OpenStack Ironic — Images, Config-drive, Inspection Data

OpenStack Ironic — Images, Config-drive, Inspection Data A data-flow diagram generated by Archify. 01 / Artifact sources 02 / Image service 03 / On the conductor 04 / Delivered to the node 05 / Back into Ironic Glance + Swift · image UUID · 01 / Artifact sources · temp URL Glance + Swift image UUID temp URL Plain HTTP(S) · any web server · 01 / Artifact sources · file:// and NFS too Plain HTTP(S) any web server file:// and NFS too OCI registry · oci:// reference · 01 / Artifact sources OCI registry oci:// reference Image service · scheme picks driver · 02 / Image service Image service scheme picks driver Checksum check · sha256 or md5 · 03 / On the conductor · blocking Checksum check sha256 or md5 blocking Image cache · master_images · 03 / On the conductor · hard-linked Image cache master_images hard-linked Config-drive · from instance_info · 03 / On the conductor Config-drive from instance_info TFTP / HTTP root · per node UUID · 04 / Delivered to the node TFTP / HTTP root per node UUID Node + IPA · writes the disk · 04 / Delivered to the node Node + IPA writes the disk nodes row · properties, inventory · 05 / Back into Ironic nodes row properties, inventory ports rows · MAC, link, PXE flag · 05 / Back into Ironic ports rows MAC, link, PXE flag Ramdisk logs · local dir or Swift · 05 / Back into Ironic Ramdisk logs local dir or Swift image UUID + temp URL image_source qcow2 + checksum image_source manifest + digest image_source downloaded bytes verified qcow2 kernel + ramdisk root disk image config-drive ISO iPXE script + ramdisk inspection payload inventory discovered NICs + LLDP inventory ramdisk logs on failure Legend primary data policy / PII async batch data store data flow

Walkthrough 1/2 — fetching the image

  • • 1. You set image_source on the node
  • • 2. The conductor reads the URL scheme to pick a driver
  • • 3. It downloads the image to its own disk, not the node's
  • • 4. It checks the file against the checksum you gave

Walkthrough 2/2 — onto the disk

  • • 5. The verified file is hard-linked into the cache
  • • 6. Kernel and ramdisk are served per node over HTTP
  • • 7. The node PXE-boots the IPA ramdisk
  • • 8. IPA fetches the image and writes it to local disk

What to remember

  • • The URL scheme picks the driver: glance, http(s), oci, file
  • • Inspection sends back an inventory and creates port rows