What is the best way to copy a file during a provision script?

[etho201]

Let's say I have a directory with my project files:

.
├── README.md
├── files
│   ├── Dockerfile
│   └── local-yum.repo
├── oraclelinux9.yaml
└── variables.yaml

In my oraclelinux9.yaml file, I have a provision section where I want to copy the files/local-yum.repo file to some other directory in the VM.

For example:

provision:
  - mode: system
    script: |
      #!/bin/bash
      mkdir -p /var/www/html/yum
      cp files/local-yum.repo /var/www/html/yum/

In addition to specifying a relative path, I tried specifying cp $LIMA_WORKDIR/files/local-yum.repo /var/www/html/yum/ but that doesn't work. I also tried adding a mount so I could predict where in the VM it will show up but that doesn't seem to be working either. What is the best way to do this?

[jandubois]

You should be able to do this with a "data" provisioning file. Something like:

provision:
- mode: data
  file: files/local-yum.repo
  path: /var/www/html/yum/local-yum.repo

This also requires Lima 1.1.0-alpha.0 or later.

[jandubois]

What about when/if I need a folder with several files (or if the file was a binary of sorts)?

Yes, data provisioning needs to specify each file individually.

Binary files will work as long as they are short. This can probably be fixed to work with long files too (#3403), but embedding long binary files in YAML (e.g. base64 encoded) will become unwieldy quickly.

❯ printf "\x00\x01" > binary.data

❯ hexdump -C binary.data
00000000  00 01                                             |..|
00000002

❯ cat tmpl.yaml
base: template://alpine
provision:
- mode: data
  file: binary.data
  path: /tmp/binary.data

❯ limactl tmpl copy --embed tmpl.yaml -
WARN[0000] `provision[*].file` and `probes[*].file` are experimental
base: template://alpine
provision:
- mode: data
  content: \x00\x01
  path: /tmp/binary.data

[etho201]

Very cool that binary files can be passed through YAML as well. Thank you.

By the way, I was able to get the mount stuff working... the problem I faced yesterday is because I was using 1.1.0-alpha.0 to start the VM, but was using 1.0.7 to connect to the shell since that is what's in my environment path.

mounts:
  - location: files/
    mountPoint: /tmp/files
    writable: true

The error was WARN[0000] instance "ksplice-offline" has errors errors="[field mounts[2].location must be an absolute path, got \"files/\"]" but I guess that's just something that isn't supported in 1.0.7.

[jandubois]

No, the mount location must always be an absolute path, even with 1.1.0.

Things that can be relative paths are base and provision[].file locators, which are resolved when the instance is created, not when it is started (like the mounts).

Note that the relative locators are resolved relative to the location of the template that references them, not relative to your current directory. Assuming your recent example template:

limactl create https://example.com/oraclelinux.yaml

In that case values.yaml will be fetched from https://example.com/values.yaml and not from ./values.yaml.

[jandubois]

I've just created #3404 to allow combination of external templates and local settings without requiring you to create yet another local base template.

[jandubois]

Binary files will work as long as they are short. This can probably be fixed to work with long files too (#3403), but embedding long binary files in YAML (e.g. base64 encoded) will become unwieldy quickly.

I've implemented embedding of binary files as multi-line base64 strings in #3421 (but has not yet been merged).