details at: https://istio.io/docs/reference/config/networking/proxy-config.html'
            properties:
              concurrency:
                description: The number of worker threads to run.
                format: int32
                nullable: true
                type: integer
              environmentVariables:
                additionalProperties:
                  type: string

  // cachingMode is the Host Caching mode: None, Read Only, Read Write.
  // +optional
  optional string cachingMode = 3;

  // fsType is Filesystem type to mount.
  // Must be a filesystem type supported by the host operating system.
  // Ex. "ext4", "xfs", "ntfs". Implicitly inferred to be "ext4" if unspecified.
  // +optional
  optional string fsType = 4;

  // readOnly Defaults to false (read/write). ReadOnly here will force