Oct 29, 2019

Article

How to install Sentry on Centos 7

In this manual we will tell you how to install Sentry on Centos 7, and do it quickly, correctly and reliably. In addition, we will prepare the configuration for Supervisor, with which we will manage the main Sentry services.

So, first of all, we will install all the necessary dependencies:

yum install epel-release -y
yum install wget python-setuptools.noarch python2-pip.noarch python-devel.x86_64 libxslt.x86_64 libxslt-devel.x86_64 libxml2 libxml2-devel.x86_64 libzip libzip-devel libffi.x86_64 libffi-devel.x86_64 openssl-libs.x86_64 libpqxx libpqxx-devel libyaml libyaml-devel libjpeg libjpeg-devel libpng libpng12 libpng12-devel libpng-devel net-tools gcc gcc-c++ -y

Sentry uses PostgreSQL as the database, so install the postgresql package with the command:

yum install postgresql-server.x86_64 postgresql-contrib -y
postgresql-setup initdb
systemctl enable postgresql.service
systemctl start postgresql.service

Sentry also needs Redis to work, so we can also install it using the command:

yum install redis -y
systemctl enable redis.service
systemctl start redis.service

And of course, we need to install Supervisor, with which we will control the operation of Sentry:

yum install supervisor -y
systemctl enable supervisord.service

Now update pip:

pip install --upgrade pip

Next, install virtualenv to create an isolated Python environment:

pip install -U virtualenv

In order to ensure the necessary level of security, we will run Sentry under a user created separately for it, which we will create with the command:

useradd sentry

All the necessary packages are installed, so now let's get started and create a sentrydb database and a sentry database user first:

su - postgres
psql template1
create user sentry with password 'your_strong_password';
alter user sentry with superuser;
create database sentrydb with owner sentry;
\q
exit

The user and the database are ready, now log in as the user of the centry command:

su - sentry

Create a virtual environment in the sentry user’s home directory:

virtualenv /home/sentry/sentry_app

We activate the shell inside the environment:

source /home/sentry/sentry_app/bin/activate

Now we proceed to install Sentry itself, for this we execute the command:

pip install -U sentry

After the installation process is completed, we will initialize Sentry:

/home/sentry/sentry_app/bin/sentry init

Next, we need to configure the Sentry configuration files, so open the first config file:

nano /home/sentry/.sentry/sentry.conf.py

and change the following lines, specifying the data from the db user and the db name that we created above:

…

 DATABASES = {
 'default': {
 'ENGINE': 'sentry.db.postgres',
 'NAME': 'sentrydb',
 'USER': 'sentry',
 'PASSWORD': 'your_strong_password',
 'HOST': '127.0.0.1',
 'PORT': '5432',
 'AUTOCOMMIT': True,
 'ATOMIC_REQUESTS': False,
 }
 }

…

also edit the second config file:

nano /home/sentry/.sentry/config.yml

specifying the data to connect to redis:

…

redis.clusters:
default:
hosts:
0:
host: 127.0.0.1
port: 6379

…

Now we need to configure PostgreSQL permissions so that the Sentry user can connect to the database without any problems. Edit the file with the command:

nano /var/lib/pgsql/data/pg_hba.conf

we bring it to the following form:

# TYPE  DATABASE        USER            ADDRESS                 METHOD

local    all             postgres                                peer

# "local" is for Unix domain socket connections only
local    all             all                                     peer
# IPv4 local connections:
host     all             all             127.0.0.1/32            md5
# IPv6 local connections:
host     all             all             ::1/128                 md5
# Allow replication connections from localhost, by a user with the
# replication privilege.
#local   replication     postgres                                peer
#host    replication     postgres        127.0.0.1/32            ident
#host    replication     postgres        ::1/128                 ident

Restart PostgreSQL with the command:

systemctl restart postgresql.service

Now execute the command:

/home/sentry/sentry_app/bin/sentry upgrade

in the process you will need to enter an email for the super user.

Next, we need to configure the supervisor that will manage the Sentry services. To do this, edit the supervisr config file with the command:

nano /etc/supervisord.conf

and at the very bottom we indicate the following:

files = supervisord.d/*.conf

Thus, we indicate that in the /etc/supervisord.d/ folder there will be configuration files that must be taken into account when the service is running.

Create a configuration file for managing Sentry services with the command

nano /etc/supervisord.d/sentry.conf

and paste the following contents into it:

[program:sentry-web]
directory=/home/sentry/sentry_app/
environment=SENTRY_CONF="/home/sentry/.sentry"
command=/home/sentry/sentry_app/bin/sentry --config=/home/sentry/.sentry run web
autostart=true
autorestart=true
redirect_stderr=true
user=sentry
stdout_logfile=syslog
stderr_logfile=syslog

[program:sentry-worker]
directory=/home/sentry/sentry_app/
environment=SENTRY_CONF="/home/sentry/.sentry"
command=/home/sentry/sentry_app/bin/sentry --config=/home/sentry/.sentry run worker
autostart=true
autorestart=true
redirect_stderr=true
user=sentry
stdout_logfile=syslog
stderr_logfile=syslog
startsecs=1
startretries=3
stopsignal=TERM
stopwaitsecs=10
stopasgroup=false
killasgroup=true

[program:sentry-cron]
directory=/home/sentry/sentry_app/
environment=SENTRY_CONF="/home/sentry/.sentry"
command=/home/sentry/sentry_app/bin/sentry --config=/home/sentry/.sentry run cron
autostart=true
autorestart=true
redirect_stderr=true
user=sentry
stdout_logfile=syslog
stderr_logfile=syslog

Restart the supervisor and update its configuration with the commands:

service supervisord restart
supervisorctl reread
supervisorctl update

Sentry installation and configuration is complete. Now we can using the url of the form:

http://server_ip_address:9000