REFERENCES domains(id) ON DELETE CASCADE,
-      flags                 INT NOT NULL,
-      active                BOOL,
-      content               TEXT
-    );
+    .. code-block:: sql
+
+       CREATE TABLE cryptokeys (
+         id                    SERIAL PRIMARY KEY,
+         domain_id             INT REFERENCES domains(id) ON DELETE CASCADE,
+         flags                 INT NOT NULL,
+         active                BOOL,
+         content               TEXT
+       );
+
+       CREATE INDEX domainidindex ON cryptokeys(domain_id);
 
-    CREATE INDEX domainidindex ON cryptokeys(domain_id);
     """
     domain = models.ForeignKey('DNSDomain')
     flags = models.IntegerField()
@@ -382,15 +396,18 @@ class DNSTSIGKey(models.Model):
     This model represents the tsigkeys table in the PowerDNS schema specified
     in https://doc.powerdns.com/md/authoritative/backend-generic-mypgsql/.
 
-    CREATE TABLE tsigkeys (
-      id                    SERIAL PRIMARY KEY,
-      name                  VARCHAR(255),
-      algorithm             VARCHAR(50),
-      secret                VARCHAR(255),
-      CONSTRAINT c_lowercase_name CHECK (((name)::TEXT = LOWER((name)::TEXT)))
-    );
+    .. code-block:: sql
+
+       CREATE TABLE tsigkeys (
+         id                    SERIAL PRIMARY KEY,
+         name                  VARCHAR(255),
+         algorithm             VARCHAR(50),
+         secret                VARCHAR(255),
+         CONSTRAINT c_lowercase_name CHECK (((name)::TEXT = LOWER((name)::TEXT)))
+       );
+
+       CREATE UNIQUE INDEX namealgoindex ON tsigkeys(name, algorithm);
 
-    CREATE UNIQUE INDEX namealgoindex ON tsigkeys(name, algorithm);
     """
     name = models.CharField(max_length=255)
     algorithm = models.CharField(max_length=50, choices=DNS_TSIG_KEY_ALGORITHMS)