Agent Mount Method
For Odigos agents to run inside instrumented pod containers, certain files must be mounted into the container. In Kubernetes, these files are mounted under /var/odigos
directory, with subdirectories for each agent. There are few mechanisms to achieve this, which are explained in this document.
Mount Method
This section is for advanced users and odigos administrators.
It is recommended to use the default settings, unless you have specific requirements or run into an issue.
Supported Mount Methods
Odigos supports 2 mount methods, which can be used depending on the user preference, cluster policies, integration with existing tools, etc.
1. VirtualDevice
This is the default mount method
Pod Manifest Additions
For agents and languages that requires filesystem mounts, odigos webhook will add the following:
- For each instrumented container in the pod spec, odigos will add a resource requirement under the
spec.containers[].resources
field:
Caveats
- May sometimes not integrate well with node auto-scaling tools like Karpenter.
- Odiglet daemonset needs to be running on a node for instrumented pods to be scheduled on that node.
2. HostPath
This method is an opt-in configuration option which can be used if the virtual device method is not suitable for your cluster.
If it is supported in the cluster, it is preferred to use over the VirtualDevice method which requires odiglet component to run.
Enabling HostPath
-
Profile:
odigos profile add mount-method-k8s-host-path
-
Odigos CLI:
odigos config set mount-method k8s-host-path
-
Helm Chart: in your values file, set
instrumentor.mountMethod
tok8s-host-path
, or use helm cli--set instrumentor.mountMethod=k8s-host-path
flag with helm upgrade. -
Kubernetes Manifest: under the
odigos-config
ConfigMap in odigos namespace, set the value in themountMethod
field ofconfig.yaml
tok8s-host-path
.
Pod Manifest Additions
For agents and languages that requires filesystem mounts, odigos webhook will add the following:
- Volume to the pod spec, under the
spec.volumes
field:
- VolumeMount to the instrumented container specs, under the
spec.containers[].volumeMounts
field:
Caveats
The “HostPath” option should be enabled in the cluster. Some policy tools may block this, like:
If your cluster enforces such policies, you have the following options:
- Use the VirtualDevice method.
- Request the cluster administrator to whitelist the Odigos agent host path in the policy tool.