Implemented TLS (#25)

Close #12

Author: dee-kryvenko

CHANGELOG.md

@@ -8,6 +8,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [0.0.19] - 2022-05-14
 
+### Added
+
+- Implemented TLS mode
+
 ### Changed
 
 - Introduced `--dir` option under `git` backend - now current working directory can be changed dynamically

README.md

@@ -13,14 +13,21 @@ Git as Terraform backend? Seriously? I know, might sound like a stupid idea at f
       - [From Sources](#from-sources)
     - [Usage](#usage)
       - [As wrapper](#as-wrapper)
-      - [with Hashicorp Configuration Language (HCL)](#with-hashicorp-configuration-language-(hcl))
+      - [with Hashicorp Configuration Language (HCL)](#with-hashicorp-configuration-language-hcl)
       - [as Terraform HTTP backend](#as-terraform-http-backend)
       - [As Github Action](#as-github-action)
+        - [Setup action](#setup-action)
+        - [Inputs](#inputs)
+          - [`version`](#version)
+        - [Outputs](#outputs)
+          - [`version`](#version-1)
+        - [Example usage](#example-usage)
     - [Wrappers CLI](#wrappers-cli)
     - [Configuration](#configuration)
     - [Git Credentials](#git-credentials)
     - [State Encryption](#state-encryption)
     - [Running backend remotely](#running-backend-remotely)
+    - [TLS](#tls)
     - [Basic HTTP Authentication](#basic-http-authentication)
     - [Why not native Terraform Backend](#why-not-native-terraform-backend)
   - [Why storing state in Git](#why-storing-state-in-git)
@@ -234,6 +241,10 @@ Make sure you do not open the port in your firewall for remote connections. By d
 
 You may get creative and use something like K8s Network Policies like `calico`, or wrap backend traffic into API Gateway or ServiceMesh like Istio to add external layer of encryption and authentication, and then at your discretion you may run it with `--address=:6061` argument so the backend will bind to `0.0.0.0` and become remotely accessible.
 
+### TLS
+
+You can set `TF_BACKEND_GIT_HTTPS_CERT` and `TF_BACKEND_GIT_HTTPS_KEY` pointing to your cert and a key files. This will make HTTP backend to start in TLS mode. If you are using self-signed certificate - you can also set `TF_BACKEND_GIT_HTTPS_SKIP_VERIFICATION=true` and that will enable `skip_cert_verification` in terraform config.
+
 ### Basic HTTP Authentication
 
 You can use `TF_BACKEND_GIT_HTTP_USERNAME` and `TF_BACKEND_GIT_HTTP_PASSWORD` environment variables to add an extra layer of protection. In `wrapper` mode, same environment variables will be used to render `*.auto.tf` config for Terraform, but if you are using backend in standalone mode - you will have to tell these credentials to the Terraform explicitly:

cmd/git_backend.go

@@ -34,9 +34,10 @@ var gitBackendCmd = &cobra.Command{
 		t, err := template.New(gitHTTPBackendConfigPath).Parse(`
 terraform {
 	backend "http" {
-		address = "http://localhost:{{ .port }}/?type=git&repository={{ .repository }}&ref={{ .ref }}&state={{ .state }}"
-		lock_address = "http://localhost:{{ .port }}/?type=git&repository={{ .repository }}&ref={{ .ref }}&state={{ .state }}"
-		unlock_address = "http://localhost:{{ .port }}/?type=git&repository={{ .repository }}&ref={{ .ref }}&state={{ .state }}"
+		address = "{{ .protocol }}://localhost:{{ .port }}/?type=git&repository={{ .repository }}&ref={{ .ref }}&state={{ .state }}"
+		lock_address = "{{ .protocol }}://localhost:{{ .port }}/?type=git&repository={{ .repository }}&ref={{ .ref }}&state={{ .state }}"
+		unlock_address = "{{ .protocol }}://localhost:{{ .port }}/?type=git&repository={{ .repository }}&ref={{ .ref }}&state={{ .state }}"
+		skip_cert_verification = {{ .skipHttpsVerification }}
 		username = "{{ .username }}"
 		password = "{{ .password }}"
 	}
@@ -46,14 +47,28 @@ terraform {
 			log.Fatal(err)
 		}
 
+		_, okHttpCert := os.LookupEnv("TF_BACKEND_GIT_HTTPS_CERT")
+		_, okHttpKey := os.LookupEnv("TF_BACKEND_GIT_HTTPS_KEY")
+		protocol := "http"
+		if okHttpCert && okHttpKey {
+			protocol = "https"
+		}
+
+		skipHttpsVerification, okSkipHttpsVerification := os.LookupEnv("TF_BACKEND_GIT_HTTPS_SKIP_VERIFICATION")
+		if !okSkipHttpsVerification {
+			skipHttpsVerification = "false"
+		}
+
 		username, _ := os.LookupEnv("TF_BACKEND_GIT_HTTP_USERNAME")
 		password, _ := os.LookupEnv("TF_BACKEND_GIT_HTTP_PASSWORD")
 
 		addr := strings.Split(viper.GetString("address"), ":")
 		p := map[string]string{
-			"port":     addr[len(addr)-1],
-			"username": username,
-			"password": password,
+			"port":                  addr[len(addr)-1],
+			"protocol":              protocol,
+			"skipHttpsVerification": skipHttpsVerification,
+			"username":              username,
+			"password":              password,
 		}
 
 		for _, flag := range []string{"repository", "ref", "state"} {

server/server.go

@@ -34,7 +34,14 @@ func Start() {
 
 	address := viper.GetString("address")
 	log.Println("listen on", address)
-	log.Fatal(http.ListenAndServe(address, mux))
+
+	httpCert, okHttpCert := os.LookupEnv("TF_BACKEND_GIT_HTTPS_CERT")
+	httpKey, okHttpKey := os.LookupEnv("TF_BACKEND_GIT_HTTPS_KEY")
+	if okHttpCert && okHttpKey {
+		log.Fatal(http.ListenAndServeTLS(address, httpCert, httpKey, mux))
+	} else {
+		log.Fatal(http.ListenAndServe(address, mux))
+	}
 }
 
 // basicAuth checking for user authentication
@@ -163,7 +170,7 @@ func handleFunc(response http.ResponseWriter, request *http.Request) {
 
 		response.Header().Set("Content-Type", "application/json")
 		response.WriteHeader(http.StatusOK)
-		response.Write(state)
+		_, _ = response.Write(state)
 	case http.MethodPost:
 		log.Printf("Saving state to %s", metadata.Params.String())
 
@@ -221,25 +228,24 @@ func (handler *handler) clientError(err error) {
 // If error was unknown, just use defaultCode and defaultResponse error message.
 func (handler *handler) responseError(defaultCode int, defaultResponse string, actualErr error) {
 	log.Printf("%s", actualErr)
-	switch actualErr.(type) {
+	switch actualErr := actualErr.(type) {
 	case *types.ErrLocked:
 		handler.Response.WriteHeader(http.StatusConflict)
-		handler.Response.Write(actualErr.(*types.ErrLocked).Lock)
+		_, _ = handler.Response.Write(actualErr.Lock)
 	default:
 		switch actualErr {
 		case types.ErrLockMissing:
 			handler.Response.WriteHeader(http.StatusPreconditionRequired)
-			handler.Response.Write([]byte("428 - Locking Required"))
+			_, _ = handler.Response.Write([]byte("428 - Locking Required"))
 		case types.ErrStateDidNotExisted:
 			handler.Response.WriteHeader(http.StatusNoContent)
 		case types.ErrUnauthorized:
 			handler.Response.Header().Set("WWW-Authenticate", `Basic realm=terraform-backend-git`)
 			handler.Response.WriteHeader(http.StatusUnauthorized)
-			handler.Response.Write([]byte("401 - Unauthorized"))
+			_, _ = handler.Response.Write([]byte("401 - Unauthorized"))
 		default:
 			handler.Response.WriteHeader(defaultCode)
-			handler.Response.Write([]byte(defaultResponse))
+			_, _ = handler.Response.Write([]byte(defaultResponse))
 		}
-
 	}
 }

test/tf/localhost.crt

@@ -0,0 +1,18 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

test/tf/localhost.key

@@ -0,0 +1,28 @@
+-----BEGIN PRIVATE KEY-----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+9iWY4RMCgYEAyshJUqOp8p/M1F0jZudeAgoZ/i3pvFSJ80o2qaSKft7bx5qjhz9r
+M/mkPgObksOlzAtaoXaxmJ0P0VXWJdrJGxujskQudDub5HFNKkxbqs1p3RwxfNZt
++GY7vUKnBBqk7PBQanen1lurKpVfVcREI5lcszIvN+er7qyvtIDFnnkCgYEA2/wy
+xVUwb3AQUsFcH1BLK2hncPntTcZeobyklo6Y/syL+ZPk2Ihg85hONspKnczyv/jd
+SR3He1gEtz1YgKID8co8b9ml0d2qpaUKRMVzrIA7b+y/SRXpkQl6nruichfU+5NX
+J6AcsPpj0OWvCuRmTeWVtCIZe8E+6nItZ/g4TWcCgYEA5ioiA6/uVlOwYF/Pckxc
+9jJM6Pr+/taQkkdmrIo+kn2sBqq0v01pns9gMm243fWibp9rCanh6g5fNdgWErqB
+vOTzHENSMXZsdki+yWrlCswT9cldNcd1dYSMHVHulWQOSB5zF7YBi0WhQMa3coox
+6k4TesK9sHln8317eDYQlV0=
+-----END PRIVATE KEY-----