--wip-- architect and migration

corehq/motech/migrations/0009_partition.py

@@ -0,0 +1,109 @@
+from django.db import migrations
+from django.db.migrations.operations.models import ModelOperation
+
+from architect.commands import partition
+
+
+def get_sql():
+    next_month = '2021-09-01 00:00:00 Z'  # TODO: Calculate this
+    return f"""
+        CREATE TABLE motech_requestlog (
+            id integer NOT NULL,
+            domain character varying(126) NOT NULL,
+            "timestamp" timestamp with time zone NOT NULL,
+            request_method character varying(12) NOT NULL,
+            request_url character varying(255) NOT NULL,
+            request_headers text NOT NULL,
+            request_params text NOT NULL,
+            request_body text,
+            request_error text,
+            response_status integer,
+            response_body text,
+            log_level integer,
+            payload_id character varying(126),
+            response_headers text
+        );
+
+        CREATE SEQUENCE motech_requestlog_id_seq
+            START WITH 1
+            INCREMENT BY 1
+            NO MINVALUE
+            NO MAXVALUE
+            CACHE 1;
+
+        ALTER SEQUENCE motech_requestlog_id_seq
+            OWNED BY motech_requestlog.id;
+
+        ALTER TABLE dhis2_jsonapilog
+            ADD CONSTRAINT before_next_month
+            CHECK ("timestamp" < TIMESTAMP '{next_month}');
+
+        ALTER TABLE dhis2_jsonapilog
+            INHERIT motech_requestlog;
+    """
+
+
+reverse_sql = """
+    ALTER TABLE dhis2_jsonapilog
+        NO INHERIT motech_requestlog;
+
+    ALTER TABLE dhis2_jsonapilog
+        DROP CONSTRAINT before_next_month;
+
+    DROP SEQUENCE motech_requestlog_id_seq;
+
+    DROP TABLE motech_requestlog;
+
+"""
+
+
+class PointModelAtTable(ModelOperation):
+    """
+    Point a model to a different table.
+
+    The new table must already be set up as an exact replica of the
+    current table. This class is therefore a state operation, and
+    intentionally does not implement ``database_forwards()`` and
+    ``database_backwards()``.
+    """
+
+    def __init__(self, name, table):
+        self.table = table
+        super().__init__(name)
+
+    def deconstruct(self):
+        kwargs = {
+            'name': self.name,
+            'table': self.table,
+        }
+        return self.__class__.__qualname__, [], kwargs
+
+    def state_forwards(self, app_label, state):
+        state.models[app_label, self.name_lower].options["db_table"] = self.table
+        state.reload_model(app_label, self.name_lower, delay=True)
+
+    def describe(self):
+        return f"Point model {self.name} at table {self.table}"
+
+
+def add_partitions(apps, schema_editor):
+    partition.run({'module': 'corehq.motech.models'})
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('motech', '0008_requestlog_response_headers'),
+    ]
+
+    operations = [
+        migrations.RunSQL(
+            get_sql(),
+            reverse_sql=reverse_sql,
+            state_operations=[PointModelAtTable(
+                name='requestlog',
+                table='motech_requestlog',
+            )],
+        ),
+        migrations.RunPython(add_partitions),
+    ]

corehq/motech/models.py

@@ -6,6 +6,7 @@
 from django.utils.functional import cached_property
 from django.utils.translation import gettext as _
 
+import architect
 import attr
 import jsonfield
 
@@ -224,6 +225,13 @@ def used_by(self):
         return kinds
 
 
+@architect.install(
+    'partition',
+    type='range',
+    subtype='date',
+    constraint='month',
+    column='timestamp',
+)
 class RequestLog(models.Model):
     """
     Store API requests and responses to analyse errors and keep an audit trail
@@ -248,7 +256,7 @@ class RequestLog(models.Model):
     response_body = models.TextField(blank=True, null=True)
 
     class Meta:
-        db_table = 'dhis2_jsonapilog'
+        db_table = 'motech_requestlog'
 
     @staticmethod
     def log(level: int, log_entry: RequestLogEntry):