description	coverY
A Kubernetes operator for Databricks	0

🦀 databricks-kube-operator

A kube-rs operator to enable GitOps style management of Databricks resources. It supports the following APIs:

API	CRD
Jobs 2.1	DatabricksJob
Git Credentials 2.0	GitCredential
Repos 2.0	Repo

Experimental headed towards stable. See the GitHub project board for the roadmap. Contributions and feedback are welcome!

Read the docs

Quick Start

Looking for a more in-depth example? Read the tutorial.

Installation

Add the Helm repository and install the chart:

helm repo add mach https://mach-kernel.github.io/databricks-kube-operator
helm install databricks-kube-operator mach/databricks-kube-operator

Create a config map in the same namespace as the operator. To override the configmap name, --set configMapName=my-custom-name:

cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: ConfigMap
metadata:
  name: databricks-kube-operator
data:
  api_secret_name: databricks-api-secret
EOF

Create a secret with your API URL and credentials:

cat <<EOF | kubectl apply -f -
apiVersion: v1
data:
  access_token: $(echo -n 'shhhh' | base64)
  databricks_url: $(echo -n 'https://my-tenant.cloud.databricks.com/api' | base64)
kind: Secret
metadata:
  name: databricks-api-secret
type: Opaque
EOF

Usage

See the examples directory for samples of Databricks CRDs. Resources that are created via Kubernetes are owned by the operator: your checked-in manifests are the source of truth.

apiVersion: com.dstancu.databricks/v1
kind: DatabricksJob
metadata:
  name: my-word-count
  namespace: default
spec:
  job:
    settings:
      email_notifications:
        no_alert_for_skipped_runs: false
      format: MULTI_TASK
      job_clusters:
      - job_cluster_key: word-count-cluster
        new_cluster:
          ...
      max_concurrent_runs: 1
      name: my-word-count
      git_source:
        git_branch: misc-and-docs
        git_provider: gitHub
        git_url: https://github.com/mach-kernel/databricks-kube-operator
      tasks:
      - email_notifications: {}
        job_cluster_key: word-count-cluster
        notebook_task:
          notebook_path: examples/job.py
          source: GIT
        task_key: my-word-count
        timeout_seconds: 0
      timeout_seconds: 0

Changes made by users in the Databricks webapp will be overwritten by the operator if drift is detected:

[2024-01-11T14:20:40Z INFO  databricks_kube::traits::remote_api_resource] Resource DatabricksJob my-word-count drifted!
    Diff (remote, kube):
    json atoms at path ".settings.tasks[0].notebook_task.notebook_path" are not equal:
        lhs:
            "examples/job_oops_is_this_right.py"
        rhs:
            "examples/job.py"
[2024-01-11T14:20:40Z INFO  databricks_kube::traits::remote_api_resource] Resource DatabricksJob my-word-count reconciling drift...

Look at jobs (allowed to be viewed by the operator's access token):

$ kubectl get databricksjobs
NAME                                 STATUS
contoso-ingest-qa                      RUNNING
contoso-ingest-staging                 INTERNAL_ERROR
contoso-stats-qa                       TERMINATED
contoso-stats-staging                  NO_RUNS

$ kubectl describe databricksjob contoso-ingest-qa
...

A job's status key surfaces API information about the latest run. The status is polled every 60s:

$ kubectl get databricksjob contoso-ingest-staging -ojson | jq .status
{
  "latest_run_state": {
    "life_cycle_state": "INTERNAL_ERROR",
    "result_state": "FAILED",
    "state_message": "Task contoso-ingest-staging failed. This caused all downstream tasks to get skipped.",
    "user_cancelled_or_timedout": false
  }
}

Developers

Begin by creating the configmap as per the Helm instructions.

Generate and install the CRDs by running the crd_gen bin target:

cargo run --bin crd_gen | kubectl apply -f -

The quickest way to test the operator is with a working minikube cluster:

minikube start
minikube tunnel &

export RUST_LOG=databricks_kube
cargo run
[2022-11-02T18:56:25Z INFO  databricks_kube] boot! (build: df7e26b-modified)
[2022-11-02T18:56:25Z INFO  databricks_kube::context] Waiting for CRD: databricksjobs.com.dstancu.databricks
[2022-11-02T18:56:25Z INFO  databricks_kube::context] Waiting for CRD: gitcredentials.com.dstancu.databricks
[2022-11-02T18:56:25Z INFO  databricks_kube::context] Waiting for settings in config map: databricks-kube-operator
[2022-11-02T18:56:25Z INFO  databricks_kube::context] Found config map
[2022-11-02T18:56:25Z INFO  databricks_kube::traits::synced_api_resource] Looking for uningested GitCredential(s)
[2022-11-02T18:56:25Z INFO  databricks_kube::traits::synced_api_resource] Looking for uningested DatabricksJob(s)

Generating API Clients

The client is generated by openapi-generator and then lightly postprocessed so we get models that derive JsonSchema and fix some bugs.

TODO: Fork or fix generator/template issues instead of sed.

# Hey!! This uses GNU sed
# brew install gnu-sed

# Jobs API
openapi-generator generate -g rust -i openapi/jobs-2.1-aws.yaml -c openapi/config-jobs.yaml -o dbr_jobs

# Derive JsonSchema for all models and add schemars as dep
gsed -i -e 's/derive(Clone/derive(JsonSchema, Clone/' dbr_jobs/src/models/*
gsed -i -e 's/\/\*/use schemars::JsonSchema;\n\/\*/' dbr_jobs/src/models/*
gsed -r -i -e 's/(\[dependencies\])/\1\nschemars = "0.8.11"/' dbr_jobs/Cargo.toml

# Missing import?
gsed -r -i -e 's/(use reqwest;)/\1\nuse crate::models::ViewsToExport;/' dbr_jobs/src/apis/default_api.rs

# Git Credentials API
openapi-generator generate -g rust -i openapi/gitcredentials-2.0-aws.yaml -c openapi/config-git.yaml -o dbr_git_creds

# Derive JsonSchema for all models and add schemars as dep
gsed -i -e 's/derive(Clone/derive(JsonSchema, Clone/' dbr_git_creds/src/models/*
gsed -i -e 's/\/\*/use schemars::JsonSchema;\n\/\*/' dbr_git_creds/src/models/*
gsed -r -i -e 's/(\[dependencies\])/\1\nschemars = "0.8.11"/' dbr_git_creds/Cargo.toml

# Repos API
openapi-generator generate -g rust -i openapi/repos-2.0-aws.yaml -c openapi/config-repos.yaml -o dbr_repo

# Derive JsonSchema for all models and add schemars as dep
gsed -i -e 's/derive(Clone/derive(JsonSchema, Clone/' dbr_repo/src/models/*
gsed -i -e 's/\/\*/use schemars::JsonSchema;\n\/\*/' dbr_repo/src/models/*
gsed -r -i -e 's/(\[dependencies\])/\1\nschemars = "0.8.11"/' dbr_repo/Cargo.toml

Expand CRD macros

Deriving CustomResource uses macros to generate another struct. For this example, the output struct name would be DatabricksJob:

#[derive(Clone, CustomResource, Debug, Default, Deserialize, PartialEq, Serialize, JsonSchema)]
#[kube(
    group = "com.dstancu.databricks",
    version = "v1",
    kind = "DatabricksJob",
    derive = "Default",
    namespaced
)]
pub struct DatabricksJobSpec {
    pub job: Job,
}

rust-analyzer shows squiggles when you use crds::databricks_job::DatabricksJob, but one may want to look inside. To see what is generated with cargo-expand:

rustup default nightly
cargo expand --bin databricks_kube

Adding a new CRD

Want to add support for a new API? Provided it has an OpenAPI definition, these are the steps. Look for existing examples in the codebase:

• Download API definition into openapi/ and make a Rust generator configuration (feel free to copy the others and change name)
• Generate the SDK, add it to the Cargo workspace and dependencies for databricks-kube/
• Implement RestConfig<TSDKConfig> for your new client
• Define the new CRD Spec type (follow kube-rs tutorial)
• impl RemoteAPIResource<TAPIResource> for MyNewCRD
• impl StatusAPIResource<TStatusType> for MyNewCRD and specify TStatusType in your CRD
• Add the new resource to the context ensure CRDs condition
• Add the new resource to crdgen.rs

Running tests

Tests must be run with a single thread since we use a stateful singleton to 'mock' the state of a remote API. Eventually it would be nice to have integration tests targetting Databricks.

$ cargo test -- --test-threads=1

License