Installing Mattermost on RHEL 7

You can also use these instructions to install Mattermost on CentOS 7, Oracle Linux 7, or Scientific Linux 7. With the exception of the operating system that you install, the process is identical.

A complete Mattermost installation consists of three major components: a proxy server, a database server, and the Mattermost server. You can install all components on one machine, or you can install each component on its own machine. If you have only two machines, then install the proxy and the Mattermost server on one machine, and install the database on the other machine.

For the database, you can install either MySQL or PostgreSQL. The proxy is NGINX.

Note

If you have any problems installing Mattermost, see the troubleshooting guide. For help with inviting users to your system, see inviting team members and other getting started information. To submit an improvement or correction, click Edit at the top of this page.

Installing Red Hat Enterprise Linux 7

Install the 64-bit version of RHEL 7 on each machine that hosts one or more of the components.

To install RHEL 7 Server:

  1. To install RHEL 7, see the RedHat Installation Instructions.
  2. After the system is installed, make sure that it’s up to date with the most recent security patches. Open a terminal window and issue the following commands:

sudo yum update

sudo yum upgrade

Now that the system is up to date, you can start installing the components that make up a Mattermost system.

Installing MySQL Database Server

Install and set up the database for use by the Mattermost server. You can install either MySQL or PostgreSQL.

To install MySQL 5.7 on RHEL 7:

  1. Log in to the server that will host the database, and open a terminal window.
  2. Download the MySQL Yum repository from dev.mysql.com.
wget http://dev.mysql.com/get/mysql57-community-release-el7-9.noarch.rpm
  1. Install the Yum repository from the file that you downloaded.
sudo yum localinstall mysql57-community-release-el7-9.noarch.rpm
  1. Install MySQL.
sudo yum install mysql-community-server
  1. Start the MySQL server.

sudo systemctl start mysqld.service

Note

  1. The first time that you start MySQL, the superuser account 'root'@'localhost' is created and a temporary password is generated for it.
  2. Also the first time that you start MySQL, the validate_password plugin is installed. The plugin forces passwords to contain at least one upper case letter, one lower case letter, one digit, and one special character, and that the total password length is at least 8 characters.
  1. Obtain the root password that was generated when you started MySQL for the first time.
sudo grep 'temporary password' /var/log/mysqld.log
  1. Change the root password. Login with the password that you obtained from the previous step.
mysql -u root -p
  1. Change the password. At the mysql prompt, type the following command. Be sure to replace Password42! with the password that you want to use.
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'Password42!';
  1. Set MySQL to start automatically when the machine starts.
sudo systemctl enable mysqld
  1. Create the Mattermost user ‘mmuser’.

mysql> create user 'mmuser'@'%' identified by 'mmuser-password';

Note

  1. Use a password that is more secure than ‘mmuser-password’.
  2. The ‘%’ means that mmuser can connect from any machine on the network. However, it’s more secure to use the IP address of the machine that hosts Mattermost. For example, if you install Mattermost on the machine with IP address 10.10.10.2, then use the following command:
mysql> create user 'mmuser'@'10.10.10.2' identified by 'mmuser-password';
  1. Create the Mattermost database.
mysql> create database mattermost;
  1. Grant access privileges to the user ‘mmuser’.
mysql> grant all privileges on mattermost.* to 'mmuser'@'%';

With the database installed and the initial setup complete, you can now install the Mattermost server.

Installing PostgreSQL Database

  1. Log in to the server that will host the database, and open a terminal window.
  2. Download the PostgreSQL 9.4 Yum repository.
For RHEL 7
curl -O https://download.postgresql.org/pub/repos/yum/9.4/redhat/rhel-7-x86_64/pgdg-redhat94-9.4-3.noarch.rpm
For CentOS 7
curl -O https://download.postgresql.org/pub/repos/yum/9.4/redhat/rhel-7-x86_64/pgdg-centos94-9.4-3.noarch.rpm
For Scientific Linux
curl -O https://download.postgresql.org/pub/repos/yum/9.4/redhat/rhel-7-x86_64/pgdg-sl94-9.4-3.noarch.rpm
For Oracle
curl -O https://download.postgresql.org/pub/repos/yum/9.4/redhat/rhel-7-x86_64/pgdg-oraclelinux-9.4-3.noarch.rpm
  1. Install the Yum repository from the file that you downloaded.
sudo yum localinstall pgdg-*-9.4-3.noarch.rpm
  1. Install PostgreSQL.
sudo yum install postgresql94-server postgresql94-contrib
  1. Initialize the database.
sudo /usr/pgsql-9.4/bin/postgresql94-setup initdb
  1. Set PostgreSQL to start on boot.
sudo systemctl enable postgresql-9.4
  1. Start the PostgreSQL server.
sudo systemctl start postgresql-9.4
  1. Switch to the postgres Linux user account that was created during the installation.
sudo -iu postgres
  1. Start the PostgreSQL interactive terminal.
psql
  1. Create the Mattermost database.
postgres=# CREATE DATABASE mattermost;
  1. Create the Mattermost user ‘mmuser’.

postgres=# CREATE USER mmuser WITH PASSWORD 'mmuser-password';

Note

Use a password that is more secure than ‘mmuser-password’.

  1. Grant the user access to the Mattermost database.
postgres=# GRANT ALL PRIVILEGES ON DATABASE mattermost to mmuser;
  1. Exit the PostgreSQL interactive terminal.
postgres=# \q
  1. Log out of the postgres account.
exit
  1. (Optional) If you use a different server for your database and the Mattermost app server, you may allow PostgreSQL to listen on all assigned IP Addresses. To do so, open /etc/postgresql/9.5/main/postgresql.conf as root in a text editor. As a best practice, ensure that only the Mattermost server is able to connect to the PostgreSQL port using a firewall.
  1. Open /var/lib/pgsql/9.4/data/postgresql.conf as root in a text editor.
  2. Find the following line:
#listen_addresses = 'localhost'
  1. Uncomment the line and change localhost to *:
listen_addresses = '*'
  1. Restart PostgreSQL for the change to take effect:
sudo systemctl restart postgresql-9.4
  1. Modify the file pg_hba.conf to allow the Mattermost server to communicate with the database.

If the Mattermost server and the database are on the same machine:

  1. Open /var/lib/pgsql/9.4/data/pg_hba.conf as root in a text editor.
  2. Find the following line:
local   all             all                        peer
  1. Change peer to trust:
local   all             all                        trust

If the Mattermost server and the database are on different machines:

  1. Open /var/lib/pgsql/9.4/data/pg_hba.conf as root in a text editor.
  2. Add the following line to the end of the file, where {mattermost-server-IP} is the IP address of the machine that contains the Mattermost server.
host all all {mattermost-server-IP}/32 md5
  1. Reload PostgreSQL:
sudo systemctl reload postgresql-9.4
  1. Verify that you can connect with the user mmuser.
  1. If the Mattermost server and the database are on the same machine, use the following command:
psql --dbname=mattermost --username=mmuser --password
  1. If the Mattermost server is on a different machine, log into that machine and use the following command:

psql --host={postgres-server-IP} --dbname=mattermost --username=mmuser --password

Note

You might have to install the PostgreSQL client software to use the command.

The PostgreSQL interactive terminal starts. To exit the PostgreSQL interactive terminal, type \q and press Enter.

With the database installed and the initial setup complete, you can now install the Mattermost server.

Installing Mattermost Server

Install Mattermost Server on a 64-bit machine.

Assume that the IP address of this server is 10.10.10.2

To install Mattermost Server on RHEL 7

  1. Log in to the server that will host Mattermost Server and open a terminal window.
  2. Download the latest version of the Mattermost Server. In the following command, replace X.X.X with the version that you want to download:
wget https://releases.mattermost.com/X.X.X/mattermost-X.X.X-linux-amd64.tar.gz
  1. Extract the Mattermost Server files.
tar -xvzf *.gz
  1. Move the extracted file to the /opt directory.
sudo mv mattermost /opt
  1. Create the storage directory for files.

sudo mkdir /opt/mattermost/data

Note

The storage directory will contain all the files and images that your users post to Mattermost, so you need to make sure that the drive is large enough to hold the anticipated number of uploaded files and images.

  1. Set up a system user and group called mattermost that will run this service, and set the ownership and permissions.
  1. sudo useradd --system --user-group mattermost
  2. sudo chown -R mattermost:mattermost /opt/mattermost
  3. sudo chmod -R g+w /opt/mattermost
  1. Set up the database driver in the file /opt/mattermost/config/config.json. Open the file as root in a text editor and make the following changes:
  • If you are using PostgreSQL:
  1. Set "DriverName" to "postgres"
  2. Set "DataSource" to the following value, replacing <mmuser-password> and <host-name-or-IP> with the appropriate values:
"postgres://mmuser:<mmuser-password>@<host-name-or-IP>:5432/mattermost?sslmode=disable&connect_timeout=10".
  • If you are using MySQL:
  1. Set "DriverName" to "mysql"
  2. Set "DataSource" to the following value, replacing <mmuser-password> and <host-name-or-IP> with the appropriate values. Also make sure that the database name is mattermost instead of mattermost_test:
"mmuser:<mmuser-password>@tcp(<host-name-or-IP>:3306)/mattermost?charset=utf8mb4,utf8&readTimeout=30s&writeTimeout=30s"

  1. Also set "SiteURL" to the full base URL of the site (e.g. "https://mattermost.example.com").

  2. Test the Mattermost server to make sure everything works.

    1. Change to the mattermost directory:

    cd /opt/mattermost

    1. Start the Mattermost server as the user mattermost:

    sudo -u mattermost ./bin/mattermost

When the server starts, it shows some log information and the text Server is listening on :8065. You can stop the server by pressing CTRL+C in the terminal window.
  1. Set up Mattermost to use the systemd init daemon which handles
supervision of the Mattermost process.
  1. Create the Mattermost configuration file:
sudo touch /etc/systemd/system/mattermost.service
  1. Open the configuration file in your favorite text editor, and copy the following lines into the file:
[Unit]
Description=Mattermost
After=syslog.target network.target postgresql-9.4.service

[Service]
Type=notify
WorkingDirectory=/opt/mattermost
User=mattermost
ExecStart=/opt/mattermost/bin/mattermost
PIDFile=/var/spool/mattermost/pid/master.pid
TimeoutStartSec=3600
LimitNOFILE=49152

[Install]
WantedBy=multi-user.target

Note

If you are using MySQL, replace postgresql-9.4.service by mysqld.service in the [unit] section.

  1. Make the service executable.
sudo chmod 664 /etc/systemd/system/mattermost.service
  1. Reload the systemd services.
sudo systemctl daemon-reload
  1. Set Mattermost to start on boot.
sudo systemctl enable mattermost
  1. Start the Mattermost server.
sudo systemctl start mattermost
  1. Verify that Mattermost is running.

curl http://localhost:8065

You should see the HTML that’s returned by the Mattermost server.

Now that Mattermost is installed and running, it’s time to create the admin user and configure Mattermost for use.

Configuring Mattermost Server

Create the System Admin user and set up Mattermost for general use.

  1. Open a browser and navigate to your Mattermost instance. For example, if the IP address of the Mattermost server is 10.10.10.2 then go to http://10.10.10.2:8065.
  2. Create the first team and user. The first user in the system has the system_admin role, which gives you access to the System Console.
  3. Open the System Console. To open the System Console, click your username at the top of the navigation panel, and in the menu that opens, click System Console.
  4. Set the Site URL:
  1. In the GENERAL section of the System Console, click Configuration in prior versions or System Console > Environment > Web Server in versions after 5.12.
  2. In the Site URL field, set the URL that users point their browsers at. For example, https://mattermost.example.com. If you are using HTTPS, make sure that you set up TLS, either on Mattermost Server or on a proxy.
  1. Set up email notifications.
  1. In the NOTIFICATIONS section of the System Console, make the following changes:
  • Set Enable Email Notifications to true
  • Set Notification Display Name to No-Reply
  • Set Notification From Address to {your-domain-name} For example, example.com
  1. In the NOTIFICATIONS section of the System Console in prior versions or System Console > Environment > SMTP in versions after 5.12, also make the following changes:
  • Set SMTP Server Username to {SMTP-username} For example, admin@example.com
  • Set SMTP Server Password to {SMTP-password}
  • Set SMTP Server to {SMTP-server} For example, mail.example.com
  • Set SMTP Server Port to 465
  • Set Connection Security to TLS or STARTTLS, depending on what the SMTP server accepts.
  1. Click Test Connection.
  2. After your connection is working, click Save.
  1. Set up the file and image storage location.

Note

  1. Files and images that users attach to their messages are not stored in the database. Instead, they are stored in a location that you specify. You can store the files on the local file system or in Amazon S3.
  2. Make sure that the location has enough free space. The amount of storage that’s required depends on the number of users and on the number and size of files that users attach to messages.
  1. In the FILES section of the System Console, click Storage in prior versions or System Console > Environment > File Storage in versions after 5.12.
  2. If you store the files locally, set File Storage System to Local File System, and then either accept the default for the Local Storage Directory or enter a location. The location must be a directory that exists and has write permissions for the Mattermost server. It can be an absolute path or a relative path. Relative paths are relative to the mattermost directory.
  3. If you store the files on Amazon S3, set File Storage System to Amazon S3 and enter the appropriate values for your Amazon account.
  4. Click Save.
  1. Review the other settings in the System Console to make sure everything is as you want it.
  2. Restart the Mattermost Service.

On Ubuntu 14.04 and RHEL 6:

sudo restart mattermost

On Ubuntu 16.04, 18.04, Debian Stretch, and RHEL 7:

sudo systemctl restart mattermost

Configuring TLS on Mattermost Server

You have two options if you want users to connect with HTTPS:

  1. Set up TLS on Mattermost Server.
  2. Install a proxy such as NGINX and set up TLS on the proxy.

The easiest option is to set up TLS on the Mattermost Server, but if you expect to have more than 200 users, use a proxy for better performance. A proxy server also provides standard HTTP request logs.

Note

Your Mattermost server must be accessible from the Let’s Encrypt CA in order to verify your domain name and issue the certificate. Be sure to open your firewall and configure any reverse proxies to forward traffic to ports 80 and 443. More information can be found at Let’s Encrypt.

Configure TLS on the Mattermost Server:

  1. In System Console > Environment > Web Server (or System Console > General > Configuration in versions prior to 5.12).
  1. Change the Listen Address setting to :443.
  2. Change the Connection Security setting to TLS.
  3. Change the Forward port 80 to 443 setting to true.
  1. Activate the CAP_NET_BIND_SERVICE capability to allow Mattermost to bind to low ports.
sudo setcap cap_net_bind_service=+ep /opt/mattermost/bin/mattermost
  1. Install the security certificate. You can use Let’s Encrypt to automatically install and setup the certificate, or you can specify your own certificate.

To use a Let’s Encrypt certificate:

The certificate is retrieved the first time that a client tries to connect to the Mattermost server. Certificates are retrieved for any hostname a client tries to reach the server at.

  1. Change the Use Let’s Encrypt setting to true.
  2. Restart the Mattermost server for these changes to take effect.

Note

If Let’s Encrypt is enabled, forward port 80 through a firewall, with Forward80To443 config.json setting set to true to complete the Let’s Encrypt certification.

To use your own certificate:

  1. Change the Use Let’s Encrypt setting to false.
  2. Change the TLS Certificate File setting to the location of the certificate file.
  3. Change the TLS Key File setting to the location of the private key file.
  4. Restart the Mattermost server for these changes to take effect.

Note

Password-protected certificates are not supported.

Installing NGINX Server

In a production setting, use a proxy server for greater security and performance of Mattermost.

The main benefits of using a proxy are as follows:

  • SSL termination
  • HTTP to HTTPS redirect
  • Port mapping :80 to :8065
  • Standard request logs

To install NGINX on RHEL 6 or 7:

  1. Log in to the server that will host the proxy, and open a terminal window.
  2. Create the file /etc/yum.repos.d/nginx.repo.
sudo touch /etc/yum.repos.d/nginx.repo
  1. Open the file as root in a text editor and add the following contents, where {version} is 6 for RHEL 6, and 7 for RHEL 7:
[nginx]
name=nginx repo
baseurl=http://nginx.org/packages/rhel/{version}/$basearch/
gpgcheck=0
enabled=1
  1. Install NGINX.
sudo yum install nginx.x86_64
  1. After the installation is complete, start NGINX.

    On RHEL 6:

    sudo service nginx start

    On RHEL 7:

    sudo systemctl start nginx

  2. Optional Set NGINX to start at system boot.

    On RHEL 6:

    sudo chkconfig nginx on

    On RHEL 7:

    sudo systemctl enable nginx

  1. Verify that NGINX is running.

curl http://localhost

If NGINX is running, you see the following output:

<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
.
.
.
<p><em>Thank you for using nginx.</em></p>
</body>
</html>

What to do next

  1. Map a fully qualified domain name (FQDN) such as mattermost.example.com to point to the NGINX server.
  2. Configure NGINX to proxy connections from the Internet to the Mattermost Server.

Configuring NGINX as a proxy for Mattermost Server

NGINX is configured using a file in the /etc/nginx/sites-available directory. You need to create the file and then enable it. When creating the file, you need the IP address of your Mattermost server and the fully qualified domain name (FQDN) of your Mattermost website.

To configure NGINX as a proxy

  1. Log in to the server that hosts NGINX and open a terminal window.
  2. Create a configuration file for Mattermost.
sudo touch /etc/nginx/sites-available/mattermost

On RHEL 7: sudo touch /etc/nginx/conf.d/mattermost

3. Open the file /etc/nginx/sites-available/mattermost as root in a text editor and replace its contents, if any, with the following lines. Make sure that you use your own values for the Mattermost server IP address and FQDN for server_name. On RHEL 7, open the file /etc/nginx/conf.d/mattermost.

upstream backend {
   server 10.10.10.2:8065;
   keepalive 32;
}

proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=mattermost_cache:10m max_size=3g inactive=120m use_temp_path=off;

server {
   listen 80;
   server_name    mattermost.example.com;

   location ~ /api/v[0-9]+/(users/)?websocket$ {
       proxy_set_header Upgrade $http_upgrade;
       proxy_set_header Connection "upgrade";
       client_max_body_size 50M;
       proxy_set_header Host $http_host;
       proxy_set_header X-Real-IP $remote_addr;
       proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
       proxy_set_header X-Forwarded-Proto $scheme;
       proxy_set_header X-Frame-Options SAMEORIGIN;
       proxy_buffers 256 16k;
       proxy_buffer_size 16k;
       client_body_timeout 60;
       send_timeout 300;
       lingering_timeout 5;
       proxy_connect_timeout 90;
       proxy_send_timeout 300;
       proxy_read_timeout 90s;
       proxy_pass http://backend;
   }

   location / {
       client_max_body_size 50M;
       proxy_set_header Connection "";
       proxy_set_header Host $http_host;
       proxy_set_header X-Real-IP $remote_addr;
       proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
       proxy_set_header X-Forwarded-Proto $scheme;
       proxy_set_header X-Frame-Options SAMEORIGIN;
       proxy_buffers 256 16k;
       proxy_buffer_size 16k;
       proxy_read_timeout 600s;
       proxy_cache mattermost_cache;
       proxy_cache_revalidate on;
       proxy_cache_min_uses 2;
       proxy_cache_use_stale timeout;
       proxy_cache_lock on;
       proxy_http_version 1.1;
       proxy_pass http://backend;
   }
}
  1. Remove the existing default sites-enabled file.
sudo rm /etc/nginx/sites-enabled/default

On RHEL 7: sudo rm /etc/nginx/conf.d/default

  1. Enable the mattermost configuration.
sudo ln -s /etc/nginx/sites-available/mattermost /etc/nginx/sites-enabled/mattermost

On RHEL 7: sudo ln -s /etc/nginx/conf.d/mattermost /etc/nginx/conf.d/default.conf

  1. Restart NGINX.

On Ubuntu 14.04 and RHEL 6: sudo service nginx restart

On Ubuntu 16.04, Ubuntu 18.04, Debian Stretch, and RHEL 7: sudo systemctl restart nginx

  1. Verify that you can see Mattermost through the proxy.

curl http://localhost

If everything is working, you will see the HTML for the Mattermost signup page.

  1. Restrict access to port 8065.
By default, the Mattermost server accepts connections on port 8065 from every machine on the network. Use your firewall to deny connections on port 8065 to all machines except the machine that hosts NGINX and the machine that you use to administer Mattermost server. If you’re installing on Amazon Web Services, you can use security groups to restrict access.

Now that NGINX is installed and running, you can configure it to use SSL, which allows you to use HTTPS connections and the HTTP/2 protocol.

NGINX Configuration FAQ

Why are Websocket connections returning a 403 error?

This is likely due to a failing cross-origin check. A check is applied for WebSocket code to see if the Origin header is the same as the host header. If it’s not, a 403 error is returned. Open the file /etc/nginx/sites-available/mattermost as root in a text editor and make sure that the host header being set in the proxy is dynamic:

location ~ /api/v[0-9]+/(users/)?websocket$ {
  proxy_pass            http://backend;
  (...)
  proxy_set_header      Host $host;
  proxy_set_header      X-Forwarded-For $remote_addr;
}

Then in config.json set the AllowCorsFrom setting to match the domain being used by clients. You may need to add variations of the host name that clients may send. Your NGINX log will be helpful in diagnosing the problem.

"EnableUserAccessTokens": false,
"AllowCorsFrom": "domain.com domain.com:443 im.domain.com",
"SessionLengthWebInDays": 30,

For other troubleshooting tips for WebSocket errors, see potential solutions here.

How do I setup an NGINX proxy with the Mattermost Docker installation?

  1. Find the name of the Mattermost network and connect it to the NGINX proxy:
docker network ls
# Grep the name of your Mattermost network like "mymattermost_default".
docker network connect mymattermost_default nginx-proxy
  1. Restart the Mattermost Docker containers
docker-compose stop app
docker-compose start app

Tip

There is no need to run the ‘web’ container, since NGINX proxy accepts incoming requests.

  1. Update your docker-compose.yml file to include a new environment variable VIRTUAL_HOST and an expose directive.
environment:
  # set same as db credentials and dbname
  - MM_USERNAME=mmuser
  - MM_PASSWORD=mmuser-password
  - MM_DBNAME=mattermost
  - VIRTUAL_HOST=mymattermost.tld
expose:
  - "80"

If you are using SSL, you may also need to expose port 443.

Why does NGINX fail when installing Gitlab CE with Mattermost on Azure?

You may need to update the Callback URLs for the Application entry of Mattermost inside your Gitlab instance.

  1. Log into your GitLab instance as the admin
  2. Go to Admin > Applications
  3. Click Edit on GitLab-Mattermost
  4. Update the Callback URLs to your new domain/URL
  5. Save the changes
  6. Update the external URL for Gitlab and Mattermost in the /etc/gitlab/gitlab.rb configuration file.

Configuring NGINX with SSL and HTTP/2

Using SSL gives greater security by ensuring that communications between Mattermost clients and the Mattermost server are encrypted. It also allows you to configure NGINX to use the HTTP/2 protocol.

Although you can configure HTTP/2 without SSL, both Firefox and Chrome browsers support HTTP/2 on secure connections only.

You can use any certificate that you want, but these instructions show you how to download and install certificates from Let’s Encrypt, a free certificate authority.

Note

If Let’s Encrypt is enabled, forward port 80 through a firewall, with Forward80To443 config.json setting set to true to complete the Let’s Encrypt certification.

To configure SSL and HTTP/2:

  1. Log in to the server that hosts NGINX and open a terminal window.
  2. Install git.

If you are using Ubuntu or Debian:

sudo apt-get install git

If you are using RHEL:

sudo yum install git

  1. Clone the Let’s Encrypt repository on GitHub.
git clone https://github.com/letsencrypt/letsencrypt
  1. Change to the letsencrypt directory.
cd letsencrypt
  1. Stop NGINX.

On Ubuntu 14.04 and RHEL 6:

sudo service nginx stop

On Ubuntu 16.04, Ubuntu 18.04 and RHEL 7:

sudo systemctl stop nginx

  1. Run netstat to make sure that nothing is listening on port 80.
netstat -na | grep ':80.*LISTEN'
  1. Run the Let’s Encrypt installer.

./letsencrypt-auto certonly --standalone

When prompted, enter your domain name. After the installation is complete, you can find the certificate in the /etc/letsencrypt/live directory.

  1. Open the file /etc/nginx/sites-available/mattermost as root in a text editor and update the server section to incorporate the highlighted lines in the following sample. Make sure to replace {domain-name} with your own domain name, in 3 places.
.
.
.
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=mattermost_cache:10m max_size=3g inactive=120m use_temp_path=off;

server {
   listen 80 default_server;
   server_name   {domain-name} ;
   return 301 https://$server_name$request_uri;
}

server {
  listen 443 ssl http2;
  server_name    {domain-name} ;

  ssl on;
  ssl_certificate /etc/letsencrypt/live/{domain-name}/fullchain.pem;
  ssl_certificate_key /etc/letsencrypt/live/{domain-name}/privkey.pem;
  ssl_session_timeout 1d;
  ssl_protocols TLSv1.2;
  ssl_ciphers 'ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256';
  ssl_prefer_server_ciphers on;
  ssl_session_cache shared:SSL:50m;
  # HSTS (ngx_http_headers_module is required) (15768000 seconds = 6 months)
  add_header Strict-Transport-Security max-age=15768000;
  # OCSP Stapling ---
  # fetch OCSP records from URL in ssl_certificate and cache them
  ssl_stapling on;
  ssl_stapling_verify on;


  location ~ /api/v[0-9]+/(users/)?websocket$ {
    proxy_set_header Upgrade $http_upgrade;
    .
    .
    .

location / {
    proxy_http_version 1.1;
    .
    .
    .
  1. Restart NGINX.

On Ubuntu 14.04 and RHEL 6:

sudo service nginx start

On Ubuntu 16.04, Ubuntu 18.04 and RHEL 7:

sudo systemctl start nginx

  1. Check that your SSL certificate is set up correctly.
  • Test the SSL certificate by visiting a site such as https://www.ssllabs.com/ssltest/index.html
  • If there’s an error about the missing chain or certificate path, there is likely an intermediate certificate missing that needs to be included.
  1. Configure cron so that the certificate will automatically renew every month.

crontab -e

In the following line, use your own domain name in place of {domain-name}

@monthly /home/ubuntu/letsencrypt/letsencrypt-auto certonly --reinstall --nginx -d {domain-name} && sudo service nginx reload