I have completed an application which was built using Ruby on Rails. I want to host it on an EC2 instance on AWS.
I have provisioned a server for it, and I am using puma HTTP server as the application server. Starting the application in production always requires me to run the RAILS_ENV=production rails s which isn't often convenient as it does not return to prompt when the application is started.
I also want to be able to manage Puma with systemd, so that I can easily start, stop, check status and restart the Puma server by running a one-line command.
I have tried a lot of solutions online, but when I try to start the server I often get an error:
● puma.service - Puma HTTP Forking Server
Loaded: error (Reason: Exec format error)
Active: activating (start) since Mon 2019-12-16 15:33:06 UTC; 59s ago
Cntrl PID: 4473 (bundle)
Tasks: 30 (limit: 4703)
CGroup: /system.slice/puma.service
├─4473 puma 3.12.1 (tcp://0.0.0.0:3000) [my-app]
├─4522 puma: cluster worker 0: 4473 [my-app]
└─4527 puma: cluster worker 1: 4473 [my-app]
Dec 16 15:33:06 ip-172-31-19-238 rbenv[4473]: [4473] * Environment: production
Dec 16 15:33:06 ip-172-31-19-238 rbenv[4473]: [4473] * Process workers: 2
Dec 16 15:33:06 ip-172-31-19-238 rbenv[4473]: [4473] * Preloading application
Dec 16 15:33:08 ip-172-31-19-238 rbenv[4473]: [4473] * Listening on tcp://0.0.0.0:3000
Dec 16 15:33:08 ip-172-31-19-238 rbenv[4473]: [4473] ! WARNING: Detected 1 Thread(s) started in app boot:
Dec 16 15:33:08 ip-172-31-19-238 rbenv[4473]: [4473] ! #<Thread:0x000055f4b08bf7e0@/home/deploy/.rbenv/versions/2.5.0/lib/ruby/gems/2.5.0/gems/a
Dec 16 15:33:08 ip-172-31-19-238 rbenv[4473]: [4473] Use Ctrl-C to stop
Dec 16 15:33:08 ip-172-31-19-238 rbenv[4473]: [4473] - Worker 0 (pid: 4522) booted, phase: 0
Dec 16 15:33:08 ip-172-31-19-238 rbenv[4473]: [4473] - Worker 1 (pid: 4527) booted, phase: 0
What can I try to resolve this?
Here's how I fixed it:
Install Puma if it is not already installed.
Run the command which puma to print the installation directory of the puma server on your machine, which is usually installed in /home/your-username/.rbenv/shims/puma directory.
Open the puma.service file located at /etc/systemd/system/puma.service by the running the command below:
sudo nano /etc/systemd/system/puma.service
Copy the Puma service configuration file below into it and save.
Puma Service Configuration
[Unit]
Description=Puma HTTP Server
After=network.target
[Service]
# Foreground process (do not use --daemon in ExecStart or config.rb)
Type=simple
# Preferably configure a non-privileged user
User=deploy
# The path to the your application code root directory
WorkingDirectory=/home/deploy/my-app
# The command to start Puma
ExecStart=/home/deploy/.rbenv/shims/puma -C /home/deploy/my-app/config/puma.rb
# The command to stop Puma
ExecStop=/home/deploy/.rbenv/shims/puma -S /home/deploy/my-app/config/puma.rb
# Path to PID file so that systemd knows which is the master process
PIDFile=/home/deploy/my-app/tmp/pids/puma.pid
# Should systemd restart puma?
# Use "no" (the default) to ensure no interference when using
# stop/start/restart via `pumactl`. The "on-failure" setting might
# work better for this purpose, but you must test it.
# Use "always" if only `systemctl` is used for start/stop/restart, and
# reconsider if you actually need the forking config.
Restart=always
[Install]
WantedBy=multi-user.target
Note:
ExecStart: ExecStart=/your-puma-directory-path -C /your-app-puma-config-file-pathExecStop: ExecStop=/your-puma-directory-path -S /your-app-puma-config-file-pathExecReload or ExecRestart, they work out of the box.You can now start the puma server using the command:
sudo systemctl start puma
OR restart the puma server using the command:
sudo systemctl restart puma
OR check the status puma server using the command:
sudo systemctl status puma
OR stop the puma server using the command:
sudo systemctl stop puma
That's all.
I hope this helps