cmd/monfront - import monfront from separate repository

This is the import from the separate monfront repository. The history
could not be imported, but this should suffice.

1 files changed, 153 insertions, 0 deletions

diff --git a/cmd/monfront/server.go b/cmd/monfront/server.go
new file mode 100644
index 0000000..2ada1d0
--- /dev/null
+++ b/cmd/monfront/server.go
@@ -0,0 +1,153 @@
+package main
+
+import (
+	"compress/gzip"
+	"database/sql"
+	"encoding/json"
+	"fmt"
+	"html/template"
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"strings"
+	"time"
+)
+
+type (
+	server struct {
+		listen net.Listener
+		db     *sql.DB
+		h      *http.ServeMux
+		tmpl   *template.Template
+		auth   func(c *Context) error // authentication
+		autho  func(c *Context) error // authorization
+	}
+
+	handleFunc func(c *Context)
+
+	Context struct {
+		// internal maintenance stuff
+		w    http.ResponseWriter
+		r    *http.Request
+		tmpl *template.Template
+		db   *sql.DB
+
+		User    string  `json:"-"`
+		Filter  *filter `json:"-"`
+		CanEdit bool    `json:"-"` // has user permission to edit stuff?
+
+		Title        string                   `json:"title,omitempty"`
+		CurrentPath  string                   `json:"-"`
+		Error        string                   `json:"error,omitempty"`
+		Mappings     map[int]map[int]MapEntry `json:"mappings,omitempty"`
+		Commands     map[string]int           `json:"commands,omitempty"`
+		Checks       []check                  `json:"checks,omitempty"`
+		CheckDetails *checkDetails            `json:"check_details,omitempty"`
+		Groups       []group                  `json:"groups,omitempty"`
+		Unhandled    bool                     `json:"-"` // set this flag when unhandled was called
+	}
+)
+
+func newServer(l net.Listener, db *sql.DB, tmpl *template.Template, auth func(c *Context) error, autho func(c *Context) error) *server {
+	s := &server{
+		listen: l,
+		db:     db,
+		tmpl:   tmpl,
+		h:      http.NewServeMux(),
+		auth:   auth,
+		autho:  autho,
+	}
+	return s
+}
+
+func (s *server) ListenAndServe() error {
+	server := http.Server{Handler: s.h}
+	return server.Serve(s.listen)
+}
+
+func (s *server) Handle(path string, fun handleFunc) {
+	s.h.HandleFunc(path, func(w http.ResponseWriter, r *http.Request) {
+		c := &Context{
+			w:    w,
+			r:    r,
+			tmpl: s.tmpl,
+			db:   s.db,
+		}
+		if err := s.auth(c); err != nil {
+			return
+		}
+		if err := s.autho(c); err != nil {
+			return
+		}
+		fun(c)
+		return
+	})
+}
+
+func (s *server) HandleStatic(path string, h func(w http.ResponseWriter, r *http.Request)) {
+	s.h.HandleFunc(path, h)
+}
+
+// Render calls the template with the given name to
+// render the appropiate content.
+// In case of an error, a error message is automatically pushed
+// to the client.
+func (c *Context) Render(t string) error {
+	var w io.Writer = c.w
+	if strings.Contains(c.r.Header.Get("Accept-Encoding"), "gzip") {
+		gz, err := gzip.NewWriterLevel(w, 5)
+		if err != nil {
+			log.Printf("could not create gzip writer: %s", err)
+			return fmt.Errorf("could not create gzip writer: %s", err)
+		}
+		defer gz.Close()
+		w = gz
+		c.w.Header().Set("Content-Encoding", "gzip")
+	}
+
+	if c.r.Header.Get("Accept") == "application/json" {
+		c.w.Header().Set("Content-Type", "application/json")
+		enc := json.NewEncoder(w)
+		enc.SetIndent("", "") // disable indentation to save traffic
+		if err := enc.Encode(c); err != nil {
+			c.w.WriteHeader(http.StatusInternalServerError)
+			c.w.Write([]byte("could not write json output"))
+			log.Printf("could not write json output: %s", err)
+			return err
+		}
+		return nil
+	}
+
+	if err := c.tmpl.ExecuteTemplate(w, t, c); err != nil {
+		c.w.WriteHeader(http.StatusInternalServerError)
+		c.w.Write([]byte("problem with a template"))
+		log.Printf("could not execute template: %s", err)
+		return err
+	}
+	return nil
+}
+
+// Get a cookie value.
+func (c *Context) GetCookieVal(name string) string {
+	cook, err := c.r.Cookie(name)
+	if err == http.ErrNoCookie {
+		return ""
+	}
+	return cook.Value
+}
+
+// Set a new key value cookie with a deadline.
+func (c *Context) SetCookie(name, val string, expire time.Time) {
+	cook := http.Cookie{
+		Name:     name,
+		Value:    val,
+		Expires:  expire,
+		Secure:   true,
+		SameSite: http.SameSiteStrictMode,
+		HttpOnly: true,
+		Path:     "/",
+	}
+	http.SetCookie(c.w, &cook)
+	return
+}