Downloading from tftp:// uses HEAD query

[borgand]

I'm trying to get Vagrant to automatically fetch my boxfile from build server using TFTP protocol.

  config.vm.box_url = "tftp://tftp.host:/devbox.box"

This results in Vagrant using HEAD query at first which downloads the entire boxfile to STDOUT, before starting actual download.

Trying it directly with embedded curl works as expected:

/opt/vagrant/embedded/bin/curl --output /tmp/box tftp://tftp.host/devbox.box

But when using the same URL in Vagrantfile, it does not. DEBUG output shows this:

INFO box_add: Downloading box: tftp://tftp.host/devbox.box => /home/laas/.vagrant.d/tmp/box2f41853e07736bc3f7ba8f307ab44f0f11e9ae47
INFO downloader: HEAD: tftp://tftp.host/devbox.box
INFO subprocess: Starting process: ["/opt/vagrant/bin/../embedded/bin/curl", "-I", "-q", "--fail", "--location", "--max-redirs", "10", "--user-agent", "Vagrant/1.7.2", "--continue-at", "-", "-H", "Accept: application/json", "tftp://tftp.host/devbox.box"]

And after that curl starts to output binary data.

When not in DEBUG-mode, I can Ctrl-C while it's waiting for the HEAD to complete and then a regular download continues and successfully adds box (then exits due to interrupt). A next vagrant up will then successfully create a VM.

Other than the HEAD query, tftp:// protocol seems to work just fine, so could you please see why it issues this HEAD query.

[sethvargo]

Hi @borgand

Vagrant needs to uses a HEAD request to check for the existence of a box before attempting to download.

[borgand]

Could you just skip HEAD in case of tftp:// protocol as TFTP can only read and write files and nothing more. If file does not exist, curl would error out as it would if the transfer got interrupted.

[borgand]

Off topic, but I wouldn't look at TFTP, if I could get scp:// URL working, but for some reason the embedded curl refuses to read host keys from ~/.ssh/known_hosts (both under Arch Linux and a different Ubuntu host). Should this be working?