From 29591a613a3eb4efe9d4e3dae5be10de01403075 Mon Sep 17 00:00:00 2001
From: Jan Prochazka <jan.prochazka@gmail.com>
Date: Thu, 17 Mar 2022 13:27:33 +0100
Subject: [PATCH] postgres - readonly connection

---
 .../dbgate-plugin-postgres/src/backend/drivers.js   | 13 +++++++++----
 .../dbgate-plugin-postgres/src/frontend/drivers.js  |  7 ++++---
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/plugins/dbgate-plugin-postgres/src/backend/drivers.js b/plugins/dbgate-plugin-postgres/src/backend/drivers.js
index 397273af..6aaa7aa6 100644
--- a/plugins/dbgate-plugin-postgres/src/backend/drivers.js
+++ b/plugins/dbgate-plugin-postgres/src/backend/drivers.js
@@ -6,9 +6,9 @@ const Analyser = require('./Analyser');
 const pg = require('pg');
 const { createBulkInsertStreamBase, makeUniqueColumnNames } = require('dbgate-tools');
 
-pg.types.setTypeParser(1082, 'text', (val) => val); // date
-pg.types.setTypeParser(1114, 'text', (val) => val); // timestamp without timezone
-pg.types.setTypeParser(1184, 'text', (val) => val); // timestamp
+pg.types.setTypeParser(1082, 'text', val => val); // date
+pg.types.setTypeParser(1114, 'text', val => val); // timestamp without timezone
+pg.types.setTypeParser(1184, 'text', val => val); // timestamp
 
 function extractPostgresColumns(result) {
   if (!result || !result.fields) return [];
@@ -31,7 +31,7 @@ const drivers = driverBases.map(driverBase => ({
   ...driverBase,
   analyserClass: Analyser,
 
-  async connect({ engine, server, port, user, password, database, databaseUrl, useDatabaseUrl, ssl }) {
+  async connect({ engine, server, port, user, password, database, databaseUrl, useDatabaseUrl, ssl, isReadOnly }) {
     let options = null;
 
     if (engine == 'redshift@dbgate-plugin-postgres') {
@@ -67,6 +67,11 @@ const drivers = driverBases.map(driverBase => ({
 
     const client = new pg.Client(options);
     await client.connect();
+
+    if (isReadOnly) {
+      await this.query(client, 'SET SESSION CHARACTERISTICS AS TRANSACTION READ ONLY');
+    }
+
     return client;
   },
   async close(pool) {
diff --git a/plugins/dbgate-plugin-postgres/src/frontend/drivers.js b/plugins/dbgate-plugin-postgres/src/frontend/drivers.js
index 9e0cd102..29b8b0c9 100644
--- a/plugins/dbgate-plugin-postgres/src/frontend/drivers.js
+++ b/plugins/dbgate-plugin-postgres/src/frontend/drivers.js
@@ -41,15 +41,16 @@ const postgresDriverBase = {
   // showConnectionField: (field, values) =>
   //   ['server', 'port', 'user', 'password', 'defaultDatabase', 'singleDatabase'].includes(field),
   getQuerySplitterOptions: () => postgreSplitterOptions,
+  readOnlySessions: true,
 
   databaseUrlPlaceholder: 'e.g. postgresql://user:password@localhost:5432/default_database',
 
   showConnectionField: (field, values) => {
     if (field == 'useDatabaseUrl') return true;
     if (values.useDatabaseUrl) {
-      return ['databaseUrl'].includes(field);
+      return ['databaseUrl', 'isReadOnly'].includes(field);
     }
-    return ['server', 'port', 'user', 'password', 'defaultDatabase', 'singleDatabase'].includes(field);
+    return ['server', 'port', 'user', 'password', 'defaultDatabase', 'singleDatabase', 'isReadOnly'].includes(field);
   },
 
   beforeConnectionSave: connection => {
@@ -153,7 +154,7 @@ const redshiftDriver = {
   title: 'Amazon Redshift',
   defaultPort: 5439,
   databaseUrlPlaceholder: 'e.g. redshift-cluster-1.xxxx.redshift.amazonaws.com:5439/dev',
-  showConnectionField: (field, values) => ['databaseUrl', 'user', 'password'].includes(field),
+  showConnectionField: (field, values) => ['databaseUrl', 'user', 'password', 'isReadOnly'].includes(field),
   beforeConnectionSave: connection => {
     const { databaseUrl } = connection;
     if (databaseUrl) {