From b3d432e6bc9ef21e6f75e35a4476946008724dc3 Mon Sep 17 00:00:00 2001
From: jwa <jwa@jammed.com>
Date: Thu, 11 Jan 2018 22:09:59 +0000
Subject: [PATCH 1/2] allow HTTP 201 & 204 when storing remote state

Apache mod_dav returns 201 (created) and 204 (no content) during PUTs;
treat these as valid responses when using Apache as a http backend.
---
 state/remote/http.go      |  2 +-
 state/remote/http_test.go | 18 ++++++++++++++++--
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/state/remote/http.go b/state/remote/http.go
index b30c15590..6473d2477 100644
--- a/state/remote/http.go
+++ b/state/remote/http.go
@@ -313,7 +313,7 @@ func (c *HTTPClient) Put(data []byte) error {
 
 	// Handle the error codes
 	switch resp.StatusCode {
-	case http.StatusOK:
+	case http.StatusOK, http.StatusCreated, http.StatusNoContent:
 		return nil
 	default:
 		return fmt.Errorf("HTTP error: %d", resp.StatusCode)
diff --git a/state/remote/http_test.go b/state/remote/http_test.go
index 15e5e8bfe..904d830b1 100644
--- a/state/remote/http_test.go
+++ b/state/remote/http_test.go
@@ -31,6 +31,14 @@ func TestHTTPClient(t *testing.T) {
 	client := &HTTPClient{URL: url, Client: cleanhttp.DefaultClient()}
 	testClient(t, client)
 
+	// test just a single PUT
+	p := &HTTPClient{
+		URL:          url,
+		UpdateMethod: "PUT",
+		Client:       cleanhttp.DefaultClient(),
+	}
+	testClient(t, p)
+
 	// Test locking and alternative UpdateMethod
 	a := &HTTPClient{
 		URL:          url,
@@ -134,12 +142,18 @@ func (h *testHTTPHandler) Handle(w http.ResponseWriter, r *http.Request) {
 	switch r.Method {
 	case "GET":
 		w.Write(h.Data)
-	case "POST", "PUT":
+	case "PUT":
+		buf := new(bytes.Buffer)
+		if _, err := io.Copy(buf, r.Body); err != nil {
+			w.WriteHeader(500)
+		}
+		w.WriteHeader(201)
+		h.Data = buf.Bytes()
+	case "POST":
 		buf := new(bytes.Buffer)
 		if _, err := io.Copy(buf, r.Body); err != nil {
 			w.WriteHeader(500)
 		}
-
 		h.Data = buf.Bytes()
 	case "LOCK":
 		if h.Locked {

From 3d4642719f273a97c1c65c142c476bda52d4821c Mon Sep 17 00:00:00 2001
From: jwa <jwa@jammed.com>
Date: Fri, 19 Jan 2018 02:30:21 +0000
Subject: [PATCH 2/2] simulate a webdav backend

---
 state/remote/http_test.go | 40 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/state/remote/http_test.go b/state/remote/http_test.go
index 904d830b1..214dffa5c 100644
--- a/state/remote/http_test.go
+++ b/state/remote/http_test.go
@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"net/url"
+	"reflect"
 	"testing"
 
 	"github.com/hashicorp/go-cleanhttp"
@@ -60,6 +61,19 @@ func TestHTTPClient(t *testing.T) {
 	}
 	TestRemoteLocks(t, a, b)
 
+	// test a WebDAV-ish backend
+	davhandler := new(testHTTPHandler)
+	ts = httptest.NewServer(http.HandlerFunc(davhandler.HandleWebDAV))
+	defer ts.Close()
+
+	url, err = url.Parse(ts.URL)
+	c := &HTTPClient{
+		URL:          url,
+		UpdateMethod: "PUT",
+		Client:       cleanhttp.DefaultClient(),
+	}
+	testClient(t, c) // first time through: 201
+	testClient(t, c) // second time, with identical data: 204
 }
 
 func assertError(t *testing.T, err error, expected string) {
@@ -171,3 +185,29 @@ func (h *testHTTPHandler) Handle(w http.ResponseWriter, r *http.Request) {
 		w.Write([]byte(fmt.Sprintf("Unknown method: %s", r.Method)))
 	}
 }
+
+// mod_dav-ish behavior
+func (h *testHTTPHandler) HandleWebDAV(w http.ResponseWriter, r *http.Request) {
+	switch r.Method {
+	case "GET":
+		w.Write(h.Data)
+	case "PUT":
+		buf := new(bytes.Buffer)
+		if _, err := io.Copy(buf, r.Body); err != nil {
+			w.WriteHeader(500)
+		}
+		if reflect.DeepEqual(h.Data, buf.Bytes()) {
+			h.Data = buf.Bytes()
+			w.WriteHeader(204)
+		} else {
+			h.Data = buf.Bytes()
+			w.WriteHeader(201)
+		}
+	case "DELETE":
+		h.Data = nil
+		w.WriteHeader(200)
+	default:
+		w.WriteHeader(500)
+		w.Write([]byte(fmt.Sprintf("Unknown method: %s", r.Method)))
+	}
+}