How can I enable SQL logging in PostgreSQLContainer during my Spring tests?

The problem is that passing the logging setting via .withCommand() isn’t having the desired effect because the configuration parameter you need isn’t being applied by PostgreSQL as it starts up in the container. In other words, overriding the command isn’t enough—PostgreSQL is still using its default logging configuration.

To fix this, you need to enable both the SQL statement logging and ensure that those logs are actually sent to the container’s stdout/stderr. Two key changes are required:

1. Enable the Logging Collector
   PostgreSQL may write detailed logs (including every SQL statement) only if the logging collector is enabled. In the default Docker image, logs are normally sent to stderr rather than being collected. By explicitly enabling the logging collector, you ensure that all statements (as set by log_statement) are captured. To do this, you must pass both parameters:

   • logging_collector=on
   • log_statement=all

2. Override the Container’s Command Correctly
   Instead of only passing “-c log_statement=all”, update your configuration to include both flags so that PostgreSQL applies these settings at startup.

Your Testcontainers configuration should look like this:

JAVACopied
@TestConfiguration(proxyBeanMethods = false)
public class TestcontainersConfiguration {

    @Bean
    @ServiceConnection
    PostgreSQLContainer<?> sharedDatabaseContainer() {
        return new PostgreSQLContainer<>(DockerImageName.parse("postgres:17.2"))
                .withDatabaseName("<redacted>")
                .withUsername("<redacted>")
                .withPassword("<redacted>")
                // Enable both logging_collector and log_statement so SQL logs appear
                .withCommand("postgres", "-c", "logging_collector=on", "-c", "log_statement=all")
                // Expose the proper PostgreSQL port for container internal operations (matching the image default)
                .withExposedPorts(5432);
    }
}

Additional Notes

• Port Exposure: The PostgreSQL image by default listens on port 5432. Overriding the exposed port (to 1234) may not be necessary unless you have a specific need; stick with the default or map it properly on the host.

• Container Logs: With these settings, PostgreSQL will send the logs to its standard output channels. You can then see the SQL logs with your usual Docker log command (e.g., docker logs <container_id>) during your tests.

After making these changes, re-run your tests and you should start seeing the detailed SQL logs in the PostgreSQL container logs.