6.2.6 Ensure 'Log_min_error_statement' Database Flag for Cloud SQL PostgreSQL Instance Is Set to 'Error' or Stricter

Information

The log_min_error_statement flag defines the minimum message severity level that are considered as an error statement. Messages for error statements are logged with the SQL statement. Valid values include DEBUG5, DEBUG4, DEBUG3, DEBUG2, DEBUG1, INFO, NOTICE, WARNING, ERROR, LOG, FATAL, and PANIC. Each severity level includes the subsequent levels mentioned above. Ensure a value of ERROR or stricter is set.

Rationale:

Auditing helps in troubleshooting operational problems and also permits forensic analysis. If log_min_error_statement is not set to the correct value, messages may not be classified as error messages appropriately. Considering general log messages as error messages would make is difficult to find actual errors and considering only stricter severity levels as error messages may skip actual errors to log their SQL statements. The log_min_error_statement flag should be set to ERROR or stricter. This recommendation is applicable to PostgreSQL database instances.

Impact:

Turning on logging will increase the required storage over time. Mismanaged logs may cause your storage costs to increase. Setting custom flags via command line on certain instances will cause all omitted flags to be reset to defaults. This may cause you to lose custom flags and could result in unforeseen complications or instance restarts. Because of this, it is recommended you apply these flags changes during a period of low usage.

Solution

From Google Cloud Console

Go to the Cloud SQL Instances page in the Google Cloud Console by visiting https://console.cloud.google.com/sql/instances.

Select the PostgreSQL instance for which you want to enable the database flag.

Click Edit.

Scroll down to the Flags section.

To set a flag that has not been set on the instance before, click Add item, choose the flag log_min_error_statement from the drop-down menu and set appropriate value.

Click Save to save your changes.

Confirm your changes under Flags on the Overview page.

From Google Cloud CLI

Configure the log_min_error_statement database flag for every Cloud SQL PosgreSQL database instance using the below command.

gcloud sql instances patch <INSTANCE_NAME> --database-flags log_min_error_statement=<DEBUG5|DEBUG4|DEBUG3|DEBUG2|DEBUG1|INFO|NOTICE|WARNING|ERROR>

Note: This command will overwrite all database flags previously set. To keep those and add new ones, include the values for all flags you want set on the instance; any flag not specifically included is set to its default value. For flags that do not take a value, specify the flag name followed by an equals sign ("=").

Default Value:

By default log_min_error_statement is ERROR.

See Also

https://workbench.cisecurity.org/benchmarks/9562