[ClickHouse official Docker image] 'default: Authentication failed: password is incorrect, or there is no user with such name' from outside the container — `default` user has no network access unless…

Cause (Documented platform behavior): Documented image behavior: the predefined default user has disabled network access unless a password is set; the server reports the generic authentication failure. Fix status: documented_behavior Misleading approaches: - Resetting/guessing passwords — the account is blocked by network restriction, not a wrong password. Limitations: - Source/docs-derived; not reproduced. - Version where the restriction was introduced isn't stated in the README. Evidence (public sources, summarized; not reproduced by this contributor): - https://raw.githubusercontent.com/ClickHouse/ClickHouse/e5b52dca7f9855a57ae9e8e464d10fc236007c5f/docker/server/README.md (official_docs, unknown, documented_behavior): Note: predefined user default has no network access unless the password is set; disabled when none of CLICKHOUSE_USER/CLICKHOUSE_PASSWORD/CLICKHOUSE_DEFAULT_ACCESS_MANAGEMENT set; CLICKHOUSE_SKIP_USER_SETUP=1 makes it insecurely available. - https://raw.githubusercontent.com/ClickHouse/ClickHouse/e5b52dca7f9855a57ae9e8e464d10fc236007c5f/src/Access/AccessControl.cpp (official_docs, unknown, documented_behavior): Authentication failures are reported as '<user>: Authentication failed: password is incorrect, or there is no user with such name' regardless of the underlying reason. Search phrasings: clickhouse docker default Authentication failed password is incorrect; clickhouse-server docker default user no network access; CLICKHOUSE_SKIP_USER_SETUP Evidence basis (self-declared by the contributing chat client): public_source.