Scrape MongoDB Flex Observability data with Prometheus

With the following steps you can learn how to scrape your MongoDB Flex Observability data with Prometheus.

Requirements

• You have created a MongoDB Flex instance.
  Check Create and manage instances of MongoDB Flex.
• You have a running instance of Prometheus. This guide assumes, that you use a container. This is, why we reference it in the text. You can also use a Virtual Machine or run it in another environment.

Preparation

Before configuring your Prometheus environment, you need to prepare the needed service account. This guide uses the Portal for achieving this task. You can also use the STACKIT CLI.

Create a Service Account and grant access to the API

1. Navigate to IAM and management > Service accounts.

2. Click + Create service account.

3. Give the new service account a name and click on Create. The account has been created.

4. Go into the account by clicking its name.

5. Navigate to Service account keys.

6. Click + Create service account key.

7. Select Create new key pair and click on Create.

8. Download the newly created credentials. At least you need the JSON file that contains all relevant information.

   Store the files in a safe place because they contain security sensitive information.

9. Navigate to IAM and management* Access.

10. Click + Grant Access.

11. Add the mail address (ID) of the newly created service account.

12. Select the role MongoDB Flex Reader and click Save.

Configure Prometheus

Prometheus < 3.8

1. Copy the JSON file, you downloaded in the Preparation, to your virtual machine.

   In this guide we copy it to /usr/local/etc/stackit/sa/service-account.json. If you choose another location, you need to adapt the commands in the following steps.

   The JSON file contains sensitive information. Protect it, e.g. with chown or chmod.

2. Create a cronjob for updating the Bearer Token.

   Manually try to acquire a token with the STACKIT CLI.

   stackit auth activate-service-account --service-account-key-path /usr/local/etc/stackit/sa/service-account.json --only-print-access-token

   The maximum token lifetime is 60 minutes, so the token needs to be renewed beforehand. To automate this step, you can place this command in crontab and write the token in a new file. This file should also be protected.

   */5 * * * * /usr/bin/stackit auth activate-service-account --service-account-key-path /usr/local/etc/stackit/sa/service-account.json --only-print-access-token > /run/secrets/bearer_token 2>/dev/null

3. Configure Prometheus Now configure Prometheus to your needs. Use the following code snippet for scraping the MongoDB Flex metrics. Replace projectID, region and MongoDBFlexInstanceID with the according values.

   scrape_configs:
     - job_name: "<job name>"
       metrics_path: "/v2/projects/[projectID]/regions/[region]/instances/[MongoDBFlexInstanceID]/metrics"
       scheme: "https"
       bearer_token_file: /run/secrets/bearer_token
       static_configs:
         - targets: ['mongodb-prom-proxy.api.stackit.cloud:443']

4. Restart the container or service

5. Test Prometheus

   Open your Prometheus instance with a browser. Navigate to Status > Monitoring status: “Target health”. The State of the defined scraper should be UP:

   

Prometheus >= 3.8

1. Configure Prometheus

   Configure Prometheus to your needs. Use the following code snippet for scraping the MongoDB Flex metrics. Prometheus >= 3.8 has native support for service account keys.

   Replace projectID, region, MongoDBFlexInstanceID, serviceAccountID, serviceAccountKeyID, serviceAccountKeyPrivateKey and ServiceAccountMailAddress with the according values.

   scrape_configs:
   - job_name: "<job name>"
     metrics_path: "/v2/projects/[projectID]/regions/[region]/instances/[MongoDBFlexInstanceID]/metrics"
     scheme: "https"
     oauth2:
     client_id: [serviceAccountID]
     client_certificate_key_file: [serviceAccountKeyPrivateKey]
     grant_type: urn:ietf:params:oauth:grant-type:jwt-bearer
     token_url: https://service-account.api.stackit.cloud/token
     client_certificate_key_id: [serviceAccountKeyID]
     iss: [ServiceAccountMailAddress]
     audience: https://stackit-service-account-prod.apps.01.cf.eu01.stackit.cloud
     signature_algorithm: RS512
     static_configs:
       - targets: ['mongodb-prom-proxy.api.stackit.cloud:443']

2. Restart the container or service

3. Test Prometheus

   Open your Prometheus instance with a browser. Navigate to Status > Monitoring status: “Target health”. The State of the defined scraper should be UP:

   

Hints

• If you use Grafana to visualize your metrics, use our MongoDB Flex Grafana template. Visit the Observability metrics of MongoDB Flex reference article, to download the file.