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Karan Singh Karan is a highly experienced DevOps Engineer with over 13 years of experience in the IT industry. Throughout his career, he has developed a deep understanding of the principles of DevOps, including continuous integration and deployment, automated testing, and infrastructure as code.

Container Security: Best Practices and Tools

3 min read

In today’s DevOps and cloud environments, containerization has become a standard for application deployment. Containers are convenient and flexible tools that allow for the implementation of various solutions and workflow improvements. However, containers are prone to risks, and an inappropriate security organization can harm the entire enterprise. 

For example, imagine that you are studying at a university. You applied to an online paper writing service for help in writing an essay or with a request to edit a good paper. In the process, it turned out that information about it became known to the entire faculty, including your parents and teacher. Even though applying to the service is normal, and the sites work legally, information leakage can cause reputational damage. That’s why writing services monitor the security of their client’s data, and DevOps developers should make enough effort to exclude external influence on the work with containers. Fortunately, there are a number of effective tools to do this. 

The Main Security Threats to Containers

Like any other program or technology, containers are vulnerable to several threats. These can include using old databases, misconfiguration, harm through privilege abuse, and external influence. For example, suppose you are using outdated base samples. In that case, you risk external exposure because the vulnerabilities of these databases are already known. No less harm can come from improper network configuration. A prime example of the vulnerability of mishandling network configurations is the 2019 attack on Docker Hub. 

As a result of an illegal intrusion, hackers gained access to the user database. The credentials of about 190,000 people were compromised, including logins, password hashes, and tokens for automating the Docker Hub experience.

Best-Known Container Security Practices

Use of minimal base images

Minimal base images, such as Alpine Linux, help reduce the space for possible attacks and consequently reduce the impact of a possible hack by minimizing the amount of potentially vulnerable code available. Minimal base images reduce the number of patch updates required to maintain security. Using minimal images also limits the number of optional components that can be attacked.

Regular updates and patches

When working on a network, paying attention to timely updates to containers and base images is necessary. This is not a privilege but a necessity and is one of the key defense mechanisms to protect against newly found vulnerabilities. Automating updates with CI/CD tools helps keep security at a high level. It reduces the likelihood of unauthorized intrusion and threatening changes to a minimum. Regular updates include automatic scanning and deployment of updates when new vulnerabilities are discovered.

Minimum Required Access Policy

This is a common practice for any company to protect against cyber threats. Employees should have minimum access to protected and vulnerable information sufficient to perform their job duties. This approach allows you to clearly track internal breaches and identify who may be responsible for the disruption. Limiting container privileges and using non-privileged users helps reduce the risk of vulnerability exploitation. Containers should be run with the minimum necessary access rights. For example, running containers in “no privilege” mode reduces the likelihood of an attacker exploiting a vulnerability for privilege escalation.

Scanning Container Images

Regular scanning of container images is also necessary to maintain the secure operation of the entire system. For this purpose, programs such as Clair and Trivy should be used. With their help, potential threats can be detected quickly and promptly eliminated before they are exploited. These tools are integrated with CI/CD Pipelines, which provide automatic scanning at every development and deployment stage.

Leverage network policies

Creating several segments from a single network and applying the necessary network policies can isolate vulnerable containers and prevent unauthorized access. Kubernetes offers actionable tools for configuring network policies to ensure security. For example, Network Policies allow you to control traffic between pods and restrict access to only necessary components.

Container Security Tools

Many tools are available to DevOps developers to monitor illegal activity in containers and react to potential threats in time. We will mention a few of the most popular tools that have already earned the reputation of being reliable and time-tested. 

Docker Scout

Docker Scout is a platform to help organizations secure their software supply chain. It provides tools and services for identifying and managing software assets and policies, and automated remediation of security threats. Unlike traditional security tools focusing on scheduled, point-in-time scans at specific stages in the software development lifecycle, Docker Scout uses a modern event-driven model that spans the entire software supply chain. This means that when a new vulnerability affecting your images is disclosed, your updated risk assessment is available within seconds, and earlier in the development process source.


Clair is an indispensable tool for working with containers. This static vulnerability analyzer performs deep scans of container images and provides a detailed report on identified issues. Clair integrates with various container registries and CI/CD Pipelines. Developers appreciate its convenience, and it is very popular with both them and administrators.  


Trivy is notable for its easy integration with CI/CD Pipelines. The program scans container images, source code, configuration files, and dependencies. 

Aqua Security

Aqua Security offers a comprehensive approach to container security, including vulnerability scanning, monitoring container activity, and enforcing security policies. Aqua Security enables you to manage container security at all lifecycle stages, from development to operations.

Sysdig Falco

Sysdig Falco detects anomalous activity in containers. It uses rules to identify anomalies and can integrate with various tools for notification and incident response.

Analyzing the Success of the Application

These tools have already proven effective in helping some of the largest companies. For example, one of the largest development companies, GitLab, uses Aqua and Trivy as standard container vulnerability scanning tools for its customers. According to the company, Trivy was chosen for its high accuracy, scanning speed, and offline capabilities. IMB, in turn, also uses Aqua and Trivy to monitor the security of its containers on the IBM Power platform. 


Container security should not be skimped on. Best current practices and regular vulnerability scanning are exactly what you need to keep your enterprise running securely. Establishing clear access boundaries and restricting access to vulnerable areas to employees who do not work directly in those areas is equally important. Privilege limitation and network segmentation help minimize risk and protect the infrastructure. By implementing the practices and tools described above, companies can secure containerized environments and reduce the likelihood of successful attacks.

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Karan Singh Karan is a highly experienced DevOps Engineer with over 13 years of experience in the IT industry. Throughout his career, he has developed a deep understanding of the principles of DevOps, including continuous integration and deployment, automated testing, and infrastructure as code.
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