Google CloudOverview
Enabling the log_disconnections setting logs the end of each session, including the session duration.
Rationale
PostgreSQL does not log attempted connections by default. Enabling the log_disconnections setting will create log entries at the end of each session, which can be useful in troubleshooting issues and to determine any unusual connection attempts to the server. The log_disconnections and log_connections flags work hand in hand and, generally, the pair would be enabled/disabled together. 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.
Remediation guidance
From Google Cloud Console
- Go to the
Cloud SQL Instancespage in the Google Cloud Console by visiting https://console.cloud.google.com/sql/instances - Select the PostgreSQL instance where the database flag needs to be enabled
- Click
EDIT - Scroll down to the
Flagssection - To set a flag that has not been set on the instance before, click
ADD A DATABASE FLAG, choose the flaglog_disconnectionsfrom the drop-down menu, and set its value toon - Click
SAVE - Confirm the changes under
Flagson theOverviewpage
Using Google Cloud CLI
Configure the log_disconnections database flag for every Cloud SQL PostgreSQL database instance using the below command.
gcloud sql instances patch <instanceName> --database-flags log_disconnections=on
Note: This command will overwrite all database flags that were previously set. To keep those and add new ones, include the values for all flags to be 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_disconnections is off.
References
- https://cloud.google.com/sql/docs/postgres/flags
- https://www.postgresql.org/docs/9.6/runtime-config-logging.html#RUNTIME-CONFIG-LOGGING-WHAT
Additional information
WARNING: This patch modifies database flag values, which may require the instance to be restarted. Check the list of supported flags https://cloud.google.com/sql/docs/postgres/flags - to see if your instance will be restarted when this patch is submitted.
Note: Some database flag settings can affect instance availability or stability, and remove the instance from the Cloud SQL SLA. For information about these flags, see Operational Guidelines.
Note: Configuring the above flag restarts the Cloud SQL instance.
Service-wide remediation
Recommended when many resources are affected: fix the platform baseline first so new resources inherit the secure setting, then remediate the existing flagged resources in batches.
Google Cloud
Use organization or folder policies where available, shared project templates, logs and alerting baselines, and IaC modules so new resources inherit the secure setting.
Operational rollout
- Fix the baseline first at the account, subscription, project, cluster, or tenant scope that owns this control.
- Remediate the currently affected resources in batches, starting with internet-exposed and production assets.
- Re-scan and track approved exceptions with an owner and expiry date.
Query logic
These are the stored checks tied to this control.
The 'log_disconnections' database flag for Cloud SQL PostgreSQL instance is set to 'on'
Connectors
Covered asset types
Expected check: eq []
{ cloudSqlInstances( where: { engine: "postgresql" cloudProvider: "gcp" OR: [ { dbFlags_NONE: { name: "log_disconnections" } } { dbFlags_SOME: { name: "log_disconnections", value: "off" } } ] } ) { ...AssetFragment }}
