Send logs privately from Azure container apps environment to Log analytic workspace

Question

Dear team,

I implement Azure Monitor Private Link Scopes in order to send logs from Azure container apps environment to log analytic workspace.

But I see it doesn't work. It works in the first time. I can see log in the first time. But after that I don't see the new log.

Please help to check.

Thank you!

Answer 1

Hi Van Huy Tuyen,

Looks like you're dealing with some log issues when sending data from your Azure Container Apps environment to a Log Analytics workspace. It worked at first, but now nothing’s showing up frustrating, Let’s troubleshoot this step by step:

This is the expected setup:

• Make sure everything is properly configured in Azure Monitor Private Link Scopes. Sometimes, it’s easy to miss a step when connecting to the Log Analytics workspace.
• Head to the portal and confirm your Container Apps environment is still hooked up to the Private Link Scope. There could be a hiccup there.
• Make sure the private endpoint tied to the scope is active and set up correctly. DNS settings, NSGs (network security groups), or route tables might be blocking things—worth a look.
• Check out the logs and see if there are any error messages. Also, verify that permissions are all good on the resources you're using.
• If none of this works, try removing and re-adding the connections between the environment, Private Link Scope, and Log Analytics workspace. Sometimes a clean slate fixes things.

Finally to ensure the setup works, you can test sending a log message from within the VNet to the Log Analytics workspace using Azure CLI:

# Replace these values with your own
WORKSPACE_ID="<Your-Log-Analytics-Workspace-ID>"
SHARED_KEY="<Your-Shared-Key>"
LOG_TYPE="NetworkTestLog"
MESSAGE="Testing log message through VNet."

# Create a JSON payload
JSON_PAYLOAD=$(jq -n --arg message "$MESSAGE" '[{"message": $message}]')

# Generate the authorization signature
DATE=$(date -u +"%a, %d %b %Y %H:%M:%S GMT")
STRING_TO_HASH="POST\n$(echo -n $JSON_PAYLOAD | wc -c)\napplication/json\nx-ms-date:$DATE\n/api/logs"
SIGNATURE=$(echo -en $STRING_TO_HASH | openssl dgst -sha256 -hmac "$SHARED_KEY" -binary | base64)

# Submit the log via HTTPS
curl -X POST \
  -d "$JSON_PAYLOAD" \
  -H "Content-Type: application/json" \
  -H "Log-Type: $LOG_TYPE" \
  -H "x-ms-date: $DATE" \
  -H "Authorization: SharedKey $WORKSPACE_ID:$SIGNATURE" \
  "https://$WORKSPACE_ID.ods.opinsights.azure.com/api/logs?api-version=2016-04-01"

Refences:

• https://learn.microsoft.com/en-us/azure/azure-monitor/logs/private-link-configure
• https://learn.microsoft.com/en-us/azure/container-apps/log-monitoring

If the information helped address your question, please Accept the answer.

Luis