Merge "[AIR-136] Introduce isogen command for airshipctl"
This commit is contained in:
Zuul
Gerrit Code Review
commit
d973ea29e6
264
specs/2.x/approved/airshipctl_bootstrap_isogen.rst
Normal file
264
specs/2.x/approved/airshipctl_bootstrap_isogen.rst
Normal file
@ -0,0 +1,264 @@
|
|||||||
|
..
|
||||||
|
This work is licensed under a Creative Commons Attribution 3.0 Unported
|
||||||
|
License.
|
||||||
|
|
||||||
|
http://creativecommons.org/licenses/by/3.0/legalcode
|
||||||
|
|
||||||
|
.. index::
|
||||||
|
single: airshipctl
|
||||||
|
single: bootstrap
|
||||||
|
single: ISO
|
||||||
|
single: image
|
||||||
|
single: CLI
|
||||||
|
single: ephemeral host
|
||||||
|
|
||||||
|
====================================
|
||||||
|
Airshipctl Bootstrap Image Generator
|
||||||
|
====================================
|
||||||
|
|
||||||
|
This spec defines the new ``isogen`` sub-command for ``airshipctl bootstrap``
|
||||||
|
and describes the interface for image builder. Airship CLI tool will be extended
|
||||||
|
with an ability to generate an ISO image or image for USB stick. This image
|
||||||
|
can be used to boot up an ephemeral node with Kubernetes cluster installed.
|
||||||
|
|
||||||
|
Links
|
||||||
|
=====
|
||||||
|
|
||||||
|
Jira tasks:
|
||||||
|
|
||||||
|
- `airshipctl bootstrap isogen <https://airship.atlassian.net/browse/AIR-98>`_
|
||||||
|
- `LiveCD PoC <https://airship.atlassian.net/browse/AIR-132>`_
|
||||||
|
- `ISO builder contract spec <https://airship.atlassian.net/browse/AIR-133>`_
|
||||||
|
- `isogen subcommand spec <https://airship.atlassian.net/browse/AIR-136>`_
|
||||||
|
- `Sub command implementation <https://airship.atlassian.net/browse/AIR-137>`_
|
||||||
|
- `Cloud-init generator <https://airship.atlassian.net/browse/AIR-145>`_
|
||||||
|
|
||||||
|
Problem Description
|
||||||
|
===================
|
||||||
|
|
||||||
|
Common approach for spinning new Kubernetes cluster is Cluster API deployed
|
||||||
|
on top of a small single node cluster based on ``kind`` or ``minikube``.
|
||||||
|
In order to create Kubernetes cluster on hardware nodes in Data Center user
|
||||||
|
must deploy this single node cluster on a virtual machine attached to PXE
|
||||||
|
network or to deploy operating system and Kubernetes cluster to one of the
|
||||||
|
hardware servers.
|
||||||
|
|
||||||
|
In scope of Airship 2.0 user needs to be able to bootstrap ephemeral Kubernetes
|
||||||
|
cluster with minimal required services (e.g. Cluster API, Metal3, etc).
|
||||||
|
Ephemeral Cluster should be deployed remotely (if possible) and deployment process
|
||||||
|
needs to be fully automated.
|
||||||
|
|
||||||
|
Impacted Components
|
||||||
|
===================
|
||||||
|
|
||||||
|
- airshipctl
|
||||||
|
|
||||||
|
Proposed Change
|
||||||
|
===============
|
||||||
|
|
||||||
|
Airship 2.0 command line tool (i.e. ``airshipctl``) will be able to perform
|
||||||
|
full cycle of bootstrapping ephemeral Kubernetes node.
|
||||||
|
|
||||||
|
First bootstrap step is to generate ISO or flash drive image. Image generator
|
||||||
|
is executed inside of a container and returns LiveCD or LiveUSB image.
|
||||||
|
|
||||||
|
Image generator must implement interface defined below (see
|
||||||
|
`Image Generator Container Interface`_ section) since ``isogen``
|
||||||
|
command treats image generator container as a black box.
|
||||||
|
|
||||||
|
Airshipctl Subcommand
|
||||||
|
---------------------
|
||||||
|
|
||||||
|
``airshipctl bootstrap`` is extended with ``isogen`` subcommand.
|
||||||
|
Subcommand is extendable by adding Container Runtime Interface drivers.
|
||||||
|
|
||||||
|
Command flags:
|
||||||
|
|
||||||
|
- ``-c`` or ``--conf`` Configuration file (YAML-formatted) path for ISO
|
||||||
|
builder container. If option is omitted ``airshipctl config`` is used to
|
||||||
|
determine isogen configuration file path. This configuration file is used
|
||||||
|
to identify container execution options (e.g. CRI, volume binds etc) and
|
||||||
|
as a source of ISO builder parameters (e.g. cloud-init configuration file
|
||||||
|
name). File format described in
|
||||||
|
`Command and ISO Builder Configuration File Format`_
|
||||||
|
|
||||||
|
Command arguments:
|
||||||
|
|
||||||
|
- ``-`` can be used when rendered document model has been passed to STDIN.
|
||||||
|
|
||||||
|
Subcommand should implement following steps:
|
||||||
|
|
||||||
|
- Utilize the ``airshipctl config`` to identify the location of YAML documents
|
||||||
|
which contains site information.
|
||||||
|
|
||||||
|
- Extract information for ephemeral node from the appropriate documents,
|
||||||
|
such as IP, Name, MAC, etc.
|
||||||
|
|
||||||
|
- Generate the appropriate user-data and network-config for Cloud-Init.
|
||||||
|
|
||||||
|
- Execute container with ISO builder and put YAML-formatted builder config,
|
||||||
|
user-data and network-config to a container volume.
|
||||||
|
|
||||||
|
YAML manipulations which are required for operations described above rely on
|
||||||
|
functions and methods that have been implemented as a part of
|
||||||
|
``airshipctl document`` command.
|
||||||
|
|
||||||
|
Image Generator Container Interface
|
||||||
|
-----------------------------------
|
||||||
|
|
||||||
|
Image generator container input.
|
||||||
|
|
||||||
|
- Volume (host directory) mounted to certain directory in container. Example:
|
||||||
|
``docker run -v /source/path/on/host:/dst/path/in/container ...``
|
||||||
|
|
||||||
|
- YAML-formatted configuration file saved on the mounted volume. Described in
|
||||||
|
`Command and ISO Builder Configuration File Format`_
|
||||||
|
|
||||||
|
- Shell environment variable ``BUILDER_CONFIG`` which contains ISO builder
|
||||||
|
configuration file path (e.g. if volume is bound to ``/data`` in the
|
||||||
|
container then ``BUILDER_CONFIG=/data/isogen.yaml``).
|
||||||
|
|
||||||
|
- Cloud-init configuration file named according to ``userDataFileName``
|
||||||
|
parameter of ``builder`` section specified in ISO builder configuration file.
|
||||||
|
User data file must be placed to the root of the volume which is bound to
|
||||||
|
the container.
|
||||||
|
|
||||||
|
- Network configuration for cloud init (i.e. network-config)
|
||||||
|
named according to ``networkConfigFileName`` parameter of ``builder`` section
|
||||||
|
specified in ISO builder configuration file. Network configuration file must
|
||||||
|
be placed in the root of the volume which is bound to the container.
|
||||||
|
|
||||||
|
Image generator output.
|
||||||
|
|
||||||
|
- YAML-formatted metadata file which describes output artifacts. File name for
|
||||||
|
metadata is specified in ``builder`` section of ISO builder configuration
|
||||||
|
file (see `Command and ISO Builder Configuration File Format`_ for details).
|
||||||
|
Metadata file name is specified in ``aitshipctl`` configuration files and
|
||||||
|
handeled by ``airshipctl config`` command. Metadata must satisfy
|
||||||
|
following schema.
|
||||||
|
|
||||||
|
.. code-block:: yaml
|
||||||
|
|
||||||
|
$schema: 'http://json-schema.org/schema#'
|
||||||
|
type: 'object'
|
||||||
|
properties:
|
||||||
|
bootImagePath:
|
||||||
|
type: 'string'
|
||||||
|
description: >
|
||||||
|
Image file path on host. Host path of the volume is extracted
|
||||||
|
from ISO builder confgiration file passed by isogen command to
|
||||||
|
container volume.
|
||||||
|
|
||||||
|
- ISO or flash disk image placed according to ``bootImagePath`` parameter of
|
||||||
|
output metadata file.
|
||||||
|
|
||||||
|
Command and ISO Builder Configuration File Format
|
||||||
|
-------------------------------------------------
|
||||||
|
|
||||||
|
YAML formatted configuration file is used for both isogen command and ISO
|
||||||
|
builder container. Configuration file is copied to volume directory on the
|
||||||
|
host. ISO builder uses shell environment variable ``BUILDER_CONFIG`` to read
|
||||||
|
determine configuration file path inside container.
|
||||||
|
|
||||||
|
Configuration file format.
|
||||||
|
|
||||||
|
.. code-block:: yaml
|
||||||
|
|
||||||
|
$schema: 'http://json-schema.org/schema#'
|
||||||
|
type: 'object'
|
||||||
|
properties:
|
||||||
|
container:
|
||||||
|
type: 'object'
|
||||||
|
description: 'Configuration parameters for container'
|
||||||
|
properties:
|
||||||
|
volume:
|
||||||
|
type: 'string'
|
||||||
|
description: >
|
||||||
|
Container volume directory binding.
|
||||||
|
Example: /source/path/on/host:/dst/path/in/container
|
||||||
|
image:
|
||||||
|
type: 'string'
|
||||||
|
description: 'ISO generator container image URL'
|
||||||
|
containerRuntime:
|
||||||
|
type: 'string'
|
||||||
|
description: >
|
||||||
|
(Optional) Container Runtime Interface driver (default: docker)
|
||||||
|
privileged:
|
||||||
|
type: 'bool'
|
||||||
|
description: >
|
||||||
|
(Optional)Defines if container should be started in privileged mode
|
||||||
|
(default: false)
|
||||||
|
builder:
|
||||||
|
type: 'object'
|
||||||
|
description: 'Configuration parameters for ISO builder'
|
||||||
|
properties:
|
||||||
|
userDataFileName:
|
||||||
|
type: 'string'
|
||||||
|
description: >
|
||||||
|
Cloud Init user-data file name placed to the container volume root
|
||||||
|
networkConfigFileName:
|
||||||
|
type: 'string'
|
||||||
|
description: >
|
||||||
|
Cloud Init network-config file name placed to the container
|
||||||
|
volume root
|
||||||
|
outputMetadataFileName:
|
||||||
|
type: 'string'
|
||||||
|
description: 'File name for output matadata'
|
||||||
|
|
||||||
|
Security Impact
|
||||||
|
---------------
|
||||||
|
|
||||||
|
- Kubernetes Certificates are saved on the ISO along with other Cloud Init
|
||||||
|
configuration parameters.
|
||||||
|
- Clound-init contains sensitive information (e.g. could contain ssh keys).
|
||||||
|
|
||||||
|
Performance impact
|
||||||
|
------------------
|
||||||
|
|
||||||
|
None
|
||||||
|
|
||||||
|
Alternatives
|
||||||
|
------------
|
||||||
|
|
||||||
|
- Modify existing LiveCD ISO image using Golang library.
|
||||||
|
|
||||||
|
- Requires implementation of ISO modification module in Golang.
|
||||||
|
- Each time user generated new image ISO content has to be copied to
|
||||||
|
temporary build directory since ISO 9660 is read only file system.
|
||||||
|
- Support multiple operating systems is challenging since there is no
|
||||||
|
standard for ISO image directory structure and live booting.
|
||||||
|
|
||||||
|
Implementation
|
||||||
|
==============
|
||||||
|
|
||||||
|
- Image Generator reference implementation based on Debian container from
|
||||||
|
airship/images Git repository
|
||||||
|
|
||||||
|
- Dockerfile with all packages required to build LiveCD ISO.
|
||||||
|
- Builder script.
|
||||||
|
|
||||||
|
- ``airshipctl bootstrap`` extension with new command (i.e.
|
||||||
|
``airshipctl bootstrap isogen``)
|
||||||
|
|
||||||
|
- Define interface for running container execution which enables following
|
||||||
|
methods:
|
||||||
|
|
||||||
|
- Pull image: download container image if it's not presented locally
|
||||||
|
- Run container: start container, wait for builder script is finished,
|
||||||
|
output builder log if CLI debug flag is enabled
|
||||||
|
- Run container with output: executes run container method and prints its
|
||||||
|
STDOUT
|
||||||
|
- Remove container: removes container if command execution successful.
|
||||||
|
|
||||||
|
- Implement interface for docker Container Runtime Environment
|
||||||
|
|
||||||
|
Dependencies
|
||||||
|
============
|
||||||
|
|
||||||
|
- New version of hardware nodes definition format in Treasuremap since
|
||||||
|
Metal3-IO will replace MAAS for Airship 2.0
|
||||||
|
|
||||||
|
References
|
||||||
|
==========
|
||||||
|
|
||||||
|
None
|
||||||
@ -1,18 +0,0 @@
|
|||||||
..
|
|
||||||
This work is licensed under a Creative Commons Attribution 3.0 Unported
|
|
||||||
License.
|
|
||||||
|
|
||||||
http://creativecommons.org/licenses/by/3.0/legalcode
|
|
||||||
|
|
||||||
.. index::
|
|
||||||
single: Airship
|
|
||||||
single: Shipyard
|
|
||||||
single: GUI
|
|
||||||
single: CLI
|
|
||||||
single: API
|
|
||||||
|
|
||||||
===========
|
|
||||||
Placeholder
|
|
||||||
===========
|
|
||||||
|
|
||||||
Please, remove me once any new spec is added into this directory.
|
|
||||||
Loading…
Reference in New Issue
Block a user