From dfe9ea421ac0ef9c26097812929814a2f6d6d7ec Mon Sep 17 00:00:00 2001
From: hisham waleed karam <hisham.karam@cartologic.com>
Date: Sun, 14 Oct 2018 03:20:46 +0200
Subject: [PATCH] check if database is alive

---
 datastore.go  |  7 ++++++-
 layer.go      |  6 ++++++
 utils.go      | 17 +++++++++++++++++
 utils_test.go |  9 +++++++++
 4 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/datastore.go b/datastore.go
index 24feaa5..e3ba917 100644
--- a/datastore.go
+++ b/datastore.go
@@ -11,7 +11,12 @@ type datastore struct {
 	Name   string `yaml:"name"`
 }
 
-//BuildConnectionString return postgres connection as string
+//BuildConnectionString return gdal postgres connection as string
 func (ds *datastore) BuildConnectionString() string {
 	return fmt.Sprintf("PG: host=%s port=%d dbname=%s user=%s password=%s", ds.Host, ds.Port, ds.DBName, ds.DBUser, ds.DBPass)
 }
+
+//PostgresConnectionString return postgres connection as string
+func (ds *datastore) PostgresConnectionString() string {
+	return fmt.Sprintf("postgresql://%s:%s@%s:%d/%s?sslmode=disable", ds.DBUser, ds.DBPass, ds.Host, ds.Port, ds.DBName)
+}
diff --git a/layer.go b/layer.go
index 65f4593..7bf32d6 100644
--- a/layer.go
+++ b/layer.go
@@ -55,6 +55,12 @@ func (manager *ManagerConfig) PublishGeoserverLayer(layer *GdalLayer) (ok bool,
 
 //LayerToPostgis add Layer to Postgis
 func (layer *GdalLayer) LayerToPostgis(targetSource *gdal.DataSource, manager *ManagerConfig, overwrite bool) (newLayer *GdalLayer, err error) {
+	connStr := manager.Datastore.PostgresConnectionString()
+	dbErr := DBIsAlive(connStr)
+	if dbErr != nil {
+		err = dbErr
+		return
+	}
 	if targetSource == nil {
 		err = errors.New("Invalid Datasource")
 		return
diff --git a/utils.go b/utils.go
index b94f5d1..e9b9f81 100644
--- a/utils.go
+++ b/utils.go
@@ -1,12 +1,14 @@
 package gismanager
 
 import (
+	"database/sql"
 	"io/ioutil"
 	"os"
 	"path"
 	"path/filepath"
 	"strings"
 
+	_ "github.com/lib/pq"
 	yaml "gopkg.in/yaml.v2"
 )
 
@@ -69,3 +71,18 @@ func GetGISFiles(root string) ([]string, error) {
 
 	return files, nil
 }
+
+//DBIsAlive check if database alive
+func DBIsAlive(connectionStr string) (err error) {
+	db, dbErr := sql.Open("postgres", connectionStr)
+	if dbErr != nil {
+		err = dbErr
+		return
+	}
+	if pingErr := db.Ping(); pingErr != nil {
+		db.Close()
+		err = pingErr
+		return
+	}
+	return
+}
diff --git a/utils_test.go b/utils_test.go
index 0b7f964..7900668 100644
--- a/utils_test.go
+++ b/utils_test.go
@@ -24,3 +24,12 @@ func TestGetGISFiles(t *testing.T) {
 	assert.Equal(t, 0, len(dummyFiles))
 	assert.NotNil(t, dummyFileserr)
 }
+func TestDBIsAlive(t *testing.T) {
+	manager, _ := FromConfig("./testdata/test_config.yml")
+	connStr := manager.Datastore.PostgresConnectionString()
+	dbErr := DBIsAlive(connStr)
+	assert.Nil(t, dbErr)
+	connStr = "xxxxx"
+	err := DBIsAlive(connStr)
+	assert.NotNil(t, err)
+}