Merge pull request #156 from DefangLabs/linda-config-tutorial-v2

Added config tutorial (good version)

Author: raphaeltm

docs/concepts/compose.md

@@ -20,25 +20,21 @@ One thing to keep in mind is that, at the time of this writing, Defang identifie
 
 ## Configuration
 
-If you have a service that depends on a secret like an api key, you can set that [secret](./configuration.md) using the CLI:
+If you have a service that depends on a [config value](./configuration.md) (such as an API key), you can set it using the CLI:
 
 ```
-defang config set --name MY_API_KEY
+defang config set MY_API_KEY
 ```
 
 and then connect it to the service by specifying it in the `compose.yaml`:
 
 ```yaml
 services:
   my-service:
-    secrets:
+    environment:
       - MY_API_KEY
-
-secrets:
-  MY_API_KEY:
-    external: true
 ```
 
-:::info Configuration & Secrets
-Read more about configuration in the [configuration page](./configuration.md).
+:::info
+Read more about configuration in the [Configuration page](./configuration.md).
 :::

docs/concepts/configuration.md

@@ -8,7 +8,7 @@ sidebar_position: 225
 
 Defang allows you to configure your application using environment variables. You can set environment variables in your [`compose.yaml` file](./compose.md), or in your [Pulumi program](#using-config-with-pulumi).
 
-# Sensitive Config (aka Secrets)
+# Sensitive Config Values
 
 The Defang CLI allows you to securely store sensitive information such as API keys, passwords, and other credentials. To do so, run:
 
@@ -46,7 +46,7 @@ You can find a sample of how to set sensitive config values [here](https://githu
 
 ## Interpolation
 
-Environment variables are set within the *environment* section of a service in a `compose.yaml` file. Any variables declared here will become available within the service container.
+Environment variables are set within the `environment` section of a service in a `compose.yaml` file. Any variables declared here will become available within the service container.
 
 Variables can be set by assigning a literal value, a reference to a configuration value, or a mix of literal and variable references. Variable references are declared using either **\$\{variable_name\}** or **$variable_name** forms. It is recommended to use the bracketed form. By interpolating over variable references within a string we can construct complex strings. Interpolation may be particularly useful when constructing connection strings to other services.
 
@@ -81,5 +81,6 @@ Here are the different ways sensitive config values are stored depending on the
     * [DigitalOcean](../providers/digitalocean#secrets)
     * [GCP](../providers/gcp#secrets)
 
-
-
+:::info
+Please note that while Defang supports setting sensitive config, it does not support the [`secrets`](https://docs.docker.com/reference/compose-file/secrets/) top-level element as seen in the Compose specification. Please see our [Compose](/docs/concepts/compose) page for more details.
+:::

docs/tutorials/configure-environment-variables.md

@@ -0,0 +1,75 @@
+---
+sidebar_position: 400
+title: Configure Environment Variables
+description: How to configure sensitive environment variables in Defang.
+---
+
+# Configure Environment Variables
+
+
+This tutorial will show you how to configure sensitive environment variables in Defang.
+
+## Pre-requisites
+* [A `compose.yaml` file in your project](https://docs.docker.com/compose/gettingstarted/)
+* [A Defang Account](/docs/concepts/authentication)
+* [The Defang CLI](/docs/getting-started#install-the-defang-cli)
+
+## Step 1 - Go to your `compose.yaml` file
+:::info 
+If you are using [Pulumi](/docs/concepts/pulumi) instead of Compose files to define your services, please see [Using Config With Pulumi](/docs/concepts/configuration#using-config-with-pulumi) instead.
+:::
+
+In your Compose file, you can define a sensitive config variable for your service by leaving it as a **blank or `null` value**. Defang will recognize it as a sensitive value. 
+
+In the example below, let's define `API_KEY` as an environment variable.
+
+```yaml
+services:
+  service1:
+    image: image1:latest
+    environment:
+      - API_KEY
+```
+
+The type of notation shown above is called *list notation*. Alternatively, you can use *map notation*, which is also acceptable:
+```yaml
+services:
+  service1:
+    image: image1:latest
+    environment:
+      API_KEY:
+```
+
+## Step 2 - Set the actual value in the Defang CLI
+To store the actual (sensitive) value of the variable, open up a terminal and type the command:
+```bash
+defang config set API_KEY=actualvalue
+```
+Remember to replace `API_KEY` with your variable name and `actualvalue` with your actual value. 
+
+:::tip
+You can view all the config variables you are storing in Defang by doing: `defang config ls`.
+:::
+
+### Editing a config value
+To edit a value, you can run the command again with an updated value to overwrite the current value:
+```bash
+defang config set API_KEY=newvalue
+```
+
+### Removing a config value
+To remove a value, run the command:
+```bash
+defang config rm API_KEY
+```
+:::tip
+Remember to update your Compose file if you remove an environment variable.
+:::
+
+## Step 3 - Deploy
+```bash
+defang compose up
+```
+
+---
+For a deeper discussion on how configuration works in Defang, see our [Configuration docs](/docs/concepts/configuration).