When Newlines Matter: Troubleshooting a Snowflake Connector Pod Crash

Executive Summary

An issue with our Snowflake connector for PostgreSQL revealed how a simple formatting oversight—missing newline characters in a private key file—can bring down an entire service. This post walks through the debugging process, root cause analysis, and preventive measures to help you avoid similar issues in your Kubernetes deployments.

The Issue

Initial Discovery

What started as a routine evening turned into an incident-like situation. The Snowflake connector for PostgreSQL pod was stuck in a CrashLoopBackOff state, preventing data synchronization between our PostgreSQL database and Snowflake data warehouse.

The Investigation Process

Step 1: Pod Status Verification

First, I checked the current state of our pods to confirm the issue:

$ kubectl get pods -n shared | grep postgres-snowflake-connector
postgres-snowflake-connector-6668674fdc-nxjt9  0/1  CrashLoopBackOff  ....

Step 2: Attempted Quick Fix

I attempted a deployment restart, hoping it might resolve any temporary issues:

$ kubectl rollout restart deployment postgres-snowflake-connector -n shared
deployment.apps/postgres-snowflake-connector restarted
$ kubectl get pods -n shared | grep postgres-snowflake-connector
postgres-snowflake-connector-6668674fdc-nxjt9         0/1     CrashLoopBackOff ....
postgres-snowflake-connector-786fdbdd87-6vrrt         0/1     Running            ....

While the new pod initially showed as “Running,” this was misleading—it crashed moments later.

Step 3: Log Analysis

Diving into the pod logs revealed the critical error message that pointed us toward the solution:

$ kubectl logs -f postgres-snowflake-connector-786fdbdd87-6vrrt  -n shared

.... INFO  c.s.u.a.l.Launcher - Starting agent process
....
***************************
APPLICATION FAILED TO START
***************************

Description:

We couldn't read the private key file located under /etc/private-key/private-key of size [....]. The key's format is invalid. Ensure that the private key file:

* Starts with -----BEGIN [RSA|ENCRYPTED|] PRIVATE KEY-----
* Ends with -----END [RSA|ENCRYPTED|] PRIVATE KEY-----
* Contains newline characters between the header, key content, and footer.

This error message was remarkably clear and actionable—the private key format was invalid due to missing newline characters.

Root Cause Analysis

Discovering the Formatting Issue

To confirm our hypothesis, I inspected the Kubernetes secret containing the private key:

$ kubectl get secret postgres-snowflake-connector-secrets -n shared \
    -o jsonpath='{.data.private-key}' | base64 -d | wc -l
   0

The output of 0 lines was the smoking gun. The entire private key was stored as a single continuous string without any newline characters. This explained why the Snowflake connector couldn’t parse it properly.

Tracing Back to the Source

I traced the issue back to Azure Key Vault, where the private key was originally stored:

$ az keyvault secret show \
    --vault-name "[vaultname]" \
    --name "snowflake-connector-private-key" \
    --query "value" -o tsv | wc -l
   1

The single line output confirmed that the formatting issue originated at the source. This likely occurred the key was uploaded through the Azure portal or used a method that stripped the newline characters.

Understanding the Technical Impact

Private keys in PEM format require specific formatting:

Header line: -----BEGIN PRIVATE KEY-----
Base64-encoded key content (typically 64 characters per line)
Footer line: -----END PRIVATE KEY-----
Each line must end with a newline character (\n)

Without these newline characters, cryptographic libraries cannot properly parse the key structure, leading to authentication failures.

The Solution

Immediate Fix

Instead of manually editing the secret (which risks introducing other formatting issues), I used the Azure CLI to upload the private key file directly, preserving its original formatting:

# Ensure the local key file has proper formatting
$ cat agent_private_key.p8 | head -3
-----BEGIN PRIVATE KEY-----
[key content]

# Upload to Azure Key Vault preserving formatting
$ az keyvault secret set \
    --vault-name "[vaultname]" \
    --name "snowflake-connector-private-key" \
    --file agent_private_key.p8

# Verify the fix
$ az keyvault secret show \
    --vault-name "[vaultname]" \
    --name "snowflake-connector-private-key" \
    --query "value" -o tsv | wc -l
28

This command preserved the file’s original formatting, including all necessary newline characters. The result was a properly formatted private key with the correct structure:

-----BEGIN PRIVATE KEY-----
[... key content including proper line breaks ...]
-----END PRIVATE KEY-----

After fixing the Azure Key Vault secret, I restarted the deployment and the secret was correctly fetched from Azure key vault.

Key Takeaways

Formatting matters for cryptographic keys: Private keys aren’t just about the content—the format, including newline characters, is crucial for proper parsing.
Use CLI tools for sensitive data: When dealing with certificates and keys, using command-line tools that preserve file formatting is more reliable than GUI-based approaches or copy-paste operations.

Prevention Tips

To avoid similar issues in the future:

Always use az keyvault secret set --file when uploading key files to Azure Key Vault
Implement validation checks for secret formatting in your CI/CD pipelines
Document the proper upload procedure for certificates and keys
Consider automating secret rotation and upload processes to eliminate manual errors

This incident reminded us that even the smallest details—like newline characters—can have significant impacts on system stability. When your pods are crashing, don’t overlook the fundamentals of file formatting.

Key Lessons Learned

Details Matter in Cryptography: Even whitespace and newline characters are critical for proper cryptographic key parsing. Never underestimate the importance of exact formatting.
CLI Over GUI for Sensitive Data: Command-line tools preserve file integrity better than web interfaces, which may apply unexpected transformations.
Clear Error Messages Save Time: The Snowflake connector’s explicit error message about formatting requirements significantly reduced our debugging time.
Automation Prevents Human Error: Manual processes for handling secrets are error-prone. Automation ensures consistency and reduces security risks.
Test Secret Rotation Procedures: Regular drills of secret rotation can reveal formatting issues before they become incidents.

Looking Forward

While the immediate issue is resolved, we’re evaluating long-term improvements:

Current Solution: Snowflake Connector for PostgreSQL

Status: Legacy, limited update cadence
Support: for future bug fixes and improvements are not guaranteed
Recommendation: migrate to Openflow Connector for PostgreSQL

Future Option: Openflow Connector for PostgreSQL

Status: Generally Available to all Snowflake accounts in AWS Commercial Regions
Benefits: Better performance, more features, active development
Limitation: Not yet Generally Available for Snowflake accounts on Azure or GCP

We’re monitoring Openflow Connector’s roadmap and planning our migration strategy accordingly.

Conclusion

This incident reinforced that in the cloud infrastructure, even the smallest details—like newline characters in a private key—can have significant operational impacts. By understanding the root cause, implementing proper tooling, and establishing clear procedures, we can prevent similar issues and build more resilient systems.

Remember: when dealing with cryptographic materials, always preserve the original formatting, use appropriate tools, and validate thoroughly. Your future self (and your on-call teammates) will thank you.

Have you encountered similar formatting issues with secrets in Kubernetes? Share your experiences and solutions in the comments below.

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