This page contains an analyzis on the list of test cases listed in the CNCF CNF Testsuite to determine if RA2 should contain related workload requirements.
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Test that the CNF does not crash when disk fill occurs)
Notes
- Tests defined here: https://github.com/cncf/cnf-testsuite/blob/2d875c66352e8dc5650c6fe7a1c43e744a7a2871/embedded_files/points.yml (10 out of the 15 'essential' test must be passed to get the certification)
- Rationale of the tests: https://github.com/cncf/cnf-testsuite/blob/main/RATIONALE.md
Issues raised to CNCF CNF Testsuite during this work
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Test | Note | Verdict |
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To test the increasing and decreasing of capacity | Do we request horizontal scaling from all CNF-s? Most (data plane, signalling, etc) but not all (eg OSS) | should be optional, or just fail if it scales incorrectly in case the CNF scales ( |
Test if the Helm chart is published | We should first decide on CNF packaging. RA2 can stay neutral, follow the O-RAN/ONAP ASD path or propose own solution. | should be fine - no HELM specs in RA2 today, unless some incompatible CNFs packaging specs (unlikely) ( |
Test if the Helm chart is valid | ||
Test if the Helm deploys | This should be more generic, like testing if the CNF deploys. | |
Test if the install script uses Helm v3 | ||
To test if the CNF can perform a rolling update | As there's some CNFs that actually use rolling update without keeping the service alive (because they require some post-configuration), the test should make sure that there is service continuity. this might just be a health probe or testing the k8s service, or something sufficiently straightforward. In other words, CNF service/traffic should work during the whole process (before during and after a rolling upgrade) | Needed (ra2.app.014 ) |
To check if a CNF version can be downgraded through a rolling_version_change | It is not clear what is the difference between a rolling downgrade and a rolling version change. A: Defined in the external docs in the usage guide. Some these are relevant for a ReplicaSet some of them are for a Deployment. Maybe when you request an arbitrary version? | |
To check if a CNF version can be downgraded through a rolling_downgrade | Same as above? | Needed (ra2.app.015 ) |
To check if a CNF version can be rolled back rollback | It is not clear what is the difference between a rolling downgrade and a rolled back rollback. | |
To check if the CNF is compatible with different CNIs | This covers only the default CNI, does not cover the metaplugin part. Need additional tests for cases with multiple interfaces. | Ok but needs additional tests for multiple interfaces ( |
(PoC) To check if a CNF uses Kubernetes alpha APIs | Alpha API-s are not recommended by PoC: it might happen that these testcases are removed from the Testsuite and this will be not part of the CNF certification. Probably will be a bonus case. | Ok ( |
To check if the CNF has a reasonable image size | It passes if the image size is smaller than 5GB. A: Whenever it is possible tests are configurable or parameters can be overwritten from the outside. This will be part of the CNF Certification. Valid for each image referred from the Helm chart. | Ok but should be documented or configurable? should read "pod image size" ( |
To check if the CNF have a reasonable startup time | It is not clear what reasonable startup time is. It is about the startup time of the microservices inside the CNF. Should be Check if all the Pods in the CNF have a reasonable startup time. A: Reasonable time is 60 sec. | Ok but should be documented or configurable? should read "pod startup time" ( |
To check if the CNF has multiple process types within one container | Containers in the CNF should have only one process type. even for exposing an API a separate process is required - should this test if the number of processes is less than a certain number instead? | Not required What's the rationale? do not agree with rule |
To check if the CNF exposes any of its containers as a service | Service type what? RA2 mandates that clusters must support Loadbalancer and ClusterIP, and should support Nodeport and ExternalName Should there be a test for the CNF to use Ingress or Gateway objects as well ? | May need tweaking to add Ingress? |
To check if the CNF has multiple microservices that share a database | Clarify rationale? In some cases it is good for multiple Microservices to share a DB, eg when restoring the state of a transaction from a failed service. Also good to have a shared DB across multiple services for things like HSS etc. | should not be required Clarify |
Test if the CNF crashes when node drain and rescheduling occurs. All configuration should be stateless | CNF should react gracefully (no loss of context/sessions/data/logs & service continues to run) to eviction and node draining The statelessness test should be made independent & Should be skipped for stateful pods eg Dns "crashes" actually means that either the liveness or readiness probe fails - this should be made explicit and the presence of probes should be made mandatory - added issue in RA2 | Needed - but replace "crash" with "react gracefully" (no loss of context/sessions/data/logs & service continues to run) issue: Statelessness test should be separate
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To test if the CNF uses a volume host path | should pass if the cnf doesn't have a hostPath volume What's the rationale? - A: When a cnf uses a volume host path or local storage it makes the application tightly coupled to the node that it is on. Check this with RA2 - already ok, already in RA2 | ok - just fix title ( |
To test if the CNF uses local storage | should fail if local storage configuration found What's the rationale? ok, add to RA2 (attach to previous) | ok - needed ( |
To test if the CNF uses elastic volumes | should pass if the cnf uses an elastic volume What's an elastic volume? Does this mean Ephemeral? Or is this an AWS-specific test? There should be a definition of what an elastic volume is (besides ELASTIC_PROVISIONING_DRIVERS_REGEX) | What's an elastic volume? Does this mean Ephemeral? Or is this an AWS-specific test? |
To test if the CNF uses a database with either statefulsets, elastic volumes, or both | A database may use statefulsets along with elastic volumes to achieve a high level of resiliency. Any database in K8s should at least use elastic volumes to achieve a minimum level of resilience regardless of whether a statefulset is used. Statefulsets without elastic volumes is not recommended, especially if it explicitly uses local storage. The least optimal storage configuration for a database managed by K8s is local storage and no statefulsets, as this is not tolerant to node failure. There should be a definition of what an elastic volume is (besides ELASTIC_PROVISIONING_DRIVERS_REGEX) | What's an elastic volume? Does this mean Ephemeral? Or is this an AWS-specific test? |
Test if the CNF crashes when network latency occurs | How is this tested? Where is the test running? Some traffic against a service? Latency should be configurable (default is 2s)? What should happen if latency is exceeded? Should this be more stringent than "not crashing?" What is the expectation? (not crashing = not exit with error code or (better) not stopping to process traffic) A: Explanation added to https://github.com/cncf/cnf-testsuite/blob/main/USAGE.md#heavy_check_mark-test-if-the-cnf-crashes-when-network-latency-occurs Check this with RA2 - should be ok | Needed but needs clarification issue on defining "crashing - it's probes
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Test if the CNF crashes when disk fill occurs | What is the expectation? (not crashing = not exit with error code or (better) not stopping to process traffic) RM/RA2 should add infra monitoring recommendation for disk usage alerting | Needed issue on defining "crashing - it's probes ( |
Test if the CNF crashes when pod delete occurs | What is the expectation? (not crashing = not exit with error code or (better) not stopping to process traffic) | Needed issue on defining "crashing - it's probes ( |
Test if the CNF crashes when pod memory hog occurs | What is the expectation? (not crashing = not exit with error code or (better) not stopping to process traffic) title should read "CNF pod runs out of memory"? RA2 should add recommendation to add pod memory reservation:
| Needed issue on defining "crashing - it's probes ( |
Test if the CNF crashes when pod io stress occurs | What is the expectation? (not crashing = not exit with error code or (better) not stopping to process traffic) title should read "pod disk I/O" | Needed ( |
Test if the CNF crashes when pod network corruption occurs | It is not clear what network corruption is in this context. What is the expectation? (not crashing = not exit with error code or (better) not stopping to process traffic) Rationale explains traffic manipulation:
| Needed issue on defining "crashing - it's probes ( |
Test if the CNF crashes when pod network duplication occurs | It is not clear what network duplication is in this context. What is the expectation? (not crashing = not exit with error code or (better) not stopping to process traffic) | Needed issue on defining "crashing - it's probes ( |
To test if there is a liveness entry in the Helm chart | Liveness probe should be mandatory, but RA2 does not mandate Helm at the moment. (it's in the pod definition rather than helm - maybe fix the title) RA2 now mandates helm3 - it's the pod definition - added issue to recommend probes in RA2 CH4 | Needed ( |
To test if there is a readiness entry in the Helm chart | Readiness probe should be mandatory, but RA2 does not mandate Helm at the moment. (it's in the pod definition rather than helm - maybe fix the title) RA2 now mandates helm3 - it's the pod definition - added issue to recommend probes in RA2 CH4 | Needed ( |
To check if logs are being sent to stdout/stderr | optional, as there's no way to accurately figure out if we're missing something from stdout/stderr title reads "instead of a log file" RA2 should recommend that the application streams logs out of stdout/stderr | Needed |
To check if prometheus is installed and configured for the cnf | There is a chapter for Additional required components (4.10), but without any content. should ra2 mandate prometheus? A: All the PaaS components are optionally tested, as bonus tests. RM/RA right now doesn't require specific PaaS tools | Not needed |
To check if logs and data are being routed through fluentd | There is a chapter for Additional required components (4.10), but without any content. should ra2 mandate fluent? A: All the PaaS components are optionally tested, as bonus tests. | Not needed |
To check if Open Metrics is being used and or compatible. | There is a chapter for Additional required components (4.10), but without any content. should ra2 mandate open metrics? A: All the PaaS components are optionally tested, as bonus tests. | Not needed |
To check if tracing is being used with Jaeger | There is a chapter for Additional required components (4.10), but without any content. should ra2 mandate jaeger? A: All the PaaS components are optionally tested, as bonus tests. | Not needed |
To check if a CNF is using container socket mounts | what is being tested? Make sure to not mount /var/run/docker.sock, /var/run/containerd.sock or /var/run/crio.sock on the containers? | Needed ( |
To check if containers are using any tiller images | ie test if it's NOT helm v2? | ok if not helm v2 |
To check if any containers are running in privileged mode | ie NOT privileged? | Needed ( |
To check if a CNF is running services with external IP's | does this mean "k8s service?" RA2 mandates that clusters must support Loadbalancer and ClusterIP, and should support Nodeport and ExternalName | |
To check if any containers are running as a root user | ie not Root? | Needed ( |
To check if any containers allow for privilege escalation | ie not allowed? | Needed ( |
To check if an attacker can use a symlink for arbitrary host file system access | ok if not According to the CVE this is not valid anymore in Kubernetes 1.23. | Not needed |
To check if there are service accounts that are automatically mapped | what is the expectation? Application Credentials: Developers store secrets in the Kubernetes configuration files, such as environment variables in the pod configuration. Such behavior is commonly seen in clusters that are monitored by Azure Security Center. Attackers who have access to those configurations, by querying the API server or by accessing those files on the developer’s endpoint, can steal the stored secrets and use them. Check if the pod has sensitive information in environment variables, by using list of known sensitive key names. Check if there are configmaps with sensitive information. Remediation: Use Kubernetes secrets or Key Management Systems to store credentials. See more at ARMO-C0012 | Needed issue to clarify name |
To check if there is a host network attached to a pod | should be ok with or without - eg when exposing services via cluster network as opposed to nodeport? | Needed ( |
To check if there are service accounts that are automatically mapped | Disable automatic mounting of service account tokens to PODs either at the service account level or at the individual POD level, by specifying the automountServiceAccountToken: false. Note that POD level takes precedence. See more at ARMO-C0034 | Seems to be a duplicate. |
To check if there is an ingress and egress policy defined | ok - maybe more stringent? A: There is an answer here: https://github.com/cncf/cnf-testsuite/issues/1282#issuecomment-1081228008 Check this with RA2 | issue to have more stringent network policies (only allow predefined subnets ie not 0/0 for ingress, only allow limited number of protocols/ports) |
To check if there are any privileged containers | duplicate? | #1409 - [BUG]: Duplicate tests about privileged containers |
To check for insecure capabilities | what is the expectation? | issue to clarify name |
To check for dangerous capabilities | what is the expectation? | issue to clarify name |
To check if namespaces have network policies defined | ok - maybe more stringent? duplicate? | issue to have more stringent network policies |
To check if containers are running with non-root user with non-root membership | duplicate? | ok ( |
To check if containers are running with hostPID or hostIPC privileges | ok if not | ok if not ( |
To check if security services are being used to harden containers | what services? should be configurable or optional Linux Hardening: Check if there is AppArmor, Seccomp, SELinux or Capabilities are defined in the securityContext of container and pod. If none of these fields are defined for both the container and pod, alert. Remediation: In order to reduce the attack surface, it is recommended to harden your application using security services such as SELinux®, AppArmor®, and seccomp. Starting from Kubernetes version 1.22, SELinux is enabled by default, therefore I do not think that we need to require anything in RA2. Read more at ARMO-C0055 | not needed |
To check if containers have resource limits defined | ok | ok ( |
To check if containers have immutable file systems | ok | ok ( |
To check if containers have hostPath mounts | ok if not | ( |
To check if containers are using labels | ok - maybe mandate some mandatory labels? | ok (ra2.app.043 ) |
To test if there are versioned tags on all images using OPA Gatekeeper | ok | ok ( |
To test if there are any (non-declarative) hardcoded IP addresses or subnet masks | ok - there shouldn't be any internal hardcoded nw anyway | ok ( |
To test if there are node ports used in the service configuration | ok but service type LB should be better | ok, issue to clarify service types ( |
To test if there are host ports used in the service configuration | duplicate? host ports = node ports? | |
To test if there are any (non-declarative) hardcoded IP addresses or subnet masks in the K8s runtime configuration | duplicate? | |
To check if a CNF version uses immutable configmaps | ok | ok ( |
Test if the CNF crashes when pod dns error occurs | What is the expectation? (not crashing = not exit with error code or (better) not stopping to process traffic) Not crashing = answering to probes | ok ( |
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