Allow different names for IML CLI

[ip1981]

• Determine executable name.

• Remove "IML" where possbile.

Separate packages would create a hard link for the executable and symlinks for shell completions.

Closes #2295.

Signed-off-by: Igor Pashev pashev.igor@gmail.com

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This change is 

[ip1981]

Could not come up with a generic non-trivial description :)

[jgrund]

General question: what happens if the structopt name does not match the binary name?

I.E. if we had a binary called iml still but did something like #[structopt(name = get_env_name())... within the code, where get_env_name() resolved to foo

[ip1981]

General question: what happens if the structopt name does not match the binary name?

I think nothing. The binary name is totally unrelated to the actually running code.
Under the hood structopt just calls some Clap functions. Previously it was using a static string, but actually it can execute any code which deliver a string, for example reading env var or using OS-specific hacks to get the binary's name.

[jgrund]

I think nothing. The binary name is totally unrelated to the actually running code.

So in the case above it would print foo for the help text?

[ip1981]

I think nothing. The binary name is totally unrelated to the actually running code.

So in the case above it would print foo for the help text?

Yes.

[jgrund]

I think nothing. The binary name is totally unrelated to the actually running code.

So in the case above it would print foo for the help text?

Yes.

Ok, so in that case we will want to have an environment variable to name the cli. It should default to iml if it's not present and can be used for naming both iml and iml-config cli (with the iml prefix being the common part).

[ip1981]

So it seems impossible without actually renaming the executable (or doing something dirty):

[jgrund]

These parts look interesting: https://github.com/clap-rs/clap/blob/3e9ee86713b5c407b50ba76f30cffaed25952063/src/output/usage.rs#L48-L53

[jgrund]

Can we reach into clap and set .bin_name(...)?

[ip1981]

Can we reach into clap and set .bin_name(...)?

This will be

    let matches = App::from_clap(
        &App::clap()
            .bin_name("fffffffffff")
            .name("wwwwwww")
            .get_matches(),
    );

But if we don't rename the binary and use some script, e. g.

export CLI_NAME=foo
exec /usr/bin/iml "$@"

we may have some issues anyway, for example:

1. process list
2. core dumps

[mkpankov]

Reviewed 1 of 5 files at r1, 8 of 8 files at r3.
Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @ip1981)

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iml-manager-cli/src/config-main.rs, line 28 at r3 (raw file):

    iml_tracing::init();

    let name = selfname(Some("config")).unwrap_or_else(|| "iml-config".to_string());

Would it make sense to move the default into selfname so that it concatenates iml- to whatever comes in Option?

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iml-manager-cli/src/lib.rs, line 32 at r2 (raw file):

Previously, ip1981 (Igor Pashev) wrote…

What about this:

pub fn selfname(suffix: Option<&str>) -> Option<String> {
// get var
// build with optional suffix (specific to the executable)
// default to executable name
}

I like