From 2870104a39cd44031dadcc659827b3c111229d23 Mon Sep 17 00:00:00 2001
From: Justin Travis <justin@kasmweb.com>
Date: Fri, 15 Mar 2024 15:50:05 -0400
Subject: [PATCH] KASM-5766 Add the ability to wait on the printer service

Some use-cases require the printer to be ready before an app can be
loaded. These updates allow the admin to be more agressive in the cups
startup and to use /usr/bin/printer_ready to block on the printer in
both the vnc_startup and custom_startup scripts
---
 src/common/startup_scripts/vnc_startup.sh     | 11 +++++++++++
 src/ubuntu/install/printer/install_printer.sh | 19 +++++++++++++++++++
 src/ubuntu/install/printer/start_cups.sh      |  2 +-
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/common/startup_scripts/vnc_startup.sh b/src/common/startup_scripts/vnc_startup.sh
index a376630..64ebd1b 100755
--- a/src/common/startup_scripts/vnc_startup.sh
+++ b/src/common/startup_scripts/vnc_startup.sh
@@ -344,6 +344,16 @@ function start_printer (){
 	fi
 }
 
+function wait_on_printer (){
+    # Wait for cups and the printer device to be created
+    if [[ ${KASM_SVC_PRINTER:-1} == 1 && ${KASM_PRINTER_WAIT:-0} == 1 ]]; then
+        log 'Waiting on printer service to be ready'
+        /usr/bin/printer_ready
+        log 'Printer is ready'
+    fi
+}
+
+
 function custom_startup (){
 	custom_startup_script=/dockerstartup/custom_startup.sh
 	if [ -f "$custom_startup_script" ]; then
@@ -504,6 +514,7 @@ chmod 600 $PASSWD_PATH
 
 
 # start processes
+wait_on_printer
 start_kasmvnc
 start_window_manager
 start_audio_out_websocket
diff --git a/src/ubuntu/install/printer/install_printer.sh b/src/ubuntu/install/printer/install_printer.sh
index ceb9b2f..c89ab6c 100755
--- a/src/ubuntu/install/printer/install_printer.sh
+++ b/src/ubuntu/install/printer/install_printer.sh
@@ -32,3 +32,22 @@ ARCH=$(arch | sed 's/aarch64/arm64/g' | sed 's/x86_64/amd64/g')
 mkdir -p $STARTUPDIR/printer
 wget -qO- https://kasmweb-build-artifacts.s3.amazonaws.com/kasm_printer_service/${COMMIT_ID}/kasm_printer_service_${ARCH}_${BRANCH}.${COMMIT_ID_SHORT}.tar.gz | tar -xvz -C $STARTUPDIR/printer/
 echo "${BRANCH}:${COMMIT_ID}" > $STARTUPDIR/printer/kasm_printer.version
+
+
+cat >/usr/bin/printer_ready <<EOL
+#!/usr/bin/env bash
+set -x
+if [[ ${KASM_SVC_PRINTER:-1} == 1 ]]; then
+  PRINTER_NAME=${KASM_PRINTER_NAME:-Kasm-Printer}
+  until [[ "$(lpstat -r)" == "scheduler is running" ]]; do sleep 1; done
+  echo "Scheduler is running"
+
+  until lpstat -p "$PRINTER_NAME" | grep -q "is idle"; do
+      sleep 1
+  done
+  echo "Printer $PRINTER_NAME is idle."
+else
+  echo "Printing service is not enabled"
+fi
+EOL
+chmod +x /usr/bin/printer_ready
diff --git a/src/ubuntu/install/printer/start_cups.sh b/src/ubuntu/install/printer/start_cups.sh
index 8b19823..996ba3f 100755
--- a/src/ubuntu/install/printer/start_cups.sh
+++ b/src/ubuntu/install/printer/start_cups.sh
@@ -7,7 +7,7 @@ set -ex
     # HACK: Some versions of cupsd cannot handle unlimited file descriptor limit
     # that docker sets..
     ulimit -n 1024 &&/usr/sbin/cupsd -f &
-    until [[ "$(lpstat -r)" == "scheduler is running" ]]; do sleep 15; done
+    until [[ "$(lpstat -r)" == "scheduler is running" ]]; do sleep ${KASM_CUPS_SLEEP:-15}; done
 
     echo "Creating a virtual printer: $PRINTER_NAME"
     lpadmin -p $PRINTER_NAME -E -v cups-pdf:/ -P /etc/cups/ppd/kasm.ppd