Add Hatchbox Exports Env Vars With asdf as a Devops TIL

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
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@@ -200,6 +200,7 @@ See some of the other learning resources I work on:
 - [Check The Syntax Of nginx Files](devops/check-the-syntax-of-nginx-files.md)
 - [Connect To An RDS PostgreSQL Database](devops/connect-to-an-rds-postgresql-database.md)
 - [Determine The IP Address Of A Domain](devops/determine-the-ip-address-of-a-domain.md)
+- [Hatchbox Exports Env Vars With asdf](devops/hatchbox-exports-env-vars-with-asdf.md)
 - [Path Of The Packets](devops/path-of-the-packets.md)
 - [Push Non-master Branch To Heroku](devops/push-non-master-branch-to-heroku.md)
 - [Reload The nginx Configuration](devops/reload-the-nginx-configuration.md)

devops/hatchbox-exports-env-vars-with-asdf.md

@@ -0,0 +1,44 @@
+# Hatchbox Exports Env Vars With asdf
+
+When you add env vars through the [Hatchbox](https://hatchbox.io/) UI, they get
+exported to the environment of the asdf-shimmed processes. This is handled by
+the [`asdf-vars` plugin](https://github.com/excid3/asdf-vars). That plugin
+looks for `.asdf-vars` in the current chain of directories.
+
+I can see there are many `.asdf-vars` files:
+
+```bash
+$ find . -name ".asdf-vars" -type f
+./.asdf-vars
+./my-app/.asdf-vars
+./my-app/releases/20250120195106/.asdf-vars
+./my-app/releases/20250121041054/.asdf-vars
+```
+
+And it is the one in my app's directory that contains the env vars that I set
+in the UI.
+
+```bash
+$ cat my-app/.asdf-vars
+BUNDLE_WITHOUT=development:test
+DATABASE_URL=postgresql://user_123:123456789012345@10.0.1.1/my_app_db
+PORT=9000
+RACK_ENV=production
+RAILS_ENV=production
+RAILS_LOG_TO_STDOUT=true
+RAILS_MASTER_KEY=abc123
+SECRET_KEY_BASE=abc123efg456
+```
+
+When I run a shimmed process like `ruby`, those env vars are loaded into the
+process's environment.
+
+```bash
+$ cd my-app/current
+$ which ruby
+/home/deploy/.asdf/shims/ruby
+$ ruby -e "puts ENV['DATABASE_URL']"
+postgresql://user_123:123456789012345@10.0.1.1/my_app_db
+```
+
+[source](https://www.visualmode.dev/hatchbox-manages-env-vars-with-asdf)