How To: Create a test Linux Service

Scenario

This how-to applies to creating a test service on customer’s Linux machine. This may help identify issues of CT&I Agent detecting Linux Services.

Create a test service

1. Create a script named create_test_service.sh to create and set up the service, with below content. The service named test.service, and will keep writing a log to /tmp/test_service.log every 30s.

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   #!/bin/bash # Create the script that the service will execute cat <<EOF > /usr/local/bin/test_service.sh #!/bin/bash touch /tmp/test_service.log while true; do echo "Test Service: \$(date)" >> /tmp/test_service.log sleep 30 done EOF # Give the script execution permissions chmod +x /usr/local/bin/test_service.sh # Create the systemd service file cat <<EOF > /etc/systemd/system/test.service [Unit] Description=Test Service [Service] Type=simple ExecStart=/usr/local/bin/test_service.sh Restart=always [Install] WantedBy=multi-user.target EOF # Reload systemd to make the new service take effect systemctl daemon-reload # Start the service systemctl start test.service # Enable the service to start on boot systemctl enable test.service echo "Test service created and started."

2. Use following commands to run the script

   1 2	chmod +x create_test_service.sh sudo ./create_test_service.sh

3. Use systemctl status test.service to check the service status. The output would look similar to below.

   

4. Let the service run for more than 5 mins so that CT&I Agent should be able to detect it. The result will look similar to below on Azure Portal

   

Clean up environment

1. Once test is done, create a script named cleanup_test_service.sh to clean up the test service, with below content.

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   #!/bin/bash # Stop the service systemctl stop test.service # Disable the service to prevent it from starting on boot systemctl disable test.service # Remove the service file rm /etc/systemd/system/test.service # Remove the script that the service was executing rm /usr/local/bin/test_service.sh # Remove tmp logging rm /tmp/test_service.log # Reload systemd to apply changes systemctl daemon-reload systemctl reset-failed echo "Test service has been removed."

2. Use following commands to run the script

   1 2	chmod +x cleanup_test_service.sh sudo ./cleanup_test_service.sh

3. Double check the service removal by systemctl status test.service. The result will look similar to below

How To: Manually Restart CT&I Linux Agent

Scenario

If you are ever in the position where you need to restart the CT&I Agent for Linux, the following process will give you some guidance.

Method 1 (Recommended)

This is using the same commands the Azure VM Guest Agent uses to maintain the agent. You will need to browse the installation directory from a shell and execute the script using either the -disable parameter or the -enable parameter. This will need to be done as the root user.

• Go to /var/lib/waagent/Microsoft.Azure.ChangeTrackingAndInventory.ChangeTracking-Linux-{extension-version}

• As high privilege user run ./cta_linux_handler disable

• Wait for few minutes until following processes are finished /usr/sbin/changetracking/changetracking /opt/microsoft/changetracking/change_tracking_agent_linux_amd64

• To enable the agent back ./cta_linux_handler enable

Method 2 (If method 1 does not work)

• systemctl restart cxp.service

How To: Manually Purge CT&I Linux Agent

Scenario

If you are ever in the position where you need to manually purge the CT&I Agent for Linux, the following process will give you some guidance.

Make sure to uninstall the CT&I extension from Azure Portal first, regardless of a failed uninstallation, as below process is only for the agent on OS, not for extension itself.

Method 1 (Recommended)

This is using the same commands the Azure VM Guest Agent uses to maintain the agent.

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cd /var/lib/waagent/Microsoft.Azure.ChangeTrackingAndInventory.ChangeTracking-Linux-*
./cta_linux_handler disable
./cta_linux_handler uninstall

Method 2 (If method 1 does not work)

1. Remove cxp service

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systemctl stop cxp
systemctl disable cxp
rm /lib/systemd/system/cxp.service
rm /etc/systemd/system/cxp.service
rm /usr/lib/systemd/system/cxp.service
systemctl daemon-reload (**This is optional**)

2. At this stage, cxp.service is still available via systemctl status cxp, though in failed state.. Optionally run systemctl reset-failed to remove cxp.service from systemd.
3. Remove change-tracking-retail package
   • Redhat series : yum remove -y change_tracking_retail
   • Debian series : apt remove -y change-tracking-retail
4. Remove local files
   • /opt/microsoft/changetracking/*
   • /usr/sbin/changetracking/*
   • Optional: /var/lib/waagent/Microsoft.Azure.ChangeTrackingAndInventory.ChangeTracking-Linux-/
   • Optional: /var/log/azure/Microsoft.Azure.ChangeTrackingAndInventory.ChangeTracking-Linux/*

How To: Manually Onboard CT&I Linux Agent

Scenario

If you are ever in the position where you need to manually onboard the CT&I Agent for Linux, the following process will give you some guidance.

Method 1 (Recommended)

This is using the same commands the Azure VM Guest Agent uses to maintain the agent.

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# Install package “change-tracking-retail” & setup cxp.service
cd /var/lib/waagent/Microsoft.Azure.ChangeTrackingAndInventory.ChangeTracking-Linux-*
./cta_linux_handler install

# Enable cxp.service
./cta_linux_handler enable

# Start cxp.service
systemctl start cxp.service

Method 2 (If method 1 does not work)

1. Manually install “change-tracking-retail” package

• rpm series (Redhat, CentOS, SUSE, etc.)

  1 2	cd /var/lib/waagent/Microsoft.Azure.ChangeTrackingAndInventory.ChangeTracking-Linux-* rpm --force -i change-tracking-retail_<version>.rpm

• dpkg series (Ubuntu, Debian, etc.)

  1 2	cd /var/lib/waagent/Microsoft.Azure.ChangeTrackingAndInventory.ChangeTracking-Linux-* dpkg -i change-tracking-retail_<version>.deb

2. Manually setup cxp.service

• create and add below content to /lib/systemd/system/cxp.service .

  Note: Below content has one place that needs to be modified to the correct extension version. For checking the current extension version, please use command ls /var/lib/waagent/ | grep ChangeTracking

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  [Unit] Description=Azure change tracking Parent Daemon Wants=network-online.target After=network-online.target [Service] ExecStart=/usr/sbin/changetracking/changetracking /opt/microsoft/changetracking/change_tracking_agent_linux_amd64 /var/lib/waagent/Microsoft.Azure.ChangeTrackingAndInventory.ChangeTracking-Linux-<**replace-correct-version**> Restart=on-failure [Install] WantedBy=multi-user.target

• chmod 0644 /lib/systemd/system/cxp.service

• cp /opt/microsoft/changetracking/svc/changetracking /usr/sbin/changetracking/

• chmod 0755 /usr/sbin/changetracking/changetracking

• systemctl enable cxp

• systemctl start cxp

  Note: You may backup any files in /usr/sbin/changetracking/ if exists prior to these scripts.

How To: Enable Trace Logging of CT&I Linux Agent

Scenario

If you are ever in the position where you need to trace down details on how CT&I Agent Linux works, the following process will give you some guidance.

Step 1: Change Log Level in Configuration File

In order to enable debug logging of CT&I Agent, we need to edit the configuration file /var/lib/waagent/Microsoft.Azure.ChangeTrackingAndInventory.ChangeTracking-Linux-*/application.yml. There is three parts we need to take care of:

1. Enable trace logging for /var/log/azure/Microsoft.Azure.ChangeTrackingAndInventory.ChangeTracking-Linux/cta_linux_agent.log. The is the main agent log, which contains communication with AMA and details of Files/Services/Software inventory and changes. Edit the level to TRACE.

   

2. Enable trace logging for /var/log/azure/Microsoft.Azure.ChangeTrackingAndInventory.ChangeTracking-Linux/cta_linux_handler.log. The is the log of handler services, brings up agent main process, provides basic environment parameters to the agent. Edit the level to TRACE.

   

3. Enable trace logging for /var/log/azure/Microsoft.Azure.ChangeTrackingAndInventory.ChangeTracking-Linux/cta_linux_watcher.log. The is the log of checking whether agent main process/service are running. Edit the level to TRACE.

   

Step 2: Restart CT&I Linux Agent

• For how to restart CT&I Agent, Please refer to How To: Manually Restart CT&I Linux Agent .

Note:

• After restarted the CT&I Agent, we need to wait for some time for debug logs being populated. Typically 1 hour would be good to collect a cycle run of Services, Software and Files.
• Please change the collection level back to avoid filling up disk space after debug logs are collected.