Hi all, trying to add multiple build environments ...

# android

[Corey Lanier]

Hi all, trying to add multiple build environments to my project via env files (containing api base urls, secrets and such). Coming from Javascript and unsure how to do this in in Kotlin for an android project.

[Afzal Najam]

You can use gradle flavors for this. Env can be read from the gradle build file as well and then exposed to the app using buildConfigField

[Corey Lanier]

Is there a link to anything explaining how to do this? It also sounds like the env would be written into the gradle build file? That’s something that I don’t want to do, as I want to keep the env on gitignore

[Afzal Najam]

You can totally put the env outside build.gradle file

https://medium.com/@geocohn/keeping-your-android-projects-secrets-secret-393b8855765d
https://www.lordcodes.com/articles/protecting-secrets-in-an-android-project
https://dev.to/jmfayard/configuring-gradle-with-gradle-properties-211k

🙂

[Corey Lanier]

Thanks Afzal for the help!

[Afzal Najam]

No problem!

[Corey Lanier]

Actually I have one more question after reading through everything, I might have missed it. How would I use flavors in conjunction with this, so that I could use one file for a dev environment, and another for staging, and one more for production?

[Afzal Najam]

you could use buildTypes for that:
https://www.journaldev.com/21533/android-build-types-product-flavors

Define a dev/debug, staging, and release buildType, then define the same buildConfigField in all three of them.

You could do the same with flavors as well.

define 3 flavors: dev, staging, prod.

But then because you need debug and release build types anyway, you'll have 6 total build configurations: devDebug, stagingDebug, prodDebug, devRelease, stagingRelease, prodRelease.

You can, however, prevent gradle for generating all 6 but that's slightly off-topic.

Simplest way: 3 buildTypes + buildConfigField in each of them.

It's not the prettiest though but since gradle files are just groovy files, you could use code to loop through the properties file or something.

[Corey Lanier]

I guess I’m just confused on how to tie this all together… I guess I sort of understand that I’d have to loop through the properties file to get all the env data? But I guess I don’t understand the how as in how is the app defining which env file to use? I guess I’m also struggling on creating the different builds as well then?

[Afzal Najam]

gradle.properties file are imported automatically in build.gradle files.

For importing other files, you can use the Properties API. You're defining this in the build.gradle file.

See how the designer_news_client_id is used here, defined in the gradle.properties file and then used in build.gradle
https://github.com/android/plaid/search?q=designer_news_client_id

Since the root gradle.properties file is usually checked into version control, you can create one in the app folder as well, and it will be imported automatically too.

[Corey Lanier]

I’m still confused. So I would make a different grade.properties file for each build?

[Afzal Najam]

No, you'd just make one gradle.properties to hold all variables.

In your gradle.properties , you can have:

STAGING_DOMAIN=<http://staging.com|staging.com>
PROD_DOMAIN=<http://prod.com|prod.com>

then you can access those in your build.gradle file to expose it to your app:

android {
  //... other stuff

  buildTypes {
    staging {
      buildConfigField 'String', 'API_DOMAIN', "\"${STAGING_DOMAIN}\""
    }
    release {
      buildConfigField 'String', 'API_DOMAIN', "\"${PROD_DOMAIN}\""    
    }
}

Then you can access BuildConfig.API_DOMAIN everywhere in your app code. When you select the release variant, it will be the value of PROD_DOMAIN, when you select staging variant, it'll be the value of STAGING_DOMAIN

hope that helps

[Corey Lanier]

would it be gradle.properties or local.properties? local.properties is defaulted into gitignore, but gradle.properties isn’t. If it’s gradle.properties then how would i ignore this?

[Corey Lanier]

or would I be able to make a app/gradle.properties and put that on ignore instead?

[Afzal Najam]

yeah you can do the latter. OR check the first link I sent you, that one uses a different properties file, but then you have to load it manually in build.gradle