GitHub - paholg/envswitch: A simple tool for managing sets of environment variables

envswitch

A simple tool to manage multiple sets of environment variables.

Do you ever need to make the same http request against different endpoints or with different keys? Do you ever want a simple way to toggle one or more environment variables, and have an easy way to track what you've set?

Then envswitch might be for you!

Quick example

Given this config file:

[local]
URL = "http://localhost:3000"
KEY = "test_key_123"

[prod]
URL = "https://example.com"

[prod.abc]
KEY = "super_secret"

Running es local will set:

URL=http://localhost:3000
KEY=test_key_123

Running es prod.abc will set:

URL=https://example.com
KEY=super_secret

Running es -l will show the options:

Available environments:
  local
  prod
  prod.abc

See Usage for more detailed examples.

Compatibility

Currently, envswitch is compatible with these shells:

• bash
• fish
• zsh

If you'd like to use envswitch with another shell, it should be quite easy to add; please open a ticket or a PR. See src/shell.rs.

Installation

Thanks to dist, installation on various platforms is easy.

Configuration

It is strongly recommended that you run envswitch through a shell function, as otherwise it just outputs shell commands that need to be sourced.

Please place the appropriate snippet in your shell config (e.g. ~/.bashrc). It will register the function es and generate completions for it.

Bash

source <(envswitch setup bash)

Fish

envswitch setup fish | source

Zsh

source <(envswitch setup zsh)

The prior functions will look for the file envswitch.toml in the directoy you call them in. If you'd prefer a different file, or perhaps to set an alias with a fixed file location, you can do so with the --file/-f flag.

For example, you might want to set an alias like this:

alias esh="es -f ~/.envswitch.toml"

You can see all options with envswitch --help.

Usage

The envswitch.toml file should be thought of as a tree; envswitch will walk it to your given path, overriding any more general settings.

Given this example file:

GLOBAL = "some global variable"

[staging]
URL = "staging.com"

[staging.abc]
KEY = "secret_ABC"

[staging.def]
KEY = "secret_DEF"
URL = "def.staging.com"

[prod]
GLOBAL = "override for production"
URL = "prod.com"

[prod.abc]
KEY = "prod_secret_ABC"

Here are some commands, and what variables they will cause to be set:

es staging

GLOBAL="some global variable"
URL="staging.com"

es staging.abc

GLOBAL="some global variable"
URL="staging.com"
KEY="secret_ABC"

es staging.def

GLOBAL="some global variable"
# There is a more specific URL here, so we use that.
URL="def.staging.com"
KEY="secret_DEF"

es prod.abc

GLOBAL="override for production"
URL="prod.com"
KEY="prod_secret_ABC"

es prod

GLOBAL="override for production"
URL="prod.com"
# NOTE: `KEY` will be unset here if it was previously set by envswitch.

es

GLOBAL="some global variable"
# NOTE: Running with no arguments will cause any non-global variables that were
# set by envswitch to be unset.

You can also run es -l to see available environments.

Integrations

Running envswitch get will print the name of the environment we are currently in, such as staging.def.

This can be used to show the current environment in your prompt.

Starship

If you use starship, the envswitch environment can be easily added as a custom command. Here is an example that can be added to starship.toml:

[custom.envswitch]
description = "Show which envswitch environment is currently active."
command = "envswitch get"
when = "envwitch get"
style = "yellow"
format = "[($symbol $output )]($style)"
symbol = ""

How it Works

When you run an envswitch set command, it outputs commands to set or unset variables, which are then sourced by your shell in the function setup in Configuration.

It also sets a special variable to let it track what it has set before. This enables envswitch to unset variables it has previously set even if you edit the config file or pass it a different one, such as by moving to another directory.

Perhaps this is most clear with some examples. Using the config file from Usage,

$ envswitch set -sbash staging
export ENVSWITCH_ENV="staging:GLOBAL,URL"
export GLOBAL="some global variable"
export URL="staging.com"
Environment set: staging GLOBAL URL

The 3 export lines are piped to stdout, whereas the last line is sent to stderr so that it is not captured by the pipe to source.

The ENVSWITCH_ENV variable tells us the name of the environment we're in (which is used by envswitch get) and which variables we have set.

So, when we run another set command, it can unset them:

$ envswitch get
staging

$ envswitch set -sbash prod.abc
unset GLOBAL
unset URL
export ENVSWITCH_ENV="prod.abc:GLOBAL,URL,KEY"
export GLOBAL="override for production"
export URL="prod.com"
export KEY="prod_secret_ABC"
Environment set: prod.abc GLOBAL URL KEY