Troubleshooting
Automatic log and state collection
Before you report a problem, make sure to retrieve the necessary information from your cluster.
Tetragon’s bugtool captures potentially useful information about your environment for debugging. The tool is meant to be used for debugging a single Tetragon agent node but can be run automatically in a cluster. Note that in the context of Kubernetes, the command needs to be run from inside the Tetragon Pod’s container.
Key information collected by bugtool:
- Tetragon configuration
- Network configuration
- Kernel configuration
- eBPF maps
- Process traces (if tracing is enabled)
Automatic Kubernetes cluster sysdump
You can collect information in a Kubernetes cluster using the Cilium CLI:
cilium-cli sysdump
More details can be found in the Cilium docs.
The Cilium CLI sysdump
command will automatically run tetra bugtool
on each
nodes where Tetragon is running.
Manual single node sysdump
It’s also possible to run the bug collection tool manually with the scope of a
single node using tetra bugtool
.
Kubernetes installation
-
Identify the Tetragon Pod (
<tetragon-namespace>
is likely to bekube-system
with the default install):kubectl get pods -n <tetragon-namespace> -l app.kubernetes.io/name=tetragon
-
Execute tetra bugtool within the Pod:
kubectl exec -n <tetragon-namespace> <tetragon-pod-name> -c tetragon -- tetra bugtool
-
Retrieve the created archive from the Pod’s filesystem:
kubectl cp -c tetragon <tetragon-namespace>/<tetragon-pod-name>:tetragon-bugtool.tar.gz tetragon-bugtool.tar.gz
Container installation
-
Enter the Tetragon Container:
docker exec -it <tetragon-container-id> tetra bugtool
-
Retrieve the archive using docker cp:
docker cp <tetragon-container-id>:/tetragon-bugtool.tar.gz tetragon-bugtool.tar.gz
Systemd host installation
-
Execute tetra bugtool with Elevated Permissions:
sudo tetra bugtool
Enable debug log level
When debugging, it might be useful to change the log level. The default log level is controlled by the log-level option at startup:
- Enable debug level with
--log-level=debug
- Enable trace level with
--log-level=trace
Change log level on Kubernetes
It is possible to change the log level of Tetragon’s DaemonSet Pods by setting
tetragon.debug
to true
.
Change log level dynamically
It is possible to change the log level dynamically by using the tetra loglevel
sub-command. tetra
needs access to Tetragon’s gRPC server endpoint which can
be configured via --server-address
.
localhost
. Also, it’s important to understand that this only changes the log
level of the single Tetragon instance targeted with --server-address
and not
all Tetragon instances when it’s, for example, running as DaemonSet in a
Kubernetes environment.
-
Get the current log level:
tetra loglevel get
-
Dynamically change the log level. Allowed values are
[trace|debug|info|warning|error|fatal|panic]
:tetra loglevel set debug