Traces #

The SimKube tracer collects timeseries data about the events happening in a live Kubernetes cluster and exports that data to a trace file for future replay and analysis. These trace files can then be stored in a cloud provider or downloaded locally. We describe configuration options for each of these use cases.

Cloud storage #

We support exporting traces to Amazon S3, Google Cloud Storage, and Microsoft Azure Storage through the object_store crate. The sk-tracer and sk-driver pods need to be configured with the correct permissions to write and read data to your chosen cloud storage. One option is to inject environment variables into the pod that object_store understands.

• Amazon S3: use the AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables
• Google Cloud Storage: use the GOOGLE_SERVICE_ACCOUNT environment variable and inject your service account JSON file into the sk-tracer pod
• Microsoft Azure: use the AZURE_STORAGE_ACCOUNT_NAME and AZURE_STORAGE_ACCOUNT_KEY environment variables

The object_store crate will try other authentication/authorization methods if these environment variables are not set (for example, it will try to get credentials from the instance metadata endpoint for AWS), so these are not the only ways to grant permissions to the tracer and the driver. Configuring these permissions is beyond the scope of this documentation, and we encourage you to consult the IAM documentation for your chosen cloud provider(s).

Local storage #

If you do not have access to (or do not want to use) cloud storage, you can also save a trace file to local storage using, for example, skctl export -o file:///path/to/trace. However, using this trace file in the simulator is a bit more complicated; it will need to be injected into the node(s) where your Simulation driver pods will run, and then volume-mounted into the driver pod. If you are running locally via kind, you can add the following block to your kind config to mount the trace file directory on your laptop into the kind nodes:

  - role: worker
    extraMounts:
      - hostPath: /tmp/kind-node-data
        containerPath: /data

From there, when you run a simulation, you need to specify the trace data using skctl run --trace-path file:///data/trace. This location is the location inside the Kind node docker container, not inside the driver pod. SimKube will automatically construct the appropriate volume mounts so that the driver pod can reference the trace.