Feat/blog diskless flavors (#715)

* Start blog article on diskless flavors.
* Added a few links. Filled Why SSD flavors section.
* Rename to 2023-08-21 to reflect planned publication date.
* Picture for a diskless flavor.
* Add horizon vm instance creation screenshot.
* Add openstack SDK example
* Example script to create a diskless VM.
* openstack client usage.
* terraform, capo and k8s-capi documentation complete.
* ispell found a few typos ...
* Add TL;DR.
* Fix avatar link.
* Add missing patch.
* Add link from de to en. Two wording fixes.
* Also copy _assets/scripts directory into build.
* Lots of wording fixes from Filip. 
* Avoid the term diskful(l). Clarify flavor with disk downgrade.
  This implements two suggestions from Filip in a slightly different way.
* Another attempt to the right asset syntax.

Signed-off-by: Kurt Garloff <[email protected]>
Co-authored-by: Filip Dobrovolný <[email protected]>

_assets/scripts/create_vm.py

@@ -0,0 +1,58 @@
+#!/usr/bin/env python3
+# Create a VM on a diskless flavor
+# (c) Kurt Garloff <[email protected]>, 2023-08-20
+# SPDX-License-Identifier: Apache-2.0
+
+import openstack
+import sys
+
+# OS_CLOUD will be taken from environment
+FLAVOR="SCS-1V-2"
+NETWORK=""
+IMAGE="Debian 12"
+KEYNAME="SSHkey-gxscscapi"
+
+def main(argv):
+	"""
+	Creates a server on a diskless flavor in a cloud env["OS_CLOUD"]
+	(configured in clouds.yaml+secure.yaml) with flavor FLAVOR
+	in network NETWORK (defaults to first if empty) with image IMAGE
+	injecting keypair KEYNAME.
+	"""
+	# Connect and get token   
+	conn = openstack.connect()
+	conn.authorize()
+	# Get flavor and image IDs
+	flavor = conn.compute.find_flavor(FLAVOR)
+	if not flavor:
+		raise ValueError(f"No flavor {FLAVOR} found")
+	image = conn.compute.find_image(IMAGE)
+	if not image:
+		raise ValueError(f"No image {IMAGE} found")
+	# Determine network to connect to
+	found_network = None
+	for net in conn.network.networks():
+		if not net.is_admin_state_up or net.is_router_external:
+			continue
+		if not NETWORK or net.name == NETWORK:
+			found_network = net
+			break
+	if found_network is None:
+		raise ValueError(f"No network {NETWORK} found")
+	# Create VM instance
+	vm = conn.compute.create_server(
+		name="test-diskless",
+		networks=[{"uuid": found_network.id}],
+		flavor_id=flavor.id,
+		key_name=KEYNAME,
+		block_device_mapping_v2=[{'boot_index': 0,
+			'uuid': image.id,
+			'source_type': 'image',
+			'volume_size': 12,
+			'destination_type': 'volume',
+			'delete_on_termination': True}
+		]
+	)
+
+if __name__ == "__main__":
+	main(sys.argv)

_assets/scripts/openstackclient-diskless-boot.diff

@@ -0,0 +1,11 @@
+--- openstackclient/compute/v2/server.py.orig	2021-03-20 10:17:40.000000000 +0100
++++ openstackclient/compute/v2/server.py	2023-07-03 15:59:27.301268807 +0200
+@@ -802,7 +802,7 @@ class CreateServer(command.ShowOne):
+             help=_('Create server with this flavor (name or ID)'),
+         )
+         disk_group = parser.add_mutually_exclusive_group(
+-            required=True,
++            required=False,
+         )
+         disk_group.add_argument(
+             '--image',

_config.yml

@@ -71,6 +71,7 @@ assets:
     - _assets/vendor
     - _assets/slides
     - _assets/fonts
+    - _assets/scripts
     - _assets/css/_sass
   source_maps: false
   cache: false

_i18n/de/_posts/blog/2023-08-21-diskless-flavors.md

@@ -0,0 +1 @@
+../../../en/_posts/blog/2023-08-21-diskless-flavors.md