Add S3 backend

Almost all the code is from GitbookIO#105

bin/web.js

@@ -18,11 +18,24 @@ if (process.env.ANALYTICS_TOKEN) {
 }
 
 var myNuts = nuts.Nuts({
+    backend: process.env.NUTS_BACKEND,
     repository: process.env.GITHUB_REPO,
     token: process.env.GITHUB_TOKEN,
     endpoint: process.env.GITHUB_ENDPOINT,
     username: process.env.GITHUB_USERNAME,
     password: process.env.GITHUB_PASSWORD,
+    credentials: {
+        aws: {
+            accessKeyId: process.env.AWS_ACCESS_KEY_ID,
+            secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY
+        }
+    },
+    configuration: {
+        aws: {
+            bucket: process.env.AWS_BUCKET,
+            releasesPrefix: process.env.AWS_RELEASES_PREFIX
+        }
+    },
     timeout: process.env.VERSIONS_TIMEOUT,
     cache: process.env.VERSIONS_CACHE,
     refreshSecret: process.env.GITHUB_SECRET,

lib/backends/index.js

@@ -1,7 +1,8 @@
 var _ = require('lodash');
 
 var BACKENDS = {
-    github: require('./github')
+    github: require('./github'),
+    s3: require('./s3')
 };
 
 module.exports = function(backend) {

lib/backends/s3.js

@@ -0,0 +1,108 @@
+var _ = require('lodash');
+var Q = require('q');
+var util = require('util');
+var AWS = require('aws-sdk');
+
+var Backend = require('./backend');
+
+function S3Backend() {
+    var that = this;
+    Backend.apply(this, arguments);
+
+    this.opts = _.defaults(this.opts || {}, {
+        proxyAssets: true
+    });
+
+    if (!this.opts.credentials.aws.accessKeyId || !this.opts.credentials.aws.secretAccessKey || !this.opts.configuration.aws.bucket) {
+        throw new Error('S3 backend requires "AWS_ACCESS_KEY_ID", "AWS_SECRET_ACCESS_KEY", and "AWS_BUCKET" options');
+    }
+
+    AWS.config.accessKeyId = this.opts.credentials.aws.accessKeyId;
+    AWS.config.secretAccessKey = this.opts.credentials.aws.secretAccessKey;
+
+    this.client = new AWS.S3();
+    this.releases = this.memoize(this._releases);
+}
+
+util.inherits(S3Backend, Backend);
+
+// List all releases for this repository
+S3Backend.prototype._releases = function() {
+    var client = this.client;
+    var bucket = this.opts.configuration.aws.bucket;
+    var d = Q.defer();
+    var params = {
+        Bucket: bucket,
+        Prefix: this.opts.configuration.aws.releasesPrefix + '/',
+        Delimiter: '/'
+    }
+
+    client.listObjects(params, function (err, data) {
+        if (err) d.reject(err);
+
+        var folders = data.CommonPrefixes.map(function (commonPrefix) {
+            var deferFolder = Q.defer();
+            var folderParams = {
+                Bucket: bucket,
+                Prefix: commonPrefix.Prefix
+            }
+
+            client.listObjects(folderParams, function (err, contents) {
+                if (err) d.reject(err);
+
+                return deferFolder.resolve(contents);
+            });
+
+            return deferFolder.promise;
+        });
+
+        Q.all(folders).done(function (values) {
+            var releases = values.map(function (release) {
+                var tag = release.Prefix.split('/').slice(-2)[0];
+
+                return {
+                    channel: 'stable',
+                    tag_name: tag,
+                    assets: release.Contents.map(function (content) {
+                        return {
+                            id: content.ETag,
+                            tag_name: tag,
+                            key: content.Key,
+                            name: content.Key.split('/').slice(-1)[0],
+                            size: content.Size,
+                            content_type: 'application/zip'
+                        }
+                    })
+                }
+            });
+
+            d.resolve(releases);
+        });
+    });
+
+    return d.promise;
+};
+
+S3Backend.prototype.serveAsset = function(asset, req, res) {
+    if (!this.opts.proxyAssets) {
+        var s3url = s3.getSignedUrl('getObject', {
+            Bucket: this.opts.configuration.aws.bucket,
+            Key: asset.raw.key
+        });
+        res.redirect(s3url);
+    } else {
+        return Backend.prototype.serveAsset.apply(this, arguments);
+    }
+};
+
+// Return stream for an asset
+S3Backend.prototype.getAssetStream = function(asset) {
+    var params = {
+        Bucket: this.opts.configuration.aws.bucket,
+        Key: asset.raw.key
+    };
+
+    return Q(this.client.getObject(params).createReadStream());
+};
+
+module.exports = S3Backend;

package.json

@@ -7,6 +7,7 @@
   "license": "Apache-2.0",
   "dependencies": {
     "analytics-node": "1.2.2",
+    "aws-sdk": "^2.6.6",
     "basic-auth": "1.0.3",
     "body-parser": "1.12.3",
     "destroy": "1.0.3",