Parameters for ExecStart are body, not query

Oops. Misread the docs when I initially implemented this. Nice
and easy fix, at least.

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

pkg/api/handlers/compat/exec.go

@@ -159,33 +159,23 @@ func ExecResizeHandler(w http.ResponseWriter, r *http.Request) {
 // ExecStartHandler runs a given exec session.
 func ExecStartHandler(w http.ResponseWriter, r *http.Request) {
 	runtime := r.Context().Value("runtime").(*libpod.Runtime)
-	decoder := r.Context().Value("decoder").(*schema.Decoder)
 
 	sessionID := mux.Vars(r)["id"]
 
-	// TODO: Need to support these
-	query := struct {
-		Detach bool `schema:"Detach"`
-		Tty    bool `schema:"Tty"`
-	}{
-		// override any golang type defaults
-	}
-	if err := decoder.Decode(&query, r.URL.Query()); err != nil {
+	// TODO: We should read/support Tty and Detach from here.
+	bodyParams := new(handlers.ExecStartConfig)
+
+	if err := json.NewDecoder(r.Body).Decode(&bodyParams); err != nil {
 		utils.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest,
-			errors.Wrapf(err, "Failed to parse parameters for %s", r.URL.String()))
+			errors.Wrapf(err, "failed to decode parameters for %s", r.URL.String()))
 		return
 	}
-
-	if _, found := r.URL.Query()["Detach"]; found {
+	if bodyParams.Detach == true {
 		utils.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest,
 			errors.Errorf("Detached exec is not yet supported"))
 		return
 	}
-	if _, found := r.URL.Query()["Tty"]; found {
-		utils.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest,
-			errors.Errorf("overriding terminal setting in ExecStart is not yet supported"))
-		return
-	}
+	// TODO: Verify TTY setting against what inspect session was made with
 
 	sessionCtr, err := runtime.GetExecSessionContainer(sessionID)
 	if err != nil {

pkg/api/handlers/types.go

@@ -170,6 +170,11 @@ type ExecCreateResponse struct {
 	docker.IDResponse
 }
 
+type ExecStartConfig struct {
+	Detach bool `json:"Detach"`
+	Tty    bool `json:"Tty"`
+}
+
 func ImageToImageSummary(l *libpodImage.Image) (*entities.ImageSummary, error) {
 	containers, err := l.Containers()
 	if err != nil {