10 Docker Container Patching Best Practices

Docker containers are becoming increasingly popular for deploying applications in the cloud. But with the rise of container usage, comes the need for patching and updating these containers. Patching and updating Docker containers can be a tricky task, as it requires you to be aware of the latest security vulnerabilities and ensure that your containers are up-to-date.

In this article, we will discuss 10 best practices for patching and updating Docker containers. By following these best practices, you can ensure that your containers are secure and up-to-date.

1. Keep your base images up to date

The base image is the starting point for all of your Docker containers. It contains the operating system, libraries, and other components that are necessary to run applications in a containerized environment. Keeping these images up to date ensures that any security vulnerabilities or bugs present in the underlying OS or libraries are patched quickly and efficiently.

Updating your base images can be done manually or automatically. Manual updates require you to check for new versions of the base image periodically and then download and install them on each host machine. Automated updates use a tool such as an orchestration platform like Kubernetes to detect when new versions of the base image become available and then deploy them across all hosts.

Once the updated base image has been deployed, it’s important to patch the running containers with the latest security patches. This can be done using a variety of tools, including configuration management systems like Ansible or Chef, or by using a container-specific patching solution like CoreOS Clair. These solutions will scan the running containers for known vulnerabilities and apply the appropriate patches.

2. Utilize the official Docker image library for best practices

The official Docker image library is a repository of images that have been tested and verified by the Docker team. This means that these images are more likely to be secure, reliable, and up-to-date with the latest security patches. Additionally, they often come with additional features such as automated builds, versioning, and tagging which can help streamline the patching process.

Using the official Docker image library also helps ensure that all containers in an environment are running on the same base image. This makes it easier to identify any potential vulnerabilities or outdated packages across multiple containers. It also simplifies the patching process since only one base image needs to be updated instead of each individual container.

To use the official Docker image library for best practices, start by searching for the desired application or service. Once you find the appropriate image, download it and then run it using the “docker run” command. You can then update the image periodically using the “docker pull” command. This will ensure that your containers are always running the most recent version of the image.

3. Leverage automation tools like Ansible and Puppet to deploy patches

Ansible and Puppet are both automation tools that allow for the automated deployment of patches to Docker containers. This is beneficial because it eliminates manual patching, which can be time-consuming and error-prone. Automation also ensures that all containers are patched in a consistent manner, reducing the risk of misconfigurations or vulnerabilities.

Using Ansible and Puppet also allows for more efficient patch management. Both tools provide an easy way to define patch policies and schedules, so you can ensure that your containers are always up-to-date with the latest security updates. Additionally, they make it easier to roll back any changes if something goes wrong during the patching process.

4. Run periodic vulnerability scans on containers

Vulnerability scans are a great way to identify any security issues that may exist in the container environment. By running periodic scans, organizations can ensure that their containers remain secure and up-to-date with the latest patches. This helps prevent attackers from exploiting known vulnerabilities or introducing new ones.

Periodic vulnerability scans also help organizations stay ahead of potential threats by identifying any weaknesses before they become an issue. For example, if a vulnerability is discovered during a scan, it can be addressed quickly before it becomes a major problem. Additionally, these scans can provide valuable insight into how well the organization’s patching process is working.

When performing vulnerability scans on Docker containers, there are several tools available to help automate the process. These tools can be used to detect any known vulnerabilities, as well as any newly introduced ones. They can also be configured to run regularly, ensuring that all containers are scanned at least once per month.

5. Monitor container logs and events for suspicious activity

Logs and events provide a wealth of information about the state of your containers, including when they were created, how long they have been running, what processes are running inside them, and more. By monitoring these logs and events for suspicious activity, you can quickly identify any potential security issues or vulnerabilities that may be present in your container environment.

For example, if you notice an unusually high number of failed login attempts from a particular IP address, this could indicate a malicious actor attempting to gain access to your system. Similarly, if you see a large number of requests coming from a single source, this could also be indicative of a possible attack. Monitoring logs and events can help you detect such activities before they become serious threats.

Additionally, by monitoring logs and events, you can ensure that all patches applied to your Docker containers are properly installed and functioning as expected. This is especially important when patching critical components like the kernel, which can cause significant disruption if not done correctly. Monitoring logs and events will allow you to quickly identify any problems with the patching process so that they can be addressed promptly.

6. Harden security settings in the underlying OS

Hardening security settings in the underlying OS is important because it helps to protect against malicious attacks and unauthorized access. This can be done by implementing a variety of measures, such as setting up firewalls, disabling unnecessary services, and configuring user accounts with strong passwords. Additionally, hardening security settings can help ensure that only authorized users have access to sensitive data or resources.

When patching Docker Containers, it’s important to make sure that the underlying OS has been hardened first. This means ensuring that all necessary security patches are applied, and that any vulnerable services or applications are disabled or removed. It also involves making sure that all user accounts have strong passwords, and that any other security measures (such as firewalls) are properly configured. Once this is done, then the Docker Container itself can be patched.

7. Create a patching policy and schedule

A patching policy and schedule helps ensure that all containers are kept up to date with the latest security patches. This is important because it reduces the risk of vulnerabilities being exploited by malicious actors, as well as reducing the chances of a data breach or other security incident.

Creating a patching policy and schedule also ensures that any new container images are patched before they are deployed in production. This helps prevent any potential issues from arising due to outdated software versions or unpatched vulnerabilities.

The process for creating a patching policy and schedule should include identifying which containers need to be patched, when they need to be patched, and how often they need to be patched. It should also include determining who will be responsible for applying the patches and ensuring that the patches are applied correctly.

Once the policy and schedule have been created, it’s important to regularly review them to make sure they are still relevant and up-to-date. Additionally, it’s important to monitor the patching process to ensure that all containers are being patched according to the policy and schedule.

8. Utilize orchestration tools such as Kubernetes or Swarm for managing multiple containers

Orchestration tools provide a centralized platform for managing multiple containers, allowing users to easily deploy and manage them. This makes it easier to patch Docker containers since all the containers can be managed from one place. Additionally, orchestration tools allow users to automate container deployment and scaling, which is essential when patching Docker containers.

Kubernetes and Swarm are two of the most popular orchestration tools available. Kubernetes provides an easy-to-use interface for deploying and managing containers, while Swarm allows users to quickly scale up or down their container deployments. Both tools also offer features such as automated rollbacks, health checks, and resource management, making them ideal for patching Docker containers.

9. Utilize automated build pipelines for testing and deploying patched containers

Automated build pipelines provide a consistent and repeatable process for testing and deploying patched containers. This helps to ensure that the patching process is reliable, secure, and efficient. Automation also reduces the amount of manual effort required to test and deploy patches, which can save time and money.

The automated build pipeline should include steps such as verifying the integrity of the container image, running tests on the patched container, and deploying the patched container into production. Each step in the pipeline should be tested thoroughly before being deployed. Additionally, security checks should be performed at each stage of the pipeline to ensure that the patched container does not introduce any vulnerabilities or other issues.

Once the automated build pipeline has been established, it can be used to quickly and reliably patch Docker containers. The pipeline can be triggered whenever a new patch is released, allowing for rapid deployment of the latest updates. This ensures that all containers are up-to-date with the latest security patches and bug fixes.

10. Consider using SELinux, AppArmor, or other security frameworks for additional protection

SELinux and AppArmor are two of the most popular security frameworks for Linux systems. They both provide a layer of protection by enforcing mandatory access control (MAC) policies, which restrict user privileges to only those necessary for their tasks. This helps prevent malicious users from gaining unauthorized access to sensitive data or system resources.

Using SELinux or AppArmor with Docker Containers can help protect against vulnerabilities in the underlying operating system or applications running inside the container. For example, if an application is vulnerable to a buffer overflow attack, SELinux or AppArmor can be used to limit the amount of memory that can be allocated to the application, thus preventing the attack from succeeding.

Additionally, these security frameworks can also be used to enforce isolation between containers. By using SELinux or AppArmor, administrators can ensure that each container runs in its own isolated environment, making it more difficult for attackers to gain access to other containers on the same host.