Simple Log Service:Install Logtail components in a self-managed Kubernetes cluster

View the status of Logtail

Run the following command to view the status of Logtail:

kubectl get po -n kube-system | grep logtail

The following output is returned:

NAME            READY     STATUS    RESTARTS   AGE
logtail-ds-gb92k   1/1       Running   0          2h
logtail-ds-wm7lw   1/1       Running   0          4d

View the version number and IP address of Logtail

Run the following command to view the version number and IP address of Logtail:

kubectl exec logtail-ds-gb92k -n kube-system cat /usr/local/ilogtail/app_info.json

The following output is returned:

{
   "UUID" : "",
   "hostname" : "logtail-ds-gb92k",
   "instance_id" : "0EBB2B0E-0A3B-11E8-B0CE-0A58AC140402_172.20.4.2_1517810940",
   "ip" : "192.0.2.0",
   "logtail_version" : "0.16.2",
   "os" : "Linux; 3.10.0-693.2.2.el7.x86_64; #1 SMP Tue Sep 12 22:26:13 UTC 2017; x86_64",
   "update_time" : "2021-02-05 06:09:01"
}

Upgrade components

1. Back up the description files that are related to the Logtail components.

   Important

   An upgrade requires a few seconds to complete. During an upgrade, the Logtail container is restarted, which may cause a small amount of data to be collected again or lost during collection. Before you upgrade the Logtail components, we recommend that you back up the description files that are related to the Logtail components.

   Sample command:

   kubectl get ds -n kube-system logtail-ds -o yaml > logtail-ds.yaml
   kubectl get deployment -n kube-system alibaba-log-controller -o yaml > alibaba-log-controller.yaml
   kubectl get crd aliyunlogconfigs.log.alibabacloud.com -o yaml > aliyunlogconfigs-crd.yaml
   kubectl get cm -n kube-system alibaba-log-configuration -o yaml > alibaba-log-configuration.yaml

2. Reinstall the Logtail components to complete the automatic upgrade. For more information, see Install Logtail.

Roll back Logtail

The following procedure shows how to roll back to a version.

1. Check whether to retain the new configurations of Logtail after the upgrade based on your business requirements.

2. Delete redundant information from the backup files.

   cat logtail-ds.yaml | kubectl-neat > neat-logtail-ds.yaml
   cat alibaba-log-controller.yaml | kubectl-neat > neat-alibaba-log-controller.yaml
   cat aliyunlogconfigs-crd.yaml | kubectl-neat > neat-aliyunlogconfigs-crd.yaml
   cat alibaba-log-configuration.yaml | kubectl-neat > neat-alibaba-log-configuration.yaml

3. Use the backup files after the deletion to restore the configurations of Logtail.

   kubectl apply -f neat-logtail-ds.yaml
   kubectl apply -f neat-alibaba-log-controller.yaml
   kubectl apply -f neat-aliyunlogconfigs-crd.yaml
   kubectl apply -f  neat-alibaba-log-configuration.yaml

How do I view the version of a container image?

You can view the version of a container image by visiting one of the following image repositories:

• logtail-ds image repository

• alibaba-log-controller image repository

How do I associate multiple self-managed Kubernetes clusters with the same Simple Log Service project?

If you want to collect container logs from multiple self-managed Kubernetes clusters to the same Simple Log Service project, you can set the SlsProjectName parameter to the same value for each self-managed Kubernetes cluster when you install Simple Log Service components.

How do I view the logs of Logtail?

The logs of Logtail are stored in the files named ilogtail.LOG and logtail_plugin.LOG in the /usr/local/ilogtail/ directory of a Logtail container.

The stdout of the container is irrelevant to this case. Ignore the following stdout:

start umount useless mount points, /shm$|/merged$|/mqueue$
umount: /logtail_host/var/lib/docker/overlay2/3fd0043af174cb0273c3c7869500fbe2bdb95d13b1e110172ef57fe840c82155/merged: must be superuser to unmount
umount: /logtail_host/var/lib/docker/overlay2/d5b10aa19399992755de1f85d25009528daa749c1bf8c16edff44beab6e69718/merged: must be superuser to unmount
umount: /logtail_host/var/lib/docker/overlay2/5c3125daddacedec29df72ad0c52fac800cd56c6e880dc4e8a640b1e16c22dbe/merged: must be superuser to unmount
......
xargs: umount: exited with status 255; aborting
umount done
start logtail
ilogtail is running
logtail status:
ilogtail is running

How do I view the status of Simple Log Service components in Kubernetes clusters?

Run the following commands:

kubectl get deploy alibaba-log-controller -n kube-system
kubectl get ds logtail-ds -n kube-system

What do I do if alibaba-log-controller fails to start?

Check whether alibaba-log-controller is installed by using the following method:

• Run the installation command on the master node of your Kubernetes cluster.

• Specify the ID of your Kubernetes cluster in the installation command.

If alibaba-log-controller is not installed by using the preceding method, run the kubectl delete -f deploy command to delete the installation template that is generated. Then, rerun the installation command.

How do I view the status of the Logtail DaemonSet in a Kubernetes cluster?

Run the kubectl get ds -n kube-system command to view the status of the Logtail DaemonSet.

How do I view the oeprational logs of Logtail?

The operational logs of Logtail are stored in the ilogtail.LOG file in the /usr/local/ilogtail/ directory. If the log file is rotated, the generated files are compressed and stored as ilogtail.LOG.x.gz. Run the following command to view logs:

kubectl exec logtail-ds-gb92k -n kube-system tail /usr/local/ilogtail/ilogtail.LOG

The following output is returned:

[2018-02-05 06:09:02.168693] [INFO] [9] [build/release64/sls/ilogtail/LogtailPlugin.cpp:104] logtail plugin Resume:start
[2018-02-05 06:09:02.168807] [INFO] [9] [build/release64/sls/ilogtail/LogtailPlugin.cpp:106] logtail plugin Resume:success
[2018-02-05 06:09:02.168822] [INFO] [9] [build/release64/sls/ilogtail/EventDispatcher.cpp:369] start add existed check point events, size:0
[2018-02-05 06:09:02.168827] [INFO] [9] [build/release64/sls/ilogtail/EventDispatcher.cpp:511] add existed check point events, size:0 cache size:0 event size:0 success count:0

How do I restart Logtail for a pod?

1. Stop Logtail.

2. In the following command, logtail-ds-gb92k specifies the container, and kube-system specifies the namespace. Configure the parameters based on your business scenario.

   kubectl exec logtail-ds-gb92k -n kube-system /etc/init.d/ilogtaild stop

   If the following output is returned, Logtail is stopped.

   kill process Name: ilogtail pid: 7
   kill process Name: ilogtail pid: 9
   stop success

3. Start Logtail.

4. In the following command, logtail-ds-gb92k specifies the container, and kube-system specifies the namespace. Configure the parameters based on your business scenario.

   kubectl exec logtail-ds-gb92k -n kube-system /etc/init.d/ilogtaild start

   If the following output is returned, Logtail is started.

   ilogtail is running 

How do I collect the logs of control plane components?

For information about how to collect the logs of control plane components from a self-managed Kubernetes cluster or a Container Service for Kubernetes (ACK) dedicated cluster, see Use the Simple Log Service console to collect container stdout and stderr in DaemonSet mode.

How do I uninstall the components such as logtail-ds and alibaba-log-controller?

Run the kubectl delete -R -f result command to uninstall these components.