From c5f0b46e77e528b15d5ca2a9f3d5f6a1d45930cb Mon Sep 17 00:00:00 2001
From: kolaente <k@knt.li>
Date: Sun, 5 Dec 2021 12:11:50 +0100
Subject: [PATCH] feat: add support for different postgres versions

---
 dump_postgres.go      | 16 +++++++++++++++-
 dump_postgres_test.go | 25 +++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/dump_postgres.go b/dump_postgres.go
index bb26fd9..7f32dae 100644
--- a/dump_postgres.go
+++ b/dump_postgres.go
@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"github.com/docker/docker/api/types"
+	"strings"
 )
 
 type PostgresDumper struct {
@@ -43,10 +44,23 @@ func (d *PostgresDumper) buildConnStr() string {
 	return fmt.Sprintf("postgresql://%s:%s@%s:%s/%s", user, pw, host, port, db)
 }
 
+func findPgVersion(env []string) string {
+	for _, s := range env {
+		if strings.HasPrefix(s, "PG_MAJOR=") {
+			return strings.TrimPrefix(s, "PG_MAJOR=")
+		}
+	}
+
+	return ""
+}
+
 func (d *PostgresDumper) Dump() error {
 	fmt.Printf("Dumping postgres database from container %s...\n", d.Container.Name)
 
 	connStr := d.buildConnStr()
 
-	return runAndSaveCommand(getDumpFilename(d.Container.Name), "pg_dump", "--dbname", connStr)
+	// The postgres version must match the one the db server is running
+	pgVersion := findPgVersion(d.Container.Config.Env)
+
+	return runAndSaveCommand(getDumpFilename(d.Container.Name), "pg_dump"+pgVersion, "--dbname", connStr)
 }
diff --git a/dump_postgres_test.go b/dump_postgres_test.go
index 8e31a7f..aff2f65 100644
--- a/dump_postgres_test.go
+++ b/dump_postgres_test.go
@@ -115,3 +115,28 @@ func TestPostgresDumper_buildConnStr(t *testing.T) {
 		})
 	}
 }
+
+func TestFindPGVersionFromEnv(t *testing.T) {
+	t.Run("no PG_MAJOR", func(t *testing.T) {
+		pgVersion := findPgVersion([]string{})
+		if pgVersion != "" {
+			t.Errorf("Version is not empty")
+		}
+	})
+	t.Run("pg 14", func(t *testing.T) {
+		pgVersion := findPgVersion([]string{
+			"POSTGRES_PASSWORD=test",
+			"POSTGRES_USER=user",
+			"POSTGRES_DB=test",
+			"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/lib/postgresql/14/bin",
+			"GOSU_VERSION=1.14",
+			"LANG=en_US.utf8",
+			"PG_MAJOR=14",
+			"PG_VERSION=14.1-1.pgdg110+1",
+			"PGDATA=/var/lib/postgresql/data",
+		})
+		if pgVersion != "14" {
+			t.Errorf("Version is not 14")
+		}
+	})
+}