migrations: complete migrations flow

- create and drop tables or exec any sql in order
    - important to add the last line in each sql file

Signed-off-by: HeshamTB <hishaminv@gmail.com>

cmd/sft/sft.go

@@ -82,8 +82,12 @@ func main() {
 
 	_, err = db.Exec(string(initSql))
 	if err != nil {
-		rootLog.Error("failed to exec db init for rev0", "err", err.Error())
+		if strings.Contains(err.Error(), "UNIQUE constraint failed") {
-		rootLog.Warn("assume rev0 applied")
+			rootLog.Info("db is already initilized to rev0")
+		} else {
+			rootLog.Error("can not exec on db", "err", err.Error())
+			os.Exit(EXIT_FAIL)
+		}
 	}
 
 	rootLog.Info("db initilized")
@@ -105,7 +109,7 @@ func main() {
 	// At this point we don't have fixed file names for migrations. Use prefix to increment
 	// Read all file names in embedFS and Query all migrations in _sft_db
 
-	rows, err = db.Query("SELECT db_rev FROM _sft_db;")
+	rows, err = db.Query("SELECT db_rev FROM _sft_db ORDER BY db_rev;")
 	if err != nil {
 		rootLog.Error("error", "err", err.Error())
 		os.Exit(EXIT_FAIL)
@@ -176,35 +180,53 @@ func main() {
 		migs = append(migs, rev)
 		rootLog.Debug("loaded db migration", "name", rev.Filename)
 
-
-		// FIXME: this logic is bad when we have 2 or more migrations pending
-		dbTx, err := db.Begin()
-		if err != nil {
-			rootLog.Error("failed to start migration Tx")
-			os.Exit(EXIT_FAIL)
-		}
-		if rev.Rev >= len(appliedMigs) {
-			rootLog.Info("applying migration", "name", rev.Filename)
-			_, err = dbTx.Exec(string(rev.Data))
-			if err != nil {
-				rootLog.Error("could not apply database migration", "err", err.Error())
-				dbTx.Rollback()
-				os.Exit(EXIT_FAIL)
-			}
-			rootLog.Debug("committing migration", "name", rev.Filename)
-			rootLog.Info("applied migration", "name", rev.Filename)
-		}
-
-		err = dbTx.Commit()
-		if err != nil {
-			rootLog.Error("failed to commit migration", "err", err.Error(), "name", rev.Filename)
-			os.Exit(EXIT_FAIL)
-		}
-
-
 		// NOTE: Expect migs to be ordered 0..1..2...
 
 	}
+
+	// We have migs from migrations dir and appliedMigs from the db
+
+	if len(appliedMigs) > len(migs) {
+		rootLog.Error("wtf", "migs", len(migs), "appliedmigs", len(appliedMigs))
+		os.Exit(EXIT_FAIL)
+	}
+
+	rootLog.Info("database currently",
+		"applied_count", appliedMigs[len(appliedMigs)-1] + 1,
+		"available_count", migs[len(migs)-1].Rev + 1)
+
+	needMigration := false
+	if appliedMigs[len(appliedMigs)-1] < migs[len(migs)-1].Rev {
+		needMigration = true
+	}
+
+	pRev := appliedMigs[len(appliedMigs)-1] + 1
+	for {
+		if !needMigration { break }
+		rev := migs[pRev]
+		rlog := rootLog.With("rev", pRev, "name", rev.Filename)
+		rlog.Info("applying database migration")
+		rlog.Debug("apply migrations", "sql", string(rev.Data))
+		tx, err := db.Begin()
+		if err != nil {
+			rootLog.Error("error: create db transaction", "err", err.Error())
+			os.Exit(EXIT_FAIL)
+		}
+		_, err = tx.Exec(string(rev.Data))
+		if err != nil {
+			rootLog.Error("error: tx exec migration", "err", err.Error())
+			os.Exit(EXIT_FAIL)
+		}
+
+		err = tx.Commit()
+		if err != nil {
+			rootLog.Error("error: commit migration tx", "rev", rev.Rev, "err", err.Error())
+			os.Exit(EXIT_FAIL)
+		}
+
+		pRev++
+		if pRev > migs[len(migs)-1].Rev { break }
+	}
 	rootLog.Info("database up-to-date")
 
 

migrations/2_rev2.sql

@@ -5,6 +5,6 @@ CREATE TABLE IF NOT EXISTS _sft_migtest_table2 (
     id integer PRIMARY KEY
 );
 
-INSERT INTO _sft_migtest_table (id) VALUES (42);
+INSERT INTO _sft_migtest_table2 (id) VALUES (42);
 
 INSERT INTO _sft_db (db_rev, sft_ver, applied_at) VALUES (2, "0.0.1-pre-alpha1", CURRENT_TIMESTAMP);

migrations/3_rev3.sql

@@ -4,6 +4,6 @@ CREATE TABLE IF NOT EXISTS _sft_migtest_table3 (
     id integer PRIMARY KEY
 );
 
-INSERT INTO _sft_migtest_table (id) VALUES (42);
+INSERT INTO _sft_migtest_table3 (id) VALUES (42);
 
 INSERT INTO _sft_db (db_rev, sft_ver, applied_at) VALUES (3, "0.0.1-pre-alpha1", CURRENT_TIMESTAMP);

migrations/4_rev4.sql

@@ -2,7 +2,7 @@ CREATE TABLE IF NOT EXISTS _sft_migtest_table4 (
     id integer PRIMARY KEY
 );
 
-INSERT INTO _sft_migtest_table (id) VALUES (42);
+INSERT INTO _sft_migtest_table4 (id) VALUES (42);
 
 INSERT INTO _sft_db (db_rev, sft_ver, applied_at) VALUES (4, "0.0.1-pre-alpha1", CURRENT_TIMESTAMP);