Senin, 30 Maret 2020

Creating user, database and adding access on PostgreSQL

Mar 14, 2017 · 2 min read

A nice postgres installation graphic by http://digitalocean.com. DO hosts great servers, check them out.

NOTE: Right off the bat — this is valid as on March 2017, running on Ubuntu 16.04.2, with PostgreSQL 9.6

Last login: Mon Mar 30 07:39:52 2020 from 192.168.201.104
root@ubuntu:~# su - postgres
postgres@ubuntu:~$ psql
psql (10.9 (Ubuntu 10.9-0ubuntu0.18.04.1))
Type "help" for help.

postgres=# \l

postgres=# CREATE DATABASE mydb;

postgres=# CREATE USER general WITH PASSWORD '%Y6G4pr0' ;

CREATE ROLE

postgres=# ALTER DATABASE trackyol OWNER TO track ;
ALTER DATABASE

TL;DR; version

sudo -u postgres psql
postgres=# create database mydb;
postgres=# create user myuser with encrypted password 'mypass';
postgres=# grant all privileges on database mydb to myuser;

Kalau Error kasih tanda kutip di DB nyapostgres=# GRANT ALL privileges on database "m-fusion-dev" to fusion;

One nice thing about PGSQL is it comes with some utility binaries like createuser and createdb. So we will be making use of that.

As the default configuration of Postgres is, a user called postgres is made on and the user postgres has full superadmin access to entire PostgreSQL instance running on your OS.

$ sudo -u postgres psql

The above command gets you the psql command line interface in full admin mode.

In the following commands, keep in mind the < angular brackets > are to denote variables you have to set yourself. In the actual command, omit the <>

Creating user

$ sudo -u postgres createuser <username>

Creating Database

$ sudo -u postgres createdb <dbname>

Giving the user a password

$ sudo -u postgres psql
psql=# alter user <username> with encrypted password '<password>';

Granting privileges on database

psql=# grant all privileges on database <dbname> to <username> ;

And yeah, that should be pretty much it !

Doing purely via psql

Your OS might not have the createuser or createdb binaries, or you may, for some reason want to do it purely via psql, then these are the three magic commands —

CREATE DATABASE yourdbname;
CREATE USER youruser WITH ENCRYPTED PASSWORD 'yourpass';
GRANT ALL PRIVILEGES ON DATABASE yourdbname TO youruser;

Obligatory shameless self-plug :

Kamis, 26 Maret 2020

How to Install Redis on Ubuntu 18.04 & 16.04 LTS

https://tecadmin.net/install-redis-ubuntu/

redis, redis-php

Redis is an in-memory data structure store, used as a database server, cache, and message broker. Redis is written in C programming language. It also provides a PHP module for communication between PHP script with the Redis server.

This tutorial will help you with the installation of Redis server along with PHP Redis PHP extensions on an Ubuntu 19.04, 18.04 LTS, 16.04 LTS and 14.04.

Step 1 – Prerequsities

ssh ubuntu@remote

Update the apt-get packages index files and also update existing packages to the newest versions by using the following commands:

sudo apt-get update
sudo apt-get upgrade

Step 2 – Installing Redis

The Redis packages are available under the default apt repository. For the installation of Redis on an Ubuntu VPS. Run below command from the terminal to install Redis on your machine:

sudo apt-get install redis-server

Next is to enable Redis to start on system boot. Also restart Redis service once.

sudo systemctl enable redis-server.service

Step 3 – Configure Redis

Redis can be started without a configuration file using a built-in default configuration. But to make any extra parameter changes you can use its configuration file that is: /etc/redis/redis.conf. Edit the Redis configuration file in a text editor to make changes

sudo vim /etc/redis/redis.conf

Update the following values in Redis configuration file according to your requirement. You can increase max memory limit as per available on your server.

maxmemory 256mb
maxmemory-policy allkeys-lru

The above configuration tells Redis to remove any key using the LRU algorithm when the max memory of 256mb is reached. Save the configuration file and restart the Redis service:

sudo systemctl restart redis-server.service

Step 4 – Install Redis PHP Extension

Now, if you need to use Redis from PHP application, you also need to install Redis PHP extension on your Ubuntu system. Run below command to install:

sudo apt-get install php-redis

Step 5 – Test Connection to Redis Server

Use redis-cli tool to verify the connection between the Redis server.

redis-cli

127.0.0.1:6379> ping
PONG
127.0.0.1:6379>

Few more examples of redis-cli command line tool. You can find more details about redis-cli here.

redis-cli info
redis-cli info stats
redis-cli info server

MAGENTO-elasticsearch

How to Install Elasticsearch 6.x on Ubuntu 18.04 LTS (Bionic Beaver) Linux

Josphat Mutai

August 18, 2018

10466

https://computingforgeeks.com/how-to-install-elasticsearch-6-x-on-ubuntu-18-04-lts-bionic-beaver-linux/

You can support us by downloading this article as PDF from the Link below. Download the guide as PDF

Our previous article was on how to install Elasticsearch 5.x on Ubuntu 18.04 LTS. I noticed some guys are interested in installing and using Elasticsearch 6.x on Ubuntu 18.04 instead. This guide will help you to install Elasticsearch 6.x on Ubuntu 18.04 LTS (Bionic Beaver) server.

Elasticsearch is an open-source analytics and full-text search engine based on Lucene. It provides a distributed, multitenant-capable architecture which enables you to store, search and analyze huge volumes of data faster from an HTTP web interface and schema-free JSON documents.

Follow the steps below to Install Elasticsearch 6.x on Ubuntu 18.04 LTS server.

Step 1: Import Elasticsearch GPG Key

The first step is to import Elasticsearch GPG Key which will trust elasticsearch packages downloaded from the upstream repository. Import the key by running the commands on your terminal.

$ wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | sudo apt-key add -
OK

Step 2: Add Elasticsearch 6.x APT repository

Now that the GPG key has been imported, add the apt repository by running:

echo "deb https://artifacts.elastic.co/packages/6.x/apt stable main" | sudo tee /etc/apt/sources.list.d/elastic-6.x.list

Step 3: Install OpenJDK

Elasticsearch is dependent on Java, you’ll need OpenJDK Java runtime environment installed to be able to run elasticsearch on your system.

sudo apt update
sudo apt install apt-transport-https openjdk-8-jre-headless

Step 4: Install Elasticsearch 6.x on Ubuntu 18.04

Now run apt-get update then install elasticsearch package on your Ubuntu 18.04 server:

sudo apt update
sudo apt install elasticsearch

After the installation, a default configuration file will be populated to /etc/elasticsearch/elasticsearch.ymlMost lines are commented out, edit the file to tweak and tune the configuration.

E.g, you can set the correct cluster name for your applications:

cluster.name: my-application

Note that the default minimum memory set for JVM is 2gb, if your server has small memory size, change this value:

sudo vim /etc/elasticsearch/jvm.options

Change:

-Xms2g
-Xmx2g

And set your values for minimum and maximum memory allocation. E.g to set values to 512mb of ram, use:

-Xms512m
-Xmx512m

Note that it is recommended to set the min and max JVM heap size to the same value. Xms represents the initial size of total heap space and Xmx represents the maximum size of total heap space.

After you have modified the configuration, you can start Elasticsearch:

sudo systemctl daemon-reload
sudo systemctl enable elasticsearch.service
sudo systemctl restart elasticsearch.service

Check elasticsearch service status:

$ sudo systemctl status elasticsearch.service 
● elasticsearch.service - Elasticsearch
Loaded: loaded (/usr/lib/systemd/system/elasticsearch.service; disabled; vendor preset: enabled)
Active: active (running) since Sun 2018-08-18 05:16:08 UTC; 7s ago
Docs: http://www.elastic.co
Process: 14314 ExecStartPre=/usr/share/elasticsearch/bin/elasticsearch-systemd-pre-exec (code=exited, status=0/SUCCESS)
Main PID: 14325 (java)
Tasks: 38 (limit: 2362)
CGroup: /system.slice/elasticsearch.service
└─14325 /usr/bin/java -Xms512m -Xmx512m -XX:+UseConcMarkSweepGC -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly -X

You now have a working Elasticsearch 6.x on Ubuntu 18.04 LTS (Bionic Beaver) server. Other articles related to Elasticsearch are:

MAGENTO-install nfs

Installing and configuring NFS Server on Ubuntu

To install and configure the NFS server, follow the steps outlined below.

https://www.tecmint.com/install-nfs-server-on-ubuntu/

Step 1: Install NFS Kernel Server in Ubuntu

The first step is to install the nfs-kernel-server package on the server. But before we do this, let’s first update the system packages using the following apt command.

$ sudo apt update

Once the update is complete, proceed and install the nfs-kernel-server package as shown below. This will store additional packages such as nfs-common and rpcbind which are equally crucial to the setup of the file share.

$ sudo apt install nfs-kernel-server

Install NFS Server on Ubuntu

Step 2: Create an NFS Export Directory

The second step will be creating a directory that will be shared among client systems. This is also referred to as the export directory and it’s in this directory that we shall later create files which will be accessible by client systems.

Run the command below by specifying the NFS mount directory name.

$ sudo mkdir -p /mnt/nfs_share

Since we want all the client machines to access the shared directory, remove any restrictions in the directory permissions.

$ sudo chown -R nobody:nogroup /mnt/nfs_share/

You can also tweak the file permissions to your preference. Here’s we have given the read, write and execute privileges to all the contents inside the directory.

$ sudo chmod 777 /mnt/nfs_share/

Create NFS Share in Ubuntu

Step 3: Grant NFS Share Access to Client Systems

Permissions for accessing the NFS server are defined in the /etc/exports file. So open the file using your favorite text editor:

$ sudo vim /etc/exports

You can provide access to a single client, multiple clients or specify an entire subnet.

In this guide, we have allowed en entire subnet to have access to the NFS share.

/mnt/nfs_share  192.168.43.0/24(rw,sync,no_subtree_check)

Explanation about the options used in the above command.

rw: Stands for Read/Write.
sync: Requires changes to be written to the disk before they are applied.
No_subtree_check: Eliminates subtree checking.

Set NFS Share Access

To grant access to a single client, use the syntax:

/mnt/nfs_share  client_IP_1 (re,sync,no_subtree_check)

For multiple clients, specify each client on a separate file:

/mnt/nfs_share  client_IP_1 (re,sync,no_subtree_check)
/mnt/nfs_share  client_IP_2 (re,sync,no_subtree_check)

Step 4: Export the NFS Share Directory

After granting access to the preferred client systems, export the NFS share directory and restart the NFS kernel server for the changes to come into effect.

$ sudo exportfs -a
$ sudo systemctl restart nfs-kernel-server

Export NFS Share Directory

Step 5: Allow NFS Access through the Firewall

For the client to access the NFS share, you need to allow access through the firewall otherwise, accessing and mounting the shared directory will be impossible. To achieve this run the command:

$ sudo ufw allow from 192.168.43.0/24 to any port nfs

Reload or enable the firewall (if it was turned off) and check the status of the firewall. Port 2049, which is the default file share, should be opened.

$ sudo ufw enable
$ sudo ufw status

Open NFS Port on Firewall

Install the NFS Client on the Client Systems

We’re done installing and configuring the NFS service on the Server, let’s now install NFS on the client system.

Step 1: Install the NFS-Common Package

As is the norm, begin by updating the system packages and repositories before anything else.

$ sudo apt update

Next, install nfs-common packages as shown.

$ sudo apt install nfs-common

Install NFS on Client System

Step 2: Create a NFS Mount Point on Client

Next,you need to create a mount point on which you will mount the nfs share from the NFS server. To do this, run the command:

$ sudo mkdir -p /mnt/nfs_clientshare

Step 3: Mount NFS Share on Client System

The last step remaining is mounting the NFS share that is shared by the NFS server. This will enable the client system to access the shared directory.

Let’s check the NFS Server’s IP address using the ifconfig command.

$ ifconfig

Check Ubuntu Server IP Address

To achieve this run the command:

$ sudo mount 192.168.43.234:/mnt/nfs_share  /mnt/nfs_clientshare

Step 4: Testing the NFS Share on Client System

To verify that our NFS setup is working, we are going to create a few files in the NFS share directory located in the server.

$ cd /mnt/nfs_share/
$ touch file1.txt file2.txt file3.txt

Now head back to the NFS client system and check if the files exist.

$ ls -l /mnt/nfs_clientshare/

Test NFS Share on Client

Great! The output confirms that we can access the files we just created on the NFS server!

And that about it. In this guide, we walked you through the installation and configuration of the NFS server on Ubuntu 18.04. NFS is rarely used nowadays and has been relegated in favor of the more robust and secure Samba share protocol.

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