🫧 Bubble C🫧nfig

An aero-powered config with environments aimed at Babashka tasks.

Rationale

I wanted to make my Babashka tasks simpler. Instead of doing variations of bb some-task --flag1 val1 --flag2 val2 in development/test/production etc., this library allows you to do bb some-task -e dev and the right flags for the environment will be read from a config-file and passed to the task (while allowing overrides).

Usage

Babashka tasks

This library is ideal for Babashka tasks as it allows you to call tasks with predefined flags from a config-file.

Say we have a CLI, clojore.core/prn, and create a task from it:

;; bb.edn
:tasks {
  prn (exec 'clojure.core/prn)
}

Works as expected:

$ bb prn -a 1 -b 2
{:a 1, :b 2}

Now when you have a lot of flags that also differ between, say, local development, CI and production, then it's convenient to have those environment-specific 'sets' of flags in one config.
This is what Bubble Config allows you to do:

;; config.edn
:deps  {io.github.eval/bubble-config {:git/sha "ac45fc05f889e3acfeaeb12e919908e6e42a1c66"}}
:tasks {:init
         (defn config []
           (exec 'bubble-config.core/config))

  prn (exec 'clojure.core/prn {:exec-args (config)})
}

Install a sample config:

$ bb -x bubble-config.core/sample > config.edn

Now we get:

# dev environment
$ bb prn
{:a 0, :b 1}

# test environment via flag
$ bb prn -e test
{:a 0, :b 2, :e "test"}

# test environment via env-var
$ env BBL_ENV=test bb prn
{:a 0, :b 2}

# config overrides
$ bb prn -e test -a 2
{:a 2, :b 2, :e "test"}

So instead of having long commands that differ in every environment, bb some-task suffices everywhere. Switching between envs is easy, as is inspecting what the flags per environment look like.

config

The config will be read by aero with the following additions/conventions:

• the #env tag-literal which is like #profile:

  #env{:dev  {:database-url "postgres://localhost:5432/app_dev"}
       :test {:database-url "postgres://localhost:5432/app_test"}}

  Differences with #profile:
  • In case no env is provided, the first env found in the config-file is assumed (aero uses :default as fallback).
  • Providing an unknown env triggers an exception (aero's result would be nil).
• if the config contains a key :bubble-config/root, then that will be the result
  This to allow for scratchpad keys, e.g.

  {:defaults {:a 1}
   :bubble-config/root #merge [#ref [:defaults] ,,,]}

  See also the sample.edn.

CLI

Use the bubble-config.core/print CLI to see the config for an environment:

# Use this env-var in case you want to test it without a deps.edn file
$ export BBL_DEPS='{:deps {io.github.eval/bubble-config {:git/sha "ac45fc05f889e3acfeaeb12e919908e6e42a1c66"}}}'

# Babashka/Clojure commands side by side
# a sample config
$ bb -Sdeps "${BBL_DEPS}" -x bubble-config.core/sample | tee config.edn
$ clojure -Sdeps "${BBL_DEPS}" -X bubble-config.core/sample | tee config.edn

# print config
# the default environment is the first of the detected environments in config.edn
# meta-data shows, among other things, what envs were detected (left out in following examples).
$ bb -Sdeps "${BBL_DEPS}" -x bubble-config.core/print
$ clojure -Sdeps "${BBL_DEPS}" -X bubble-config.core/print
^{:bubble-config/available-envs (:dev :test :prod),
  :bubble-config/config-file "config.edn",
  :bubble-config/current-env :dev}
{:a 0, :b 1}

# different environment via env-var
$ env BBL_ENV=prod bb -Sdeps "${BBL_DEPS}" -x bubble-config.core/print
$ env BBL_ENV=prod clojure -Sdeps "${BBL_DEPS}" -X bubble-config.core/print
{:a 0, :b 3}

# different environment via the env-flag (overrides env-var)
$ bb -Sdeps "${BBL_DEPS}" -x bubble-config.core/print -e test
$ clojure -Sdeps "${BBL_DEPS}" -X bubble-config.core/print :env test
{:a 0, :b 2}

# full help
$ bb -Sdeps "${BBL_DEPS}" -x bubble-config.core/print -h
$ clojure -Sdeps "${BBL_DEPS}" -X bubble-config.core/print :help true

# unknown env raises assert-exception
$ bb -Sdeps "${BBL_DEPS}" -x bubble-config.core/print -e foo

LICENSE

Copyright (c) 2024 Gert Goet, ThinkCreate. Distributed under the MIT license. See LICENSE.