Use environment variables

[josemiguelo]

Hi!
First up, amazing job on this plugin!

I've just started to play with templates and my use case is this: I use several java versions on my machine, and the maven tool to manage my projects. On some projects, I append the java version before executing maven like so:

JAVA_HOME=/home/user/.asdf/installs/java/adoptopenjdk-8.0.362+9 mvn ...

This lets me use the java version my project needs on every specific case. Now, I'm creating a template to automate this use case (and then chain it with some other tasks) so my component looks like this

return {
 ...
  builder = function(params)
    return {
      cmd = {"mvn" },
      args = { "--version" },
    }
  end,
  env = {
    JAVA_HOME = "/home/user/.asdf/installs/java/adoptopenjdk-8.0.362+9",
  },
  condition = { dir = utils.path },
}

but this doesn't set the JAVA_HOME the way I want. (I can see in the output I'm using a different jdk version). I tried several things like

return {
  cmd = { "JAVA_HOME=/home/user/.asdf/installs/java/adoptopenjdk-8.0.362+9", "mvn" },
  args = { "--version" },
}

or

return {
  cmd = { "JAVA_HOME=/home/user/.asdf/installs/java/adoptopenjdk-8.0.362+9 mvn" },
  args = { "--version" },
}

but the task just hangs and nothing happens.

Maybe this is not the correct way to pass those strings to the cmd field. It should receive the actual executable name and I'm missing things.

BTW if I don't use the env variable, the task executes successfully.

Can someone kindly shed some light on this issue? :)

[stevearc]

If you check the docs for template definitions, the env should be at the same level as cmd and args. For example:

return {
 ...
  builder = function(params)
    return {
      cmd = {"mvn" },
      args = { "--version" },
      env = {
        JAVA_HOME = "/home/user/.asdf/installs/java/adoptopenjdk-8.0.362+9",
      },
    }
  end,
  condition = { dir = utils.path },
}

[tony-sol]

Will this

JAVA_HOME = os.getenv("JAVA_HOME")

work?

[stevearc]

It should, but I believe that your current env should be passed through by default so that should be unnecessary.

[josemiguelo]

You're totally right. I'm sorry for my misunderstanding. But it seems that even when using the env struct correctly, the variable is not set correctly; in fact, maven yells at me saying the there's no more JAVA_HOME set.

I think it's best to not define the JAVA_HOME variable this way, but to use an external tool that sets the the appropriate JAVA_HOME (because of the way I intended to use the env var: JAVA_HOME=... mvn --version)

I use asdf as a version manager for java, and for every project I define its jdk version.If you use the cwd correctly, it will pick up the jdk correctly as well.

return {
      cwd = "some path to your project where the JAVA_HOME is already defined',
      cmd = { "mvn" },
      args = { "--version" },
    }

If you really need to define env variables before the actual binary, just create a wrapper

#!/bin/bash

cd /your/project/path
JAVA_HOME=/home/user/.asdf/installs/java/adoptopenjdk-8.0.362+9 mvn clean install