Milo flex raw log viewer endpoint

milo/appengine/logs/main.go

+// Copyright 2017 The LUCI Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+package main
+
+import (
+        "fmt"
+        "log"
+        "net/http"
+        "strings"
+
+        "github.com/luci/luci-go/milo/appengine/common"
+        "github.com/luci/luci-go/server/auth"
+        "github.com/luci/luci-go/server/router"
+)
+
+// Where it all begins!!!
+func main() {
+        r := router.New()
+
+        base := common.FlexBase()
+        r.GET("/log/raw/*path", base, rawLog)
+
+        // Health check, for the appengine flex environment.
+        http.HandleFunc("/_ah/health", healthCheckHandler)
+        // And everything else.
+        http.Handle("/", r)
+
+        log.Print("Listening on port 8080")
+        log.Fatal(http.ListenAndServe(":8080", nil))

[nodir, 2017/04/29 00:59:45]

why are we unconditionally failing?
i think this should call Fatal only if ListenAndServe returned an error

[hinoka, 2017/05/01 23:08:03]

This was how the sample code did it for the appenigne flex example, so I went
along with it.  I think the theory is that ListenAndServe should never return
anything since it's an infinite loop, and if it does, it's fatal.

+}
+
+func errorPage(c *router.Context, msg string) {
+        c.Writer.WriteHeader(http.StatusInternalServerError)
+        fmt.Fprintf(c.Writer, msg)
+}
+
+func rawLog(c *router.Context) {
+        path := c.Params.ByName("path")
+        if path == "" {
+                errorPage(c, "missing path")

[nodir, 2017/04/29 00:59:45]

this should be http 400, not 500

[hinoka, 2017/05/01 23:08:03]

Done.

+                return
+        }
+        path = strings.TrimLeft(path, "/")
+        host := c.Request.FormValue("host")
+        if host == "" {
+                host = "luci-logdog.appspot.com"
+        }
+        err := logHandler(c.Context, c.Writer, host, path)
+        switch err {
+        case nil:
+                // Everything is fine
+        case errNoAuth:
+                // Redirect to login page
+                loginURL, err := auth.LoginURL(c.Context, c.Request.URL.Path)
+                if err != nil {
+                        fmt.Fprintf(c.Writer, "Encountered error generating login url: %s\n", err.Error())
+                        return
+                }
+                http.Redirect(c.Writer, c.Request, loginURL, http.StatusTemporaryRedirect)
+                return
+        default:
+                fmt.Fprintf(c.Writer, "Encountered error: %s", err.Error())
+        }
+}
+
+func healthCheckHandler(w http.ResponseWriter, r *http.Request) {
+        fmt.Fprint(w, "ok")
+}