Merge pull request #1 from darkweak/fix/middleware/reset-and-put-back…

…-buffer

fix(middleware): Reset and put back buffer

.github/workflows/plugins.yml → .github/workflows/middlewares.yml

@@ -1,4 +1,4 @@
-name: Build and validate go-esi as plugins
+name: Build and validate go-esi as middleware
 
 on:
   - pull_request
@@ -25,10 +25,10 @@ jobs:
         run: go install github.com/caddyserver/xcaddy/cmd/xcaddy@latest
       -
         name: Build go-esi as caddy module
-        run: cd plugins/caddy && xcaddy build --with github.com/darkweak/go-esi/middleware/caddy=./ --with github.com/darkweak/go-esi@latest=../..
+        run: cd middleware/caddy && xcaddy build --with github.com/darkweak/go-esi/middleware/caddy=./ --with github.com/darkweak/go-esi@latest=../..
       -
         name: Run Caddy tests
-        run: cd plugins/caddy && go test -v ./...
+        run: cd middleware/caddy && go test -v ./...
       -
         name: Run detached caddy
-        run: cd plugins/caddy && ./caddy run &
+        run: cd middleware/caddy && ./caddy run &

README.md

@@ -3,6 +3,20 @@ go-esi
 
 go-esi is the implementation of the non-standard ESI (Edge-Side-Include) specification from the w3. With that you'll be able to use the ESI tags and process them in your favorite golang servers.
 
+## What are the ESI tags
+The ESI tags were introduced by Akamai to add some dynamic tags and only re-render these parts on the server-side.
+The goal of that is to render only specific parts. For example, we want to render a full e-commerce webpage but only the cart is user-dependent. So we could render the "static" parts and store with a predefined TTL (e.g. 60 minutes), and only the cart would be requested to render the block.
+
+There are multiple `esi` tags that we can use but the most used is the `esi:include` because that's the one to request another resource.
+
+We can have many `esi:include` tags in a single response, and each `esi:include` tags can itself have one or more `esi:include` tags.
+
+![esi page example](https://github.com/darkweak/go-esi/blob/master/docs/esi_2.jpg?sanitize=true)
+
+We can have multiple `esi:include` tags in the page to request another resource and add its content to the main page.
+
+![esi process example](https://github.com/darkweak/go-esi/blob/master/docs/esi_1.jpg?sanitize=true)
+
 ## References
 https://www.w3.org/TR/esi-lang/
 

middleware/caddy/esi.go

@@ -7,7 +7,6 @@ import (
 	"sync"
 
 	"github.com/caddyserver/caddy/v2"
-	"github.com/caddyserver/caddy/v2/caddyconfig"
 	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
 	"github.com/caddyserver/caddy/v2/caddyconfig/httpcaddyfile"
 	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
@@ -23,10 +22,7 @@ var bufPool *sync.Pool = &sync.Pool{
 func init() {
 	caddy.RegisterModule(ESI{})
 	httpcaddyfile.RegisterGlobalOption("esi", func(h *caddyfile.Dispenser, _ interface{}) (interface{}, error) {
-		return httpcaddyfile.App{
-			Name:  "http.handlers.esi",
-			Value: caddyconfig.JSON(ESI{}, nil),
-		}, nil
+		return &ESI{}, nil
 	})
 	httpcaddyfile.RegisterHandlerDirective("esi", func(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error) {
 		return &ESI{}, nil
@@ -46,7 +42,10 @@ func (ESI) CaddyModule() caddy.ModuleInfo {
 
 // ServeHTTP implements caddyhttp.MiddlewareHandler
 func (e *ESI) ServeHTTP(rw http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error {
-	cw := newWriter(bufPool.Get().(*bytes.Buffer), rw)
+	buf := bufPool.Get().(*bytes.Buffer)
+	buf.Reset()
+	defer bufPool.Put(buf)
+	cw := newWriter(buf, rw)
 	next.ServeHTTP(cw, r)
 
 	b := esi.Parse(cw.buf.Bytes(), r)

middleware/caddy/go.mod

@@ -4,7 +4,7 @@ go 1.18
 
 require (
 	github.com/caddyserver/caddy/v2 v2.5.2
-	github.com/darkweak/go-esi v0.0.1
+	github.com/darkweak/go-esi v0.0.3
 )
 
 require (
@@ -111,4 +111,4 @@ require (
 	howett.net/plist v1.0.0 // indirect
 )
 
-replace github.com/darkweak/go-esi v0.0.1 => ../..
+replace github.com/darkweak/go-esi v0.0.3 => ../..