chore: Use generic db url for postgresql container (#1493)

* Use generic db url for postgresql container

Before we where using the PG specific url format but most tools would
expect the url on the generic one (i.e https://github.com/golang-migrate/migrate).

People could indeed write their own connString mapper but that would be
unnecessary. (Ideally tools would not try to parse the url and instead
just use the string but sometimes they might need to, thus using the
generic format would work most of the times)

* use strings.join

modules/postgres/postgres.go

@@ -3,7 +3,9 @@ package postgres
 import (
 	"context"
 	"fmt"
+	"net"
 	"path/filepath"
+	"strings"
 
 	"github.com/testcontainers/testcontainers-go"
 )
@@ -35,12 +37,8 @@ func (c *PostgresContainer) ConnectionString(ctx context.Context, args ...string
 		return "", err
 	}
 
-	extraArgs := ""
-	for _, arg := range args {
-		extraArgs += " " + arg
-	}
-
-	connStr := fmt.Sprintf("host=%s port=%s user=%s password=%s dbname=%s %s", host, containerPort.Port(), c.user, c.password, c.dbName, extraArgs)
+	extraArgs := strings.Join(args, "&")
+	connStr := fmt.Sprintf("postgres://%s:%s@%s/%s?%s", c.user, c.password, net.JoinHostPort(host, containerPort.Port()), c.dbName, extraArgs)
 	return connStr, nil
 }
 
@@ -58,7 +56,6 @@ func WithConfigFile(cfg string) testcontainers.CustomizeRequestOption {
 		req.Files = append(req.Files, cfgFile)
 		req.Cmd = append(req.Cmd, "-c", "config_file=/etc/postgresql.conf")
 	}
-
 }
 
 // WithDatabase sets the initial database to be created when the container starts

modules/postgres/postgres_test.go

@@ -78,6 +78,11 @@ func TestPostgres(t *testing.T) {
 			assert.NoError(t, err)
 			// }
 
+			// Ensure connection string is using generic format
+			id, err := container.MappedPort(ctx, "5432/tcp")
+			assert.NoError(t, err)
+			assert.Equal(t, fmt.Sprintf("postgres://%s:%s@%s:%s/%s?sslmode=disable&application_name=test", user, password, "localhost", id.Port(), dbname), connStr)
+
 			// perform assertions
 			db, err := sql.Open("postgres", connStr)
 			assert.NoError(t, err)