Container Security for base images and runtime | Anexia

For image hardening, we first examine what a container image contains and how it is built. A lean base image can reduce the attack surface, but it does not replace an assessment of the application and its dependencies. Build tools, temporary files or credentials do not belong in the published result by accident. The provenance of the image must remain linked to the delivery process.

In the container review, we then look at execution. User rights, file system access, network connections and mounted secrets determine the consequences an error inside the container can have. For Container Security, we check which restrictions are compatible with the application and which adjustments become necessary. Otherwise, a blanket hardening rule can block production functions. In an orchestrated environment, admission rules and the separation of workloads are added. Acceptance therefore covers both image checks and concrete runtime configurations. In this way, container security makes it clear which risks are addressed in the delivery path and which in actual operation.

Scope of services for Container Security

The agreed scope for image hardening can include the following deliverables: image inventory, baseline, scanning process, runtime rules, registry concept and release tests. For each key deliverable, we define what it is for, who reviews it and in what form it is handed over. This allows development, operations and procurement to assess the same service. Vague umbrella terms in the proposal are replaced by concrete work packages.

The container review also includes coordinating the necessary interfaces with your team. We clarify access, contacts and available testing options before the relevant implementation steps. Changes to the scope are described together with their impact on effort and sequence. This gives you a clear overview of delivered results, outstanding prerequisites and additional requests.

The key technical decision in Container Security

The choice of base image takes maintainability and the required diagnostic options into account. The smallest possible image only makes sense if it can be reliably maintained. For container security, we document the relevant assumptions and justify the chosen approach. Key alternatives are considered against the same functional requirements. This makes later adjustments easier when load, data volume or organisational responsibilities change.

A sound decision also takes maintainability and handover into account. For image hardening, we review which skills are available internally and what additional support is needed. This connects technical possibilities with a realistic operating model. The client can see which tasks will recur after the project and which decisions remain with them.

An unprivileged process can still reach confidential data if volumes, network access or service accounts are granted too generously. In the container review, we treat this point as a concrete test question. Each risk is linked to the affected process, its possible impact and a suitable measure. Where prerequisites are still missing, the statement remains explicitly open until the necessary investigation has taken place.

We test package inventory, user rights, file system access, network connections and the impact of an updated base version. For Container Security, we record the starting point, the tested configuration and the result. Acceptance refers to the agreed scope. Open limitations are documented visibly and assigned to an owned next step. This allows your team to distinguish between proven functionality, a deliberate decision and an assumption that has not yet been confirmed.

Project example as an illustrative scenario

The following scenario is a use case example and not a customer reference. A web service is containerised, but inherits far-reaching rights and unnecessary tools from a generic base image. With Container Security, the pilot would examine a production-like service. Relevant questions would be which files need to be written, which network targets are required and whether elevated rights can be justified on functional grounds.

For container security, the image would be reduced step by step to the required components. Changed rights and file system rules would need to be tested at startup, during operation and when updating. A scan result would be linked to the component version actually in use and the reachable functions. The image's path into the registry and on into the runtime environment would also be part of the review. The pilot would examine whether an unapproved image can be started and how changes to security policies are tracked.

Approval after image hardening would document functionality and protection boundaries together. A smaller image size would not yet be proof of security; what would matter are unnecessary rights, reachable attack surfaces and addressed findings. The plan would include a suitable image structure, justified runtime rules and a repeatable review process. Required exceptions would remain visible. The measures would then be transferred to further services, insofar as their operational requirements are actually comparable.

Our experience and our engineering approach

We combine custom software development with the technical tasks of introduction and further development. For container security, we bring the perspectives of application, integration and operations together in a shared workflow. The functional requirements remain connected to the technical decisions. You work with a defined scope of services and traceable results.

Our experience should become concretely verifiable for your project. That is why, in a technical exchange, we explain how we investigate the relevant risks, which deliverables are planned and how your team can assess them. For image hardening, we match the roles involved to the actual need. Available references are put into context with their respective project and company relationship; confidential customer details are not used as general marketing claims.

Effort for image hardening

The number of images, update frequency, runtime environment and compatibility of older applications determine the scope. We therefore calculate Container Security based on a clearly defined scope and explicitly stated prerequisites. An initial analysis step can be useful if key technical information is still missing. Work packages and acceptance criteria can then be agreed on a more solid basis.

Container security can be organised as a limited project, as a joint implementation with your team or with subsequent support. Usage rights, access, documentation and responsibilities are clarified in the contract. Ongoing operating hours, response times and external consumption costs are separate agreements. This makes it clear which services are provided once and which tasks recur after go-live.

What Container Security does not cover

Container security is relevant even without Kubernetes; a platform migration is not assumed by default. For the container review, we already set out this boundary in the proposal. Required additional services are included with their functional justification and are not tacitly assumed. Your team can therefore plan suitable internal skills and divide the overall work sensibly between those involved.