From 3b34367f710069871e22c270e986c9be950bcb69 Mon Sep 17 00:00:00 2001
From: Maksym Pavlenko <pavlenko.maksym@gmail.com>
Date: Wed, 10 Jul 2019 00:13:35 -0700
Subject: [PATCH] Initial lambda proxy implementation

---
 cmd/lambda/main.go | 82 ++++++++++++++++++++++++++++++++++++++++++++++
 go.mod             |  1 +
 go.sum             |  2 ++
 3 files changed, 85 insertions(+)
 create mode 100644 cmd/lambda/main.go

diff --git a/cmd/lambda/main.go b/cmd/lambda/main.go
new file mode 100644
index 0000000..32a63fa
--- /dev/null
+++ b/cmd/lambda/main.go
@@ -0,0 +1,82 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/lambda"
+	"github.com/go-chi/chi"
+	"github.com/go-chi/chi/middleware"
+)
+
+var (
+	sess = session.Must(session.NewSession())
+	svc  = lambda.New(sess)
+)
+
+type response struct {
+	StatusCode int               `json:"statusCode"`
+	StatusDesc string            `json:"statusDescription"`
+	Headers    map[string]string `json:"headers"`
+}
+
+func resolve(w http.ResponseWriter, r *http.Request) {
+	var (
+		feedID  = chi.URLParam(r, "feedID")
+		videoID = chi.URLParam(r, "videoID")
+		path    = fmt.Sprintf("/download/%s/%s", feedID, videoID)
+		params  = map[string]string{"path": path}
+	)
+
+	// Serialize lambda request payload
+	payload, err := json.Marshal(params)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	request := &lambda.InvokeInput{}
+	request.SetPayload(payload)
+	request.SetFunctionName("Resolver")
+	request.SetQualifier("PROD")
+
+	// Invoke lambda function
+	output, err := svc.Invoke(request)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	// Deserialize lambda response
+	var out response
+	if err := json.Unmarshal(output.Payload, &out); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	// Write response
+	for name, value := range out.Headers {
+		w.Header().Set(name, value)
+	}
+	w.WriteHeader(out.StatusCode)
+	fmt.Fprintln(w, out.StatusDesc)
+}
+
+func main() {
+	r := chi.NewRouter()
+
+	r.Use(middleware.Logger)
+	r.Use(middleware.Recoverer)
+	r.Use(middleware.GetHead)
+
+	r.Use(middleware.Timeout(15 * time.Second))
+
+	r.Route("/download", func(r chi.Router) {
+		r.Get("/{feedID}/{videoID}", resolve)
+	})
+
+	http.ListenAndServe(":5002", r)
+}
diff --git a/go.mod b/go.mod
index 7e80e0b..63eab23 100644
--- a/go.mod
+++ b/go.mod
@@ -13,6 +13,7 @@ require (
 	github.com/gin-contrib/gzip v0.0.1
 	github.com/gin-contrib/sessions v0.0.0-20170731012558-a71ea9167c61
 	github.com/gin-gonic/gin v1.3.0
+	github.com/go-chi/chi v4.0.2+incompatible
 	github.com/go-pg/pg v6.14.2+incompatible
 	github.com/go-redis/redis v6.15.2+incompatible
 	github.com/golang/mock v1.2.0
diff --git a/go.sum b/go.sum
index 1511065..5381f57 100644
--- a/go.sum
+++ b/go.sum
@@ -30,6 +30,8 @@ github.com/gin-contrib/sse v0.0.0-20170109093832-22d885f9ecc7 h1:AzN37oI0cOS+cou
 github.com/gin-contrib/sse v0.0.0-20170109093832-22d885f9ecc7/go.mod h1:VJ0WA2NBN22VlZ2dKZQPAPnyWw5XTlK1KymzLKsr59s=
 github.com/gin-gonic/gin v1.3.0 h1:kCmZyPklC0gVdL728E6Aj20uYBJV93nj/TkwBTKhFbs=
 github.com/gin-gonic/gin v1.3.0/go.mod h1:7cKuhb5qV2ggCFctp2fJQ+ErvciLZrIeoOSOm6mUr7Y=
+github.com/go-chi/chi v4.0.2+incompatible h1:maB6vn6FqCxrpz4FqWdh4+lwpyZIQS7YEAUcHlgXVRs=
+github.com/go-chi/chi v4.0.2+incompatible/go.mod h1:eB3wogJHnLi3x/kFX2A+IbTBlXxmMeXJVKy9tTv1XzQ=
 github.com/go-pg/pg v6.14.2+incompatible h1:FrOgsHDUhC3V3wkBGAIN5LVj4nJczFPyy1YNFnetfIQ=
 github.com/go-pg/pg v6.14.2+incompatible/go.mod h1:a2oXow+aFOrvwcKs3eIA0lNFmMilrxK2sOkB5NWe0vA=
 github.com/go-redis/redis v6.15.2+incompatible h1:9SpNVG76gr6InJGxoZ6IuuxaCOQwDAhzyXg+Bs+0Sb4=