// assignSecurityContext creates a security context for each container in the pod
// and validates that the sc falls within the scc constraints. All containers must validate against
// the same scc or is not considered valid.
func assignSecurityContext(provider scc.SecurityContextConstraintsProvider, pod *kapi.Pod, fldPath *field.Path) field.ErrorList {
generatedSCs := make([]*kapi.SecurityContext, len(pod.Spec.Containers))
errs := field.ErrorList{}
psc, err := provider.CreatePodSecurityContext(pod)
if err != nil {
errs = append(errs, field.Invalid(field.NewPath("spec", "securityContext"), pod.Spec.SecurityContext, err.Error()))
}
// save the original PSC and validate the generated PSC. Leave the generated PSC
// set for container generation/validation. We will reset to original post container
// validation.
originalPSC := pod.Spec.SecurityContext
pod.Spec.SecurityContext = psc
errs = append(errs, provider.ValidatePodSecurityContext(pod, field.NewPath("spec", "securityContext"))...)
// Note: this is not changing the original container, we will set container SCs later so long
// as all containers validated under the same SCC.
for i, containerCopy := range pod.Spec.Containers {
// We will determine the effective security context for the container and validate against that
// since that is how the sc provider will eventually apply settings in the runtime.
// This results in an SC that is based on the Pod's PSC with the set fields from the container
// overriding pod level settings.
containerCopy.SecurityContext = sc.DetermineEffectiveSecurityContext(pod, &containerCopy)
sc, err := provider.CreateContainerSecurityContext(pod, &containerCopy)
if err != nil {
errs = append(errs, field.Invalid(field.NewPath("spec", "containers").Index(i).Child("securityContext"), "", err.Error()))
continue
}
generatedSCs[i] = sc
containerCopy.SecurityContext = sc
errs = append(errs, provider.ValidateContainerSecurityContext(pod, &containerCopy, field.NewPath("spec", "containers").Index(i).Child("securityContext"))...)
}
if len(errs) > 0 {
// ensure psc is not mutated if there are errors
pod.Spec.SecurityContext = originalPSC
return errs
}
// if we've reached this code then we've generated and validated an SC for every container in the
// pod so let's apply what we generated. Note: the psc is already applied.
for i, sc := range generatedSCs {
pod.Spec.Containers[i].SecurityContext = sc
}
return nil
}
// resolveContainerSecurityContext checks the provided container against the provider, returning any
// validation errors encountered on the resulting security context, or the security context that was
// resolved. The SecurityContext field of the container is updated, so ensure that a copy of the original
// container is passed here if you wish to preserve the original input.
func resolveContainerSecurityContext(provider scc.SecurityContextConstraintsProvider, pod *kapi.Pod, container *kapi.Container, path *field.Path) (*kapi.SecurityContext, field.ErrorList) {
// We will determine the effective security context for the container and validate against that
// since that is how the sc provider will eventually apply settings in the runtime.
// This results in an SC that is based on the Pod's PSC with the set fields from the container
// overriding pod level settings.
container.SecurityContext = sc.DetermineEffectiveSecurityContext(pod, container)
csc, err := provider.CreateContainerSecurityContext(pod, container)
if err != nil {
return nil, field.ErrorList{field.Invalid(path.Child("securityContext"), "", err.Error())}
}
container.SecurityContext = csc
return csc, provider.ValidateContainerSecurityContext(pod, container, path.Child("securityContext"))
}
