Virtual hosting schema and logic changes (#2876)

Note that virtual users cannot federate correctly yet.

userapi/storage/postgres/deltas/2022110411000000_server_names.go

@@ -0,0 +1,81 @@
+package deltas
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+
+	"github.com/lib/pq"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+var serverNamesTables = []string{
+	"userapi_accounts",
+	"userapi_account_datas",
+	"userapi_devices",
+	"userapi_notifications",
+	"userapi_openid_tokens",
+	"userapi_profiles",
+	"userapi_pushers",
+	"userapi_threepids",
+}
+
+// These tables have a PRIMARY KEY constraint which we need to drop so
+// that we can recreate a new unique index that contains the server name.
+// If the new key doesn't exist (i.e. the database was created before the
+// table rename migration) we'll try to drop the old one instead.
+var serverNamesDropPK = map[string]string{
+	"userapi_accounts":      "account_accounts",
+	"userapi_account_datas": "account_data",
+	"userapi_profiles":      "account_profiles",
+}
+
+// These indices are out of date so let's drop them. They will get recreated
+// automatically.
+var serverNamesDropIndex = []string{
+	"userapi_pusher_localpart_idx",
+	"userapi_pusher_app_id_pushkey_localpart_idx",
+}
+
+// I know what you're thinking: you're wondering "why doesn't this use $1
+// and pass variadic parameters to ExecContext?" — the answer is because
+// PostgreSQL doesn't expect the table name to be specified as a substituted
+// argument in that way so it results in a syntax error in the query.
+
+func UpServerNames(ctx context.Context, tx *sql.Tx, serverName gomatrixserverlib.ServerName) error {
+	for _, table := range serverNamesTables {
+		q := fmt.Sprintf(
+			"ALTER TABLE IF EXISTS %s ADD COLUMN IF NOT EXISTS server_name TEXT NOT NULL DEFAULT '';",
+			pq.QuoteIdentifier(table),
+		)
+		if _, err := tx.ExecContext(ctx, q); err != nil {
+			return fmt.Errorf("add server name to %q error: %w", table, err)
+		}
+	}
+	for newTable, oldTable := range serverNamesDropPK {
+		q := fmt.Sprintf(
+			"ALTER TABLE IF EXISTS %s DROP CONSTRAINT IF EXISTS %s;",
+			pq.QuoteIdentifier(newTable), pq.QuoteIdentifier(newTable+"_pkey"),
+		)
+		if _, err := tx.ExecContext(ctx, q); err != nil {
+			return fmt.Errorf("drop new PK from %q error: %w", newTable, err)
+		}
+		q = fmt.Sprintf(
+			"ALTER TABLE IF EXISTS %s DROP CONSTRAINT IF EXISTS %s;",
+			pq.QuoteIdentifier(newTable), pq.QuoteIdentifier(oldTable+"_pkey"),
+		)
+		if _, err := tx.ExecContext(ctx, q); err != nil {
+			return fmt.Errorf("drop old PK from %q error: %w", newTable, err)
+		}
+	}
+	for _, index := range serverNamesDropIndex {
+		q := fmt.Sprintf(
+			"DROP INDEX IF EXISTS %s;",
+			pq.QuoteIdentifier(index),
+		)
+		if _, err := tx.ExecContext(ctx, q); err != nil {
+			return fmt.Errorf("drop index %q error: %w", index, err)
+		}
+	}
+	return nil
+}

userapi/storage/postgres/deltas/2022110411000001_server_names.go

@@ -0,0 +1,28 @@
+package deltas
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+
+	"github.com/lib/pq"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+// I know what you're thinking: you're wondering "why doesn't this use $1
+// and pass variadic parameters to ExecContext?" — the answer is because
+// PostgreSQL doesn't expect the table name to be specified as a substituted
+// argument in that way so it results in a syntax error in the query.
+
+func UpServerNamesPopulate(ctx context.Context, tx *sql.Tx, serverName gomatrixserverlib.ServerName) error {
+	for _, table := range serverNamesTables {
+		q := fmt.Sprintf(
+			"UPDATE %s SET server_name = %s WHERE server_name = '';",
+			pq.QuoteIdentifier(table), pq.QuoteLiteral(string(serverName)),
+		)
+		if _, err := tx.ExecContext(ctx, q); err != nil {
+			return fmt.Errorf("write server names to %q error: %w", table, err)
+		}
+	}
+	return nil
+}