feat: Enhance API gateway to be able to use OVH Swift backend instead…

… of AWS S3 backend (closes #251)

build/express-gateway/plugins/s3.js

@@ -3,7 +3,8 @@ const aws = require('aws-sdk');
 
 const s3 = new aws.S3({
   accessKeyId: process.env.S3_ACCESS_KEY,
-  secretAccessKey: process.env.S3_SECRET_ACCESS_KEY
+  secretAccessKey: process.env.S3_SECRET_ACCESS_KEY,
+  endpoint: process.env.S3_ENDPOINT
 })
 
 module.exports = {

docs/.vuepress/config.js

@@ -59,6 +59,7 @@ function getTipsSidebar () {
     'using-artillery',
     'handling-long-running-process',
     'using-mongodb-atlas',    
-    'extracting-osm-data'
+    'extracting-osm-data',    
+    'running-express-gateway'
   ]
 }

docs/tips/running-express-gateway.md

@@ -0,0 +1,43 @@
+---
+sidebarDepth: 3
+---
+
+# Running express-gateway locally
+
+It is sometimes required to play with the API gateway on your local development environment for debug purpose. As Kargo relies on a specific image built with plugins, etc. you can use it but it might not be so convenient. Otherwise you can clone [express-gateway](https://github.com/ExpressGateway/express-gateway) and do the following to run it locally with e.g. the S3 plugin:
+
+1. Add AWS SDK dependency to the `package.json` file (`"aws-sdk": "^2.607.0"`)
+
+2. Copy the Kargo plugin into the `lib` directory
+
+3. Add S3 plugin at the end of the `lib/config/system.config.yml` file:
+```yml
+plugins:
+  s3:
+    package: ./s3
+```
+
+4. Add S3 endpoint/pipeline the `lib/config/gateway.config.yml` file:
+```yml
+apiEndpoints:
+  s3: 
+    hosts: '*'
+    paths: '/s3/*'
+serviceEndpoints:
+  s3:
+    url: 'http://localhost:9876/s3'
+pipelines:
+  s3:
+    apiEndpoints:
+      - s3
+    policies:   
+      - proxy:
+          - action:
+              serviceEndpoint: s3
+              changeOrigin: true
+              stripPath: true
+```
+
+Configure the required environment variables (`S3_ACCESS_KEY`, `S3_SECRET_ACCESS_KEY`, `S3_ENDPOINT`) then launch the gateway: `npm run start:dev`.
+
+Now you should be able to access objects using the following URL: http://localhost:9876/s3/bucket/key.