Method SetupEphemeralDiskWithPath

platform/linux_platform.go:655–743

(realPath string, desiredSwapSizeInBytes *uint64, labelPrefix string)

}

func (p linux) SetupEphemeralDiskWithPath(realPath string, desiredSwapSizeInBytes *uint64, labelPrefix string) error {
	p.logger.Info(logTag, "Setting up ephemeral disk...")
	mountPoint := p.dirProvider.DataDir()

	mountPointGlob := path.Join(mountPoint, "*")
	contents, err := p.fs.Glob(mountPointGlob)
	if err != nil {
		return bosherr.WrapErrorf(err, "Globbing ephemeral disk mount point `%s'", mountPointGlob)
	}

	if len(contents) > 0 {
		// When agent bootstraps for the first time data directory should be empty.
		// It might be non-empty on subsequent agent restarts. The ephemeral disk setup
		// should be idempotent and partitioning will be skipped if disk is already
		// partitioned as needed. If disk is not partitioned as needed we still want to
		// partition it even if data directory is not empty.
		p.logger.Debug(logTag, "Existing ephemeral mount `%s' is not empty. Contents: %s", mountPoint, contents)
	}

	err = p.fs.MkdirAll(mountPoint, ephemeralDiskPermissions)
	if err != nil {
		return bosherr.WrapError(err, "Creating data dir")
	}

	if p.options.SkipDiskSetup {
		return nil
	}

	var swapPartitionPath, dataPartitionPath string

	// Agent can only setup ephemeral data directory either on ephemeral device
	// or on separate root partition.
	// The real path can be empty if CPI did not provide ephemeral disk
	// or if the provided disk was not found.
	if realPath == "" {
		if !p.options.CreatePartitionIfNoEphemeralDisk {
			// Agent can not use root partition for ephemeral data directory.
			return bosherr.Error("No ephemeral disk found, cannot use root partition as ephemeral disk")
		}

		swapPartitionPath, dataPartitionPath, err = p.createEphemeralPartitionsOnRootDevice(desiredSwapSizeInBytes, labelPrefix)
		if err != nil {
			return bosherr.WrapError(err, "Creating ephemeral partitions on root device")
		}
	} else {
		swapPartitionPath, dataPartitionPath, err = p.partitionEphemeralDisk(realPath, desiredSwapSizeInBytes, labelPrefix)
		if err != nil {
			return bosherr.WrapError(err, "Partitioning ephemeral disk")
		}
	}

	if len(swapPartitionPath) > 0 {
		canonicalSwapPartitionPath, err := resolveCanonicalLink(p.cmdRunner, swapPartitionPath)
		if err != nil {
			return err
		}

		p.logger.Info(logTag, "Formatting `%s' (canonical path: %s) as swap", swapPartitionPath, canonicalSwapPartitionPath)