debian help

how to install adminer in debian better than phpmyadmin

2019-01-02T09:10:00.001+02:00

https://www.vultr.com/docs/install-adminer-on-debian-ubuntu

From Debian/Ubuntu repositories

This is an older version, 3.3.3-1.

sudo apt-get install adminer

From the Adminer project homepage

Newer versions are offered here, such as 4.2.1.

sudo mkdir /usr/share/adminer
sudo wget "http://www.adminer.org/latest.php" -O /usr/share/adminer/latest.php
sudo ln -s /usr/share/adminer/latest.php /usr/share/adminer/adminer.php
echo "Alias /adminer.php /usr/share/adminer/adminer.php" | sudo tee /etc/apache2/conf-available/adminer.conf
sudo a2enconf adminer.conf

Once the installation completes, restart Apache.

sudo service apache2 restart

At this point, the setup is complete. You can access Adminer at either of the following addresses.

http://[SERVER_IP]/adminer  

http://[SERVER_IP]/adminer.php

Replace [SERVER_IP] with the IP address of your VPS.

and the entry in nginx

server {

listen 80;

server_name example.ro;

root /usr/share/adminer;

# If you want to use a .htpass file, uncomment the three following lines.

auth_basic "Admin-Area! Password needed!";

auth_basic_user_file /usr/share/adminer/.htpass;

access_log /var/log/nginx/adminer-access.log;

error_log /var/log/nginx/adminer-error.log;

location / {

index index.php;

try_files $uri $uri/ /index.php?$args;

}

location ~ .php$ {

include fastcgi.conf;

#fastcgi_pass localhost:9000;

fastcgi_pass unix:/var/run/php5-fpm.sock;

fastcgi_index index.php;

fastcgi_param SCRIPT_FILENAME /usr/share/adminer$fastcgi_script_name;

}

Phusion Passenger is currently not serving any applications

2019-01-01T02:48:00.001+02:00

Thanks to: AntonAL

Ruby on Rails, Meteor, Node.js, Bitrix (Битрикс)

and

https://stackoverflow.com/questions/33200648/phusion-passenger-is-currently-not-serving-any-applications

passenger_app_root /path/to/your/app/code; # <<< Point Passenger to application code

How To Install Node.js on Debian 9

2018-12-31T00:53:00.002+02:00

https://www.digitalocean.com/community/tutorials/how-to-install-node-js-on-debian-9

Introduction

Node.js is a JavaScript platform for general-purpose programming that allows users to build network applications quickly. By leveraging JavaScript on both the front and backend, Node.js makes development more consistent and integrated.

In this guide, we'll show you how to get started with Node.js on a Debian 9 server.

Prerequisites

This guide assumes that you are using Debian 9. Before you begin, you should have a non-root user account with sudo privileges set up on your system. You can learn how to set this up by following the initial server setup for Debian 9.

Installing the Distro-Stable Version for Debian

Debian contains a version of Node.js in its default repositories. At the time of writing, this version is 4.8.2, which will reach end-of-life at the end of April 2018. If you would like to experiment with the language using a stable and sufficient option, then installing from the repositories may make sense. It is recommended, however, that for development and production use cases you install a more recent version with a PPA. We will discuss how to install from a PPA in the next step.

To get the distro-stable version of Node.js, you can use the apt package manager. First, refresh your local package index:


sudo apt update

Then install the Node.js package from the repositories:


sudo apt install nodejs

If the package in the repositories suits your needs, then this is all you need to do to get set up with Node.js.

To check which version of Node.js you have installed after these initial steps, type:


nodejs -v

Because of a conflict with another package, the executable from the Debian repositories is called nodejsinstead of node. Keep this in mind as you are running software.

Once you have established which version of Node.js you have installed from the Debian repositories, you can decide whether or not you would like to work with different versions, package archives, or version managers. Next, we'll discuss these elements, along with more flexible and robust methods of installation.

Installing Using a PPA

To work with a more recent version of Node.js, you can add the PPA (personal package archive) maintained by NodeSource. This will have more up-to-date versions of Node.js than the official Debian repositories, and will allow you to choose between Node.js v4.x (the older long-term support version, which will be supported until the end of April 2018), Node.js v6.x (supported until April of 2019), Node.js v8.x (the current LTS version, supported until December of 2019), and Node.js v10.x (the latest version, supported until April of 2021).

Let's first update the local package index and install curl, which you will use to access the PPA:


sudo apt update

sudo apt install curl

Next, let's install the PPA in order to get access to its contents. From your home directory, use curl to retrieve the installation script for your preferred version, making sure to replace 10.x with your preferred version string (if different):


cd ~

curl -sL https://deb.nodesource.com/setup_10.x -o nodesource_setup.sh

You can inspect the contents of this script with nano or your preferred text editor:


nano nodesource_setup.sh

Run the script under sudo:


sudo bash nodesource_setup.sh

The PPA will be added to your configuration and your local package cache will be updated automatically. After running the setup script, you can install the Node.js package in the same way you did above:


sudo apt install nodejs

To check which version of Node.js you have installed after these initial steps, type:


nodejs -v


Output

v10.9.0

The nodejs package contains the nodejs binary as well as npm, so you don't need to install npmseparately.

npm uses a configuration file in your home directory to keep track of updates. It will be created the first time you run npm. Execute this command to verify that npm is installed and to create the configuration file:


npm -v


Output

6.2.0

In order for some npm packages to work (those that require compiling code from source, for example), you will need to install the build-essential package:


sudo apt install build-essential

You now have the necessary tools to work with npm packages that require compiling code from source.

Installing Using NVM

An alternative to installing Node.js through apt is to use a tool called nvm, which stands for "Node.js Version Manager". Rather than working at the operating system level, nvm works at the level of an independent directory within your home directory. This means that you can install multiple self-contained versions of Node.js without affecting the entire system.

Controlling your environment with nvm allows you to access the newest versions of Node.js and retain and manage previous releases. It is a different utility from apt, however, and the versions of Node.js that you manage with it are distinct from those you manage with apt.

To download the nvm installation script from the project's GitHub page, you can use curl. Note that the version number may differ from what is highlighted here:


curl -sL https://raw.githubusercontent.com/creationix/nvm/v0.33.11/install.sh -o install_nvm.sh

Inspect the installation script with nano:


nano install_nvm.sh

Run the script with bash:


bash install_nvm.sh

It will install the software into a subdirectory of your home directory at ~/.nvm. It will also add the necessary lines to your ~/.profile file to use the file.

To gain access to the nvm functionality, you'll need to either log out and log back in again or source the ~/.profile file so that your current session knows about the changes:


source ~/.profile

With nvm installed, you can install isolated Node.js versions. For information about the versions of Node.js that are available, type:


nvm ls-remote


Output

...
         v8.11.1   (Latest LTS: Carbon)
         v9.0.0
         v9.1.0
         v9.2.0
         v9.2.1
         v9.3.0
         v9.4.0
         v9.5.0
         v9.6.0
         v9.6.1
         v9.7.0
         v9.7.1
         v9.8.0
         v9.9.0
        v9.10.0
        v9.10.1
        v9.11.0
        v9.11.1
        v10.0.0  
        v10.1.0
        v10.2.0
        v10.2.1
        v10.3.0
        v10.4.0
        v10.4.1
        v10.5.0
        v10.6.0
        v10.7.0
        v10.8.0
        v10.9.0

As you can see, the current LTS version at the time of this writing is v8.11.1. You can install that by typing:


nvm install 8.11.1

Usually, nvm will switch to use the most recently installed version. You can tell nvm to use the version you just downloaded by typing:


nvm use 8.11.1

When you install Node.js using nvm, the executable is called node. You can see the version currently being used by the shell by typing:


node -v


Output

v8.11.1

If you have multiple Node.js versions, you can see what is installed by typing:


nvm ls

If you wish to default one of the versions, type:


nvm alias default 8.11.1

This version will be automatically selected when a new session spawns. You can also reference it by the alias like this:


nvm use default

Each version of Node.js will keep track of its own packages and has npm available to manage these.

You can also have npm install packages to the Node.js project's ./node_modules directory. Use the following syntax to install the express module:


npm install express

If you'd like to install the module globally, making it available to other projects using the same version of Node.js, you can add the -g flag:


npm install -g express

This will install the package in:

~/.nvm/versions/node/node_version/lib/node_modules/express

Installing the module globally will let you run commands from the command line, but you'll have to link the package into your local sphere to require it from within a program:


npm link express

You can learn more about the options available to you with nvm by typing:


nvm help

Removing Node.js

You can uninstall Node.js using apt or nvm, depending on the version you want to target. To remove versions installed from the repositories or from the PPA, you will need to work with the apt utility at the system level.

To remove either of these versions, type the following:


sudo apt remove nodejs

This command will remove the package and the configuration files.

To uninstall a version of Node.js that you have enabled using nvm, first determine whether or not the version you would like to remove is the current active version:


nvm current

If the version you are targeting is not the current active version, you can run:


nvm uninstall node_version

This command will uninstall the selected version of Node.js.

If the version you would like to remove is the current active version, you must first deactivate nvm to enable your changes:


nvm deactivate

You can now uninstall the current version using the uninstall command above, which will remove all files associated with the targeted version of Node.js except the cached files that can be used for reinstallation.

Conclusion

There are a quite a few ways to get up and running with Node.js on your Debian 9 server. Your circumstances will dictate which of the above methods is best for your needs. While using the packaged version in the Debian repository is an option for experimentation, installing from a PPA and working with npm or nvm offers additional flexibility.

2018-12-30T23:44:00.001+02:00

How To Set Up a Node.js Application for Production on Debian 9

https://www.digitalocean.com/community/tutorials/how-to-set-up-a-node-js-application-for-production-on-debian-9

PostedSeptember 6, 2018 6.4k

Introduction

Node.js is an open-source JavaScript runtime environment for building server-side and networking applications. The platform runs on Linux, macOS, FreeBSD, and Windows. Though you can run Node.js applications at the command line, this tutorial will focus on running them as a service. This means that the applications will restart on reboot or failure and are safe for use in a production environment.

In this tutorial, you will set up a production-ready Node.js environment on a single Debian 9 server. This server will run a Node.js application managed by PM2, and provide users with secure access to the application through an Nginx reverse proxy. The Nginx server will offer HTTPS, using a free certificate provided by Let's Encrypt.

Prerequisites

This guide assumes that you have the following:

A Debian 9 server setup, as described in the initial server setup guide for Debian 9. You should have a non-root user with sudo privileges and an active firewall.
A domain name pointed at your server's public IP. This tutorial will use the domain name example.com throughout.
Nginx installed, as covered in How To Install Nginx on Debian 9.
Nginx configured with SSL using Let's Encrypt certificates. How To Secure Nginx with Let's Encrypt on Debian 9 will walk you through the process.

When you've completed the prerequisites, you will have a server serving your domain's default placeholder page at https://example.com/.

Step 1 — Installing Node.js

Let's begin by installing the latest LTS release of Node.js, using the NodeSource package archives.

To install the NodeSource PPA and access its contents, you will first need to update your package index and install curl:


sudo apt update

sudo apt install curl

Make sure you're in your home directory, and then use curl to retrieve the installation script for the Node.js 8.x archives:


cd ~

curl -sL https://deb.nodesource.com/setup_8.x -o nodesource_setup.sh

You can inspect the contents of this script with nano or your preferred text editor:


nano nodesource_setup.sh

When you're done inspecting the script, run it under sudo:


sudo bash nodesource_setup.sh

The PPA will be added to your configuration and your local package cache will be updated automatically. After running the setup script from Nodesource, you can install the Node.js package:


sudo apt install nodejs

To check which version of Node.js you have installed after these initial steps, type:


nodejs -v


Output

v8.11.4

Note: When installing from the NodeSource PPA, the Node.js executable is called nodejs, rather than node.

The nodejs package contains the nodejs binary as well as npm, a package manager for Node modules, so you don't need to install npm separately.


npm -v


Output

5.6.0

In order for some npm packages to work (those that require compiling code from source, for example), you will need to install the build-essential package:


sudo apt install build-essential

You now have the necessary tools to work with npm packages that require compiling code from source.

With the Node.js runtime installed, let's move on to writing a Node.js application.

Step 2 — Creating a Node.js Application

Let's write a Hello World application that returns "Hello World" to any HTTP requests. This sample application will help you get Node.js set up. You can replace it with your own application — just make sure that you modify your application to listen on the appropriate IP addresses and ports.

First, let's create a sample application called hello.js:


cd ~

nano hello.js

Insert the following code into the file:

~/hello.js

const http = require('http');

const hostname = 'localhost';
const port = 3000;

const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello World!\n');
});

server.listen(port, hostname, () => {
  console.log(`Server running at http://${hostname}:${port}/`);
});

Save the file and exit the editor.

This Node.js application listens on the specified address (localhost) and port (3000), and returns "Hello World!" with a 200 HTTP success code. Since we're listening on localhost, remote clients won't be able to connect to our application.

To test your application, type:


node hello.js

You will see the following output:


Output

Server running at http://localhost:3000/

Note: Running a Node.js application in this manner will block additional commands until the application is killed by pressing CTRL+C.

To test the application, open another terminal session on your server, and connect to localhost with curl:


curl http://localhost:3000

If you see the following output, the application is working properly and listening on the correct address and port:


Output

Hello World!

If you do not see the expected output, make sure that your Node.js application is running and configured to listen on the proper address and port.

Once you're sure it's working, kill the application (if you haven't already) by pressing CTRL+C.

Step 3 — Installing PM2

Next let's install PM2, a process manager for Node.js applications. PM2 makes it possible to daemonize applications so that they will run in the background as a service.

Use npm to install the latest version of PM2 on your server:


sudo npm install pm2@latest -g

The -g option tells npm to install the module globally, so it's available system-wide.

Let's first use the pm2 start command to run your application, hello.js, in the background:


pm2 start hello.js

This also adds your application to PM2's process list, which is outputted every time you start an application:


Output

[PM2] Spawning PM2 daemon with pm2_home=/home/sammy/.pm2
[PM2] PM2 Successfully daemonized
[PM2] Starting /home/sammy/hello.js in fork_mode (1 instance)
[PM2] Done.
┌──────────┬────┬──────┬──────┬────────┬─────────┬────────┬─────┬───────────┬───────┬──────────┐
│ App name │ id │ mode │ pid  │ status │ restart │ uptime │ cpu │ mem       │ user  │ watching │
├──────────┼────┼──────┼──────┼────────┼─────────┼────────┼─────┼───────────┼───────┼──────────┤
│ hello    │ 0  │ fork │ 1338 │ online │ 0       │ 0s     │ 0%  │ 23.0 MB   │ sammy │ disabled │
└──────────┴────┴──────┴──────┴────────┴─────────┴────────┴─────┴───────────┴───────┴──────────┘
 Use `pm2 show <id|name>` to get more details about an app

As you can see, PM2 automatically assigns an App name (based on the filename, without the .jsextension) and a PM2 id. PM2 also maintains other information, such as the PID of the process, its current status, and memory usage.

Applications that are running under PM2 will be restarted automatically if the application crashes or is killed, but we can take an additional step to get the application to launch on system startup using the startup subcommand. This subcommand generates and configures a startup script to launch PM2 and its managed processes on server boots:


pm2 startup systemd

The last line of the resulting output will include a command to run with superuser privileges to set PM2 to start on boot:


Output

[PM2] Init System found: systemd
[PM2] To setup the Startup Script, copy/paste the following command:
sudo env PATH=$PATH:/usr/bin /usr/lib/node_modules/pm2/bin/pm2 startup systemd -u sammy --hp /home/sammy

Run the command from the output, with your username in place of sammy:


sudo env PATH=$PATH:/usr/bin /usr/lib/node_modules/pm2/bin/pm2 startup systemd -u sammy --hp /home/sammy

As an additional step, we can save the PM2 process list and corresponding environments:


pm2 save

You have now created a systemd unit that runs pm2 for your user on boot. This pm2 instance, in turn, runs hello.js.

Start the service with systemctl:


sudo systemctl start pm2-sammy

Check the status of the systemd unit:


systemctl status pm2-sammy

For a detailed overview of systemd, see Systemd Essentials: Working with Services, Units, and the Journal.

In addition to those we have covered, PM2 provides many subcommands that allow you to manage or look up information about your applications.

Stop an application with this command (specify the PM2 App name or id):


pm2 stop app_name_or_id

Restart an application:


pm2 restart app_name_or_id

List the applications currently managed by PM2:


pm2 list

Get information about a specific application using its App name:


pm2 info app_name

The PM2 process monitor can be pulled up with the monit subcommand. This displays the application status, CPU, and memory usage:


pm2 monit

Note that running pm2 without any arguments will also display a help page with example usage.

Now that your Node.js application is running and managed by PM2, let's set up the reverse proxy.

Step 4 — Setting Up Nginx as a Reverse Proxy Server

Your application is running and listening on localhost, but you need to set up a way for your users to access it. We will set up the Nginx web server as a reverse proxy for this purpose.

In the prerequisite tutorial, you set up your Nginx configuration in the /etc/nginx/sites-available/example.com file. Open this file for editing:


sudo nano /etc/nginx/sites-available/example.com

Within the server block, you should have an existing location / block. Replace the contents of that block with the following configuration. If your application is set to listen on a different port, update the highlighted portion to the correct port number:

/etc/nginx/sites-available/example.com

server {
...
    location / {
        proxy_pass http://localhost:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }
...
}

This configures the server to respond to requests at its root. Assuming our server is available at example.com, accessing https://example.com/ via a web browser would send the request to hello.js, listening on port 3000 at localhost.

You can add additional location blocks to the same server block to provide access to other applications on the same server. For example, if you were also running another Node.js application on port 3001, you could add this location block to allow access to it via https://example.com/app2:

/etc/nginx/sites-available/example.com — Optional

server {
...
    location /app2 {
        proxy_pass http://localhost:3001;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }
...
}

Once you are done adding the location blocks for your applications, save the file and exit your editor.

Make sure you didn't introduce any syntax errors by typing:


sudo nginx -t

Restart Nginx:


sudo systemctl restart nginx

Assuming that your Node.js application is running, and your application and Nginx configurations are correct, you should now be able to access your application via the Nginx reverse proxy. Try it out by accessing your server's URL (its public IP address or domain name).

Conclusion

Congratulations! You now have your Node.js application running behind an Nginx reverse proxy on a Debian 9 server. This reverse proxy setup is flexible enough to provide your users access to other applications or static web content that you want to share.

how to enable mod rewrite

2018-12-04T16:45:00.000+02:00

cat /etc/apache2/mods-available/rewrite.load
a2enmod rewrite
ls -al /etc/apache2/mods-enabled/rewrite.load
vim /etc/apache2/sites-available/000-default.conf

<Directory /var/www/>
        Options Indexes FollowSymLinks
        AllowOverride All
        Require all granted
</Directory>

 /etc/init.d/apache2 restart

install php 7.3 in debian

2018-12-04T16:44:00.003+02:00

Thanks to:
https://computingforgeeks.com/how-to-install-php-7-3-on-ubuntu-18-04-ubuntu-16-04-debian/

 sudo apt-get install php7.3-<entension-name>

sudo apt-get install php7.3-fpm  php7.3-curl php7.3-mysql php7.3-xml php7.3-zip php7.3-gd
apt policy php7.3-fpm

Drupal 8: Mismatched entity and/or field definitions

2017-07-07T14:03:00.001+03:00

Thanks to: https://www.fuelforbrain.com/drupal-8-mismatched-entity-andor-field-definitions

If you don't have Drush for drupal 8, please add the following script before $response->send(); in index.php file(located in Drupal root folder) and reload the web page.

try {
  \Drupal::entityDefinitionUpdateManager()->applyUpdates();
}
catch (EntityStorageException $e) {
  print_r($e);
}

font awesome error drupal

2017-07-07T13:27:00.001+03:00

How to resolve it:
1. Download from: https://github.com/FortAwesome/Font-Awesome package font awesome
2. Copy unziped files from it to sites/all/libraries/fontawesome
3. Clear cache

Change server name for apache2 -

2017-06-24T12:50:00.002+03:00

ServerTokens Full
SecServerSignature “Tecmint_Web”

HUGE THANKS TO: https://www.tecmint.com/change-apache-server-name-to-anything-in-server-headers/?utm_content=buffercc205&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer

MySQL Error 1064: You have an error in your SQL syntax - import database DRUPAL

2017-05-30T17:39:00.001+03:00

Thanx to: owntheweb

https://www.drupal.org/node/2496331

Change this:

CREATE TABLE `key_value` (
  `collection` varchar(128) CHARACTER SET ascii NOT NULL DEFAULT '' COMMENT 'A named collection of key and value pairs.'
`value` longblob NOT NULL COMMENT 'The value.',
  PRIMARY KEY (`collection`,`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='Generic key-value storage table. See the state system for…'

to this:

CREATE TABLE `key_value` (
  `collection` varchar(128) CHARACTER SET ascii NOT NULL DEFAULT '' COMMENT 'A named collection of key and value pairs.',
  `name` varchar(128) CHARACTER SET ascii NOT NULL DEFAULT '' COMMENT 'The key of the key-value pair. As KEY is a SQL reserved keyword, name was chosen instead.',
  `value` longblob NOT NULL COMMENT 'The value.',
  PRIMARY KEY (`collection`,`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='Generic key-value storage table. See the state system for';

then remove this near the end to prevent another error:

ALTER TABLE `key_value`
 ADD `name` varchar(128) CHARACTER SET ascii NOT NULL DEFAULT '' COMMENT 'The key of the key-value pair. As KEY is a SQL reserved keyword, name was chosen instead.';

MySQL Error 1064: You have an error in your SQL syntax

Change this:

CREATE TABLE `key_value` (
  `collection` varchar(128) CHARACTER SET ascii NOT NULL DEFAULT '' COMMENT 'A named collection of key and value pairs.'
`value` longblob NOT NULL COMMENT 'The value.',
  PRIMARY KEY (`collection`,`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='Generic key-value storage table. See the state system for…'

to this:

CREATE TABLE `key_value` (
  `collection` varchar(128) CHARACTER SET ascii NOT NULL DEFAULT '' COMMENT 'A named collection of key and value pairs.',
  `name` varchar(128) CHARACTER SET ascii NOT NULL DEFAULT '' COMMENT 'The key of the key-value pair. As KEY is a SQL reserved keyword, name was chosen instead.',
  `value` longblob NOT NULL COMMENT 'The value.',
  PRIMARY KEY (`collection`,`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='Generic key-value storage table. See the state system for';

then remove this near the end to prevent another error:

ALTER TABLE `key_value`
 ADD `name` varchar(128) CHARACTER SET ascii NOT NULL DEFAULT '' COMMENT 'The key of the key-value pair. As KEY is a SQL reserved keyword, name was chosen instead.';

SOLVED read(anvil) failed

2017-05-22T18:39:00.002+03:00

There is a simple error:

vim /etc/dovecot/conf.d/10-ssl.conf

and change ssl = required to

ssl = yes

restart dovecot and YES!

DIGITALOCEAN How To Set Up a Postfix E-Mail Server with Dovecot

2017-05-21T13:38:00.001+03:00

How To Set Up a Postfix E-Mail Server with Dovecot

PostedNovember 14, 2013 451.5k EMAIL UBUNTU

Postfix Introduction

This tutorial will tell you how to setup a basic mail server and teach you a bit about the Postfix MTA (Mail Transfer Agent) in the process.

Postfix is extremely flexible. Its architecture is based on a loose composition of services that receive emails and pass them on to other services (with services like "smtp" on the receiving outer edge, and "local" and "virtual" on the delivering outer edge, if you're looking at receiving mail). Postfix itself implements the core requirements to receive, route, and deliver mail, and relies on third-party extensions to do the rest.

Postfix has several hundred configuration parameters. If you want to administer a mail server that reliably delivers business requirements to a sizable organization, you should make yourself intimate with all of them (man 5 postconf). This tutorial will not be enough, on its own, to make you a competent professional email admin. However, if you want to become familiar with postfix or set up a mail server for yourself and a few friends, this tutorial, and the ones to follow, will be your friend.

Dovecot Introduction

I'm not going to spend a lot of introductory words on dovecot. Dovecot is also huge (here is the wiki for dovecot 2), but we only want a very small set of features from dovecot.

This article explains almost every single setting to be set in detail. You can go ahead and skim over the explanations if you want - at your own risk.

This tutorial assumes (and was built using) the following setup:

Debian 7.1 wheezy x64_86
Postfix 2.9.6-2
dovecot 1:2.1.7-7

While any Debian-based OS should be fine, Postfix is in use in a wide array of versions, including Postfix 1.x, Postfix 2.9, and Postfix 2.10, which have some mutually incompatible settings and features - and using Postfix 2.9, this tutorial is not on the bleeding edge.

This tutorial also assumes a few things about you:

That you are comfortable on a GNU/Linux commandline and with the general layout and working principles of a GNU/Linux system like Debian.
That your local system is a GNU/Linux or reasonably compatible (MinGW, Cygwin, Mac OS X, *BSD)
That you know how to get a rootshell on your droplet
That you know how to use a text editor (e.g. vim, nano, emacs, or the standard editor, ed) on linux

By default, commands will be entered and files edited from a rootshell on the droplet. As in most other DigitalOcean articles, parts of commands that you need to customize will be highlighted in red.

System Setup

The following ingredients are necessary to make your droplet ready to be a mail server:

A domain, let's assume it is "mydomain.com"
A hostname for your mail server, let's assume "mail.mydomain.com"
An SSL certificate that is valid for "mail.mydomain.com"

Setting up SSL certificate

For SSL, you need a certificate and a private key. In this tutorial, we're going to assume that the certificate is saved in /etc/ssl/certs/mailcert.pem and the key is saved in /etc/ssl/private/mail.key. Make sure the key is only readable by the root user!

How to set up SSL certificates for your website and e-mail depends on your website structure and the CA you use (self-signed, organisational (sub)-ca, or commercial ca for example). Creating a self-signed test certificate is as easy as executing

sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/ssl/private/mail.key -out /etc/ssl/certs/mailcert.pem

and leaving the default values in by just hitting enter on all questions asked. Don't use this certificate in production!

Most CAs will require you to submit a certificate signing request. (CSR) You can generate one like this:

sudo openssl req -nodes -days 365 -newkey rsa:2048 -keyout /etc/ssl/private/mail.key -out mailcert.csr

Fill in the information queried properly, like in this transcript: (Check with the CA you intend to use on what information needs to be in the CSR)

Generating a 2048 bit RSA private key
.............................+++
................+++
writing new private key to 'mail.key'
-----
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [AU]: US
State or Province Name (full name) [Some-State]: Virginia
Locality Name (eg, city) []: Langley
Organization Name (eg, company) [Internet Widgits Pty Ltd]: Network Services Association
Organizational Unit Name (eg, section) []: Infrastructure Services
Common Name (e.g. server FQDN or YOUR name) []: mail.mydomain.com
Email Address []: postmaster@mydomain.com

Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:

(Note that this way you cannot create a certificate valid for more than one domain using the subjectAltName field without some additional work - again, check the CA's documentation!)

Setting up DNS

You have to set up your DNS with an A record that points to your mail server IP and an MX record that points to the mail servers hostname.

Here is how to do it if you're using DigitalOcean's DNS:

Go to the "DNS" area in your DigitalOcean panel
Create a new domain or select one you've created before
Click the "Add record" button in the top right
Add an A record:

Click "Add record" again and add an MX record that points to the A record:

Additional information can be found in the Host Name setup and DNS tips and tricks articles.

Verify DNS

DNS will take a few hours to propagate all over the internet, but it should be set on your DNS server after a few minutes. You can check with dig & host:

[root@yourbase] ~# dig MX mydomain.com +short @ns1.digitalocean.com
50 mail.mydomain.com.
[root@yourbase] ~# host mail.mydomain.com ns1.digitalocean.com
Using domain server:
Name: ns1.digitalocean.com
Address: 198.199.120.125#53
Aliases:

mail.mydomain.com has address 82.196.9.119

Postfix

We will now set up Postfix to receive and deliver mail for local users.

Packages

The default MTA on Debian is exim. Off with it! We'll also stop postfix after it has been installed, because we don't want it to be running yet.

aptitude remove exim4 && aptitude install postfix && postfix stop

A small insert: Postfix manages its daemons by itself and doesn't need the service (init.d) system. postfix start, postfix stop, and postfix reload are equivalent to service postfix start, service postfix stop and service postfix reload.

Postfix Configuration

Postfix has two main config files: main.cf, which specifies what you would think of as config options, and master.cf, which specifies the services postfix should run.

First, configure the master.cf file (in /etc/postfix/). Add an extra "smtpd" instance called "submission" that will take mail from trusted clients for delivery to the world at large, which we don't allow for anyone else.
To do that, open master.cf (take a look at man 5 master if you want to understand what's going on) and uncomment the submission config and add options to enable SASL:

submission inet n       -       -       -       -       smtpd
  -o syslog_name=postfix/submission
  -o smtpd_tls_wrappermode=no
  -o smtpd_tls_security_level=encrypt
  -o smtpd_sasl_auth_enable=yes
  -o smtpd_recipient_restrictions=permit_mynetworks,permit_sasl_authenticated,reject
  -o milter_macro_daemon_name=ORIGINATING
  -o smtpd_sasl_type=dovecot
  -o smtpd_sasl_path=private/auth

This warrants a bit of explanation. The -o ... options override the settings that are taken from defaults or define in the config, which we'll set later.
In a nutshell what happens here is that this enables the "submission" daemon with TLS to secure the outer connection, and dovecot-mediated SASL to check the username and password of connecting clients. (We will set that up in dovecot later).

The important detail is one that can't be seen: The smtpd_recipient_restrictions is missing reject_unauth_destination, which is present as a default and restricts relaying.

Then we move on to main.cf. We'll start with a clean slate here - run cp /etc/postfix/main.cf /etc/postfix/main.cf.orig if you want to save the default config file (it's also in /usr/share/postfix/main.cf.dist though), then open it and clear it out!

Let's first set the network information: (information about the domains postfix is handling mail for, and a bit of extra info)

myhostname = mail.domain.com
myorigin = /etc/mailname
mydestination = mail.domain.com, domain.com, localhost, localhost.localdomain
relayhost =
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all

We set the hostname and the default origin, which is sourced from /etc/mailname by debian convention. You can set it explicitly if you don't have /etc/mailname. The default origin is used to construct the 'From' address for local users. mydestination sets the domains that postfix accepts emails for as final destination, and we set "relayhost" empty to disable relaying mail (relaying means accepting mail and then forwarding to a mail server that is not the final destination for the mail and we have no need for that; that is useful e.g. in a corporate intranet where a central mail server should check mail before it leaves the network.)

Additional note: This has nothing to do with the term "open relay", which is a mail server that accepts email from anybody without authentication and sends it to MTAs for domains that aren't in their own network - for this the other `relay_` settings are used, which we leave on default and disabled)

Let's now set the local alias maps. We don't have to set this setting since we're just keeping the default setting, but it's good to make it explicit in case we later want to add another method of defining alias maps. (like a real DBMS)

alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases

Then we set up SSL:

smtpd_tls_cert_file=/etc/ssl/certs/mailcert.pem
smtpd_tls_key_file=/etc/ssl/private/mail.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_tls_security_level=may
smtpd_tls_protocols = !SSLv2, !SSLv3

We set the cert file and the key for it, enable tls, and set the cache files. Then we make TLS optional, because we're not allowed to make TLS required on a public smtp server per RFC2487. We also disallow SSLv2 and SSLv3, so that only TLSv1.0 and higher is allowed (read a SSL tutorial if you want to know why - in a nutshell, SSLv2 and SSLv3 are obsolete).

Another setting that is fine as default but should be specified explicitly in case you want to add to it later is the localrecipientmaps:

local_recipient_maps = proxy:unix:passwd.byname $alias_maps

This setting tells Postfix to check a lookup table and reject email to users that cannot be found in the table. This is important because the alternative behaviour, if local_recipient_maps is unset, is to accept mail first and then bounce it later. This causes "backscatter": If postfix cannot determine all valid users immediately (in the smtpd service), like when local_recipients_maps is unset, it will accept mail and then send a non-delivery notice later (when it finds out the mail is undeliverable after it has been handed off by smptd). These non-delivery notices usually hit innocent people whose addresses have been spoofed in spam and scam mails and contribute to the spam problem.

Sane Alias Config

There are a few mail accounts you should set up in your alias config that are important. For example the SMTP RFC mandates that any publicly accessible mailserver that accepts any mail at all must also accept mail to the 'postmaster' account, and some people might expect "hostmaster", "abuse", "webmaster", and other mailboxes to be present. You can either redirect those mail addresses to root, or to a specific user. Here is a sane default for /etc/aliases, presuming that you check email for root:

mailer-daemon: postmaster
postmaster: root
nobody: root
hostmaster: root
usenet: root
news: root
webmaster: root
www: root
ftp: root
abuse: root

If you want to redirect all of that to a specific local user, say, "yourname" just add

root: yourname

Postfix will resolve the entire chain of aliases for you and forward all those mail addresses to "yourname". (This is done by the local daemon using the aliases specification.)

As "aliases" says, after updating the /etc/aliases file, you have to run

newaliases

to compile the file into the database Postfix uses for fast lookup.

Dovecot

This one will be less wall-of-text-y! Take a deep breath, we're almost done.

Packages

aptitude install dovecot-core dovecot-imapd

Should do it. If you want all the default packages, run

aptitude install dovecot-common

Then go into /etc/dovecot/dovecot.conf and clear out the file again. (that's important this time - the default config includes a bunch of subordinate config files in /etc/dovecot/conf.d that we don't want).

Now enter the following config:

disable_plaintext_auth = no
mail_privileged_group = mail
mail_location = mbox:~/mail:INBOX=/var/mail/%u
userdb {
  driver = passwd
}
passdb {
  args = %s
  driver = pam
}
protocols = " imap"

This enables plaintext auth (The "plaintext" authentication will be tunneled through TLS), tells dovecot to use the mail system group for accessing the local mailboxes (plus the location of the mailboxes), use the unix authentication system to authenticate users, and enable imap only.

If you want, you can have dovecot automatically add a Trash and Sent folder to mailboxes:

protocol imap {
  mail_plugins = " autocreate"
}
plugin {
  autocreate = Trash
  autocreate2 = Sent
  autosubscribe = Trash
  autosubscribe2 = Sent
}

Next, we need to open a socket that postfix can use to piggy-back on dovecot's authentication:

service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0660
    user = postfix
  }
}

And finally the ssl config:

ssl=required
ssl_cert = </etc/ssl/certs/mailcert.pem
ssl_key = </etc/ssl/private/mail.key

Note the angle brackets! They tell dovecot to read from a file.

The End

Save and close all the config files, and execute

newaliases
postfix start
service dovecot restart

And you should be good to go. Test your config with a mail client, e.g. Mozilla Thunderbird. You should be able to send and receive mails from everywhere and to everywhere!

Continued

If you want to add virtual mailboxes (mail boxes that are not tied to a local user account, but can instead be configured using a local database) continue with Part 2.***

You can now test that sending e-mail both ways works, from a terminal on the droplet:

~# mail someotheremail@gmail.com
Subject: test email from postfix
this is a test
.
EOT

The mail from "root@yourdomain.com" should shortly arrive at "someotheremail@gmail.com" (fill in an email adress you control, obviously). If you reply to it and call mail again, you should see this: (it might take a minute for the mail to arrive).

~# mail
Heirloom mailx version 12.5 6/20/10.  Type ? for help.
"/var/mail/root": 1 message
>N  1 Your Name          Wed Nov 13 23:45   41/1966  Re: test email from postf

And if you hit the Enter key, it will show the message. (then type q and hit Enter to leave the mail client)

The same thing will work with a local e-mail client. Set up a new system user:

~# adduser joe
Adding user `joe' ...
Adding new group `joe' (1001) ...
Adding new user `joe' (1001) with group `joe' ...
Creating home directory `/home/joe' ...
Copying files from `/etc/skel' ...
Enter new UNIX password: Enter password here
Retype new UNIX password: Enter password here
passwd: password updated successfully
Changing the user information for joe
Enter the new value, or press ENTER for the default
        Full Name []:
        Room Number []:
        Work Phone []:
        Home Phone []:
        Other []:
Is the information correct? [Y/n] Y

The password you entered here is the password to use for e-mail. Joe can now use the address joe@yourdomain.com with a local mail client like Thunderbird. In Thunderbird, just add a new Account (File -> New -> Existing Mail Account) and enter joe@yourdomain.com and the password in the dialog.

If your mail client doesn't auto-detect the necessary settings: The username for the IMAP connection is joe, the port is 143, and the authentication method is unencrypted password via STARTTLS. For SMTP it's the same, but port 587.

If anything isn't working, check for error messages in the system log with tail -n 50 /var/log/syslogand in the mail log with tail -n 50 /var/log/mail.log.

Submitted by: Lukas Erlacher

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151 Comments

ethno-urban November 16, 2013
I have to put: mail_location = mbox:~/mail:INBOX=/var/mail/%u at the end of "dovecot.conf"
l.erlacher+do November 17, 2013
Thanks for the note. I don't have that set, that's weird - I'll do some testing and check it out!
l.erlacher+do November 17, 2013
It appears you are correct - I'll try to get that fixed in the article!
kamaln7 MOD November 17, 2013
@Lukas, ethno-urban: Thanks, I've updated the article :]
pauldavidmena November 17, 2013
Just tested this out on my Droplet and it all worked on the first try! Thanks for the detailed instructions.
haprog November 19, 2013
Thanks! Now I finally have a self configured mail server up. :)
dan106525 November 19, 2013
Is there any GUI for setting up new mail accounts so anyone don't need to enter ssh for account creation?
l.erlacher+do November 19, 2013
No - in this setup, mail accounts are directly tied to system users. I am working on a follow-up article to allow adding users to a database!
cyborg101010 November 20, 2013
Hi, For SMTP, should I use smtp.yourdomain.com, or mail.yourdomain.com? I can send mail from the server fine now, just not from a remote location.
l.erlacher+do November 20, 2013
Postfix is running smtp directly on the mail server you configured, so at 'mail.yourdomain.com'. It will accept mail for delivery to **local** mail addresses via standard smtp on port 25, and it will receive mail for delivery to **any** mail addresses via authenticated, encrypted submission server (which is also smtp, postfix just calls it submission) on port 587. Make sure that your mail client uses port 587 with plain password auth and starttls.
mkhitar.mikaelyan November 21, 2013
Great tutorial. I have just one issue. I can send with 'sendmail somebody@gmail.com', but with 'mail somebody@gmail.com' -> -bash: mail: command not found. I am root user. Could you help me with this?
alexandru.vladoiu November 22, 2013
I'm trying to setup a simple mail server on a debian vps with postfix and dovecot. I can send and receive email from the server via mutt but when i try to connect to IMAP via Thunderbird for example, it does not work: Nov 22 11:45:22 localhost dovecot: imap-login: Fatal: Can't load ssl_cert: The file contains a private key (you've mixed ssl_cert and ssl_key settings) Nov 22 11:45:22 localhost dovecot: master: Error: service(imap-login): command startup failed, throttling for 16 secs Extract from main.cf postifx file: smtpd_tls_cert_file = /etc/ssl/private/dovecot.pem smtpd_tls_key_file = /etc/ssl/private/dovecot.key smtpd_use_tls=yes smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache smtpd_tls_security_level=may smtpd_tls_protocols = !SSLv2, !SSLv3 Extract from dovecot.conf: protocols = "imap" protocol imap { mail_plugins = " autocreate" } plugin { autocreate = Trash autocreate2 = Sent autosubscribe = Trash autosubscribe2 = Sent } service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0660 user = postfix } } ssl=required ssl_cert =
kamaln7 MOD November 22, 2013
@mkhitar.mikaelyan: Run
sudo apt-get install mailutils
kamaln7 MOD November 22, 2013
@alexandru.vladoiu:
Nov 22 11:45:22 localhost dovecot: imap-login: Fatal: Can't load ssl_cert: The file contains a private key (you've mixed ssl_cert and ssl_key settings)
The SSL file you configured dovecot to use is invalid.
paulo November 25, 2013
When can we find part 2 and 3? Cheers,
alifaziz November 26, 2013
I have this error on Thunderbird setup, dovecot: auth: Fatal: No passdbs specified in configuration file. PLAIN mechanism needs one What probably went wrong? Thanks!
kamaln7 MOD November 28, 2013
@alifaziz: Please pastebin dovecot's config file.
roy.bottomley November 29, 2013
same as Alifaziz, in my logs in have dovecot: auth: Fatal: No passdbs specified in configuration file. PLAIN mechanism needs one postfix seems to be able to send and receive mails ok but can't get past this probelm with dovecot this is my dovecot conf file disable_plaintext_auth = no mail_privileged_group = mail mail_location = mbox:~/mail:INBOX=/var/mail/%u userdb { driver = passwd } protocols = " imap" protocol imap { mail_plugins = " autocreate" } plugin { autocreate = Trash autocreate2 = Sent autosubscribe = Trash autosubscribe2 = Sent } service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0660 user = postfix } } ssl=required ssl_cert =
roy.bottomley November 29, 2013
opps last bit of fiel went wrong here it is ssl=required ssl_cert =
roy.bottomley November 29, 2013
taken the angle brackets off after ssl_cert = and ssl_key = in the hope it posts this time ssl=required ssl_cert = /etc/ssl/certs/mailcert.pem ssl_key = /etc/ssl/private/mail.key mail_location = mbox:~/mail:INBOX=/var/mail/%u

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DIGITALOCEAN How To Set Up a Postfix E-Mail Server with Dovecot

How To Set Up a Postfix E-Mail Server with Dovecot

Postfix Introduction

Dovecot Introduction

System Setup

Setting up SSL certificate

Setting up DNS

Verify DNS

Postfix

Packages

Postfix Configuration

Sane Alias Config

Dovecot

Packages

The End

Continued

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