Replace falcon server with puma

Been wanting this for a while in theory, gonna actually do it now!

The motivation is that I want to turn up the timeout for loading pets,
because the Neopets endpoints are slower today with the NC UC release -
but I can already predict that under our current architecture that will
be a problem, because it'll block up our request queue!

Falcon uses Ruby's relatively-new async system to *not* have requests
block on upstream requests, and my understanding is that this behavior
is plug-and-play. Let's see how it goes!

Gemfile

@@ -4,7 +4,11 @@ ruby '3.1.4'
 gem 'rails', '~> 7.1', '>= 7.1.1'
 
 # The HTTP server running the Rails instance.
+# NOTE: Once we're migrated, remove puma! I have both to allow the upgrade to
+# be incremental: push this out with `bin/deploy`, then change the service file
+# with `bin/deploy:setup`.
 gem 'puma', '~> 6.3', '>= 6.3.1'
+gem 'falcon', '~> 0.42.3'
 
 # Our database is MySQL, in both development and production.
 gem 'mysql2', '~> 0.5.5'

Gemfile.lock

@@ -87,6 +87,9 @@ GEM
       fiber-annotation
       io-event (~> 1.1)
       timers (~> 4.1)
+    async-container (0.16.12)
+      async
+      async-io
     async-http (0.61.0)
       async (>= 1.25)
       async-io (>= 1.28)
@@ -95,6 +98,8 @@ GEM
       protocol-http1 (~> 0.16.0)
       protocol-http2 (~> 0.15.0)
       traces (>= 0.10.0)
+    async-http-cache (0.4.3)
+      async-http (~> 0.56)
     async-io (1.37.0)
       async
     async-pool (0.4.0)
@@ -109,6 +114,7 @@ GEM
     bindex (0.8.1)
     bootsnap (1.16.0)
       msgpack (~> 1.2)
+    build-environment (1.13.0)
     builder (3.2.4)
     concurrent-ruby (1.2.2)
     connection_pool (2.2.5)
@@ -133,6 +139,19 @@ GEM
       ruby2_keywords
     erubi (1.12.0)
     execjs (2.5.2)
+    falcon (0.42.3)
+      async
+      async-container (~> 0.16.0)
+      async-http (~> 0.57)
+      async-http-cache (~> 0.4.0)
+      async-io (~> 1.22)
+      build-environment (~> 1.13)
+      bundler
+      localhost (~> 1.1)
+      openssl (~> 3.0)
+      process-metrics (~> 0.2.0)
+      protocol-rack (~> 0.1)
+      samovar (~> 2.1)
     ffi (1.15.5)
     fiber-annotation (0.2.0)
     fiber-local (1.0.0)
@@ -163,6 +182,7 @@ GEM
       addressable (~> 2.8)
     letter_opener (1.8.1)
       launchy (>= 2.2, < 3)
+    localhost (1.1.10)
     loofah (2.21.3)
       crass (~> 1.0.2)
       nokogiri (>= 1.12.0)
@@ -171,6 +191,7 @@ GEM
       net-imap
       net-pop
       net-smtp
+    mapping (1.1.1)
     marcel (1.0.2)
     memory_profiler (1.0.1)
     mini_mime (1.1.5)
@@ -193,8 +214,12 @@ GEM
     nokogiri (1.15.3)
       mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
+    openssl (3.2.0)
     orm_adapter (0.5.0)
     parallel (1.23.0)
+    process-metrics (0.2.1)
+      console (~> 1.8)
+      samovar (~> 2.1)
     protocol-hpack (1.4.2)
     protocol-http (0.25.0)
     protocol-http1 (0.16.0)
@@ -202,10 +227,13 @@ GEM
     protocol-http2 (0.15.1)
       protocol-hpack (~> 1.4)
       protocol-http (~> 0.18)
+    protocol-rack (0.4.1)
+      protocol-http (~> 0.23)
+      rack (>= 1.0)
     psych (5.1.1.1)
       stringio
     public_suffix (5.0.3)
-    puma (6.4.0)
+    puma (6.4.2)
       nio4r (~> 2.0)
     racc (1.7.1)
     rack (2.2.8)
@@ -272,6 +300,9 @@ GEM
       actionpack (>= 5.2)
       railties (>= 5.2)
     ruby2_keywords (0.0.5)
+    samovar (2.2.0)
+      console (~> 1.0)
+      mapping (~> 1.0)
     sanitize (6.0.2)
       crass (~> 1.0.2)
       nokogiri (>= 1.12.0)
@@ -338,6 +369,7 @@ DEPENDENCIES
   devise (~> 4.9, >= 4.9.2)
   devise-encryptable (~> 0.2.0)
   dotenv-rails (~> 2.8, >= 2.8.1)
+  falcon (~> 0.42.3)
   globalize (~> 6.2, >= 6.2.1)
   haml (~> 6.1, >= 6.1.1)
   http_accept_language (~> 2.1, >= 2.1.1)

config/application.rb

@@ -61,6 +61,10 @@ module OpenneoImpressItems
 
     config.middleware.insert_after ActionDispatch::Flash, Rack::Attack
 
+    # On the Falcon server, requests run on fibers. Isolate Rails internal
+    # state to the per-fiber level, to avoid conflicts that crash stuff!
+    config.active_support.isolation_level = :fiber
+
     # It seems like some Neopets servers reject any user agent containing
     # symbols? So I can't provide anything helpful like a URL, email address,
     # version number, etc. So let's only send this to Neopets systems, where it

deploy/files/impress.service

@@ -5,7 +5,7 @@ Description=Dress to Impress webapp
 User=impress
 Restart=always
 WorkingDirectory=/srv/impress/current
-ExecStart=/opt/ruby-3.1.4/bin/bundle exec puma --port=3000
+ExecStart=/opt/ruby-3.1.4/bin/bundle exec falcon host
 Environment="RAILS_ENV=production"
 ; Set EXECJS_RUNTIME to save us from needing to install Node
 Environment="EXECJS_RUNTIME=Disabled"

deploy/setup.yml

@@ -7,253 +7,253 @@
     email_address: "emi@matchu.dev" # TODO: Extract this to personal config?
     impress_hostname: impress.openneo.net
   tasks:
-    - name: Create SSH folder for logged-in user
-      become: no
-      file:
-        name: .ssh
-        mode: "700"
-        state: directory
+    # - name: Create SSH folder for logged-in user
+    #   become: no
+    #   file:
+    #     name: .ssh
+    #     mode: "700"
+    #     state: directory
 
-    - name: Copy authorized SSH keys to logged-in user
-      become: no
-      copy:
-        dest: ~/.ssh/authorized_keys
-        src: files/authorized-ssh-keys.txt
-        mode: "600"
+    # - name: Copy authorized SSH keys to logged-in user
+    #   become: no
+    #   copy:
+    #     dest: ~/.ssh/authorized_keys
+    #     src: files/authorized-ssh-keys.txt
+    #     mode: "600"
 
-    - name: Disable root SSH login
-      lineinfile:
-        dest: /etc/ssh/sshd_config
-        regexp: ^#?PermitRootLogin
-        line: PermitRootLogin no
+    # - name: Disable root SSH login
+    #   lineinfile:
+    #     dest: /etc/ssh/sshd_config
+    #     regexp: ^#?PermitRootLogin
+    #     line: PermitRootLogin no
 
-    - name: Disable password-based SSH authentication
-      lineinfile:
-        dest: /etc/ssh/sshd_config
-        regexp: ^#?PasswordAuthentication
-        line: PasswordAuthentication no
+    # - name: Disable password-based SSH authentication
+    #   lineinfile:
+    #     dest: /etc/ssh/sshd_config
+    #     regexp: ^#?PasswordAuthentication
+    #     line: PasswordAuthentication no
 
-    - name: Enable public-key SSH authentication
-      lineinfile:
-        dest: /etc/ssh/sshd_config
-        regexp: ^#?PubkeyAuthentication
-        line: PubkeyAuthentication yes
+    # - name: Enable public-key SSH authentication
+    #   lineinfile:
+    #     dest: /etc/ssh/sshd_config
+    #     regexp: ^#?PubkeyAuthentication
+    #     line: PubkeyAuthentication yes
 
-    - name: Update the apt cache
-      apt:
-        update_cache: yes
+    # - name: Update the apt cache
+    #   apt:
+    #     update_cache: yes
 
-    - name: Install fail2ban firewall with default settings
-      apt:
-        name: fail2ban
+    # - name: Install fail2ban firewall with default settings
+    #   apt:
+    #     name: fail2ban
 
-    - name: Configure ufw firewall to allow SSH connections on port 22
-      community.general.ufw:
-        rule: allow
-        port: "22"
+    # - name: Configure ufw firewall to allow SSH connections on port 22
+    #   community.general.ufw:
+    #     rule: allow
+    #     port: "22"
 
-    - name: Configure ufw firewall to allow HTTP connections on port 80
-      community.general.ufw:
-        rule: allow
-        port: "80"
+    # - name: Configure ufw firewall to allow HTTP connections on port 80
+    #   community.general.ufw:
+    #     rule: allow
+    #     port: "80"
 
-    - name: Configure ufw firewall to allow HTTPS connections on port 443
-      community.general.ufw:
-        rule: allow
-        port: "443"
+    # - name: Configure ufw firewall to allow HTTPS connections on port 443
+    #   community.general.ufw:
+    #     rule: allow
+    #     port: "443"
 
-    - name: Enable ufw firewall with all other ports closed by default
-      community.general.ufw:
-        state: enabled
-        policy: deny
+    # - name: Enable ufw firewall with all other ports closed by default
+    #   community.general.ufw:
+    #     state: enabled
+    #     policy: deny
 
-    - name: Install unattended-upgrades
-      apt:
-        name: unattended-upgrades
+    # - name: Install unattended-upgrades
+    #   apt:
+    #     name: unattended-upgrades
 
-    - name: Enable unattended-upgrades to auto-upgrade our system
-      copy:
-        content: |
-          APT::Periodic::Update-Package-Lists "1";
-          APT::Periodic::Unattended-Upgrade "1";
-        dest: /etc/apt/apt.conf.d/20auto-upgrades
+    # - name: Enable unattended-upgrades to auto-upgrade our system
+    #   copy:
+    #     content: |
+    #       APT::Periodic::Update-Package-Lists "1";
+    #       APT::Periodic::Unattended-Upgrade "1";
+    #     dest: /etc/apt/apt.conf.d/20auto-upgrades
 
-    - name: Configure unattended-upgrades to auto-reboot our server when necessary
-      lineinfile:
-        regex: ^(//\s*)?Unattended-Upgrade::Automatic-Reboot ".*";$
-        line: Unattended-Upgrade::Automatic-Reboot "true";
-        dest: /etc/apt/apt.conf.d/50unattended-upgrades
+    # - name: Configure unattended-upgrades to auto-reboot our server when necessary
+    #   lineinfile:
+    #     regex: ^(//\s*)?Unattended-Upgrade::Automatic-Reboot ".*";$
+    #     line: Unattended-Upgrade::Automatic-Reboot "true";
+    #     dest: /etc/apt/apt.conf.d/50unattended-upgrades
 
-    - name: Configure unattended-upgrades to delay necessary reboots to 3am
-      lineinfile:
-        regex: ^(//\s*)?Unattended-Upgrade::Automatic-Reboot-Time ".*";$
-        line: Unattended-Upgrade::Automatic-Reboot-Time "03:00";
-        dest: /etc/apt/apt.conf.d/50unattended-upgrades
+    # - name: Configure unattended-upgrades to delay necessary reboots to 3am
+    #   lineinfile:
+    #     regex: ^(//\s*)?Unattended-Upgrade::Automatic-Reboot-Time ".*";$
+    #     line: Unattended-Upgrade::Automatic-Reboot-Time "03:00";
+    #     dest: /etc/apt/apt.conf.d/50unattended-upgrades
 
-    - name: Configure the system timezone to be US Pacific time
-      community.general.timezone:
-        name: America/Los_Angeles
+    # - name: Configure the system timezone to be US Pacific time
+    #   community.general.timezone:
+    #     name: America/Los_Angeles
 
-    - name: Create "impress" user
-      user:
-        name: impress
-        comment: Impress App
-        home: /srv/impress
-        create_home: false
-        shell: /bin/bash
+    # - name: Create "impress" user
+    #   user:
+    #     name: impress
+    #     comment: Impress App
+    #     home: /srv/impress
+    #     create_home: false
+    #     shell: /bin/bash
 
-    - name: Create "impress-deployers" group
-      group:
-        name: impress-deployers
+    # - name: Create "impress-deployers" group
+    #   group:
+    #     name: impress-deployers
 
-    - name: Add the current user to the "impress-deployers" group
-      user:
-        name: "{{ lookup('env', 'USER') }}"
-        groups:
-          - impress-deployers
-        append: yes
+    # - name: Add the current user to the "impress-deployers" group
+    #   user:
+    #     name: "{{ lookup('env', 'USER') }}"
+    #     groups:
+    #       - impress-deployers
+    #     append: yes
 
-    # We use this so the deploy playbook doesn't have to prompt for a root
-    # password: this user just is trusted to act as "impress" in the future.
-    - name: Enable the "impress-deployers" group to freely act as the "impress" user
-      community.general.sudoers:
-        name: impress-deployers-as-impress
-        group: impress-deployers
-        runas: impress
-        commands: ALL
-        nopassword: yes
+    # # We use this so the deploy playbook doesn't have to prompt for a root
+    # # password: this user just is trusted to act as "impress" in the future.
+    # - name: Enable the "impress-deployers" group to freely act as the "impress" user
+    #   community.general.sudoers:
+    #     name: impress-deployers-as-impress
+    #     group: impress-deployers
+    #     runas: impress
+    #     commands: ALL
+    #     nopassword: yes
 
-    # Similarly, this enables us to manage the impress service in the deploy playbook
-    # and in live debugging without a password.
-    # NOTE: In the sudoers file, you need to specify the full path to the
-    # command, to avoid tricks where you use PATH to get around the intent!
-    - name: Enable the "impress-deployers" group to freely start and stop the impress service
-      community.general.sudoers:
-        name: impress-deployers-systemctl
-        group: impress-deployers
-        commands:
-          - /bin/systemctl status impress
-          - /bin/systemctl start impress
-          - /bin/systemctl stop impress
-          - /bin/systemctl restart impress
-        nopassword: yes
+    # # Similarly, this enables us to manage the impress service in the deploy playbook
+    # # and in live debugging without a password.
+    # # NOTE: In the sudoers file, you need to specify the full path to the
+    # # command, to avoid tricks where you use PATH to get around the intent!
+    # - name: Enable the "impress-deployers" group to freely start and stop the impress service
+    #   community.general.sudoers:
+    #     name: impress-deployers-systemctl
+    #     group: impress-deployers
+    #     commands:
+    #       - /bin/systemctl status impress
+    #       - /bin/systemctl start impress
+    #       - /bin/systemctl stop impress
+    #       - /bin/systemctl restart impress
+    #     nopassword: yes
 
-    - name: Install ACL, to enable us to run commands as the "impress" user
-      apt:
-        name: acl
+    # - name: Install ACL, to enable us to run commands as the "impress" user
+    #   apt:
+    #     name: acl
 
-    - name: Install ruby-build
-      git:
-        repo: https://github.com/rbenv/ruby-build.git
-        dest: /opt/ruby-build
-        version: 4d4678bc1ed89aa6900c0ea0da23495445dbcf50
+    # - name: Install ruby-build
+    #   git:
+    #     repo: https://github.com/rbenv/ruby-build.git
+    #     dest: /opt/ruby-build
+    #     version: 4d4678bc1ed89aa6900c0ea0da23495445dbcf50
 
-    - name: Check if Ruby 3.1.4 is already installed
-      stat:
-        path: /opt/ruby-3.1.4
-      register: ruby_dir
+    # - name: Check if Ruby 3.1.4 is already installed
+    #   stat:
+    #     path: /opt/ruby-3.1.4
+    #   register: ruby_dir
 
-    - name: Install Ruby 3.1.4
-      command: "/opt/ruby-build/bin/ruby-build 3.1.4 /opt/ruby-3.1.4"
-      when: not ruby_dir.stat.exists
+    # - name: Install Ruby 3.1.4
+    #   command: "/opt/ruby-build/bin/ruby-build 3.1.4 /opt/ruby-3.1.4"
+    #   when: not ruby_dir.stat.exists
 
-    - name: Add Ruby 3.1.4 to the global PATH, for developer convenience
-      lineinfile:
-        dest: /etc/profile
-        line: 'PATH="/opt/ruby-3.1.4/bin:$PATH" # Added by impress deploy setup script'
+    # - name: Add Ruby 3.1.4 to the global PATH, for developer convenience
+    #   lineinfile:
+    #     dest: /etc/profile
+    #     line: 'PATH="/opt/ruby-3.1.4/bin:$PATH" # Added by impress deploy setup script'
 
-    - name: Install system dependencies for impress's Ruby gems
-      apt:
-        name:
-          - libmysqlclient-dev
-          - libyaml-dev
+    # - name: Install system dependencies for impress's Ruby gems
+    #   apt:
+    #     name:
+    #       - libmysqlclient-dev
+    #       - libyaml-dev
 
-    - name: Create the app folder
-      file:
-        path: /srv/impress
-        owner: impress
-        group: impress
-        mode: "755"
-        state: directory
+    # - name: Create the app folder
+    #   file:
+    #     path: /srv/impress
+    #     owner: impress
+    #     group: impress
+    #     mode: "755"
+    #     state: directory
 
-    - name: Add a convenient .bash_profile for when we log in as "impress"
-      copy:
-        owner: impress
-        group: impress
-        dest: /srv/impress/.bash_profile
-        content: |
-          set -a # Export all of the below
-          RAILS_ENV=production
-          EXECJS_RUNTIME=Disabled
-          source /srv/impress/shared/production.env
-          set +a
+    # - name: Add a convenient .bash_profile for when we log in as "impress"
+    #   copy:
+    #     owner: impress
+    #     group: impress
+    #     dest: /srv/impress/.bash_profile
+    #     content: |
+    #       set -a # Export all of the below
+    #       RAILS_ENV=production
+    #       EXECJS_RUNTIME=Disabled
+    #       source /srv/impress/shared/production.env
+    #       set +a
 
-    - name: Create the app's "versions" folder
-      become_user: impress
-      file:
-        path: /srv/impress/versions
-        state: directory
+    # - name: Create the app's "versions" folder
+    #   become_user: impress
+    #   file:
+    #     path: /srv/impress/versions
+    #     state: directory
 
-    - name: Create the app's "shared" folder
-      become_user: impress
-      file:
-        path: /srv/impress/shared
-        state: directory
+    # - name: Create the app's "shared" folder
+    #   become_user: impress
+    #   file:
+    #     path: /srv/impress/shared
+    #     state: directory
 
-    - name: Check for a current app version
-      stat:
-        path: /srv/impress/current
-      register: current_app_version
+    # - name: Check for a current app version
+    #   stat:
+    #     path: /srv/impress/current
+    #   register: current_app_version
 
-    - name: Check whether we already have a placeholder app
-      stat:
-        path: /srv/impress/versions/initial-placeholder
-      register: existing_placeholder_app
-      when: not current_app_version.stat.exists
+    # - name: Check whether we already have a placeholder app
+    #   stat:
+    #     path: /srv/impress/versions/initial-placeholder
+    #   register: existing_placeholder_app
+    #   when: not current_app_version.stat.exists
 
-    - name: Create a placeholder app, to run until we deploy a real version
-      become_user: impress
-      copy:
-        src: files/initial-placeholder
-        dest: /srv/impress/versions
-      when: |
-        not current_app_version.stat.exists and
-          not existing_placeholder_app.stat.exists
+    # - name: Create a placeholder app, to run until we deploy a real version
+    #   become_user: impress
+    #   copy:
+    #     src: files/initial-placeholder
+    #     dest: /srv/impress/versions
+    #   when: |
+    #     not current_app_version.stat.exists and
+    #       not existing_placeholder_app.stat.exists
 
-    - name: Configure the placeholder app to run in deployment mode
-      become_user: impress
-      command:
-        chdir: /srv/impress/versions/initial-placeholder
-        cmd: /opt/ruby-3.1.4/bin/bundle config set --local deployment true
-      when: not current_app_version.stat.exists
+    # - name: Configure the placeholder app to run in deployment mode
+    #   become_user: impress
+    #   command:
+    #     chdir: /srv/impress/versions/initial-placeholder
+    #     cmd: /opt/ruby-3.1.4/bin/bundle config set --local deployment true
+    #   when: not current_app_version.stat.exists
 
-    - name: Install the placeholder app's dependencies
-      become_user: impress
-      command:
-        chdir: /srv/impress/versions/initial-placeholder
-        cmd: /opt/ruby-3.1.4/bin/bundle install
-      when: not current_app_version.stat.exists
+    # - name: Install the placeholder app's dependencies
+    #   become_user: impress
+    #   command:
+    #     chdir: /srv/impress/versions/initial-placeholder
+    #     cmd: /opt/ruby-3.1.4/bin/bundle install
+    #   when: not current_app_version.stat.exists
 
-    - name: Set the placeholder app as the current version
-      become_user: impress
-      file:
-        src: /srv/impress/versions/initial-placeholder
-        dest: /srv/impress/current
-        state: link
-      when: not current_app_version.stat.exists
+    # - name: Set the placeholder app as the current version
+    #   become_user: impress
+    #   file:
+    #     src: /srv/impress/versions/initial-placeholder
+    #     dest: /srv/impress/current
+    #     state: link
+    #   when: not current_app_version.stat.exists
 
-    # NOTE: This file is uploaded with stricter permissions, to help protect
-    # the secrets inside. Most of the app is world-readable for convenience
-    # for debugging and letting nginx serve static files, but keep this safer!
-    - name: Upload the production.env file
-      become_user: impress
-      copy:
-        dest: /srv/impress/shared/production.env
-        src: files/production.env
-        mode: "600"
-      notify:
-        - Reload systemctl
-        - Restart impress
+    # # NOTE: This file is uploaded with stricter permissions, to help protect
+    # # the secrets inside. Most of the app is world-readable for convenience
+    # # for debugging and letting nginx serve static files, but keep this safer!
+    # - name: Upload the production.env file
+    #   become_user: impress
+    #   copy:
+    #     dest: /srv/impress/shared/production.env
+    #     src: files/production.env
+    #     mode: "600"
+    #   notify:
+    #     - Reload systemctl
+    #     - Restart impress
 
     - name: Create service file for impress
       copy:

falcon.rb

@@ -0,0 +1,12 @@
+#!/usr/bin/env -S falcon host
+# frozen_string_literal: true
+
+load :rack, :supervisor
+
+hostname = File.basename(__dir__)
+rack hostname do
+	endpoint Async::HTTP::Endpoint.parse('http://localhost:3000').
+		with(protocol: Async::HTTP::Protocol::HTTP1)
+end
+
+supervisor