wallet: add list of upgrades.

Useful for debugging a db.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tests/test_lightningd.py

@@ -1047,6 +1047,29 @@ class LightningDTests(BaseLightningDTests):
         wait_forget_channels(l1)
         wait_forget_channels(l2)
 
+    def test_db_upgrade(self):
+        l1 = self.node_factory.get_node()
+        l1.stop()
+
+        version = subprocess.check_output(['lightningd/lightningd',
+                                           '--version']).decode('utf-8').splitlines()[0]
+
+        upgrades = l1.db_query("SELECT * from db_upgrades;")
+        assert len(upgrades) == 1
+        assert(upgrades[0]['upgrade_from'] == -1)
+        assert(upgrades[0]['lightning_version'] == version)
+
+        # Try resetting to earlier db state.
+        os.unlink(os.path.join(l1.daemon.lightning_dir, "lightningd.sqlite3"))
+        l1.db_manip("CREATE TABLE version (version INTEGER);")
+        l1.db_manip("INSERT INTO version VALUES (1);")
+
+        l1.daemon.start()
+        upgrades = l1.db_query("SELECT * from db_upgrades;")
+        assert len(upgrades) == 1
+        assert(upgrades[0]['upgrade_from'] == 1)
+        assert(upgrades[0]['lightning_version'] == version)
+
     def test_closing_different_fees(self):
         l1 = self.node_factory.get_node()
 

tests/utils.py

@@ -365,6 +365,16 @@ class LightningNode(object):
         db.close()
         return result
 
+    # Assumes node is stopped!
+    def db_manip(self, query):
+        db = sqlite3.connect(os.path.join(self.daemon.lightning_dir, "lightningd.sqlite3"))
+        db.row_factory = sqlite3.Row
+        c = db.cursor()
+        c.execute(query)
+        db.commit()
+        c.close()
+        db.close()
+
     def stop(self, timeout=10):
         """ Attempt to do a clean shutdown, but kill if it hangs
         """

wallet/db.c

@@ -2,6 +2,7 @@
 
 #include <ccan/tal/str/str.h>
 #include <ccan/tal/tal.h>
+#include <common/version.h>
 #include <inttypes.h>
 #include <lightningd/lightningd.h>
 #include <lightningd/log.h>
@@ -193,6 +194,8 @@ char *dbmigrations[] = {
     "CREATE INDEX channel_idx ON htlc_sigs (channelid)",
     /* Get rid of OPENINGD entries; we don't put them in db any more */
     "DELETE FROM channels WHERE state=1",
+    /* Keep track of db ugprades, for debugging */
+    "CREATE TABLE db_upgrades (upgrade_from INTEGER, lightning_version TEXT);",
     NULL,
 };
 
@@ -386,11 +389,11 @@ static int db_migration_count(void)
 static void db_migrate(struct db *db, struct log *log)
 {
 	/* Attempt to read the version from the database */
-	int current, available;
+	int current, orig, available;
 
 	db_begin_transaction(db);
 
-	current = db_get_version(db);
+	orig = current = db_get_version(db);
 	available = db_migration_count();
 
 	if (current == -1)
@@ -408,6 +411,12 @@ static void db_migrate(struct db *db, struct log *log)
 	/* Finally update the version number in the version table */
 	db_exec(__func__, db, "UPDATE version SET version=%d;", available);
 
+	/* Annotate that we did upgrade, if any. */
+	if (current != orig)
+		db_exec(__func__, db,
+			"INSERT INTO db_upgrades VALUES (%i, '%s');",
+			orig, version());
+
 	db_commit_transaction(db);
 }
 

wallet/test/Makefile

@@ -10,6 +10,7 @@ WALLET_TEST_COMMON_OBJS :=			\
 	common/timeout.o			\
 	common/utils.o				\
 	common/wireaddr.o			\
+	common/version.o			\
 	wire/towire.o				\
 	wire/fromwire.o