From e2be689a05528893060a5b86cf2bb9c96c4edfae Mon Sep 17 00:00:00 2001
From: Dan Sosedoff <dan.sosedoff@gmail.com>
Date: Wed, 25 Apr 2018 23:29:18 -0500
Subject: [PATCH] Check if pg_dump is available before running database export

---
 pkg/api/api.go          | 7 +++++++
 pkg/client/dump.go      | 5 +++++
 pkg/client/dump_test.go | 6 +++++-
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/pkg/api/api.go b/pkg/api/api.go
index ab0f435..dd4017e 100644
--- a/pkg/api/api.go
+++ b/pkg/api/api.go
@@ -472,6 +472,13 @@ func DataExport(c *gin.Context) {
 		Table: strings.TrimSpace(c.Request.FormValue("table")),
 	}
 
+	// If pg_dump is not available the following code will not show an error in browser.
+	// This is due to the headers being written first.
+	if !dump.CanExport() {
+		c.JSON(400, Error{"pg_dump is not found"})
+		return
+	}
+
 	formattedInfo := info.Format()[0]
 	filename := formattedInfo["current_database"].(string)
 	if dump.Table != "" {
diff --git a/pkg/client/dump.go b/pkg/client/dump.go
index c9bae40..68a3aaa 100644
--- a/pkg/client/dump.go
+++ b/pkg/client/dump.go
@@ -11,6 +11,11 @@ type Dump struct {
 	Table string
 }
 
+func (d *Dump) CanExport() bool {
+	err := exec.Command("pg_dump", "--version").Run()
+	return err == nil
+}
+
 func (d *Dump) Export(url string, writer io.Writer) error {
 	errOutput := bytes.NewBuffer(nil)
 
diff --git a/pkg/client/dump_test.go b/pkg/client/dump_test.go
index 95d1c3a..67c2a13 100644
--- a/pkg/client/dump_test.go
+++ b/pkg/client/dump_test.go
@@ -24,8 +24,12 @@ func test_DumpExport(t *testing.T) {
 		os.Remove(savePath)
 	}()
 
-	// Test full db dump
 	dump := Dump{}
+
+	// Test for pg_dump presence
+	assert.True(t, dump.CanExport())
+
+	// Test full db dump
 	err = dump.Export(url, saveFile)
 	assert.NoError(t, err)