设置ClickHouse默认用户default的密码

1、明文密码

（1）查找user.xml文件

[root@elastic1 app]# cd /etc/clickhouse-server/
[root@elastic1 clickhouse-server]# ll
total 40
drwxr-xr-x 2 root root  4096 Sep 11 13:39 config.d
-rw-r--r-- 1 root root 22601 Sep 11 13:45 config.xml
lrwxrwxrwx 1 root root    41 Sep 11 13:39 preprocessed -> /var/lib/clickhouse//preprocessed_configs
drwxr-xr-x 2 root root  4096 Sep 11 13:39 users.d
-rw-r--r-- 1 root root  5190 May 19 00:26 users.xml
[root@elastic1 clickhouse-server]# vi users.xml

（2）修改密码

<!-- Users and ACL. -->
    <users>
        <!-- If user name was not specified, 'default' user is used. -->
        <default>
            <!-- Password could be specified in plaintext or in SHA256 (in hex format).

                 If you want to specify password in plaintext (not recommended), place it in 'password' element.
                 Example: <password>qwerty</password>.
                 Password could be empty.

                 If you want to specify SHA256, place it in 'password_sha256_hex' element.
                 Example: <password_sha256_hex>65e84be33532fb784c48129675f9eff3a682b27168c0ea744b2cf58ee02337c5</password_sha256_hex>
                 Restrictions of SHA256: impossibility to connect to ClickHouse using MySQL JS client (as of July 2019).

                 If you want to specify double SHA1, place it in 'password_double_sha1_hex' element.
                 Example: <password_double_sha1_hex>e395796d6546b1b65db9d665cd43f0e858dd4303</password_double_sha1_hex>

                 How to generate decent password:
                 Execute: PASSWORD=$(base64 < /dev/urandom | head -c8); echo "$PASSWORD"; echo -n "$PASSWORD" | sha256sum | tr -d '-'
                 In first line will be password and in second - corresponding SHA256.

                 How to generate double SHA1:
                 Execute: PASSWORD=$(base64 < /dev/urandom | head -c8); echo "$PASSWORD"; echo -n "$PASSWORD" | sha1sum | tr -d '-' | xxd -r -p | sha1sum | tr -d '-'
                 In first line will be password and in second - corresponding double SHA1.
            -->
            <password>123456</password>

（3）重启服务

[root@elastic1 clickhouse-server]# systemctl restart clickhouse-server

2、SHA256密码

（1）SHA256加密例如对密码123456进行SHA256加密

[root@elastic1 clickhouse-server]# echo -n 123456 | openssl dgst -sha256
(stdin)= 8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c92
[root@elastic1 clickhouse-server]#

（2）修改default用户密码

    <!-- Users and ACL. -->
    <users>
        <!-- If user name was not specified, 'default' user is used. -->
        <default>
            <!-- Password could be specified in plaintext or in SHA256 (in hex format).

                 If you want to specify password in plaintext (not recommended), place it in 'password' element.
                 Example: <password>qwerty</password>.
                 Password could be empty.

                 If you want to specify SHA256, place it in 'password_sha256_hex' element.
                 Example: <password_sha256_hex>65e84be33532fb784c48129675f9eff3a682b27168c0ea744b2cf58ee02337c5</password_sha256_hex>
                 Restrictions of SHA256: impossibility to connect to ClickHouse using MySQL JS client (as of July 2019).

                 If you want to specify double SHA1, place it in 'password_double_sha1_hex' element.
                 Example: <password_double_sha1_hex>e395796d6546b1b65db9d665cd43f0e858dd4303</password_double_sha1_hex>

                 How to generate decent password:
                 Execute: PASSWORD=$(base64 < /dev/urandom | head -c8); echo "$PASSWORD"; echo -n "$PASSWORD" | sha256sum | tr -d '-'
                 In first line will be password and in second - corresponding SHA256.

                 How to generate double SHA1:
                 Execute: PASSWORD=$(base64 < /dev/urandom | head -c8); echo "$PASSWORD"; echo -n "$PASSWORD" | sha1sum | tr -d '-' | xxd -r -p | sha1sum | tr -d '-'
                 In first line will be password and in second - corresponding double SHA1.
            -->
            <!--
            <password>123456</password>
            -->
            <password_sha256_hex>8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c92</password_sha256_hex>

（3）重启服务