internal/database: allow running db tests under different db name

On a mac, brew install postgresql installs postgres without the postgres user: it uses $USER instead. The current tests don't take that into account. This CL changes that by:

- Amending the connecting URI to explicitly specify the db name (the current "" approach makes use of the postgres user, which by coincidence is the same name as the database we want: now instead of we specify the postgres user).
- One user test is amended to use the env var provided user if necessary.

Also adds some logging to make it more clear why failures around the URI are happening.

Change-Id: I03d5b40a62d7034e00f45ba8151292688ab61de4
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/685995
Reviewed-by: Michael Knyszek <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Jonathan Amsterdam <[email protected]>
kokoro-CI: kokoro <[email protected]>
Reviewed-by: Michael Pratt <[email protected]>

Author: jeanbza

internal/database/dbutil.go

@@ -36,9 +36,9 @@ func DBConnURI(dbName string) string {
 		host     = serverconfig.GetEnv("GO_DISCOVERY_DATABASE_HOST", "localhost")
 		port     = serverconfig.GetEnv("GO_DISCOVERY_DATABASE_PORT", "5432")
 	)
-	cs := fmt.Sprintf("postgres://%s/%s?sslmode=disable&user=%s&password=%s&port=%s&timezone=UTC",
-		host, dbName, url.QueryEscape(user), url.QueryEscape(password), url.QueryEscape(port))
-	return cs
+	// https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING-URIS
+	return fmt.Sprintf("postgresql://%s:%s@%s:%s/%s?sslmode=disable&timezone=UTC",
+		url.QueryEscape(user), url.QueryEscape(password), url.QueryEscape(host), url.QueryEscape(port), dbName)
 }
 
 // MultiErr can be used to combine one or more errors into a single error.
@@ -79,17 +79,21 @@ func ConnectAndExecute(uri string, dbFunc func(*sql.DB) error) (outerErr error)
 
 // CreateDB creates a new database dbName.
 func CreateDB(dbName string) error {
-	return ConnectAndExecute(DBConnURI(""), func(pg *sql.DB) error {
+	uri := DBConnURI("postgres")
+	err := ConnectAndExecute(uri, func(pg *sql.DB) error {
 		if _, err := pg.Exec(fmt.Sprintf(`
 			CREATE DATABASE %q
 				TEMPLATE=template0
 				LC_COLLATE='C'
 				LC_CTYPE='C';`, dbName)); err != nil {
 			return fmt.Errorf("error creating %q: %v", dbName, err)
 		}
-
 		return nil
 	})
+	if err != nil {
+		return fmt.Errorf("error connecting to %q: %v", uri, err)
+	}
+	return nil
 }
 
 // DropDB drops the database named dbName.
@@ -118,7 +122,8 @@ func CreateDBIfNotExists(dbName string) error {
 func checkIfDBExists(dbName string) (bool, error) {
 	var exists bool
 
-	err := ConnectAndExecute(DBConnURI(""), func(pg *sql.DB) error {
+	uri := DBConnURI("postgres")
+	err := ConnectAndExecute(uri, func(pg *sql.DB) error {
 		rows, err := pg.Query("SELECT 1 from pg_database WHERE datname = $1 LIMIT 1", dbName)
 		if err != nil {
 			return err
@@ -132,8 +137,11 @@ func checkIfDBExists(dbName string) (bool, error) {
 
 		return rows.Err()
 	})
+	if err != nil {
+		return false, fmt.Errorf("error connecting to %q: %w", uri, err)
+	}
 
-	return exists, err
+	return exists, nil
 }
 
 // TryToMigrate attempts to migrate the database named dbName to the latest

internal/postgres/postgres_test.go

@@ -8,6 +8,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"os"
 	"testing"
 	"time"
 
@@ -118,7 +119,11 @@ func TestGetUserInfo(t *testing.T) {
 	testDB, release := acquire(t)
 	defer release()
 
-	got, err := testDB.GetUserInfo(ctx, "postgres")
+	dbUser := "postgres"
+	if u := os.Getenv("GO_DISCOVERY_DATABASE_USER"); u != "" {
+		dbUser = u
+	}
+	got, err := testDB.GetUserInfo(ctx, dbUser)
 	if err != nil {
 		t.Fatal(err)
 	}