数据库用户

Tenax 使用一个用户 tenax 备份每个数据库，其密码保存在数据库旁边一个名为 tenax-* 的 Secret 中。 它从不使用管理员账号。创建该用户只需两条命令；如需恢复到任意一秒，再加一行服务器配置。

PostgreSQL 15、16、17MySQL 8.4

NS=team-a                         # the database's namespace
PASSWORD=$(openssl rand -hex 24)  # hex: no quoting surprises

# 1. The Secret Tenax reads
kubectl -n $NS create secret generic tenax-postgres \
  --from-literal=username=tenax --from-file=password=<(printf %s "$PASSWORD")

# 2. The user, as a superuser, through the database's pod (deploy/…, sts/… or a pod)
kubectl -n $NS exec -i deploy/postgres -- psql -U postgres -v ON_ERROR_STOP=1 <<SQL
\set tenax_password '$PASSWORD'
SELECT 'CREATE ROLE tenax LOGIN REPLICATION' WHERE NOT EXISTS (SELECT 1 FROM pg_roles WHERE rolname = 'tenax') \gexec
ALTER ROLE tenax WITH LOGIN REPLICATION PASSWORD :'tenax_password';
GRANT pg_read_all_data, pg_monitor TO tenax;
ALTER SYSTEM SET max_slot_wal_keep_size = '2GB';
SELECT pg_reload_conf();
SQL

3. 如需恢复到任意一秒，请允许该用户进行复制：把下面这行加到 pg_hba.conf 并重新加载配置（无需重启）。

host  replication  tenax  all  scram-sha-256

如果 Postgres 由 Operator 或 Helm Chart 管理，请在它配置 pg_hba 的地方添加这一行（例如 CloudNativePG 中的 spec.postgresql.pg_hba，或 Chart 的 pgHbaConfiguration 值）。

同样的 SQL，带注释的文件版（docs/sql/postgres-users.sql）

docs/sql/postgres-users.sql

-- Tenax's database user for PostgreSQL 15/16/17 (run once as a superuser, e.g. with psql):
--
--   psql -v tenax_password="$TENAX_PASSWORD" -f postgres-users.sql
--
-- One user, `tenax`, does everything (ADR 0016): inventory queries, logical dumps (pg_dump), exports and checks
-- with pg_read_all_data + pg_monitor; physical base backups (pg_basebackup) and the WAL stream with REPLICATION.
--
-- For physical backups and point-in-time restore pg_hba.conf must also allow it to replicate, then reload:
--     host replication tenax all scram-sha-256
-- Without that rule Tenax still works: it takes logical backups and tells you the rule to add.
-- Also needed: wal_level = replica (the default) and max_wal_senders >= 2 (default 10).
\set ON_ERROR_STOP on

SELECT format('CREATE ROLE tenax LOGIN REPLICATION PASSWORD %L', :'tenax_password')
WHERE NOT EXISTS (SELECT 1 FROM pg_roles WHERE rolname = 'tenax') \gexec
ALTER ROLE tenax WITH LOGIN REPLICATION NOSUPERUSER NOCREATEDB NOCREATEROLE PASSWORD :'tenax_password';
GRANT pg_read_all_data, pg_monitor TO tenax;
-- Keep backup sessions bounded.
ALTER ROLE tenax SET idle_in_transaction_session_timeout = '10min';

-- A stopped streamer must never fill the database disk: cap WAL retained by replication slots (no restart needed).
ALTER SYSTEM SET max_slot_wal_keep_size = '2GB';
SELECT pg_reload_conf();

NS=team-a
PASSWORD=$(openssl rand -hex 24)

# 1. The Secret Tenax reads
kubectl -n $NS create secret generic tenax-mysql \
  --from-literal=username=tenax --from-file=password=<(printf %s "$PASSWORD")

# 2. The user, as root (the official image has the root password in MYSQL_ROOT_PASSWORD)
kubectl -n $NS exec -i deploy/mysql -- sh -c 'MYSQL_PWD="$MYSQL_ROOT_PASSWORD" mysql -uroot' <<SQL
CREATE USER IF NOT EXISTS 'tenax'@'%' IDENTIFIED BY '$PASSWORD';
GRANT SELECT, SHOW VIEW, TRIGGER, EVENT, LOCK TABLES, PROCESS, RELOAD, SHOW_ROUTINE,
      REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'tenax'@'%';
SQL

3. 恢复到任意一秒需要开启 binlog 并使用行格式：两者都是 MySQL 8 的默认设置。 select @@log_bin, @@binlog_format 会显示 1, ROW。

同样的 SQL，带注释的文件版（docs/sql/mysql-users.sql）

docs/sql/mysql-users.sql

-- Tenax's database user for MySQL 8.4 (run once as root, replace the password):
--
--   mysql -uroot -p < mysql-users.sql
--
-- One user, `tenax`, does everything (ADR 0016): consistent logical dumps (mysqldump --single-transaction
-- --source-data=2), inventory and checks, and the binlog stream (mysqlbinlog --read-from-remote-server).
-- Without REPLICATION SLAVE / REPLICATION CLIENT Tenax still takes dumps, but without point-in-time restore.
--
-- Server settings (all MySQL 8 defaults except GTIDs): log_bin=ON, binlog_format=ROW, a unique server_id;
-- gtid_mode=ON with enforce_gtid_consistency=ON is recommended; binlog_expire_logs_seconds long enough for the
-- streamer to catch up after an outage (default 30 days).
CREATE USER IF NOT EXISTS 'tenax'@'%' IDENTIFIED BY 'CHANGE_ME_PASSWORD';
GRANT SELECT, SHOW VIEW, TRIGGER, EVENT, LOCK TABLES, PROCESS, RELOAD, SHOW_ROUTINE,
      REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'tenax'@'%';
FLUSH PRIVILEGES;

就这么简单。让目标指向这个 Secret：

spec:
  credentials:
    secretRef: { name: tenax-postgres }

不做第 3 步

不会有任何失败。Tenax 会尝试用该用户进行复制，如果数据库拒绝：

• 全量备份为逻辑备份，按策略的计划执行；
• 目标的 Replication 状态条件、控制台以及每个备份的警告都会准确说明需要添加什么；
• Tenax 每隔几分钟重新检查一次，一旦你添加完成，就会自动开始流式传输。

用户可以	你将获得	权限
读取全部数据	逻辑备份、清单、导出、检查	Postgres pg_read_all_data + pg_monitor；MySQL SELECT、SHOW VIEW、TRIGGER、EVENT、LOCK TABLES、PROCESS、RELOAD、SHOW_ROUTINE
复制	物理备份（Postgres）和变更流：恢复到任意一秒	Postgres REPLICATION 加上 pg_hba.conf 规则；MySQL REPLICATION SLAVE、REPLICATION CLIENT

复制槽

Postgres 流会把 WAL 保留在复制槽中，直到 Tenax 将其存储完毕。上面的 SQL 把已停止的流式传输程序最多能保留的量 限制为 2 GB（max_slot_wal_keep_size），Tenax 会在远未达到该值之前就发出 TenaxSlotWALRetentionHigh 告警， 并在目标被删除或关闭时间点恢复时删除该复制槽。

进阶：自动保持用户同步，适用于密码会轮换、数据库会重建的 GitOps 环境。