githubmirror/ignition

NEWS
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Benjamin Gilbert
news: add notes for 2.8.1
02 дек 2020, 22:19
02 дек 2020, 22:191b3dd36
02-Dec-2020 Ignition 2.8.1

  Bug Fixes:

    - Correctly merge config fields behind a struct pointer (e.g. clevis)

25-Nov-2020 Ignition 2.8.0

  Features:

    - Support unmasking systemd units

  Changes:

    - Switch system base config from single file to .d directory
    - Add Go merge API that produces a transcript of merge operations

13-Oct-2020 Ignition 2.7.0

  Features:

    - Support resizing existing partitions (3.2.0)
    - Support reusing LUKS devices not bound to Clevis (3.2.0)

  Changes:

    - Mark the 3.2.0 config spec as stable
    - No longer accept configs with version 3.2.0-experimental
    - Create new 3.3.0-experimental config spec from 3.2.0
    - Require presence of a config source on CloudStack/OpenStack, and
      wait indefinitely for it to appear
    - When executing in non-default AWS partitions (GovCloud or AWS
      China), fetch s3:// resources from the same partition

  Bug Fixes:

    - Fix bundled library unconditionally blocking for entropy at
      startup
    - Fix config fetching on AzureStack
    - Fix partition offset/length calculation on big-endian systems
    - Fix premature logging of successful config fetch

07-Aug-2020 Ignition 2.6.0

  Features:

    - Add "release" tag to ignition-validate container for latest release
    - Support creating ephemeral LUKS volumes (3.2.0-exp)
    - Support deleting users/groups (3.2.0-exp)

  Bug Fixes:

    - Request network when needed on CloudStack/OpenStack

23-Jul-2020 Ignition 2.5.0

  Changes:

    - Merge ignition-dracut into the Ignition repository

  Bug Fixes:

    - Fix udev race determining filesystem type when creating filesystem

16-Jul-2020 Ignition 2.4.1

  Changes:

    - Set LUKS key file directory to mode 700

  Bug Fixes:

    - Fix nondeterministic config provider precedence causing fetch failures
    - Don't relabel symlink to home directory, since it might not be writable
    - Fix failure looking up users/groups

13-Jul-2020 Ignition 2.4.0

  Features:

    - Support creating LUKS volumes with Clevis or static key file (3.2.0-exp)
    - Support Google Cloud Storage (gs://) resource URLs
    - Support AWS IMDSv2
    - Allow specifying multiple CA certificates in one resource
    - Add Azure Stack platform
    - Allow OS to avoid starting network if the config doesn't need it

  Changes:

    - When creating a filesystem, run wipefs on target device first
    - Warn if filesystem probe finds multiple filesystem signatures
    - Don't warn about unset file/directory mode in config
    - Fetch AWS metadata version 2019-10-01 instead of 2009-04-04
    - Refactor SELinux relabeling

  Bug Fixes:

    - Fix compressed CA certificates
    - Fix hard links to files deeper than the hard link
    - Write empty systemd dropin if requested
    - Remember to relabel /etc/systemd/system-preset
    - Ensure configs are only fetched during fetch stage
    - Clarify docs about interaction between file contents and overwrite

05-May-2020 Ignition 2.3.0

  Features:

    - Allow specifying HTTP headers when fetching remote resources (3.1.0)
    - Support compression for CA certs and merged/replaced configs (3.1.0)
    - Support sha256 verification hashes (3.1.0)
    - Support compression for data URIs
    - Log structured journal entry when user config is found
    - Log structured journal entry when SSH keys are written

  Changes:

    - Unify CaReference, ConfigReference, FileContents structs into
      Resource (3.1.0)
    - Mark the 3.1.0 config spec as stable
    - No longer accept configs with version 3.1.0-experimental
    - Create new 3.2.0-experimental config spec from 3.1.0

  Bug Fixes:

    - Fix ignition-validate for config versions other than 3.0.0
    - Fix config fetch and status reporting on Packet

24-Mar-2020 Ignition 2.2.1

  Bug Fixes:

    - Fix build failure on arches other than amd64, arm64, ppc64le, or s390x

23-Mar-2020 Ignition 2.2.0

  Features:

    - Add Exoscale and Vultr providers
    - On QEMU/s390x and QEMU/ppc64le, fetch Ignition config from a virtio
      block device (experimental)

  Changes:

    - Don't relabel /root and /home

  Bug Fixes:

    - Fix enabling systemd instantiated services
    - Fail if SSH keys cannot be written
    - Fix partition creation on s390x

13-Dec-2019 Ignition 2.1.1

  Bug Fixes:

    - Fix panics when processes Ignition starts fail

  Features:

    - An ignition-validate container is now built and can be used instead of
      the ignition-validate binaries

12-Dec-2019 Ignition 2.1.0

  Bug Fixes:

    - Do not panic when filesystem paths are unspecified
    - Specify the correct config version HTTP Accept headers when fetching
      configs
    - Write the config cache file atomically
    - Relabel symlinks for masking systemd units
    - Fix bug where empty GPT labels were treated as errors
    - Do not generate warnings if mode is unset for files with only an append
      section
    - Validate HTTP(S) proxy urls in spec 3.1.0-experimental

  Features:

    - Ignition now logs the name of the stage it is running
    - Ignition now relabels files directly instead of writing systemd units to
      do so. Requires Linux 5.4.0+ or a patch. See operator notes for more
      details
    - Add optional "fetch" stage to cache the rendered config, but not apply
      any of it
    - Add support for aliyun cloud
    - Add support for zVM hypervisor
    - Add support for specifying mount options for filesystems in spec
      3.1.0-experimental

  Dependency Changes:

    - Ignition no longer needs the chroot or id binaries in the initramfs

24-Jul-2019 Ignition 2.0.1

  Bug Fixes:

    - Fix getting AWS region when networking is slow to come up
    - Validate file/directory paths correctly

03-Jun-2019 Ignition 2.0.0

  Bug Fixes:

    - Use /run/ignition/dev_aliases instead of /dev_aliases when creating our
      own symlinks to devices in /dev

  Test Changes:

    - Rename tests to use dots.with.lowercase

  Public Go API Changes:

    - Replace config/validate api with github.com/coreos/vcontext
    - Validate() functions in config/* now follow the vcontext validation
      interface

26-Apr-2019 Ignition 2.0.0-beta

  Features:
    - Add configuration spec 3.1.0-experimental
    - Allow specifying HTTP(S) proxies in spec 3.1.0-experimental
    - Validate hard links do not link to directories
    - Validate paths do not include links specified in the config

  Bug Fixes:
    - Include major version in go.mod correctly
    - Fix SELinux relabeling of systemd unit files
    - Update documentation for spec 3.0.0+

  Changes:
    - Remove all deprecated fields in configuration specs
    - Remove `ec2` platform id in favor of `aws`
    - Remove `pxe` platform as it is not a platform
    - Fail if files, links, and directories conflict after symlink resolution
    - Do not fail when writing directories or links if overwrite is false and a
      matching directory or link already exists

25-Mar-2019 Ignition 2.0.0-alpha

  NOTE: This is an alpha release. While the spec is marked as stable (i.e no
    "-experimental" suffix) we still reserve the right to change it until the
    stable 2.0.0 release. However, we do not anticipate any backwards
    incompatible changes aside from removing deprecated fields.

  NOTE: In order to allow types from both the 2.x.y and 3.0.0 specs to be
    vendored and imported in the same project, we are skipping version 1.0.0.
    Go mod (and some other tools) treat v0.x and v1.x as the same when
    importing packages with semantic import versioning.

  Features:

    - Ignition now understands config specification 3.0.0
    - Configs are now merged instead of appended

  Changes:

    - Configs with version < 3.0.0 are now rejected
    - Duplicate entries are now disallowed in lists
    - Removal of almost all deprecated fields

14-Dec-2018 IGNITION v0.30.0

  Features:

    - Parallelize filesystem creation

  Changes:

    - Increase default config fetch timeout to 2 minutes

  Test Changes:

    - Add -list option to list blackbox tests
    - Skip backward compatibility tests with -test.short

06-Dec-2018 IGNITION v0.29.1

  Bug Fixes:

    - When writing files, directories, or links, do not follow symlinks if they
      are the last path element

30-Nov-2018 IGNITION v0.29.0

  Features:

    - Add support for ?versionId on s3:// URLs

  Changes:

    - Mark the 2.3.0 config spec as stable
    - No longer accept configs with version 2.3.0-experimental
    - Create new 2.4.0-experimental config spec from 2.3.0

  Bug Fixes:

    - Don't allow HTTPS connections to block on system entropy pool
    - Relabel /var/home and /var/roothome when SELinux is enabled
    - Fix race where files were relabeled after systemd-sysctl.service
    - Do not run udevadm settle after the disks stage if the disks stage did
      nothing
    - Allow writing relative symlinks
    - Resolve absolute symlinks relative to specified filesystem instead of the
      initramfs root
    - Report status to Packet as "running" instead of "succeeded"

  Test Changes:

    - Fix race with umount when running blackbox tests

22-Aug-2018 IGNITION v0.28.0

  Features:

    - Refactor blackbox tests to allow testing disks with 4k sectors

  Bug Fixes:

    - Correctly detect disks with 4k sectors when scanning existing partitions
    - Fix race between HTTP backoff tests
    - Set the minimum config versions in tests to the actual minimum required
    - Relabel /root when SELinux relabeling is enabled

09-Aug-2018 IGNITION v0.27.0

  Features:

    - Ignition is now built as a Position Independent Executable (PIE)
    - Blackbox tests now run against all spec versions (within the same major
      version) greater than their minimum version
    - Ignition now reports its status when running on Packet
    - Add a compile-time flag to enable SELinux file relabeling after boot

  Bug Fixes:

    - Directories specified in both base and appended configs are always
      created with the permissions specified in the appended config
    - Call `chdir()` after `chroot()` to silence static checkers

11-June-2018 IGNITION v0.26.0

  Features:

    - Support partition matching, specifying that a partition should not 
      exist, and recreating existing partitions
    - Fail blackbox tests when Ignition encounters critical-level logs

  Bug Fixes:

    - Fix an issue in timeout logic causing http(s) requests to sometimes fail
    - Do not log non-critical errors with CRITICAL log level

22-May-2018 IGNITION v0.25.1

  Bug Fixes:

    - Fix an issue in timeout logic causing http(s) requests to sometimes fail

22-May-2018 IGNITION v0.24.1

  Bug Fixes:

    - Fix an issue in timeout logic causing http(s) requests to sometimes fail

17-May-2018 IGNITION v0.25.0

  Features:

     - Blackbox tests can now be run in parallel

  Changes:

     - Remove Oracle Cloud Infrastructure support

  Bug Fixes:

     - No longer leave a stray file when appending to an existing file
     - Fix multiple blackbox test validation errors
     - Fix v1 config parsing to return ErrUnknownVersion if version is
       unrecognized

06-Mar-2018 IGNITION v0.24.0

  Features

    - Warn when adding and enabling a systemd unit and there is no "Install"
      section in the unit contents
    - Add highlights to reports generated by "Validate" functions on config
      structs

  Changes

    - Move a helper validation function to the "config/validate" package
    - Move unit validation helpers to "config/shared/validations"
    - Add common error types to "config/shared/errors", refactor "config/v*" to
      use these errors

12-Mar-2018 IGNITION v0.23.0

  Changes

    - Latest experimental package has been moved from config/types to
      config/v2_3_experimental.
    - Each config package's Parse function will now transparently handle any
      configs of a lesser version than itself (e.g. config/v2_2 will handle a
      2.0.0 config).
    - Validation in config/v1 reworked to use config/validate.
    - Common error types from the config package moved to config/errors.

09-Feb-2018 IGNITION v0.22.0

  Changes

    - Mark the 2.2.0 config spec as stable
    - No longer accept configs with version 2.2.0-experimental
    - Create new 2.3.0-experimental config spec from 2.2.0

26-Jan-2018 IGNITION v0.21.0

  Features

    - Add support for networkd drop-ins
    - Add new program, ignition-validate, for validating Ignition configs
    - Add "overwrite" field to "files", "directories", and "links" sections for
      deleting preexisting items at the node's path
    - Add "options" field to "raid" section for specifying arbitrary mdadm
      options
    - Add "append" field to "files" section for appending to preexisting files
    - Add support for specifying additional certificate authorities to use when
      fetching objects over HTTPS

  Changes

    - Validate that partition labels don't contain colons, as sgdisk will
      silently truncate the label
    - Remove "-validate" flag from Ignition that was introduced in v0.20.0
    - Warn when the mode for a file or directory is unset
    - Log retries of HTTP fetches at info loglevel so messages appear on console

  Bug Fixes

    - Fix issue where unspecified fields in an appended config could "unset"
      fields specified in a config earlier in the chain
    - Use timeouts specified in a config when fetching other configs referenced
      by it

12-Jan-2018 IGNITION v0.20.1

  Changes

    - Add support for fetching S3 objects from non-default AWS partitions when
      running in one such partition

13-Dec-2017 IGNITION v0.20.0

  Features

    - Add validate flag for validating Ignition configs without running any
      stages
    - Add support for reading user configs from initramfs

  Changes

    - Move update-ssh-keys from dependency into internal library
    - Move constants such as paths for invoked binaries into dedicated package
      to allow for easy overriding at link time
    - Read base and default configs from initramfs instead of hardcoding them
    - Use the golang DNS resolver instead of the default glibc DNS resolver

22-Sep-2017 IGNITION v0.19.0

  Features

    - Add support for CloudStack network metadata
    - Add blackbox tests for TFTP URLs
    - Remove dependency on kpartx for blackbox tests

  Changes

    - Stop adding extra quotes around GECOS field when creating users

  Bug Fixes

    - Fix regression in validation logic causing inaccurate line and column
      reporting
    - Fix regression in validation logic where JSON syntax errors were not
      reported correctly
    - Add warning if a non-existent filesystem is specified when creating links
      and directories
    - Fix udev race causing systemd units depending on the Ignition disks stage and 
      a device unit to fail when no filesystems are created
    - Fix udev race where symlinks are deleted before Ignition can create its own
      copy

08-Sep-2017 IGNITION v0.18.0

  Features

    - On VMWare allow guest variables to override values specified in the OVF
      environment
    - Add partial support for CloudStack
    - Add blackbox tests
    - Add support for Oracle OCI provider

  Changes

    - Chmod pre-existing directories to match defined permissions in config
    - Chown pre-existing links to match defined owner in config
    - Add "--homehost any" arguments to mdadm raid creation to ensure consistent
      device name under /dev/md
    - On GCE, don't bind-mount docker binary into Google Cloud SDK container
    - On GCE, remove gcutil alias

  Bug Fixes

    - Properly error out when a user or group set by name in the config cannot
      be resolved to an id
    - Fix typo in gcloud alias preventing connection to the docker daemon in
      some cases
    - Fix partition number validation where multiple partitions on a disk were
      unable to specify 0 for the next available partition number

28-Jul-2017 IGNITION v0.17.2

  Bug Fixes

    - Fix failure to create files/directories/links on correct filesystem
    - Fix failure to force filesystem creation when legacy force flag was set
    - Prevent VFAT filesystem creation from unconditionally overwriting existing
      filesystem
    - Fix deprecation warning on enable field in OEM systemd units
    - Fix failure where hard link targets would be on incorrect filesystem,
      causing creation to fail
    - Fix incorrect filesystem UUID check when deciding whether to reuse
      existing filesystem, causing Ignition to fail

05-Jul-2017 IGNITION v0.17.1

  Bug Fixes

    - Fix failure when user data was not provided on EC2 and GCE
    - Fix failure to fetch user data on packet.net

30-Jun-2017 IGNITION v0.17.0

  Features

    - Add support for S3 fetching and IAM role credential use in EC2
    - Add enabled flag to services to allow disabling services
    - Add new vagrant-virtualbox oem

  Changes

    - Mark 2.1.0 as stable
    - No longer accept 2.1.0-experimental configs
    - Create new 2.2.0-experimental spec from 2.1.0

  Bug Fixes

    - Mask user-configdrive.service and user-configvirtfs.service on brightbox
      and openstack to prevent cloudinit from running a second time
    - Use value given in root flag everywhere, instead of hard coding /sysroot

16-Jun-2017 IGNITION v0.16.0

  Experimental (2.1.0-experimental)

    - Fix TFTP URL validation
    - Fix nil pointer dereference when uid or gid for a file is unspecified
    - Add support for VFAT filesystem creation
    - Fix raid device validation

  Changes

    - Validate length of filesystem labels
    - Remove all OEM etcd v0 drop-in units
    - Remove xendom0 OEM

  Features

    - Add support for VMware's OVF environment
    - Add support for VirtualBox OEM

23-May-2017 IGNITION v0.15.0

  Experimental (2.1.0-experimental)

    - Define the Ignition Config schema in a JSON Schema file. Generate golang
      structs from this file
    - Add partition GUID to the filesystem object, create or modify the
      partition as appropriate
    - Add support for swap filesystems
    - Add support for links, both symbolic and hard
    - Deprecate the user level create object, add relevant fields directly to
      the user object
    - Add support for referencing users and groups by name when creating files,
      directories, and links
    - Deprecate the filesystem level create object, add relevant fields directly
      to the filesystem object
    - Add support for reusing existing filesystems, toggled via the new
      `wipeFilesystem` field in the filesystem object
    - Add filesystem UUID and label to the filesystem object
    - Correctly handle timeouts, instead of ignoring timeout settings in the
      Ignition config

  Bug Fixes

    - Fix file path validation on Windows
    - On Brightbox correctly fetch the config, instead of failing with a noop
    - Fix a race with udev events which could cause filesystem creation to fail

  Changes

    - Modify existing users, instead of attempting to create them

  Features

    - Support for TFTP URLs

13-Mar-2017 IGNITION v0.14.0

  Changes

    - Update the services for the Azure OEM
    - Update the services for the BrightBox OEM
    - Update the services for the EC2 OEM
    - Update the services for the OpenStack OEM
    - Update the services for the Packet OEM
    - Update the services for the VMware OEM

01-Mar-2017 IGNITION v0.13.0

  Bug Fixes

    - Read from both the config-drive and metadata service when using the
      OpenStack provider
    - Properly reports errors encountered while creating files
    - Fix GCE gcloud alias to properly invoke the container

  Features

    - Add support for experimental features via a newer config spec
    - Allow file provider's config path to be overridden
    - Perform basic syntactic validation on the contents of systemd units

  Experimental (2.1.0-experimental)

    - Add ability to explicitly create directories
    - Add configuration for HTTP-related timeouts

14-Dec-2016 IGNITION v0.12.1

  Bug Fixes

    - Enable coreos-metadata-sshkeys on Packet
    - Assert validity of data URLs during config validation

29-Nov-2016 IGNITION v0.12.0

  Features

    - Allow kernel command-line parameter to override OEM config

07-Oct-2016 IGNITION v0.11.2

  Bug Fixes

    - Correctly set the partition typecode

  Changes

    - Update the services for the GCE OEM

20-Sep-2016 IGNITION v0.11.1

  Bug Fixes

    - Fix potential deadlock when waiting for multiple disks

07-Sep-2016 IGNITION v0.11.0

  Features

    - Add support for DigitalOcean
    - Add experimental support for OpenStack

26-Aug-2016 IGNITION v0.10.1

  Bug Fixes

    - Fix handling of oem:// URLs
    - Use stable symlinks when operating on devices
    - Retry failed requests when fetching Packet userdata
    - Log the raw configurations instead of the parsed result

23-Aug-2016 IGNITION v0.10.0

  Features

    - Add support for QEMU Firmware Configuration Device

15-Aug-2016 IGNITION v0.9.2

  Bug Fixes

    - Do not retry HTTP requests that result in non-5xx status codes

11-Aug-2016 IGNITION v0.9.1

  Bug Fixes

    - Properly validate data URLs

11-Aug-2016 IGNITION v0.9.0

  Features

    - Add detailed configuration validation

  Bug Fixes

    - Add retry to all HTTP requests
    - Fix potential panic when parsing certain URLs

26-Jul-2016 IGNITION v0.8.0

  Features

    - Add support for Packet

13-Jul-2016 IGNITION v0.7.1

  Bug Fixes

    - Interpret files without a URL to be empty instead of invalid
    - HTTP fetches time out while waiting for response header instead of body
    - Stream remote assets to disk instead of loading them into memory

  Changes

    - Improve configuration validation

15-Jun-2016 IGNITION v0.7.0

  Features

    - Allow HTTPS URLs

  Bug Fixes

    - Don't overwrite existing data when formatting ext4 unless force is set
    - Ensure service unit in /etc doesn't exist before masking
    - Capture and log stdout of subprocesses

  Changes

    - Drop YAML tags from the config package

18-May-2016 IGNITION v0.6.0

  Features

    - All URL schemes (currently http, oem, and data) are now supported
      everywhere a URL can be provided
    - Add base OEM and default user configurations for GCE

04-May-2016 IGNITION v0.5.0

  Features

    - Add support for GCE

  Bug Fixes

    - Write files after users and home directories are created

  Changes

    - Strip support for EC2 SSH keys (these are handled by coreos-metadata now)
    - Add OEM-specific base configs and execute even if user config is empty

05-Apr-2016 IGNITION v0.4.0

  Features

    - Update the config spec to v2.0.0 (see the migration guide for more info)
      - v1 configs will be automatically translated to v2.0.0
    - Add HTTP "User-Agent" and "Accept" headers to all requests

  Changes

    - Use Go's vendor directory for all dependencies
    - Split source into a public "config" package and "internal"

25-Mar-2016 IGNITION v0.3.3

  Bug Fixes

    - Fix compilation errors when building for ARM
    - Properly fetch configs from EC2

17-Mar-2016 IGNITION v0.3.2

  Bug Fixes

    - Properly decode VMware guest variables before parsing config

  Changes

    - Move config structures from config package to config/types

02-Mar-2016 IGNITION v0.3.1

  Bug Fixes

    - Allow building on non-AMD64 architectures

  Changes

    - Major refactoring of the internal processing of OEMs and providers

24-Feb-2016 IGNITION v0.3.0

  Features

    - Add support for VMware

13-Jan-2016 IGNITION v0.2.6

  Features

    - Improve validation of storage.filesystems options

  Bug Fixes

    - Properly zap GPT tables when they are partially valid

06-Jan-2016 IGNITION v0.2.5

  Bug Fixes

    - Recognize and ignore gzipped cloud-configs

19-Nov-2015 IGNITION v0.2.4

  Bug Fixes

    - Correctly escape device unit names

17-Nov-2015 IGNITION v0.2.3

  Features

    - Provide logging to pinpoint JSON errors in invalid configs

  Bug Fixes

    - Ensure that /mnt/oem exists before mounting
    - Remove /sysroot/ prefix from alternate config path

20-Oct-2015 IGNITION v0.2.2

  Bug Fixes

    - Mount the oem partition for oem:// schemes when needed

15-Oct-2015 IGNITION v0.2.1

  Bug Fixes

    - Allow empty CustomData on Azure

29-Sep-2015 IGNITION v0.2.0

  Features

    - Added support for Azure
    - Added support for formatting partitions as xfs

  Bug Fixes

    - Removed online timeout for EC2

09-Sep-2015 IGNITION v0.1.6

  Features

    - --fetchtimeout becomes --online-timeout
    - --online-timeout of 0 now represents infinity
    - Added recognition of "interoute" OEM

  Documentation

    - Examples have been removed and supported platforms added
    - Various minor cleanups

  Bug Fixes

    - Ensure added SSH keys are newline terminated

  Build System Changes

    - Fix gofmt invocation from test script to fail when appropriate

28-Aug-2015 IGNITION v0.1.5

  Bug Fixes

    - Disable EC2 provider for now

27-Aug-2015 IGNITION v0.1.4

  Features

    - Add support for oem:// scheme config urls

  Documentation

    - Added guides
    - Updated config specification

  Bug Fixes

    - Add DefaultDependencies=false to WaitOnDevices() transient unit
    - Updated JSON configuration keys to match style

  Build System Changes

    - Added script for tagging releases

11-Aug-2015 IGNITION v0.1.3

  Features

    - Add support for ssh keys on EC2
    - Log version at runtime

  Bug Fixes

    - Log ssh keys as they are added
    - Various small cleanups

  Build System Changes

    - Derive version from git describe at build time
    - Use bash build and test scripts instead of make

22-Jul-2015 IGNITION v0.1.2

  Bug Fixes

    - Fix validation of drop-in names
    - Properly handle a lack of userdata on EC2

22-Jul-2015 IGNITION v0.1.1

  Bug Fixes

    - Ignore empty configs
    - Ignore unsupported CoreOS OEMs
    - Panic on incorrect OEM flag configurations

14-Jul-2015 IGNITION v0.1.0

  Features

    - Initial release of Ignition!
    - Support for disk partitioning, partition formatting, writing files,
      RAID, systemd units, networkd units, users, and groups.
    - Supports reading the config from a remote URL (via
      config.coreos.url) or from the Amazon EC2 metadata service.