Diagnostic Settings Missing¶

Use this playbook when the environment is configured for Azure Monitor log routing, but no container app logs arrive in the target Log Analytics workspace.

Symptom¶

• The environment log destination is azure-monitor, but Log Analytics queries return no ContainerAppConsoleLogs_CL or ContainerAppSystemLogs_CL rows.
• Teams expected Azure Monitor routing to be enough by itself, but downstream workspace ingestion never starts.
• A new environment or app was created successfully and still shows no logs after traffic or restart activity.

Possible Causes¶

• No diagnostic setting exists on the Container Apps environment resource.
• The diagnostic setting exists, but the wrong categories were enabled.
• Logs are routed to a different workspace than the operator expects.
• Diagnostic settings were added only after the incident and no fresh signal was produced afterward.
• The environment is actually configured for a different log destination.

Diagnosis Steps¶

flowchart TD
    A[Notice empty Log Analytics tables] --> B[Check environment log destination]
    B --> C{Destination is azure-monitor?}
    C -->|No| D[Use the playbook for the actual destination]
    C -->|Yes| E[List diagnostic settings on the environment resource]
    E --> F[Confirm workspace resource ID and enabled log categories]
    F --> G[Generate a fresh system event]
    G --> H{Rows arrive in workspace?}
    H -->|Yes| I[Configuration is now complete]
    H -->|No| J[Fix diagnostic settings scope or target workspace]

1. Verify the environment log destination.

az containerapp env show \
    --name "$CONTAINER_ENV" \
    --resource-group "$RG" \
    --query "properties.appLogsConfiguration.destination" \
    --output tsv

1. Capture the environment and workspace resource IDs you will use for diagnostic-setting checks.

az containerapp env show \
    --name "$CONTAINER_ENV" \
    --resource-group "$RG" \
    --query "id" \
    --output tsv

1. List diagnostic settings on the environment resource.

az monitor diagnostic-settings list \
    --resource "$ENV_RESOURCE_ID" \
    --output json

1. Query for recent rows after traffic or a restart event.

let AppName = "ca-myapp";
ContainerAppConsoleLogs_CL
| where ContainerAppName_s == AppName
| where TimeGenerated > ago(30m)
| project TimeGenerated, RevisionName_s, Log_s
| order by TimeGenerated desc

let AppName = "ca-myapp";
ContainerAppSystemLogs_CL
| where ContainerAppName_s == AppName
| where TimeGenerated > ago(30m)
| project TimeGenerated, RevisionName_s, Reason_s, Log_s
| order by TimeGenerated desc

Resolution¶

1. Create or correct the diagnostic setting on the scope your team uses for collection.

az monitor diagnostic-settings create \
    --name "aca-observability" \
    --resource "$ENV_RESOURCE_ID" \
    --workspace "$WORKSPACE_RESOURCE_ID" \
    --logs '[{"category":"ContainerAppConsoleLogs","enabled":true},{"category":"ContainerAppSystemLogs","enabled":true}]' \
    --metrics '[{"category":"AllMetrics","enabled":true}]'

1. Generate a fresh request or revision event after creating the setting, then query the workspace again.
2. If you also collect app-level metrics, keep that as a separate metric-only diagnostic setting rather than mixing it with environment log routing.
3. Record that environment scope owns log routing so the next incident does not become a scope-discovery exercise.

Prevention¶

• Document that environment scope owns log-routing diagnostic settings when azure-monitor is the destination.
• Keep the workspace resource ID in deployment outputs or operational notes.
• Validate ContainerAppConsoleLogs and ContainerAppSystemLogs immediately after new environment creation.
• Add a post-deployment smoke test that checks for fresh rows in the workspace within an agreed delay window.

See Also¶

• Diagnostic Settings Missing Lab
• Log Analytics Ingestion Gap
• Observability Tracing Lab
• CrashLoop OOM and Resource Pressure

Sources¶

• Log storage and monitoring options in Azure Container Apps
• Monitor logs in Azure Container Apps with Log Analytics
• ContainerAppConsoleLogs table reference