Add examples for rbenv and nvm

docsite/rst/playbooks_environment.rst

@@ -56,6 +56,61 @@ to define an environment hash might be a group_vars file, like so::
       http_proxy: http://proxy.bos.example.com:8080
       https_proxy: http://proxy.bos.example.com:8080
 
+
+Working With Language-Specific Version Managers
+===============================================
+
+Some language-specific version managers (such as rbenv and nvm) require environment variables be set while these tools are in use. When using these tools manually, they usually require sourcing some environment variables via a script or lines added to your shell configuration file. In Ansible, you can instead use the environment directive::
+
+    ---
+    ### A playbook demonstrating a common npm workflow:
+    # - Check for package.json in the application directory
+    # - If package.json exists:
+    #   * Run npm prune
+    #   * Run npm install
+
+    - hosts: application
+      become: false
+
+      vars:
+        node_app_dir: /var/local/my_node_app
+
+      environment:
+        NVM_DIR: /var/local/nvm
+        PATH: /var/local/nvm/versions/node/v4.2.1/bin:{{ ansible_env.PATH }}
+
+      tasks:
+      - name: check for package.json
+        stat:
+          path: '{{ node_app_dir }}/package.json'
+        register: packagejson
+
+      - name: npm prune
+        command: npm prune
+        args:
+          chdir: '{{ node_app_dir }}'
+        when: packagejson.stat.exists
+
+      - name: npm install
+        npm:
+          path: '{{ node_app_dir }}'
+        when: packagejson.stat.exists
+
+You might also want to simply specify the environment for a single task::
+
+    ---
+    - name: install ruby 2.3.1
+      command: rbenv install {{ rbenv_ruby_version }}
+      args:
+        creates: '{{ rbenv_root }}/versions/{{ rbenv_ruby_version }}/bin/ruby'
+      vars:
+        rbenv_root: /usr/local/rbenv
+        rbenv_ruby_version: 2.3.1
+      environment:
+        CONFIGURE_OPTS: '--disable-install-doc'
+        RBENV_ROOT: '{{ rbenv_root }}'
+        PATH: '{{ rbenv_root }}/bin:{{ rbenv_root }}/shims:{{ rbenv_plugins }}/ruby-build/bin:{{ ansible_env.PATH }}'
+
 .. note::
    ``environment:`` is not currently supported for Windows targets