ClickHouse Docker Compose: Password Configuration Guide

Hey guys! So, you’re diving into the world of ClickHouse and using Docker Compose to get things up and running, right? Awesome! One of the first things you’ll want to tackle is setting up a secure environment, and that includes managing those pesky passwords. Trust me, it’s super important to lock down your database, especially if you’re dealing with any kind of sensitive data. In this guide, we’ll walk through how to configure passwords for your ClickHouse instance within a Docker Compose setup, making sure your data stays safe and sound. We will cover how to set up the default user and password, how to create custom users and passwords, and how to securely manage these passwords in your Docker Compose file. Let’s get started and make sure your ClickHouse installation is locked down tight!

Setting the Default User and Password

First things first, let’s talk about the default user. ClickHouse , by default, has a user named ‘default’ with no password. This is fine for testing or local development, but it’s a huge security risk in any production or shared environment. So, let’s get that changed, stat! The most straightforward way to set a password for the default user in your Docker Compose setup is through environment variables. This method is easy to understand and implement, making it a great starting point for beginners. To do this, you’ll need to modify your docker-compose.yml file. If you don’t have one, create it. Here’s a basic example. In this file, you’ll define your ClickHouse service and set the CLICKHOUSE_USER and CLICKHOUSE_PASSWORD environment variables. The CLICKHOUSE_USER variable sets the username, while CLICKHOUSE_PASSWORD sets the password for that user. This approach directly tells the ClickHouse container what username and password to use upon startup. Pretty cool, huh?

version: "3.8"
services:
  clickhouse:
    image: clickhouse/clickhouse-server:latest
    ports:
      - "8123:8123"
      - "9000:9000"
    environment:
      - CLICKHOUSE_USER=myuser
      - CLICKHOUSE_PASSWORD=mypassword
    volumes:
      - clickhouse_data:/var/lib/clickhouse
      - ./config.d:/etc/clickhouse-server/config.d
    ulimits:
      nofile:
        soft: 262144
        hard: 262144
    restart: always
volumes:
  clickhouse_data:

In this example, we’re setting the user to ‘myuser’ and the password to ‘mypassword’. Make sure to replace these with a strong, unique password! Now, when you start your Docker Compose setup ( docker-compose up -d ), ClickHouse will start with the specified user and password. You can then connect to your ClickHouse instance using these credentials. Once the container is running, you can verify this setup by using a ClickHouse client (like the clickhouse-client command-line tool) to connect with the new username and password. Try it out! This step is crucial for securing your ClickHouse installation. It’s like the first line of defense against unauthorized access, so don’t skip it. Setting up passwords is just one piece of the puzzle. Once you’ve got your password in place, you can move on to other security measures, such as access control lists (ACLs) to manage user permissions. Remember, a strong password is the foundation of a secure database!

Creating Custom Users and Passwords

Alright, so you’ve got the default user password sorted. Great job! But what if you need more than one user? Maybe you want different users with different levels of access. That’s where creating custom users comes in. Adding custom users is super handy for managing roles and permissions in your ClickHouse database. To create custom users, we’ll use a slightly different approach: the config.d directory. The config.d directory is a place where you can add configuration files that ClickHouse will load at startup. This method allows for more complex configurations and is generally preferred for production environments. First, create a new directory named config.d in the same directory as your docker-compose.yml file. Inside this directory, you’ll create an XML file, such as users.xml . This file will define your custom users and their passwords. This approach is more structured and allows for greater flexibility. Let’s create a user with read-only access. In the users.xml file, you’ll define your user within the <users> section. Here’s an example:

<clickhouse>
  <users>
    <readonly_user>
      <password>readonly_password</password>
      <networks>
        <ip>::/0</ip>
      </networks>
      <profile>default</profile>
      <roles>readonly</roles>
    </readonly_user>
  </users>
  <profiles>
    <default>
      <max_memory_usage>10000000000</max_memory_usage>
    </default>
  </profiles>
  <roles>
    <readonly>
      <readonly>1</readonly>
    </readonly>
</clickhouse>

In this example, we’ve created a user named ‘readonly_user’ with the password ‘readonly_password’. The <networks><ip>::/0</ip></networks> part allows the user to connect from any IP address. We also assign this user the ‘readonly’ role, which provides read-only access to the database. Make sure you adjust the networks part for your needs. Now, you need to tell your Docker Compose file to mount this configuration file into the container. This is done using the volumes section of your docker-compose.yml file. Add the following lines to your docker-compose.yml under the clickhouse service:

    volumes:
      - clickhouse_data:/var/lib/clickhouse
      - ./config.d:/etc/clickhouse-server/config.d

This maps the config.d directory from your host machine to /etc/clickhouse-server/config.d inside the container. After restarting your Docker Compose setup ( docker-compose up -d ), ClickHouse will load the users.xml file, and the new user will be available. You can now use the readonly_user credentials to connect to your database. This approach gives you granular control over user permissions. You can define different roles with different access levels, making your database much more secure. Always remember to use strong, unique passwords for each user. Also, consider limiting user access based on IP addresses and network configurations to enhance security.

Securely Managing Passwords in Docker Compose

Okay, we’ve covered setting passwords and creating users. But here’s a crucial question: how do you manage passwords securely in your Docker Compose setup? Directly embedding passwords in your docker-compose.yml file, like we did earlier, is okay for development, but it’s a big no-no for production environments. It’s like leaving your keys under the doormat – convenient, but risky! So, let’s explore more secure methods. One of the best practices is to use environment variables in conjunction with a .env file. This file lets you store your passwords outside of your docker-compose.yml file, making it easier to manage and less likely to accidentally expose your secrets. Create a .env file in the same directory as your docker-compose.yml file. Inside this file, define your environment variables. For example:

CLICKHOUSE_USER=secureuser
CLICKHOUSE_PASSWORD=SuperSecretPassword123

In your docker-compose.yml file, you can then reference these variables. This keeps your docker-compose.yml file cleaner and prevents accidental exposure of your passwords. Another robust approach is to use Docker secrets. Docker secrets are a secure way to manage sensitive data, such as passwords, within your Docker environment. Docker secrets are stored encrypted, and only the services that need them can access them. To use Docker secrets , you first need to create a secret. You can do this using the docker secret create command. Here’s how you can create a secret for your ClickHouse password:

”`bash docker secret create clickhouse_password <<<