tftp assets from disk + pxelinux.cfg from Hardware

[rpardini]

tftp assets from disk + pxelinux.cfg from Hardware

• tftp: hardware +PXELinux, TFTP getting a Backend
• smee: tftp: introduce tftp-asset-dir flag (string)
  • if non-empty, should be path (in-pod) from where non-embedded assets can be served out by Smee's TFTP
  • flag: tftp-asset-dir
  • env: TINKERBELL_TFTP_ASSET_DIR
  • helm: deployment.envs.smee.tftpAssetDir
• smee: tftp: actually serve files from AssetDir if found
• helm/tinkerbell: bump tftpBlockSize from 512 to 8192
  • vmlinuz and initrd's are much larger than ipxe
• smee: tftp: stream directly from disk for assets from assetDir
• smee: tftp: log actual params (blockSize/sizePort/timeout) when starting tftp
• smee: tftp: EnableTFTPSinglePort: true -> false
• smee: tftp: introduce tftp-single-port flag (bool, default true)
  • helm: deployment.envs.smee.tftpSinglePort (default true)
  • env: TINKERBELL_TFTP_SINGLE_PORT
• smee: tftp: serve pxelinux.cfg from Hardware, by MAC or IP

[codecov[bot]]

Codecov Report

:x: Patch coverage is 1.05263% with 94 lines in your changes missing coverage. Please review. :white_check_mark: Project coverage is 52.24%. Comparing base (844148a) to head (eb1e9e2).

Files with missing lines	Patch %	Lines
smee/internal/ipxe/binary/tftp.go	0.00%	87 Missing :warning:
smee/smee.go	0.00%	3 Missing :warning:
pkg/backend/kube/smee.go	33.33%	1 Missing and 1 partial :warning:
smee/internal/ipxe/script/ipxe.go	0.00%	2 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #444      +/-   ##
==========================================
- Coverage   52.83%   52.24%   -0.59%     
==========================================
  Files         107      107              
  Lines        7203     7290      +87     
==========================================
+ Hits         3806     3809       +3     
- Misses       3111     3195      +84     
  Partials      286      286              

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[rpardini]

Reworked after I split the tftp-single-port flag to a separate PR.

This is not ready yet:

1. Commit xx has a TODO for the RPi EEPROM netboot stuff (with a serial# prefix) which I'd like to make more generic, and would need input as how to model it in Hardware object.
2. This is generally just adding a lot of conditionals while trying to appease cyclops et al, while proper "route" support for TFTP would probably be best.