feat: allow setting up only web/worker deployments for linux (#12004)

## cwctl
-  allow setting up only web/worker deployments for linux
- allow upgrades to a custom branch - experimental

```
Usage Examples:
  # Convert existing full deployment to web-only (for web ASG)
  cwctl --convert web

  # Convert existing full deployment to worker-only (for worker ASG)
   cwctl --convert worker

  # Convert specialized deployment back to full
  cwctl --convert full

  # Fresh installs still work as before
    cwctl -i --web-only    # New web-only install
    cwctl -i --worker-only # New worker-only instal
```

- Upgrading to custom branches is risky, as other dependencies like node
or db might have changed

```
  cwctl --upgrade        # Upgrade to master branch - default
  cwctl -U v4.3.0         # Upgrade to specific release branch 
  cwctl --upgrade feat/new-feature  # Upgrade to feature branch
```

VERSION_CW

@@ -1 +1 @@
-3.13.0
+4.4.0

VERSION_CWCTL

@@ -1 +1 @@
-3.2.0
+3.3.0

deployment/chatwoot-web.target

@@ -0,0 +1,6 @@
+[Unit]
+Description=Chatwoot Web Server
+Wants=chatwoot-web.1.service
+
+[Install]
+WantedBy=multi-user.target

deployment/chatwoot-worker.target

@@ -0,0 +1,6 @@
+[Unit]
+Description=Chatwoot Background Worker
+Wants=chatwoot-worker.1.service
+
+[Install]
+WantedBy=multi-user.target

deployment/setup_20.04.sh

@@ -17,9 +17,9 @@ fi
 
 # Global variables
 # option --output/-o requires 1 argument
-LONGOPTS=console,debug,help,install,Install:,logs:,restart,ssl,upgrade,webserver,version
+LONGOPTS=console,debug,help,install,Install:,logs:,restart,ssl,upgrade,Upgrade:,webserver,version,web-only,worker-only,convert:
-OPTIONS=cdhiI:l:rsuwv
+OPTIONS=cdhiI:l:rsuU:wvWK
-CWCTL_VERSION="3.2.0"
+CWCTL_VERSION="3.3.0"
 pg_pass=$(head /dev/urandom | tr -dc A-Za-z0-9 | head -c 15 ; echo '')
 CHATWOOT_HUB_URL="https://hub.2.chatwoot.com/events"
 
@@ -42,7 +42,7 @@ fi
 # read getopt’s output this way to handle the quoting right:
 eval set -- "$PARSED"
 
-c=n d=n h=n i=n I=n l=n r=n s=n u=n w=n v=n BRANCH=master SERVICE=web
+c=n d=n h=n i=n I=n l=n r=n s=n u=n U=n w=n v=n W=n K=n C=n BRANCH=master SERVICE=web DEPLOYMENT_TYPE=full CONVERT_TO=""
 # Iterate options in order and nicely split until we see --
 while true; do
     case "$1" in
@@ -83,6 +83,12 @@ while true; do
             ;;
         -u|--upgrade)
             u=y
+            BRANCH="master"
+            break
+            ;;
+        -U|--Upgrade)
+            U=y
+            BRANCH="$2"
             break
             ;;
         -w|--webserver)
@@ -93,6 +99,36 @@ while true; do
             v=y
             shift
             ;;
+        -W|--web-only)
+            W=y
+            DEPLOYMENT_TYPE=web
+            shift
+            ;;
+        -K|--worker-only)
+            K=y
+            DEPLOYMENT_TYPE=worker
+            shift
+            ;;
+        --convert)
+            C=y
+            CONVERT_TO="$2"
+            case "$CONVERT_TO" in
+                web)
+                    DEPLOYMENT_TYPE=web
+                    ;;
+                worker)
+                    DEPLOYMENT_TYPE=worker
+                    ;;
+                full)
+                    DEPLOYMENT_TYPE=full
+                    ;;
+                *)
+                    echo "Invalid conversion type. Use: web, worker, or full"
+                    exit 3
+                    ;;
+            esac
+            shift 2
+            ;;
         --)
             shift
             break
@@ -107,7 +143,7 @@ done
 # log if debug flag set
 if [ "$d" == "y" ]; then
   echo "console: $c, debug: $d, help: $h, install: $i, Install: $I, BRANCH: $BRANCH, \
-  logs: $l, SERVICE: $SERVICE, ssl: $s, upgrade: $u, webserver: $w"
+  logs: $l, SERVICE: $SERVICE, ssl: $s, upgrade: $u, Upgrade: $U, webserver: $w, web-only: $W, worker-only: $K, convert: $C, convert-to: $CONVERT_TO, deployment-type: $DEPLOYMENT_TYPE"
 fi
 
 # exit if script is not run as root
@@ -379,23 +415,84 @@ EOF
 ##############################################################################
 # Setup Chatwoot systemd services and cwctl CLI
 # Globals:
-#   None
+#   DEPLOYMENT_TYPE
 # Arguments:
 #   None
 # Outputs:
 #   None
 ##############################################################################
 function configure_systemd_services() {
+  # Check if this is a conversion from existing deployment
+  local existing_full_deployment=false
+  if [ -f "/etc/systemd/system/chatwoot.target" ]; then
+    existing_full_deployment=true
+  fi
+
+  if [ "$DEPLOYMENT_TYPE" == "web" ]; then
+    echo "Setting up web-only deployment"
+    
+    # Stop and disable existing services if converting
+    if [ "$existing_full_deployment" = true ]; then
+      echo "Converting from full deployment to web-only"
+      systemctl stop chatwoot.target || true
+      systemctl disable chatwoot.target || true
+      systemctl stop chatwoot-worker.1.service || true
+      systemctl disable chatwoot-worker.1.service || true
+    fi
+    
+    cp /home/chatwoot/chatwoot/deployment/chatwoot-web.1.service /etc/systemd/system/chatwoot-web.1.service
+    cp /home/chatwoot/chatwoot/deployment/chatwoot-web.target /etc/systemd/system/chatwoot-web.target
+    
+    systemctl daemon-reload
+    systemctl enable chatwoot-web.target
+    systemctl start chatwoot-web.target
+    
+  elif [ "$DEPLOYMENT_TYPE" == "worker" ]; then
+    echo "Setting up worker-only deployment"
+    
+    # Stop and disable existing services if converting
+    if [ "$existing_full_deployment" = true ]; then
+      echo "Converting from full deployment to worker-only"
+      systemctl stop chatwoot.target || true
+      systemctl disable chatwoot.target || true
+      systemctl stop chatwoot-web.1.service || true
+      systemctl disable chatwoot-web.1.service || true
+    fi
+    
+    cp /home/chatwoot/chatwoot/deployment/chatwoot-worker.1.service /etc/systemd/system/chatwoot-worker.1.service
+    cp /home/chatwoot/chatwoot/deployment/chatwoot-worker.target /etc/systemd/system/chatwoot-worker.target
+    
+    systemctl daemon-reload
+    systemctl enable chatwoot-worker.target
+    systemctl start chatwoot-worker.target
+    
+  else
+    echo "Setting up full deployment (web + worker)"
+    
+    # Stop existing specialized deployments if converting back to full
+    if [ -f "/etc/systemd/system/chatwoot-web.target" ]; then
+      echo "Converting from web-only to full deployment"
+      systemctl stop chatwoot-web.target || true
+      systemctl disable chatwoot-web.target || true
+    fi
+    if [ -f "/etc/systemd/system/chatwoot-worker.target" ]; then
+      echo "Converting from worker-only to full deployment"
+      systemctl stop chatwoot-worker.target || true
+      systemctl disable chatwoot-worker.target || true
+    fi
+    
     cp /home/chatwoot/chatwoot/deployment/chatwoot-web.1.service /etc/systemd/system/chatwoot-web.1.service
     cp /home/chatwoot/chatwoot/deployment/chatwoot-worker.1.service /etc/systemd/system/chatwoot-worker.1.service
     cp /home/chatwoot/chatwoot/deployment/chatwoot.target /etc/systemd/system/chatwoot.target
 
+    systemctl daemon-reload
+    systemctl enable chatwoot.target
+    systemctl start chatwoot.target
+  fi
+
   cp /home/chatwoot/chatwoot/deployment/chatwoot /etc/sudoers.d/chatwoot
   cp /home/chatwoot/chatwoot/deployment/setup_20.04.sh /usr/local/bin/cwctl
   chmod +x /usr/local/bin/cwctl
-
-  systemctl enable chatwoot.target
-  systemctl start chatwoot.target
 }
 
 ##############################################################################
@@ -427,7 +524,15 @@ function setup_ssl() {
   cd chatwoot
   sed -i "s/http:\/\/0.0.0.0:3000/https:\/\/$domain_name/g" .env
 EOF
+  
+  # Restart the appropriate chatwoot target
+  if [ -f "/etc/systemd/system/chatwoot-web.target" ]; then
+    systemctl restart chatwoot-web.target
+  elif [ -f "/etc/systemd/system/chatwoot-worker.target" ]; then
+    systemctl restart chatwoot-worker.target
+  else
     systemctl restart chatwoot.target
+  fi
 }
 
 ##############################################################################
@@ -624,17 +729,27 @@ Usage: cwctl [OPTION]...
 Install and manage your Chatwoot installation.
 
 Example: cwctl -i master
+Example: cwctl -i --web-only     (for web server ASG)
+Example: cwctl -i --worker-only  (for worker ASG)
+Example: cwctl --convert web     (convert existing to web-only)
+Example: cwctl --convert worker  (convert existing to worker-only)
+Example: cwctl --convert full    (convert back to full deployment)
+Example: cwctl --upgrade         (upgrade to latest master)
+Example: cwctl -U develop        (upgrade to develop branch)
 Example: cwctl -l web
 Example: cwctl --logs worker
-Example: cwctl --upgrade
 Example: cwctl -c
 
 Installation/Upgrade:
   -i, --install             Install the latest stable version of Chatwoot
-  -I                        Install Chatwoot from a git branch
+  -I BRANCH                 Install Chatwoot from a git branch
   -u, --upgrade             Upgrade Chatwoot to the latest stable version
+  -U BRANCH                 Upgrade Chatwoot from a git branch (EXPERIMENTAL)
   -s, --ssl                 Fetch and install SSL certificates using LetsEncrypt
   -w, --webserver           Install and configure Nginx webserver with SSL
+  -W, --web-only            Install only the web server (for ASG deployment)
+  -K, --worker-only         Install only the background worker (for ASG deployment)
+      --convert TYPE        Convert existing deployment (TYPE: web, worker, full)
 
 Management:
   -c, --console             Open ruby console
@@ -831,7 +946,31 @@ EOF
 function upgrade() {
   cwctl_upgrade_check
   get_cw_version
-  echo "Upgrading Chatwoot to v$CW_VERSION"
+  echo "Upgrading Chatwoot to v$CW_VERSION (branch: $BRANCH)"
+
+  # Warning for non-master branch upgrades
+  if [ "$BRANCH" != "master" ]; then
+    cat << EOF
+
+⚠️  WARNING: Branch-specific upgrades are EXPERIMENTAL
+⚠️  Switching between different versions/branches may cause:
+   - Database migration conflicts
+   - Asset compilation errors
+   - Configuration incompatibilities
+   - Data corruption or loss
+
+⚠️  This is NOT recommended for production environments.
+⚠️  Always backup your database before proceeding.
+
+EOF
+    read -p "Do you understand the risks and want to continue? [y/N]: " user_input
+    user_input=${user_input:-N}
+    if [[ ! "$user_input" =~ ^([yY][eE][sS]|[yY])$ ]]; then
+      echo "Upgrade cancelled."
+      exit 1
+    fi
+  fi
+
   sleep 3
 
    # Check if CW_VERSION is 4.0 or above
@@ -857,8 +996,9 @@ function upgrade() {
   # Navigate to the Chatwoot directory
   cd chatwoot
 
-  # Pull the latest version of the master branch
+  # Pull the latest version of the specified branch
-  git checkout master && git pull
+  git fetch
+  git checkout "$BRANCH" && git pull
 
   # Ensure the ruby version is upto date
   # Parse the latest ruby version
@@ -878,18 +1018,35 @@ function upgrade() {
 
 EOF
 
-  # Copy the updated targets
+  # Copy the updated services and targets based on existing deployment
+  if [ -f "/etc/systemd/system/chatwoot-web.target" ]; then
+    echo "Updating web-only deployment"
+    cp /home/chatwoot/chatwoot/deployment/chatwoot-web.1.service /etc/systemd/system/chatwoot-web.1.service
+    cp /home/chatwoot/chatwoot/deployment/chatwoot-web.target /etc/systemd/system/chatwoot-web.target
+  elif [ -f "/etc/systemd/system/chatwoot-worker.target" ]; then
+    echo "Updating worker-only deployment"
+    cp /home/chatwoot/chatwoot/deployment/chatwoot-worker.1.service /etc/systemd/system/chatwoot-worker.1.service
+    cp /home/chatwoot/chatwoot/deployment/chatwoot-worker.target /etc/systemd/system/chatwoot-worker.target
+  else
+    echo "Updating full deployment"
     cp /home/chatwoot/chatwoot/deployment/chatwoot-web.1.service /etc/systemd/system/chatwoot-web.1.service
     cp /home/chatwoot/chatwoot/deployment/chatwoot-worker.1.service /etc/systemd/system/chatwoot-worker.1.service
     cp /home/chatwoot/chatwoot/deployment/chatwoot.target /etc/systemd/system/chatwoot.target
+  fi
 
   cp /home/chatwoot/chatwoot/deployment/chatwoot /etc/sudoers.d/chatwoot
   # TODO:(@vn) handle cwctl updates
 
   systemctl daemon-reload
 
-  # Restart the chatwoot server
+  # Restart the appropriate chatwoot target
+  if [ -f "/etc/systemd/system/chatwoot-web.target" ]; then
+    systemctl restart chatwoot-web.target
+  elif [ -f "/etc/systemd/system/chatwoot-worker.target" ]; then
+    systemctl restart chatwoot-worker.target
+  else
     systemctl restart chatwoot.target
+  fi
 
 }
 
@@ -903,8 +1060,40 @@ EOF
 #   None
 ##############################################################################
 function restart() {
+  if [ -f "/etc/systemd/system/chatwoot-web.target" ]; then
+    systemctl restart chatwoot-web.target
+    systemctl status chatwoot-web.target
+  elif [ -f "/etc/systemd/system/chatwoot-worker.target" ]; then
+    systemctl restart chatwoot-worker.target
+    systemctl status chatwoot-worker.target
+  else
     systemctl restart chatwoot.target
     systemctl status chatwoot.target
+  fi
+}
+
+##############################################################################
+# Convert existing Chatwoot deployment to different type (--convert)
+# Globals:
+#   DEPLOYMENT_TYPE
+# Arguments:
+#   None
+# Outputs:
+#   None
+##############################################################################
+function convert_deployment() {
+  echo "Converting Chatwoot deployment to: $DEPLOYMENT_TYPE"
+  
+  # Check if Chatwoot is installed
+  if [ ! -d "/home/chatwoot/chatwoot" ]; then
+    echo "Chatwoot installation not found. Use --install first."
+    exit 1
+  fi
+  
+  # Run the systemd service configuration which handles conversion logic
+  configure_systemd_services
+  
+  echo "Deployment converted successfully to: $DEPLOYMENT_TYPE"
 }
 
 ##############################################################################
@@ -1107,7 +1296,7 @@ function main() {
     ssl
   fi
 
-  if [ "$u" == "y" ]; then
+  if [ "$u" == "y" ] || [ "$U" == "y" ]; then
     report_event "cwctl" "upgrade"  > /dev/null 2>&1
     upgrade
   fi
@@ -1122,6 +1311,11 @@ function main() {
     version
   fi
 
+  if [ "$C" == "y" ]; then
+    report_event "cwctl" "convert"  > /dev/null 2>&1
+    convert_deployment
+  fi
+
 }
 
 main "$@"