Require environment variables to be set

[a-h]

In C projects (and others), it's common practice to require an environment variable to be set to inject things like WIFI SSIDs.

https://gitlab.com/slimhazard/picow-http-example

$ cmake -DPICO_BOARD=pico_w -DWIFI_SSID=my_wifi -DWIFI_PASSWORD=wifi_pass \
        -DHOSTNAME=picow-sample -DPICO_MBEDTLS_PATH=${PWD}/../lib/mbedtls ..

It would be awesome if XC could require that an environment variable is set from outside, or could pick up a file that could be .gitignored to load that.

[joerdav]

This would be useful, how do you think the syntax of this could look? A new Attribute, or modify the syntax of the Environment Attribute?

[joerdav]

Required env vars

The current syntax for environment variables is:

## Tasks
### Task1
Env: ENVIRONMENT=PRODUCTION, VERSION=1.2

echo $ENVIRONMENT echo $VERSION

If we were to expand those attributes the syntax could be:

Env: ENVIRONMENT=PRODUCTION, SOME_PARAMETER

Or

Env: ENVIRONMENT=PRODUCTION, !SOME_PARAMETER

Alternatively it could be a new attribute:

Env: ENVIRONMENT=PRODUCTION, VERSION=1.2
Parameters: SOME_PARAMETER

[joerdav]

Arguments

Another concept I've previously thought about is arguments:

## Tasks
### Task1
Env: ENVIRONMENT=PRODUCTION, VERSION=1.2
Args: SOME_PARAMETER

echo $ENVIRONMENT echo $VERSION echo $SOME_PARAMETER

The following would be the behaviour:

$ xc Task1 "hello world"
PRODUCTION
1.2
hello world

And:

$ xc Task1
Missing argument SOME_PARAMETER.
Usage: xc Task1 <SOME_PARAMETER>

And you could have multiple:

## Tasks
### Task1
Env: ENVIRONMENT=PRODUCTION, VERSION=1.2
Args: SOME_PARAMETER, ANOTHER_PARAMETER

echo $ENVIRONMENT echo $VERSION echo $SOME_PARAMETER echo $ANOTHER_PARAMETER

The following would be the behaviour:

$ xc Task1 "hello world" "goodbye"
PRODUCTION
1.2
hello world
goodbye

[a-h]

I like that! That's exactly what I was thinking.

I don't think there's a need to add positional handling of args though, since you can set env variables on the fly for the process. I don't like positional args, since if you change the order, it messes things up.

This works without having to parse the extra args in the CLI:

SOME_PARAMETER="hello world" ANOTHER_PARAMETER="goodbye" xc Task1

In terms of documentation, then the Env: configuration in xc is used to set environment variables to specific values, while the Args: configuration is used to ensure that specific environment variables are present (even if they're an empty value?).

Args is probably not the most understandable name though.

[joerdav]

Yeah I'm torn between adding a new attribute, or modifying the Env: attribute:

Env: DAY=MONDAY, TIME

Could mean: DAY is set to MONDAY And TIME is required as an input.

I want it to be as human readable as possible though so maybe a new attribute called Parameter/Param

[joerdav]

Released in https://github.com/joerdav/xc/tree/v0.0.154