chore: only eval env when not using dotfiles

- add docs for .ghs.yaml fields
- update default name for template config map to template-map.yaml
- update env eval for template and header values to only express when
not using dotfiles
- update to check for config files and exit cleanly if not found

docs/configuration.md

@@ -10,7 +10,7 @@
 | `APP_PORT_METRICS`                  | The port to bind for metrics traffic                          | `:2112`          |
 | `APP_HTTP_REAL_IP_HEADER`           | The HTTP header to use for real IPs                           | `""`             |
 | `APP_SERVE_FOLDER` / `KO_DATA_PATH` | The local folder path to serve                                | `./site`         |
-| `APP_TEMPLATE_MAP_PATH`             | The path to a template map                                    | `./map.yaml`     |
+| `APP_TEMPLATE_MAP_PATH`             | The path to a template map                                    | `./template-map.yaml`     |
 | `APP_VUEJS_HISTORY_MODE`            | Enable Vuejs history mode path rewriting                      | `false`          |
 | `APP_HEADER_SET_ENABLE`             | Enable header setting for requests                            | `false`          |
 | `APP_HEADER_MAP_PATH`               | The path to the header map                                    | `./headers.yaml` |
@@ -71,9 +71,22 @@ When a file called `.ghs.yaml` exists in the serve folder, it will be loaded in
 Current values for configuration are
 
 ```yaml
-historyMode: bool
-redirectRoutes: map[string]string
+error404FilePath: string
+headerMap:        map[string][]string
+historyMode:      bool
+redirectRoutes:   map[string]string
+templateMap:      map[string]string
 ```
 
 for overriding the value set by the server.
 
+## Fields
+
+The dotfile config supports a smaller and limited subset of the go-http-server settings. This is to ensure that in a self-service environment, certain configs cannot be set. The following fields are:
+
+**error404FilePath**: the path to a html document to serve the file not found message
+**headerMap**: a key+value-array pair to set headers. Values are env-evaluated (e.g: `X-Something-Important: ["Value-Here", "${SOME_ENV}"]`)
+**historyMode**: when set, rewrites all requests with the exception of assets to _index.html_
+**redirectRoutes**: a key+value pair to direct paths URLs to other URLs. (e.g: `/a: /b`)
+**templateMap**: combined with `historyMode`, use Go html templating to replace Go templating expressions in an _index.html_
+

docs/usage.md

@@ -38,28 +38,28 @@ COPY dist /app/dist
 Serve your site using history mode and Go html templating for index.html
 
 ```dockerfile
-FROM registry.gitlab.com/bobymcbobs/go-http-server:1.7.0
-env APP_SERVE_FOLDER=./dist \
+FROM registry.gitlab.com/bobymcbobs/go-http-server:latest
+ENV APP_SERVE_FOLDER=./dist \
   APP_VUEJS_HISTORY_MODE=true \
-  APP_TEMPLATE_MAP_PATH=/app/map.yaml
+  APP_TEMPLATE_MAP_PATH=/app/template-map.yaml
 COPY dist /app/dist
-COPY templatemap.yaml /app/map.yaml
+COPY template-map.yaml /app/template-map.yaml
 ```
 
 ## Vuejs + template map + headers
 
 Serve your site using history mode and Go html templating for index.html, with setting headers
 
 ```dockerfile
-FROM registry.gitlab.com/bobymcbobs/go-http-server:1.7.0
-env APP_SERVE_FOLDER=./dist \
+FROM registry.gitlab.com/bobymcbobs/go-http-server:latest
+ENV APP_SERVE_FOLDER=./dist \
   APP_VUEJS_HISTORY_MODE=true \
-  APP_TEMPLATE_MAP_PATH=/app/map.yaml \
+  APP_TEMPLATE_MAP_PATH=/app/template-map.yaml \
   APP_HEADER_SET_ENABLE=true \
   APP_HEADER_MAP_PATH=./headers.yaml
 COPY dist /app/dist
 COPY headers.yaml /app/headers.yaml
-COPY templatemap.yaml /app/map.yaml
+COPY template-map.yaml /app/template-map.yaml
 ```
 
 # Import and use

pkg/common/common.go

@@ -102,7 +102,7 @@ func GetServeFolder() (output string) {
 // GetTemplateMapPath ...
 // return the path of the template map
 func GetTemplateMapPath() (output string) {
-	return GetEnvOrDefault("APP_TEMPLATE_MAP_PATH", "./map.yaml")
+	return GetEnvOrDefault("APP_TEMPLATE_MAP_PATH", "./template-map.yaml")
 }
 
 // GetVuejsHistoryMode ...
@@ -175,17 +175,20 @@ func GetEnvOrDefault(envName string, defaultValue string) (output string) {
 
 // EvaluateEnvFromMap ...
 // evaluates environment variables from map[string]string{}
-func EvaluateEnvFromMap(input map[string]string) (output map[string]string) {
+func EvaluateEnvFromMap(input map[string]string, fromEnv bool) (output map[string]string) {
 	output = map[string]string{}
 	for index, value := range input {
-		output[index] = os.ExpandEnv(value)
+		if fromEnv {
+			value = os.ExpandEnv(value)
+		}
+		output[index] = value
 	}
 	return output
 }
 
-// LoadMapConfig ...
+// LoadTemplateMapConfig ...
 // loads map config as YAML
-func LoadMapConfig(path string) (output map[string]string, err error) {
+func LoadTemplateMapConfig(path string) (output map[string]string, err error) {
 	mapBytes, err := os.ReadFile(path)
 	if err != nil {
 		return output, fmt.Errorf("Failed to load map file: %v", err.Error())
@@ -199,11 +202,15 @@ func LoadMapConfig(path string) (output map[string]string, err error) {
 
 // EvaluateEnvFromHeaderMap ...
 // evaluates environment variables from map[string][]string
-func EvaluateEnvFromHeaderMap(input map[string][]string) (output map[string][]string) {
+func EvaluateEnvFromHeaderMap(input map[string][]string, fromEnv bool) (output map[string][]string) {
 	output = map[string][]string{}
 	for key, value := range input {
 		for _, valueSub := range value {
-			output[key] = append(output[key], os.ExpandEnv(valueSub))
+			value := valueSub
+			if fromEnv {
+				value = os.ExpandEnv(valueSub)
+			}
+			output[key] = append(output[key], value)
 		}
 	}
 	return output
@@ -212,6 +219,9 @@ func EvaluateEnvFromHeaderMap(input map[string][]string) (output map[string][]st
 // LoadHeaderMapConfig ...
 // loads map config as YAML
 func LoadHeaderMapConfig(path string) (output map[string][]string, err error) {
+	if _, err := os.Stat(path); err != nil {
+		return nil, nil
+	}
 	mapBytes, err := os.ReadFile(path)
 	if err != nil {
 		return map[string][]string{}, fmt.Errorf("Failed to load map file: %v", err.Error())
@@ -272,11 +282,11 @@ func Logging(next http.Handler) http.Handler {
 // DotfileConfig ...
 // dotfiles found in the web root
 type DotfileConfig struct {
+	Error404FilePath string              `json:"error404FilePath"`
 	HeaderMap        map[string][]string `json:"headerMap"`
 	HistoryMode      bool                `json:"historyMode"`
 	RedirectRoutes   map[string]string   `json:"redirectRoutes"`
 	TemplateMap      map[string]string   `json:"templateMap"`
-	Error404FilePath string              `json:"error404FilePath"`
 }
 
 // LoadDotfileConfig ...
@@ -300,6 +310,9 @@ func LoadDotfileConfig(serveFolder string) (cfg *DotfileConfig, err error) {
 // LoadRedirectRoutesConfig ...
 // loads map config as YAML
 func LoadRedirectRoutesConfig(path string) (output map[string]string, err error) {
+	if _, err := os.Stat(path); err != nil {
+		return nil, nil
+	}
 	mapBytes, err := os.ReadFile(path)
 	if err != nil {
 		return map[string]string{}, fmt.Errorf("Failed to load map file: %v", err.Error())

pkg/httpserver/httpserver.go

@@ -59,9 +59,10 @@ type WebServer struct {
 	TemplateMapPath       string
 	VueJSHistoryMode      bool
 
-	handler   *handlers.Handler
-	server    *http.Server
-	serverTLS *http.Server
+	handler       *handlers.Handler
+	server        *http.Server
+	serverTLS     *http.Server
+	dotfileLoaded bool
 }
 
 // NewWebServer returns a default WebServer, as per environment configuration
@@ -98,6 +99,7 @@ func NewWebServer() *WebServer {
 	if err != nil {
 		log.Printf("error loading dotfile config: %v\n", err)
 	} else if cfg != nil {
+		w.dotfileLoaded = true
 		w.VueJSHistoryMode = cfg.HistoryMode
 		if cfg.RedirectRoutes != nil {
 			w.RedirectRoutes = cfg.RedirectRoutes
@@ -210,37 +212,31 @@ func (w *WebServer) LoadTLS() *WebServer {
 
 // LoadTemplateMap loads the template map from the path
 func (w *WebServer) LoadTemplateMap() *WebServer {
-	if w.VueJSHistoryMode {
-		return w
-	}
-	if w.TemplateMap == nil {
+	if w.TemplateMap == nil && !w.dotfileLoaded {
 		if _, err := os.Stat(w.TemplateMapPath); os.IsNotExist(err) {
 			log.Printf("[notice] history mode templating is enabled, template maps (currently set to '%v') can also be used\n", w.TemplateMapPath)
 			return w
 		}
-		configMap, err := common.LoadMapConfig(w.TemplateMapPath)
+		configMap, err := common.LoadTemplateMapConfig(w.TemplateMapPath)
 		if err != nil {
 			log.Panicf("[fatal] Error template map: %v\n", err)
 		}
 		w.TemplateMap = configMap
 	}
-	w.TemplateMap = common.EvaluateEnvFromMap(w.TemplateMap)
+	w.TemplateMap = common.EvaluateEnvFromMap(w.TemplateMap, !w.dotfileLoaded)
 	w.handler.TemplateMap = w.TemplateMap
 	return w
 }
 
 // SetTemplateMap set the template map
 func (w *WebServer) SetTemplateMap(input map[string]string) *WebServer {
-	w.handler.TemplateMap = common.EvaluateEnvFromMap(input)
+	w.handler.TemplateMap = common.EvaluateEnvFromMap(input, !w.dotfileLoaded)
 	return w
 }
 
 // LoadHeaderMap loads the header map from the path
 func (w *WebServer) LoadHeaderMap() *WebServer {
-	if !w.HeaderMapEnabled {
-		return w
-	}
-	if w.HeaderMap == nil {
+	if w.HeaderMap == nil && !w.dotfileLoaded {
 		if _, err := os.Stat(w.HeaderMapPath); os.IsNotExist(err) {
 			log.Printf("[notice] header templating is enabled, header template maps (currently set to '%v') can also be used\n", w.HeaderMapPath)
 			return w
@@ -251,14 +247,14 @@ func (w *WebServer) LoadHeaderMap() *WebServer {
 		}
 		w.HeaderMap = headerMap
 	}
-	w.HeaderMap = common.EvaluateEnvFromHeaderMap(w.HeaderMap)
+	w.HeaderMap = common.EvaluateEnvFromHeaderMap(w.HeaderMap, !w.dotfileLoaded)
 	w.handler.HeaderMap = w.HeaderMap
 	return w
 }
 
 // SetHeaderMap sets the header map
 func (w *WebServer) SetHeaderMap(input map[string][]string) *WebServer {
-	w.handler.HeaderMap = common.EvaluateEnvFromHeaderMap(input)
+	w.handler.HeaderMap = common.EvaluateEnvFromHeaderMap(input, !w.dotfileLoaded)
 	return w
 }