tools-deps 2020-04-03 | Slack Archive

practicalli-johnny07:04:24

@jaime.sangcap Storing environment variables in a file that you then version control is the best way to add a huge security hole in your application and isn't following 12 factor app approach. If you are using a service like Heroku, then that service manages the Environment variables securely for each application and you can the just read them in from Clojure as Sean mentioned or using environ.

jaime08:04:11

I agree. Thank you for pointing it. However, what I meant was commit in version control an example file. Let's say .env.example , this will contain all the env vars that are needed by your application.

APP_PORT=8000
DATABASE_URL=
AWS_ACCESS_KEY_ID
SOME_PATH=/temp

Notice that env vars don't have values, but are there so that when other devs can copy the .env.example and create .env and provide the values. I think an advantage of this one is you can check the .env file if there are missing keys from .env.example and throw an error before the app starts to prevent it from running in unpredictable state.

teodorlu07:04:58

Option: store config defaults in an .edn file, and create a custom read-config function that reads an env var if it is present, otherwise defaults to the file. Then you can set defaults, and override them with environment variables. Note: env vars are named by strings. We often like to use keywords as identifiers in Clojure. You might want to set a naming scheme that lets you query with keywords rather than strings.

dominicm08:04:17

Sounds like aero :)

👍 4

teodorlu09:04:27

Aero seems to make all of this possible to do from within the config file. README[1] excerpt:

{:port #or [#env PORT 8080]}

[1]: https://github.com/juxt/aero

jaime09:04:05

@seancorfield Yes I think I got that one. Given I have this deps.edn

{:deps
 {org.clojure/clojure {:mvn/version "1.9.0"}}

 :paths ["src"]

 :aliases {:dev {:extra-paths ["dev"]
                 :extra-deps {nrepl/nrepl {:mvn/version "0.6.0"}}
                 :main-opts ["-m" "nrepl.cmdline"]}}}

I could imagine intellij when you add env var DATABASE_URL to it, it will just run using DATABASE_URL=jdbc-url clj -A:dev Looking at environ code, all functions are private 🙂 Maybe I could just do this. (copied from this convo https://github.com/weavejester/environ/issues/14)

(require '[environ.core :as environ])
(defonce env (merge (read-my-custom-config-file) environ/env)

Where config file is in .gitignore and will be used in local dev. Thanks to @teodorlu for the idea

👍 4

Alex Miller (Clojure team)12:04:21

I’ve done something very similar to that in a real app

jjttjj13:04:25

Is there a "recommended" way to have a repl start in a particular namespace and load that file?

jjttjj13:04:05

I've been trying various arrangments of this but none seem to really be what I'm going for

:main-opts ["-i" "src/jt/jt15.clj"
            "-e" "(in-ns,'jt.jt15)"
            "-r"]

jjttjj13:04:11

nevermind, had a typo in the namespace, this is working

2020-04-03

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