Container Probe

Configure Container probes to execute commands inside containers during chaos experiments

Container probe executes commands inside a new container and validates the output. Unlike the Command probe which runs inside the experiment pod (inline mode) or a simple source pod, the Container probe gives you full control over the container specification - image, volumes, security context, resource limits, and more.

Container probe is only supported on Kubernetes infrastructure driven by Harness Delegate (Kubernetes HD).

When to use

• Run validation commands that require a specific container image with pre-installed tools (e.g., database clients, custom SDKs)

• Execute checks that need mounted volumes, secrets, or ConfigMaps from the cluster

• Validate application state where the command needs specific security contexts, resource limits, or service account permissions

• Perform checks that must run with specific node affinity, tolerations, or network access

Steps to configure

1. Navigate to Project Settings > Chaos Probes and click + New Probe

2. Select Container Probe and provide a name, and optionally a description and tags

3. Under Variables, define any reusable values you want to reference in probe properties or run properties. For each variable, specify the type (String or Number), name, value (fixed or runtime input), and whether it's required at runtime.

4. Under Probe Properties, configure:

   Field	Description
   Container Image	The image to use (e.g., bitnami/kubectl:latest)
   Command	The command to execute (e.g., /bin/sh, -c)
   Arguments	The script or arguments to pass (e.g., echo "Hello World")
   Environment Variables (optional)	Name-value pairs passed to the container
   Namespace	Target Kubernetes namespace (e.g., default)
   Image Pull Policy	IfNotPresent, Always, or Never

   Advanced Configuration (optional):

   Field	Description
   Service Account Name	Service account for the probe pod (e.g., default)
   Image Pull Secrets	Secrets for pulling private container images
   Labels	Key-value labels for the probe pod
   Annotations	Key-value annotations for the probe pod
   Node Selector	Key-value pairs to constrain pod scheduling
   Tolerations	Tolerations for node taints
   Required/Preferred Node Affinity	Node affinity rules for pod scheduling
   Resource Limits	Limit Memory and Limit CPU for the container
   Resource Requests	Request Memory and Request CPU for the container

   Volumes (optional):

   Field	Description
   Name	Volume name (e.g., my-volume)
   Type	Volume type (e.g., EmptyDir)
   Medium	Storage medium for EmptyDir
   Size Limit	Maximum size (e.g., 1Gi)

   Volume Mounts (optional):

   Field	Description
   Name	Volume name to mount
   Mount Path	Path inside the container (e.g., /mnt/data)
   Sub Path / Sub Path Expression	Subpath within the volume
   Mount Propagation	Mount propagation mode
   Read Only	Whether the mount is read-only

   Security Configuration (optional):

   Field	Description
   Host Network, HostPID, Host IPC	Toggle access to host namespaces
   Allow Privilege Escalation	Allow container process to gain more privileges
   Read Only Root Filesystem	Mount root filesystem as read-only
   Privileged	Run container in privileged mode
   Run As Non Root	Require the container to run as a non-root user
   Run as user / Run as group	UID/GID for the container process (e.g., 1000)
   FS Group	Filesystem group for volumes (e.g., 2000)

   Data Comparison:

   Field	Description
   Type	Data type of the output: String, Int, or Float
   Comparison Criteria	Comparison operator: matches, ==, !=, >, <, >=, <=
   Value	The expected value to compare against (e.g., Hello World)

5. Provide the Run Properties:

   Field	Description
   Timeout	Maximum time for probe execution (e.g., 10s)
   Interval	Time between successive executions (e.g., 2s)
   Attempt	Number of retry attempts (e.g., 1)
   Polling Interval	Time between retries (e.g., 30s)
   Initial Delay	Delay before first execution (e.g., 5s)
   Verbosity	Log detail level
   Stop On Failure (optional)	Stop the experiment if the probe fails

6. Click Create Probe