codewithgun · May 17, 2021 18:24 · May 17, 2021 · May 17, 2021 · May 10, 2021
diff --git a/postgres.md b/postgres.md
@@ -22,7 +22,7 @@ This will allow remote request to postgres database.
 
 Last but not least, we going to configure postgres to listen request coming from all ip address instead of localhost only. Open up `postgresql.conf` by running `vi /etc/postgres/{version}/main/postgres.conf`. Then, change `#listen_addresses = 'localhost'` to `listen_addresses = '*'`
 
-Last, remember to restart your postgres database by running `sudo systemctl restart postgresql`. If still doesn't work, try run `sudo ufw status` to check whether the firewall is enabled. If it was enabled, run `sudo ufw allow postgres` to make the firewall unlock the remote request for postgres using port 5432.
+Last, remember to restart your postgres database by running `sudo systemctl restart postgresql`. If still doesn't work, try run `sudo ufw status` to check whether the firewall is enabled. If it wasn't enabled, run `sudo ufw allow postgres` to make the firewall unlock the remote request for postgres using port 5432.
 
 Now, you should be able to connect to your postgres database remotely.
 

diff --git a/postgres.md b/postgres.md
@@ -8,7 +8,7 @@ If the output shows `status: active`, it shows that the database is up and runni
 
 In Postgres, there was few type of authentication methods. However, most of the time, the authentication will be `password authentication` or `local socket authentication`.
 
-By default, when request come from localhost, `peer` (local socket authentication) will be used automatically. Local socket authentication authenticate the user based on the current logged in UNIX/LINUX user. This is reason why you can access to postgres after switch to postgres user `sudo su postgres`, then run `psql` to access to the database.
+By default, when request come from localhost, `peer` (local socket authentication) will be used automatically. Local socket authentication authenticate the user based on the current logged in UNIX/LINUX user. This is the reason why you can access to postgres after switch to postgres user `sudo su postgres`, then run `psql` to access to the database.
 
 Now, let's start fix it.
 
@@ -18,7 +18,7 @@ Second, if you are accessing postgresql remotely, please make sure that postgres
 
 > Remember to change 127.0.0.1/32 to your ip address. Eg: 218.11.66.102/32
 
-This will allow remote request to postgres databse.
+This will allow remote request to postgres database.
 
 Last but not least, we going to configure postgres to listen request coming from all ip address instead of localhost only. Open up `postgresql.conf` by running `vi /etc/postgres/{version}/main/postgres.conf`. Then, change `#listen_addresses = 'localhost'` to `listen_addresses = '*'`
 

diff --git a/postgres.md b/postgres.md
@@ -0,0 +1,29 @@
+# Unable to connect Postgresql from client
+
+There was several reasons causes client unable to connect to Postgres database.
+
+First, run `sudo systemctl status postgresql` to check whether the database is running.
+
+If the output shows `status: active`, it shows that the database is up and running. The problems might due to authentication, listening port, or firewall.
+
+In Postgres, there was few type of authentication methods. However, most of the time, the authentication will be `password authentication` or `local socket authentication`.
+
+By default, when request come from localhost, `peer` (local socket authentication) will be used automatically. Local socket authentication authenticate the user based on the current logged in UNIX/LINUX user. This is reason why you can access to postgres after switch to postgres user `sudo su postgres`, then run `psql` to access to the database.
+
+Now, let's start fix it.
+
+First, switch to `postgres` user by running `sudo su postgres` in terminal. After that, access the postgres database by running `psql`. Then, change the password of `postgres` user by running `\password postgres` then enter your new password.
+
+Second, if you are accessing postgresql remotely, please make sure that postgres database doesn't blocking the accessing ip address. Open up `postgres_hba.conf` by running `vi /etc/postgres/{version}/main/pg_hba.conf`. After that, add `host all all 127.0.0.1/32 md5`
+
+> Remember to change 127.0.0.1/32 to your ip address. Eg: 218.11.66.102/32
+
+This will allow remote request to postgres databse.
+
+Last but not least, we going to configure postgres to listen request coming from all ip address instead of localhost only. Open up `postgresql.conf` by running `vi /etc/postgres/{version}/main/postgres.conf`. Then, change `#listen_addresses = 'localhost'` to `listen_addresses = '*'`
+
+Last, remember to restart your postgres database by running `sudo systemctl restart postgresql`. If still doesn't work, try run `sudo ufw status` to check whether the firewall is enabled. If it was enabled, run `sudo ufw allow postgres` to make the firewall unlock the remote request for postgres using port 5432.
+
+Now, you should be able to connect to your postgres database remotely.
+
+> You may troubleshoot whether the postgres is listening on port 5432 by running `telnet {ip address} 5432`. If you get connection closed by foreign host, means the database is running and listening on port 5432, this narrow down the area for troubleshooting to authentication and postgres configuration file.