Soda Agent extras

Last modified on 20-Nov-24

When you deploy a self-hosted Soda Agent to a Kubernetes cluster in your cloud service provider environment, you need to provide several key parameters and values to ensure optimal operation and to allow the agent to connect to your Soda Cloud account (API keys), and connect to your data sources (data source login credentials) so that Soda can run data quality scans on the data.

Handle sensitive values
Optimize performance

Handle sensitive values

By default, Soda uses Kubernetes Secrets as part of the Soda Agent deployment. The agent automatically converts any sensitive values you add to a values YAML file, or directly via the CLI, into Kubernetes Secrets.

As these values are sensitive, you may wish to employ the following alternative strategies to keep them secure.

Use a values YAML file to store API key values
Use a values file to store private key authentication values
Use environment variables to store data source connection credentials
Integrate with a secrets manager
Use Soda Cloud API Keys from an existing secret

Use a values YAML file to store API key values

When you deploy a self-hosted Soda Agent from the command-line, you provide values for the API key id and API key secret which the agent uses to connect to your Soda Cloud account. You can provide these values during agent deployment in one of two ways:

directly in the helm install command that deploys the agent and stores the values as Kubernetes secrets in your cluster; see deploy using CLI only
OR
in a values.yml file which you store locally but reference in the helm install command as in the example below.

soda:
  apikey:
    id: "***"
    secret: "***"
  agent:
    name: "myuniqueagent"

helm install soda-agent soda-agent/soda-agent \
  --values values.yml \
  --namespace soda-agent

Refer to the exhaustive cloud service provider-specific instructions for more detail on how to deploy an agent using a values YAML file.

Use a values file to store private key authentication values

If you use private key with Snowflake or BigQuery, you can provide the required private key values in a values.yml file when you deploy or redeploy the agent.

Use environment variables to store data source connection credentials

When you, or someone in your organization, follows the guided steps to use a self-hosted Soda Agent to add a data source in Soda Cloud, one of the steps involves providing the connection details and credentials Soda needs to connect to the data source to run scans.

You can add those details directly in Soda Cloud, but because any user can then access these values, you may wish to store them securely in the values YAML file as environment variables.

Create or edit your local values YAML file to include the values for the environment variables you input into the connection configuration.

soda:
 apikey:
   id: "***"
   secret: "***"
 agent:
   name: "myuniqueagent"
 env:
   POSTGRES_USER: "sodalibrary"
   POSTGRES_PASS: "sodalibrary"

After adding the environment variables to the values YAML file, update the Soda Agent using the following command:
```
helm upgrade soda-agent soda-agent/soda-agent \
  --values values.yml \
  --namespace soda-agent
```
In step 2 of the add a data source guided steps, add data source connection configuration which look something like the following example for a PostgreSQL data source. Note the environment variable values for username and password.
```
data_source local_postgres_test:
 type: postgres
 host: 172.17.0.7
 port: 5432
 username: ${POSTGRES_USER}
 password: ${POSTGRES_PASS}
 database: postgres
 schema: new_york
```
Follow the remaining guided steps to add a new data source in Soda Cloud. When you save the data source and test the connection, Soda Cloud uses the values you stored as environment variables in the values YAML file you supplied during redeployment.

Integrate with a secrets manager

Use External Secrets Operator (ESO) to integrate your self-hosted Soda Agent with your secrets manager, such as a Hashicorp Vault, AWS Secrets Manager, or Azure Key Vault, and securely reconcile the login credentials that Soda Agent uses for your data sources.

For example, imagine you use a Hashicorp Vault to store data source login credentials and your security protocol demands frequent rotation of passwords. In this situation, the challenge is that apps running in your Kubernetes cluster, such as a Soda Agent, need access to the up-to-date passwords.

To address the challenge, you can set up and configure ESO in your Kubernetes cluster to regularly reconcile externally-stored password values so that your apps always have the credentials they need. Doing so obviates the need to manually redeploy a values YAML file with new passwords for apps running in the cluster each time your system refreshes the passwords.

The current integration of Soda Agent and a secrets manager does not yet support the configuration of the Soda Cloud credentials. For those credentials, use a tool such as helm-secrets or vals.

To integrate Soda Agent with a secret manager, you need the following:

External Secrets Operator (ESO) which is a Kubernetes operator that facilitates a connection between the Soda Agent and your secrets manager
a ClusterSecretStore resource which provides a central gateway with instructions on how to access your secret backend
an ExternalSecret resource which instructs the cluster on what values to fetch, and references the ClusterSecretStore

Read more about the ESO’s Resource Model.

The following procedure outlines how to use ESO to integrate with a Hashicorp Vault that uses a KV Secrets Engine v2. Extrapolate from this procedure to integrate with another secrets manager such as:

Prerequisites

You have set up a Kubernetes cluster in your cloud services environment and deployed a self-hosted Soda Agent in the cluster.
For the purpose of this example procedure, you have set up and are using a Hashicorp Vault which contains a key-value pair for POSTGRES_USERNAME and POSTGRES_PASSWORD at the path local/soda.

Install and set up the External Secrets Operator

Consider referencing the use case guide for integrating an External Secrets Manager with a Soda Agent which offers step-by-step instructions to set everything up locally to see the integration in action.

Use helm to install the External Secrets Operator from the Helm chart repository into the same Kubernetes cluster in which you deployed your Soda Agent.

 helm repo add external-secrets https://charts.external-secrets.io

 helm install external-secrets \
    external-secrets/external-secrets \
     -n external-secrets \
     --create-namespace

Verify the installation using the following command:
```
kubectl -n external-secrets get all
```
Create a cluster-secret-store.yml file for the ClusterSecretStore configuration. The details in this file instruct the Soda Agent how to access the external secrets manager vault.
This example uses Hashicorp Vault AppRole authentication. AppRole authenticates with Vault using the App Role auth mechanism to access the contents of the secret store. It uses the SecretID in the Kubernetes secret, referenced by secretRef and the roleID, to acquire a temporary access token so that it can fetch secrets.
Access external-secrets.io documentation for configuration examples for:
- AWS Secrets Manager
- Azure Key Vault
```
 apiVersion: external-secrets.io/v1beta1
 kind: ClusterSecretStore
 metadata:
 name: vault-app-role
 spec:
 provider:
   vault:
     auth:
       appRole:
         path: approle
         roleId: 3e****54-****-936e-****-5c5a19a5eeeb
         secretRef:
           key: appRoleSecretId
           name: external-secrets-vault-app-role-secret-id
           namespace: external-secrets
     path: kv
     server: http://vault.vault.svc.cluster.local:8200
     version: v2
```

Deploy the ClusterSecretStore to your cluster.

kubectl apply -f cluster-secret-store.yaml

Create an soda-secret.yml file for the ExternalSecret configuration. The details in this file instruct the Soda Agent which values to fetch from the external secrets manager vault.

apiVersion: external-secrets.io/v1beta1
kind: ExternalSecret
metadata:
  name: soda-agent
  namespace: soda-agent
spec:
  data:
  - remoteRef:
       key: local/soda
       property: POSTGRES_USERNAME
     secretKey: POSTGRES_USERNAME
  - remoteRef:
       key: local/soda
       property: POSTGRES_PASSWORD
     secretKey: POSTGRES_PASSWORD
  refreshInterval: 1m
  secretStoreRef:
     kind: ClusterSecretStore
     name: vault-app-role
  target:
     name: soda-agent-secrets
     template:
       data:
         soda-agent.conf: |
           POSTGRES_USERNAME={{ .POSTGRES_USERNAME }}
           POSTGRES_PASSWORD={{ .POSTGRES_PASSWORD }}
       engineVersion: v2

This example identifies:

the namespace of the Soda Agent
two remoteRef configurations, including the file path in the vault, one each for POSTGRES_USERNAME and POSTGRES_PASSWORD, to detail what the ExternalSecret must fetch from the Hashicorp Vault
a refreshInterval to indicate how often the ESO must reconcile the remoteRef values; this ought to correspond to the frequency with which your passwords are reset
the secretStoreRef to indicate the ClusterSecretStore through which to access the vault
a target template that creates a file called soda-agent.conf into which it adds the username and password values in the dotenv format that the Soda Agent expects.

Deploy the ExternalSecret to your cluster.

kubectl  apply -n soda-agent -f soda-secret.yaml

Use the following command to get the ExternalSecret to authenticate to the Hashicorp Vault using the ClusterSecretStore and fetch secrets.
```
kubectl get secret -n soda-agent soda-agent-secrets
```
Output:
```
NAME                 TYPE     DATA   AGE
soda-agent-secrets   Opaque   1      24h
```

Prepare a values.yml file to deploy the Soda Agent with the existingSecrets parameter that instructs it to access the ExternalSecret file to fetch data source login credentials. Refer to complete deploy instructions, or redeploy instructions if you already have an agent running in a cluster.

 soda:
   apikey:
     id: "154k***889"
     secret: "9sfjf****ff4"
   agent:
     name: "my-soda-agent-external-secrets"
   scanlauncher:
     existingSecrets:
       # from spec.target.name in the ExternalSecret file
       - soda-agent-secrets 
   cloud:
     # Use https://cloud.us.soda.io for US region 
     # Use https://cloud.soda.io for EU region
     endpoint: "https://cloud.soda.io"

Deploy the Soda Agent using the following command:

helm install soda-agent soda-agent/soda-agent \
  --values values.yml \
  --namespace soda-agent

Output:

  NAME: soda-agent
  LAST DEPLOYED: Tue Aug 29 13:08:51 2023
  NAMESPACE: soda-agent
  STATUS: deployed
  REVISION: 1
  TEST SUITE: None
  NOTES:
  Success, the Soda Agent is now running. 
  You can inspect the Orchestrators logs if you like, but if all was configured correctly, the Agent should show up in Soda Cloud. 
  Check the logs using:
     kubectl logs -l agent.soda.io/component=orchestrator -n soda-agent

Use Soda Cloud API Keys from an existing secret

By default, the Soda Agent creates a secret for storing the Soda Cloud API Key details securely in your cluster. If you want to use a different secret, you can point the Soda Agent to an existing Kubernetes Secret in your cluster using the soda.apikey.existingSecret property.

To use an existing Kubernetes secret for Soda Agent’s Cloud API credentials, add existingSecret and the secretKeys values to your agent’s values YAML file, as in the following example.

soda:
  apikey:
    existingSecret: "<existing-secret-name>"
    secretKeys:
      idKey: "<key-for-api-id>"
      secretKey: "<key-for-api-secret>"

Optimize performance

The default Soda Agent settings balance performance and cost-efficiency. You can adjust these settings to better suit your needs, optimizing for larger datasets, faster scans, or improved resource management.

Change sample data and failed rows memory limits

The hard query cursor limit setting controls how many rows Soda Library can store in memory during a scan. By default, this value is 10,000 rows, preventing Out-Of-Memory (OOM) errors by capping the number of rows Soda holds in memory at any given time.

If you need to work with larger sets of sample data or failed rows, you can raise the query_cursor_hard_limit. Be aware that if you increase or remove the limit, you must ensure that the Soda Agent has enough memory to prevent it from causing OOM errors.

To turn off the limit completely, set the value of query_cursor_hard_limit to null.

The example below demonstrates how you can clear the limit and increase the memory limit using settings in your values.yml file:

soda:
  scanlauncher:
    config:
      query_cursor_hard_limit: null
    resources:
      limits:
        memory: 2Gi

Go further

Consider referencing the use case guide for integrating an External Secrets Manager with a Soda Agent which offers step-by-step instructions to set everything up locally to see the integration in action.
Learn more about Soda Agent basic concepts.
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Documentation always applies to the latest version of Soda products
Last modified on 20-Nov-24