### Define Environment Profiles in profiles.clj

Source: https://github.com/weavejester/environ/blob/master/README.md

Example of setting `database-url` for development and testing environments within a `profiles.clj` file, which merges with `project.clj` profiles.

```Clojure
{:dev  {:env {:database-url "jdbc:postgresql://localhost/dev"}}
 :test {:env {:database-url "jdbc:postgresql://localhost/test"}}}
```

--------------------------------

### Set Environment Variables via Boot CLI

Source: https://github.com/weavejester/environ/blob/master/README.md

Example of setting an environment variable directly via the Boot command line using the `environ` task, useful for quick testing or specific runs.

```Bash
boot environ -e database-url=jdbc:postgresql://localhost/dev repl
```

--------------------------------

### Add Environ Dependency to Boot Project

Source: https://github.com/weavejester/environ/blob/master/README.md

For Boot toolchain users, include the `boot-environ` dependency in your `build.boot` file to read and write settings from build pipelines.

```Clojure
:dependencies '[[boot-environ "1.2.0"]]
```

--------------------------------

### Set Java System Property for Production Deployment

Source: https://github.com/weavejester/environ/blob/master/README.md

Illustrates setting a Java system property (e.g., `database.url`) via the command line when running a standalone JAR, which Environ can then pick up.

```Bash
java -Ddatabase.url=jdbc:postgresql://localhost/prod -jar standalone.jar
```

--------------------------------

### Set Environment Variables Programmatically with Boot Environ

Source: https://github.com/weavejester/environ/blob/master/README.md

Demonstrates how to programmatically set environment variables using the `environ` task within a Boot build pipeline or `task-options!`.

```Clojure
(environ :env {:database-url "jdbc:postgresql://localhost/dev"})
```

--------------------------------

### Lookup Project Map Keys with Environ

Source: https://github.com/weavejester/environ/blob/master/README.md

Illustrates how to reference keys from the Leiningen project map (e.g., `:version`) within the `:env` map using a `project` namespace keyword.

```Clojure
{:env {:app-version :project/version}}
```

--------------------------------

### Access Environment Variables with Environ

Source: https://github.com/weavejester/environ/blob/master/README.md

Demonstrates how to require `environ.core` and access environment variables, such as a database URL, from the `env` map.

```Clojure
(require '[environ.core :refer [env]])

(def database-url
  (env :database-url))
```

--------------------------------

### Require Environ Boot Task

Source: https://github.com/weavejester/environ/blob/master/README.md

After adding the `boot-environ` dependency, require the `environ.boot` namespace to use the `environ` task in your Boot build.

```Clojure
(require '[environ.boot :refer [environ]])
```

--------------------------------

### Set Environment Variable for Production Deployment

Source: https://github.com/weavejester/environ/blob/master/README.md

Shows how to set an environment variable (e.g., `DATABASE_URL`) directly in the shell when deploying a standalone JAR for production environments.

```Bash
DATABASE_URL=jdbc:postgresql://localhost/prod java -jar standalone.jar
```

--------------------------------

### Add Leiningen Environ Plugin

Source: https://github.com/weavejester/environ/blob/master/README.md

To draw settings from the Leiningen project map, add the `lein-environ` plugin to your `project.clj` file.

```Clojure
:plugins [[lein-environ "1.2.0"]]
```

--------------------------------

### Add Environ Dependency to Leiningen Project

Source: https://github.com/weavejester/environ/blob/master/README.md

Include the Environ library as a dependency in your `project.clj` file for Leiningen projects to enable environment setting management.

```Clojure
:dependencies [[environ "1.2.0"]]
```

--------------------------------

### Create Composite Profiles in project.clj

Source: https://github.com/weavejester/environ/blob/master/README.md

Shows how to define composite profiles in `project.clj` to ensure that profiles from `profiles.clj` are merged rather than replacing profiles defined in `project.clj`.

```Clojure
:profiles {:dev [:project/dev :profiles/dev]
           :test [:project/test :profiles/test]
           ;; only edit :profiles/* in profiles.clj
           :profiles/dev  {}
           :profiles/test {}
           :project/dev {:source-paths ["src" "tool-src"]
                         :dependencies [[midje "1.6.3"]]
                         :plugins [[lein-auto "0.1.3"]]}
           :project/test {}}
```

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