command/meta: Enable migration from PSS to a backend (#37949)

* command/meta: Enable migration from PSS to a backend

* Address PR feedback

* Update internal/command/meta_backend.go

Co-authored-by: Sarah French <[email protected]>

* meta_backend: Rename stateStore_c_S to stateStore_to_backend

---------

Co-authored-by: Sarah French <[email protected]>

Author: radeksimko

internal/backend/remote-state/http/client_test.go

@@ -4,13 +4,9 @@
 package http
 
 import (
-	"bytes"
-	"fmt"
-	"io"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
-	"reflect"
 	"testing"
 
 	"github.com/hashicorp/go-retryablehttp"
@@ -23,7 +19,7 @@ func TestHTTPClient_impl(t *testing.T) {
 }
 
 func TestHTTPClient(t *testing.T) {
-	handler := new(testHTTPHandler)
+	handler := new(TestHTTPBackend)
 	ts := httptest.NewServer(http.HandlerFunc(handler.Handle))
 	defer ts.Close()
 
@@ -66,7 +62,7 @@ func TestHTTPClient(t *testing.T) {
 	remote.TestRemoteLocks(t, a, b)
 
 	// test a WebDAV-ish backend
-	davhandler := new(testHTTPHandler)
+	davhandler := new(TestHTTPBackend)
 	ts = httptest.NewServer(http.HandlerFunc(davhandler.HandleWebDAV))
 	defer ts.Close()
 
@@ -84,8 +80,8 @@ func TestHTTPClient(t *testing.T) {
 	remote.TestClient(t, client) // second time, with identical data: 204
 
 	// test a broken backend
-	brokenHandler := new(testBrokenHTTPHandler)
-	brokenHandler.handler = new(testHTTPHandler)
+	brokenHandler := new(TestBrokenHTTPBackend)
+	brokenHandler.handler = new(TestHTTPBackend)
 	ts = httptest.NewServer(http.HandlerFunc(brokenHandler.Handle))
 	defer ts.Close()
 
@@ -97,77 +93,12 @@ func TestHTTPClient(t *testing.T) {
 	remote.TestClient(t, client)
 }
 
-type testHTTPHandler struct {
-	Data   []byte
-	Locked bool
-}
-
-func (h *testHTTPHandler) Handle(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)
-		}
-		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 {
-			w.WriteHeader(423)
-		} else {
-			h.Locked = true
-		}
-	case "UNLOCK":
-		h.Locked = false
-	case "DELETE":
-		h.Data = nil
-		w.WriteHeader(200)
-	default:
-		w.WriteHeader(500)
-		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)))
-	}
-}
-
-type testBrokenHTTPHandler struct {
+type TestBrokenHTTPBackend struct {
 	lastRequestWasBroken bool
-	handler              *testHTTPHandler
+	handler              *TestHTTPBackend
 }
 
-func (h *testBrokenHTTPHandler) Handle(w http.ResponseWriter, r *http.Request) {
+func (h *TestBrokenHTTPBackend) Handle(w http.ResponseWriter, r *http.Request) {
 	if h.lastRequestWasBroken {
 		h.lastRequestWasBroken = false
 		h.handler.Handle(w, r)

internal/backend/remote-state/http/test_backend.go

@@ -0,0 +1,92 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: BUSL-1.1
+package http
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+	"reflect"
+)
+
+type TestHTTPBackend struct {
+	Data   []byte
+	Locked bool
+
+	GetCalled    int
+	PutCalled    int
+	PostCalled   int
+	LockCalled   int
+	UnlockCalled int
+	DeleteCalled int
+}
+
+func (h *TestHTTPBackend) Handle(w http.ResponseWriter, r *http.Request) {
+	switch r.Method {
+	case "GET":
+		h.GetCalled++
+		w.Write(h.Data)
+	case "PUT":
+		h.PutCalled++
+		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":
+		h.PostCalled++
+		buf := new(bytes.Buffer)
+		if _, err := io.Copy(buf, r.Body); err != nil {
+			w.WriteHeader(500)
+		}
+		h.Data = buf.Bytes()
+	case "LOCK":
+		h.LockCalled++
+		if h.Locked {
+			w.WriteHeader(423)
+		} else {
+			h.Locked = true
+		}
+	case "UNLOCK":
+		h.UnlockCalled++
+		h.Locked = false
+	case "DELETE":
+		h.DeleteCalled++
+		h.Data = nil
+		w.WriteHeader(200)
+	default:
+		w.WriteHeader(500)
+		w.Write([]byte(fmt.Sprintf("Unknown method: %s", r.Method)))
+	}
+}
+
+// mod_dav-ish behavior
+func (h *TestHTTPBackend) HandleWebDAV(w http.ResponseWriter, r *http.Request) {
+	switch r.Method {
+	case "GET":
+		h.GetCalled++
+		w.Write(h.Data)
+	case "PUT":
+		h.PutCalled++
+		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.DeleteCalled++
+		h.Data = nil
+		w.WriteHeader(200)
+	default:
+		w.WriteHeader(500)
+		w.Write([]byte(fmt.Sprintf("Unknown method: %s", r.Method)))
+	}
+}