Authors: Jakub Hrozek, Juan Antonio Osorio, Paulo Gomes, Sascha Grunert
The Security Profiles Operator (SPO)is an out-of-tree Kubernetes enhancement to make the management ofseccomp,SELinux andAppArmor profiles easier and more convenient. We're happy to announce that we recently released v0.4.0of the operator, which contains a ton of new features, fixes and usability improvements.
What's new
It has been a while since the lastv0.3.0release of the operator. We added new features, fine-tuned existing ones and reworked our documentation in 290 commits over the past half year.
One of the highlights is that we're now able to record seccomp and SELinux profiles using the operators log enricher. This allows us to reduce the dependencies required for profile recording to haveauditd orsyslog (as fallback) running on the nodes. All profile recordings in the operator work in the same way by using theProfileRecording CRD as well as their corresponding label selectors. The log enricher itself can be also used to gather meaningful insights about seccomp and SELinux messages of a node. Checkout the official documentationto learn more about it.
seccomp related improvements
Beside the log enricher based recording we now offer an alternative to record seccomp profiles by utilizing ebpf. This optional feature can be enabled by setting enableBpfRecorder to true. This results in running a dedicated container, which ships a custom bpf module on every node to collect the syscalls for containers. It even supports older Kernel versions which do not expose the BPF Type Format (BTF) per default as well as the amd64 and arm64 architectures. Checkoutour documentationto see it in action. By the way, we now add the seccomp profile architecture of the recorder host to the recorded profile as well.
We also graduated the seccomp profile API from v1alpha1 to v1beta1. This aligns with our overall goal to stabilize the CRD APIs over time. The only thing which has changed is that the seccomp profile type Architectures now points to[]Arch instead of []*Arch.
SELinux enhancements
Managing SELinux policies (an equivalent to using semodule that you would normally call on a single server) is not done by SPO itself, but by another container called selinuxd to provide better isolation. This release switched to using selinuxd containers from a personal repository to images located under our team's quay.io repository. The selinuxd repository has moved as well to the containers GitHub organization.
Please note that selinuxd links dynamically to libsemanage and mounts the SELinux directories from the nodes, which means that the selinuxd container must be running the same distribution as the cluster nodes. SPO defaults to using CentOS-8 based containers, but we also build Fedora based ones. If you are using another distribution and would like us to add support for it, please file an issue against selinuxd.
Profile Recording
This release adds support for recording of SELinux profiles. The recording itself is managed via an instance of a ProfileRecording Custom Resource as seen in anexamplein our repository. From the user's point of view it works pretty much the same as recording of seccomp profiles.
Under the hood, to know what the workload is doing SPO installs a special permissive policy called selinuxrecordingon startup which allows everything and logs all AVCs to audit.log. These AVC messages are scraped by the log enricher component and when the recorded workload exits, the policy is created.
SELinuxProfile CRD graduation
An v1alpha2 version of the SelinuxProfile object has been introduced. This removes the raw Common Intermediate Language (CIL) from the object itself and instead adds a simple policy language to ease the writing and parsing experience.
Alongside, a RawSelinuxProfile object was also introduced. This contains a wrapped and raw representation of the policy. This was intended for folks to be able to take their existing policies into use as soon as possible. However, on validations are done here.
AppArmor support
This version introduces the initial support for AppArmor, allowing users to load and unload AppArmor profiles into cluster nodes by using the new AppArmorProfile CRD.
To enable AppArmor support use the enableAppArmor feature gate switch of your SPO configuration. Then use our apparmor example to deploy your first profile across your cluster.
Metrics
The operator now exposes metrics, which are described in detail in our new metrics documentation. We decided to secure the metrics retrieval process by usingkube-rbac-proxy, while we ship an additional spo-metrics-client cluster role (and binding) to retrieve the metrics from within the cluster. If you're usingOpenShift, then we provide an out of the box workingServiceMonitorto access the metrics.
Debuggability and robustness
Beside all those new features, we decided to restructure parts of the Security Profiles Operator internally to make it better to debug and more robust. For example, we now maintain an internal gRPC API to communicate within the operator across different features. We also improved the performance of the log enricher, which now caches results for faster retrieval of the log data. The operator can be put into a more verbose log modeby setting verbosity from 0 to 1.
We also print the used libseccomp and libbpf versions on startup, as well as expose CPU and memory profiling endpoints for each container via theenableProfiling option. Dedicated liveness and startup probes inside of the operator daemon will now additionally improve the life cycle of the operator.
Conclusion
Thank you for reading this update. We're looking forward to future enhancements of the operator and would love to get your feedback about the latest release. Feel free to reach out to us via the Kubernetes slack#security-profiles-operatorfor any feedback or question.
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