func()

in gce-containers-startup/volumes/volumes.go [194:243]

• 41 lines of code
• 13 McCabe index (conditional complexity)

func (env Env) PrepareVolumesAndGetBindings(spec api.ContainerSpecStruct) (map[string][]HostPathBindConfiguration, error) {
	// First, build maps that will allow to verify logical consistency:
	//  - All volumes must be referenced at least once.
	//  - All volume mounts must refer an existing volume.
	volumesReferencesCount := map[string]int{}
	volumeMountWantsReadWriteMap := map[string]bool{}
	for _, apiVolume := range spec.Volumes {
		volumesReferencesCount[apiVolume.Name] = 0
		volumeMountWantsReadWriteMap[apiVolume.Name] = false
	}

	for containerIndex, container := range spec.Containers {
		log.Printf("Found %d volume mounts in container %s declaration.", len(container.VolumeMounts), container.Name)
		for _, volumeMount := range container.VolumeMounts {
			if _, present := volumesReferencesCount[volumeMount.Name]; !present {
				return nil, fmt.Errorf("Invalid container declaration: Volume %s referenced in container %s (index: %d) not found in volume definitions.", volumeMount.Name, container.Name, containerIndex)
			} else {
				volumesReferencesCount[volumeMount.Name] += 1
				volumeMountWantsReadWriteMap[volumeMount.Name] = volumeMountWantsReadWriteMap[volumeMount.Name] || !volumeMount.ReadOnly
			}
		}
	}
	for volumeName, referenceCount := range volumesReferencesCount {
		if referenceCount == 0 {
			return nil, fmt.Errorf("Invalid container declaration: Volume %s not referenced by any container.", volumeName)
		}
	}

	volumeNameToHostPathMap, volumeNameMapBuildingError := env.buildVolumeNameToHostPathMap(spec.Volumes, volumeMountWantsReadWriteMap)
	if volumeNameMapBuildingError != nil {
		return nil, volumeNameMapBuildingError
	}

	containerBindingConfigurationMap := map[string][]HostPathBindConfiguration{}
	for _, container := range spec.Containers {
		var hostPathBinds []HostPathBindConfiguration
		for _, volumeMount := range container.VolumeMounts {
			// It has already been checked that the volume is present.
			volumeHostPathAndMode, _ := volumeNameToHostPathMap[volumeMount.Name]

			if volumeHostPathAndMode.readOnly && !volumeMount.ReadOnly {
				return nil, fmt.Errorf("Container %s: volumeMount %s specifies read-write access, but underlying volume is read-only.", container.Name, volumeMount.Name)
			}
			hostPathBinds = append(hostPathBinds, HostPathBindConfiguration{HostPath: volumeHostPathAndMode.hostPath, ContainerPath: volumeMount.MountPath, ReadOnly: volumeMount.ReadOnly})
		}
		containerBindingConfigurationMap[container.Name] = hostPathBinds
	}

	return containerBindingConfigurationMap, nil
}