Solving the ssl ca.crt Conundrum: A Step-by-Step Guide to Using SSL CA Certificates with OpenTelemetry OTLP Span Exporter

Introduction

Are you struggling to use your SSL CA certificate with OpenTelemetry’s OTLP Span Exporter? You’re not alone! Many developers face this common challenge, but fear not, dear reader, for we’re about to embark on a troubleshooting adventure to get your SSL CA certificate working seamlessly with OTLP Span Exporter.

Understanding the Problem

Before we dive into the solution, let’s quickly understand the problem. When trying to use an SSL CA certificate with OTLP Span Exporter, you might encounter errors, such as ” unable to load CA certificate” or “invalid certificate”. This is often due to the way OTLP Span Exporter expects the certificate to be formatted or the lack of proper configuration.

What is OTLP Span Exporter?

OTLP Span Exporter is a part of OpenTelemetry, a popular open-source observability framework. It enables the export of telemetry data, such as traces, metrics, and logs, to various backends, including services like Zipkin, Jaeger, and New Relic. OTLP Span Exporter plays a crucial role in sending span data to these backends, but it requires proper configuration, including SSL certificates, to establish secure connections.

Step 1: Preparing Your SSL CA Certificate

To use an SSL CA certificate with OTLP Span Exporter, you’ll need to ensure it’s in the correct format. Here are the steps to prepare your certificate:

1. Obtain your SSL CA certificate in PEM format (usually with a .pem or .crt extension).

2. Verify the certificate is in the correct format by checking the header and footer. A valid PEM certificate should start with -----BEGIN CERTIFICATE----- and end with -----END CERTIFICATE-----.

3. If your certificate is in a different format, such as DER or PFX, convert it to PEM using tools like OpenSSL:

   openssl x509 -inform der -in certificate.der -out certificate.pem

Step 2: Configuring OTLP Span Exporter

Now that your SSL CA certificate is ready, it’s time to configure OTLP Span Exporter to use it. You can do this through environment variables, configuration files, or programmatically, depending on your application and infrastructure.

Environment Variables

Set the following environment variables to configure OTLP Span Exporter:

• OTEL_EXPORTER_OTLP_CERTFILE: path to your SSL CA certificate (e.g., /path/to/ca.crt)

• OTEL_EXPORTER_OTLP_CERTKEYFILE: path to your private key (if applicable)

Configuration Files

Create a configuration file (e.g., otlp.yaml) with the following content:

exporters:
  otlp:
    certificate:
      file: /path/to/ca.crt
    private_key:
      file: /path/to/private_key.pem

In your application, load this configuration file using the relevant OpenTelemetry SDK or API.

Programmatic Configuration

In your code, create an instance of the OTLP Span Exporter and set the certificate and private key programmatically:

import { OTLPExporter } from '@opentelemetry/exporter-otlp';

const exporter = new OTLPExporter({
  url: 'https://your-backend.com',
  certificate: fs.readFileSync('/path/to/ca.crt'),
  privateKey: fs.readFileSync('/path/to/private_key.pem'),
});

Step 3: Verifying the Configuration

After configuring OTLP Span Exporter, verify that it’s using the SSL CA certificate correctly:

• Check the OTLP Span Exporter logs for any certificate-related errors or warnings.

• Use tools like OpenSSL to test the connection to your backend, ensuring the certificate is being presented correctly:

  openssl s_client -connect your-backend.com:443 -CAfile /path/to/ca.crt

Troubleshooting Common Issues

If you’re still encountering issues, check the following common problems:

Issue	Solution
Unable to load CA certificate	Verify the certificate is in the correct format (PEM) and the path is correct.
Invalid certificate	Check the certificate’s expiration date, ensure it’s trusted by the backend, and verify the private key matches the certificate.
Connection refused or timeout	Verify the backend is reachable, and the URL and port are correct.

Conclusion

With these steps and troubleshooting tips, you should now be able to successfully use your SSL CA certificate with OpenTelemetry’s OTLP Span Exporter. Remember to verify your configuration, check for common issues, and test your connection to ensure secure and reliable telemetry data export.

If you’re still having trouble, don’t hesitate to reach out to the OpenTelemetry community or seek help from experts in the field.

Happy tracing!

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Frequently Asked Question

Having trouble configuring SSL/TLS certificates with OpenTelemetry’s OTLPSpanExporter? We’ve got you covered!