feat(aws-lambda) adding support for 'isBase64Encoded' flag in Lambda function responses (#37)

Implementing functionality to support 'isBase64Encoded' flag in Lambda function response, plugin will now base64 decode response body from Lambda before forwarding to caller

Author: jonminter

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Kong AWS Lambda plugin changelog
 
+## unreleased
+
+- feat(body) adding support for 'isBase64Encoded' flag in Lambda function
+  responses
+
 ## aws-lambda 3.4.0 12-May-2020
 
 - Change `luaossl` to `lua-resty-openssl`

kong/plugins/aws-lambda/handler.lua

@@ -36,6 +36,7 @@ local tonumber             = tonumber
 local type                 = type
 local fmt                  = string.format
 local ngx_encode_base64    = ngx.encode_base64
+local ngx_decode_base64    = ngx.decode_base64
 local ngx_update_time      = ngx.update_time
 local ngx_now              = ngx.now
 local kong                 = kong
@@ -94,6 +95,11 @@ local function extract_proxy_response(content)
 
   local headers = serialized_content.headers or {}
   local body = serialized_content.body or ""
+  local isBase64Encoded = serialized_content.isBase64Encoded or false
+  if isBase64Encoded then
+    body = ngx_decode_base64(body)
+  end
+
   headers["Content-Length"] = #body
 
   return {

spec/plugins/aws-lambda/99-access_spec.lua

@@ -42,6 +42,9 @@ local fixtures = {
                     elseif string.match(ngx.var.uri, "functionWithNoResponse") then
                       ngx.header["Content-Length"] = 0
 
+                    elseif string.match(ngx.var.uri, "functionWithBase64EncodedResponse") then
+                      ngx.say("{\"statusCode\": 200, \"body\": \"dGVzdA==\", \"isBase64Encoded\": true}")
+
                     elseif type(res) == 'string' then
                       ngx.header["Content-Length"] = #res + 1
                       ngx.say(res)
@@ -184,6 +187,12 @@ for _, strategy in helpers.each_strategy() do
         service     = null,
       }
 
+      local route16 = bp.routes:insert {
+        hosts       = { "lambda16.com" },
+        protocols   = { "http", "https" },
+        service     = null,
+      }
+
       bp.plugins:insert {
         name     = "aws-lambda",
         route    = { id = route1.id },
@@ -393,6 +402,19 @@ for _, strategy in helpers.each_strategy() do
         },
       }
 
+      bp.plugins:insert {
+        name     = "aws-lambda",
+        route    = { id = route16.id },
+        config                 = {
+          port                 = 10001,
+          aws_key              = "mock-key",
+          aws_secret           = "mock-secret",
+          aws_region           = "us-east-1",
+          function_name        = "functionWithBase64EncodedResponse",
+          is_proxy_integration = true,
+        }
+      }
+
       assert(helpers.start_kong({
         database   = strategy,
         plugins = "aws-lambda",
@@ -946,6 +968,18 @@ for _, strategy in helpers.each_strategy() do
         assert.equal("some_value1", body.key1)
         assert.is_nil(res.headers["X-Amz-Function-Error"])
       end)
+
+      it("returns decoded base64 response from a Lambda function", function()
+        local res = assert(proxy_client:send {
+          method  = "GET",
+          path    = "/get?key1=some_value1&key2=some_value2&key3=some_value3",
+          headers = {
+            ["Host"] = "lambda16.com"
+          }
+        })
+        assert.res_status(200, res)
+        assert.equal("test", res:read_body())
+      end)
     end)
   end)
 end