[2.6.8] model-config prints a cryptic error message if a file was not found

[Dmitrii Shcherbakov]

ubuntu@maas:~/bundles$ juju model-config -h | grep path/to
    juju model-config ftp-proxy=10.0.0.1:8000 path/to/file.yaml
    juju model-config path/to/file.yaml

ubuntu@maas:~/bundles$ juju model-config bundles/k8s-model-config.yaml
ERROR key "bundles/k8s-model-config.yaml" not found in {<nil> ""} model.

ubuntu@maas:~/bundles$ juju model-config ~/bundles/k8s-model-config.yaml
ubuntu@maas:~/bundles$ echo $?
0

[Ian Booth (wallyworld)]

You will get this error if the supplied file doesn't exist, since in that case the arg is treated as a config key.

The arg currently must be an absolute path. I think adding support for relative paths is reasonable. Plus, if the supplied arg looks like a file path, we can do better with the error message.

[Dmitrii Shcherbakov (dmitriis)]

Right, I was in the "bundles" directory already so it was treated a key because the file did not exist.

ubuntu@maas:~$ juju model-config bundles/k8s-model-config.yaml && echo $?
0

It looks like relative paths are supported but the error message is a bit cryptic.

I'll rename the bug.

[Nam Nguyen (nammn)]

So I was looking into it. I see the following ways to fix it:
1. kind of parsing/regexing to check this a kind-of path and return earlier with an error. But how do we want to make this check? Because the input used is not actually a path, detecting it to be possibly one can be difficult, depending on the case. Possible checks: File-ending, Slash in name,

2. another way is to just change the error message
"ERROR key "bundlesk8s-dsds" not found in {<nil> ""} model." and if {<nil> ""} comes, this means neither key, nor model exists and thus just change the error message

3.?

[Richard Harding (rharding)]

My preference is that we take a more explicit approach:

Step 1: can we reverse that. e.g. "does this match one of the model-config keys?"

Step 2: and if not, "does it look like a file?"

Step 3: "if it looks like a file can I see it"

If we pass step one, then we attempt to set the config.

If we fail on step 2, then we get a "ERROR: key XXX is not a valid model-config"

And if we fail step 3, then we get "ERROR: file XXX is not found"

[Nam Nguyen (nammn)]

This is the corresponding PR: https://github.com/juju/juju/pull/10665