Disable x/gdm daemon on compute instance (#837)

* Set default systemd runlevel to multi-user.target on all OSes during ami creation. The runlevel is set to graphical.target only when DCV is enabled.
* In ParallelCluster 2.10.0, centos7/centos8 use multi-user.target and ubuntu1804/alinux2 use graphical.target. multi-user.target won't start x/gdm service when booting. So, the solution is during ubuntu1804/alinux2 AMI build, switching graphical.target to multi-user.target to disable x/gdm service, then if dcv is enabled, switch multi-user.target to graphical.target and enable x/gdm service on head node.

Signed-off-by: Yulei Wang <yuleiwan@amazon.com>
Co-authored-by: Francesco De Martino <demartinof@icloud.com>

Author: 2 people

CHANGELOG.md

@@ -9,6 +9,7 @@ This file is used to list changes made in each version of the AWS ParallelCluste
 **ENHANCEMENTS**
 - Configure NFS threads to be max(8, num_cores) for performance. This enhancement will not take effect on Ubuntu 16.04 unless the instance is rebooted.
 - EFA kernel module now installed also on ARM instances with `alinux2` and `ubuntu1804`
+- Set default systemd runlevel to multi-user.target on all OSes during ami creation. The runlevel is set to graphical.target only when DCV is enabled.
 
 **CHANGES**
 - Upgrade EFA installer to version 1.11.0

recipes/dcv_config.rb

@@ -20,16 +20,6 @@
 
 # Configure the system to enable NICE DCV to have direct access to the Linux server's GPU and enable GPU sharing.
 def allow_gpu_acceleration
-  # On CentOS fix circular dependency multi-user.target -> cloud-init-> isolate multi-user.target.
-  # multi-user.target doesn't start until cloud-init run is finished. So isolate multi-user.target
-  # is stuck into starting, which keep hanging chef until the 3600s timeout.
-  unless node['platform'] == 'centos'
-    # Turn off X
-    execute "Turn off X" do
-      command "systemctl isolate multi-user.target"
-    end
-  end
-
   # Update the xorg.conf to set up NVIDIA drivers.
   # NOTE: --enable-all-gpus parameter is needed to support servers with more than one NVIDIA GPU.
   nvidia_xconfig_command = "nvidia-xconfig --preserve-busid --enable-all-gpus"
@@ -82,6 +72,15 @@ def allow_gpu_acceleration
   if node.default['cfncluster']['dcv']['is_graphic_instance']
     # Enable graphic acceleration in dcv conf file for graphic instances.
     allow_gpu_acceleration
+  else
+    bash 'set default systemd runlevel to graphical.target' do
+      user 'root'
+      code <<-SETUPX
+        set -e
+        systemctl set-default graphical.target
+        systemctl isolate graphical.target &
+      SETUPX
+    end
   end
 
   case node['platform']

recipes/dcv_install.rb

@@ -228,3 +228,10 @@ def disable_lock_screen
     end
   end
 end
+
+# Switch runlevel to multi-user.target
+if node['init_package'] == 'systemd'
+  execute "set default systemd runlevel to multi-user.target" do
+    command "systemctl set-default multi-user.target"
+  end
+end

recipes/tests.rb

@@ -250,6 +250,26 @@
   end
 end
 
+if node['conditions']['dcv_supported'] && node['cfncluster']['dcv_enabled'] == "master" && node['cfncluster']['cfn_node_type'] == "MasterServer"
+  execute 'check systemd default runlevel' do
+    command "systemctl get-default | grep -i graphical.target"
+  end
+  if node['cfncluster']['os'] == "ubuntu1804" || node['cfncluster']['os'] == "alinux2"
+    execute 'check gdm service is running' do
+      command "systemctl show -p SubState gdm | grep -i running"
+    end
+  end
+elsif node['init_package'] == 'systemd'
+  execute 'check systemd default runlevel' do
+    command "systemctl get-default | grep -i multi-user.target"
+  end
+  if node['cfncluster']['os'] == "ubuntu1804" || node['cfncluster']['os'] == "alinux2"
+    execute 'check gdm service is stopped' do
+      command "systemctl show -p SubState gdm | grep -i dead"
+    end
+  end
+end
+
 ###################
 # EFA - Intel MPI
 ###################
@@ -547,4 +567,4 @@ module load armpl/#{node['cfncluster']['armpl']['version']}
     ARMPL
     user node['cfncluster']['cfn_cluster_user']
   end
-end
+end