Simple Log Service:Install Logtail components in an ACK 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"
}

Back up files

Before you upgrade the Logtail components, we recommend that you back up the description files that are related to the Logtail components.

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

Upgrade components

We recommend that you use the automatic upgrade method in common scenarios. If you have modified parameters such as environment variables in the logtail-ds DaemonSet or alibaba-log-controller Deployment, we recommend that you use the manual upgrade method to retain your modifications.

Roll back an upgrade

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

1. Check whether to retain the new configurations of Logtail after the upgrade.

   If you do not need to retain the new configurations of Logtail after the upgrade, delete the configurations.

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 you delete redundant information 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 visit one of the following image repositories to view the version of a container image:

• logtail-ds image repository

• alibaba-log-controller image repository

How do I collect container logs from multiple Kubernetes clusters to the same Simple Log Service project?

If you want to collect container logs from multiple ACK clusters to the same Simple Log Service project, you must select the same project when you create the ACK clusters.

How do I view the logs of Logtail?

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

The stdout and stderr of the container do not apply to the sample scenario. Ignore the following stdout and stderr:

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 fails to be 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-ds 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 operational 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 the 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 -n 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 -n 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 

References

• For more information about how to install Logtail in a self-managed Kubernetes cluster, see Install Logtail components in a self-managed Kubernetes cluster.

• To collect the logs of control plane components from an ACK managed cluster, you can enable the log collection feature in the ACK console. For more information, see Collect the logs of control plane components in ACK Pro clusters.

• For more information about how to collect container logs from an ASK cluster, see Logs of control plane components in ASK Pro clusters.

• For more information about how to troubleshoot issues when you create a Logtail configuration, see What do I do if a Logtail machine group has no heartbeats? The issues include that no machine group exists and no heartbeat is detected in machine groups.

• For more information about how to troubleshoot errors when you collect logs, see What do I do if an error occurs when I use Logtail to collect logs from containers?

• For more information about how to filter containers when you configure Logtail, see Use the Simple Log Service console to collect container stdout and stderr in DaemonSet mode.