Setup Nginx+Redis+Ruby+Passenger+Monit+Swap on AWS

Steps are for Ubuntu 16.04 LTS

01). Change timezone to IST

sudo timedatectl set-timezone Asia/Kolkata

02). Upgrade NodeJs

sudo apt-get update
sudo npm cache clean -f
sudo npm install -g n
sudo n stable

03). Install NPM

sudo apt-get install npm

04). Install PIP and PIP3

sudo apt-get -y install python-pip
sudo apt-get -y install python3-pip

05). Install AWS Client (try without sudo first)

<sudo> pip install awscli —user

06). Run AWS Configure and configure it 

aws configure

AWS Access Key ID [None]: <IAM access key ID>
AWS Secret Access Key [None]: <IAM secret access key>
Default region name [None]: <check instance zone and paste it here>
output format [None]: json

07). Install libcurl

sudo apt-get install libcurl4-openssl-dev

08). Install Ruby

sudo apt-get update
sudo apt-get install -y curl gnupg build-essential

Install RVM

sudo gpg —keyserver hkp://keys.gnupg.net —recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
curl -sSL https://get.rvm.io | sudo bash -s stable
sudo usermod -a -G rvm `whoami`


if sudo grep -q secure_path /etc/sudoers; then sudo sh -c "echo export rvmsudo_secure_path=1 >> /etc/profile.d/rvm_secure_path.sh" && echo Environment variable installed; fi

When you are done with all this, re-login to your server to activate RVM

Install Ruby 2.5.0

rvm install ruby-2.5.0
rvm —default use ruby-2.5.0

Install Bundler for managing application gem dependencies

gem install bundler —no-rdoc —no-ri

09). Install latest Nginx

sudo add-apt-repository ppa:nginx/stable
sudo apt-get update
sudo apt-get install nginx

10). Install Passenger packages

# Install PGP key and add HTTPS support for APT

sudo apt-get install -y dirmngr gnupg
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 561F9B9CAC40B2F7
sudo apt-get install -y apt-transport-https ca-certificates

# Add our APT repository
sudo sh -c 'echo deb https://oss-binaries.phusionpassenger.com/apt/passenger xenial main > /etc/apt/sources.list.d/passenger.list'
sudo apt-get update

# Install Passenger + Nginx
sudo apt-get install -y nginx-extras passenger

Check Installation (if rvmsudo won't work then try sudo)

rvmsudo /usr/bin/passenger-config validate-install

You should now see Nginx processes and Passenger processes

rvmsudo /usr/sbin/passenger-memory-stats

If you do not see any Nginx processes or Passenger processes, then you probably have some kind of installation problem or configuration problem.

Update Regularly

sudo apt-get update
sudo apt-get upgrade

11). Install Monit

sudo apt-get install monit
sudo chmod 700 /etc/monit/monitrc
sudo vim /etc/monit/monitrc

Comment as follows, and save the ‘monitrc’ file
#include /etc/monit/conf.d/*
#include /etc/monit/conf-enabled/*

Need to create application-specific configurations in /etc/monit/conf.d
then uncomment above comment for conf.d and reload monit by "sudo monit reload"

12). Add Swap Space

Create a Swap File at data EBS volume's (mount-dir) swapspace folder, make sure you allocate 50% of RAM (4 GB in case of m5.large)

sudo mkdir swapspace
sudo fallocate -l 4G /mount-dir/swapspace/swapfile

Verify that the correct amount of space was reserved

ls -lh /mount-dir/swapspace/swapfile

Output should be something like

-rw-r—r-- 1 root root 4.0G Aug 20 11:14 /mount-dir/swapspace/swapfile

Enabling the Swap File

sudo chmod 600 /mount-dir/swapspace/swapfile

Verify the permissions change by typing:

ls -lh /mount-dir/swapspace/swapfile

Output

-rw------- 1 root root 1.0G Aug 20 11:15 /mount-dir/swapspace/swapfile

Now mark the file as swap space

sudo mkswap /mount-dir/swapspace/swapfile

Enable the swap file, allowing our system to start utilizing it

sudo swapon /mount-dir/swapspace/swapfile

Verify that the swap is available

sudo swapon —show

Output

NAME TYPE SIZE USED PRIO
/swapfile file 1024M 0B -1

13). Install Redis

sudo apt-get update
sudo apt-get install build-essential tcl

Download and Extract the Source Code

cd /tmp
curl -O http://download.redis.io/redis-stable.tar.gz
tar xzvf redis-stable.tar.gz
cd redis-stable

Build and Install Redis

make
make test
sudo make install

Configure Redis

sudo mkdir /etc/redis
sudo cp /tmp/redis-stable/redis.conf /etc/redis
sudo vim /etc/redis/redis.conf

In the file, find the supervised directive. Currently, this is set to no. Since we are running an operating system that uses the systemd init system, we can change this to systemd:

/etc/redis/redis.conf

. . .

# If you run Redis from upstart or systemd, Redis can interact with your
# supervision tree. Options:
#   supervised no      - no supervision interaction
#   supervised upstart - signal upstart by putting Redis into SIGSTOP mode
#   supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET
#   supervised auto    - detect upstart or systemd method based on
#                        UPSTART_JOB or NOTIFY_SOCKET environment variables
# Note: these supervision methods only signal "process is ready."
#       They do not enable continuous liveness pings back to your supervisor.
supervised systemd

. . .

Next, find the dir directory. This option specifies the directory that Redis will use to dump persistent data. We need to pick a location that Redis will have write permission and that isn't viewable by normal users.

We will use the /var/lib/redis directory for this, which we will create in a moment:

/etc/redis/redis.conf

. . .

# The working directory.
#
# The DB will be written inside this directory, with the filename specified
# above using the 'dbfilename' configuration directive.
#
# The Append Only File will also be created inside this directory.
#
# Note that you must specify a directory here, not a file name.
dir /var/lib/redis

. . .

Save and close the file when you are finished.

Create a Redis systemd Unit File

Next, we can create a systemd unit file so that the init system can manage the Redis process.

Create and open the /etc/systemd/system/redis.service file to get started:

·      sudo nano /etc/systemd/system/redis.service

Inside, we can begin the [Unit] section by adding a description and defining a requirement that networking be available before starting this service:

/etc/systemd/system/redis.service

[Unit]
Description=Redis In-Memory Data Store
After=network.target

In the [Service] section, we need to specify the service's behavior. For security purposes, we should not run our service as root. We should use a dedicated user and group, which we will call redis for simplicity. We will create these momentarily.

To start the service, we just need to call the redis-server binary, pointed at our configuration. To stop it, we can use the Redis shutdown command, which can be executed with the redis-cli binary. Also, since we want Redis to recover from failures when possible, we will set the Restart directive to "always":

/etc/systemd/system/redis.service

[Unit]
Description=Redis In-Memory Data Store
After=network.target
[Service]User=redisGroup=redisExecStart=/usr/local/bin/redis-server /etc/redis/redis.confExecStop=/usr/local/bin/redis-cli shutdownRestart=always

Finally, in the [Install] section, we can define the systemd target that the service should attach to if enabled (configured to start at boot):

/etc/systemd/system/redis.service

[Unit]
Description=Redis In-Memory Data Store
After=network.target

[Service]
User=redis
Group=redis
ExecStart=/usr/local/bin/redis-server /etc/redis/redis.conf
ExecStop=/usr/local/bin/redis-cli shutdown
Restart=always
[Install]WantedBy=multi-user.target

Save and close the file when you are finished.

Create the Redis User, Group and Directories

Now, we just have to create the user, group, and directory that we referenced in the previous two files.

Begin by creating the redis user and group. This can be done in a single command by typing:

sudo adduser --system --group --no-create-home redis

Now, we can create the /var/lib/redis directory by typing:

sudo mkdir /var/lib/redis

We should give the redis user and group ownership over this directory:

sudo chown redis:redis /var/lib/redis

Adjust the permissions so that regular users cannot access this location:

sudo chmod 770 /var/lib/redis

Add the line vm.overcommit_memory=1 and net.core.somaxconn=65535 to the bottom of /etc/sysctl.conf

 sudo vi /etc/sysctl.conf

Existing permissions don't allow you to edit THP as the warning suggests, so instead do

sudo apt install hugepages

then add the command sudo hugeadm --thp-never at the bottom of your .bashrc, with something like sudo vim ~/.bashrc. Then reboot

 sudo reboot

Start the Redis Service

Start up the systemd service by typing:

·      sudo systemctl start redis

Check that the service had no errors by running:

·      sudo systemctl status redis

You should see something that looks like this:

Output● redis.service - Redis Server
   Loaded: loaded (/etc/systemd/system/redis.service; enabled; vendor preset: enabled)
   Active: active (running) since Wed 2016-05-11 14:38:08 EDT; 1min 43s ago
  Process: 3115 ExecStop=/usr/local/bin/redis-cli shutdown (code=exited, status=0/SUCCESS)
 Main PID: 3124 (redis-server)
    Tasks: 3 (limit: 512)
   Memory: 864.0K
      CPU: 179ms
   CGroup: /system.slice/redis.service
           └─3124 /usr/local/bin/redis-server 127.0.0.1:6379      

. . .

Test the Redis Instance Functionality

To test that your service is functioning correctly, connect to the Redis server with the command-line client:

redis-cli

In the prompt that follows, test connectivity by typing:

ping

You should see:

Output

PONG

Check that you can set keys by typing:

set test "It's working!"

Output

OK

Now, retrieve the value by typing:

get test

You should be able to retrieve the value we stored:

Output

"It's working!"

Exit the Redis prompt to get back to the shell:

exit

As a final test, let's restart the Redis instance:

sudo systemctl restart redis

Now, connect with the client again and confirm that your test value is still available:

redis-cli

get test

The value of your key should still be accessible:

Output

"It's working!"

Back out into the shell again when you are finished:

exit

Enable Redis to Start at Boot

If all of your tests worked, and you would like to start Redis automatically when your server boots, you can enable the systemd service.

To do so, type:

sudo systemctl enable redis

Output

Created symlink from /etc/systemd/system/multi-user.target.wants/redis.service to /etc/systemd/system/redis.service.