Add "Authentication from environment"

[alekseytomin]

I have to use the private nexus repository in gitlab-ci.
We use only authenticated access to it. But I mustn't write a password in scripts.

PS: I've chosen '@' as a symbol ('$' isn't possible in Kotlin). Maybe You will choose another one.

PPS: I have not found any other point to use environment variables.

[holgerbrandl]

Great suggestion. I would also never include credentials in scripts.

Indeed @ feels a bit odd. Maybe {{MY_PW}} could feel a bit more templaty?

I think before we should merge it, the fallback behaviour when a variable is not defined should be changed to make kscript stop script execution. Tis may clash with the rare cases that a pw is actually starting with {{ and ends with }}, but it seems preferable to be than using wrong credentials, just because the user forgot to export the variables in bash before invoking kscript.. What do you think?

[alekseytomin]

Great suggestion. I would also never include credentials in scripts.

Indeed @ feels a bit odd. Maybe {{MY_PW}} could feel a bit more templaty?

Ok. I've forgotten this.

I think before we should merge it, the fallback behaviour when a variable is not defined should be changed to make kscript stop script execution.

System.getenv() in Kotlin is a nonnull function.
Without any changes we have an exception:

Exception in thread "main" java.lang.IllegalStateException: System.getenv(value.subs…ing(2, value.length - 2)) must not be null
	at kscript.app.DependencyUtilKt.decodeEnv(DependencyUtil.kt:72)
...

I think better to write something like

Exception in thread "main" java.lang.RuntimeException: environment variable 'HEXUS_USER' doesn't found
	at kscript.app.DependencyUtilKt.decodeEnv(DependencyUtil.kt:76)
...

Or maybe hide the stacktrace?

[holgerbrandl]

3 minor aspects (which I typically would just do myself, but I'm a bit in a hurry this week)

1. In the docs the example pw artifactory_password should be uppercase ARTIFACTORY_PASSWORD since bash variables are typically uppercase
2. I like the more custom error. But the wording seems slightly wrong. Couldn't we just say

"Could not resolve environment variable {{bla}} in maven repository credentials"

3. Instead of rethrowing the exception, we should better exit with

errorMsg(lazyMessage().toString())
quit(1)

This will prefix the message with [kscript] [ERROR] which will help the user to distinguish script logic errors from kscript runtime errors.

[alekseytomin]

Done

[alekseytomin]

c8fc911
I've found than System.getenv(key) has a wrong type (String! instead of String?) and remove from code. System.getenv()[key] returns String?

[alekseytomin]

Is it okay?

[holgerbrandl]

Great PR, thanks for your support and patience. A release including your feature is planned for later today.

[alekseytomin]

Thanks!