web status: add alert_msg

implement a simple way for action ressources to report errors to users

if action resource returns a tuple, then it is URL, alert_msg, the message is displayed
in the next web page

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>

master/buildbot/status/web/base.py

@@ -213,6 +213,7 @@ def getContext(self, request):
                     welcomeurl = rootpath,
                     authz = self.getAuthz(request),
                     request = request,
+                    alert_msg = request.args.get("alert_msg", [""])[0],
                     )
 
 
@@ -230,11 +231,17 @@ def performAction(self, request):
 
         @param request: the web request
         @returns: URL via Deferred
+		  can also return (URL, alert_msg) to display simple 
+		  feedback to user in case of failure
         """
 
     def render(self, request):
         d = defer.maybeDeferred(lambda : self.performAction(request))
         def redirect(url):
+            if isinstance(url, tuple):
+                url, alert_msg = url
+                if alert_msg:
+                    url += "?alert_msg="+urllib.quote(alert_msg, safe='')
             request.redirect(url)
             request.write("see <a href='%s'>%s</a>" % (url,url))
             try:

master/buildbot/status/web/build.py

@@ -58,19 +58,24 @@ def performAction(self, req):
             comments = req.args.get("comments", ["<no reason specified>"])[0]
             reason = ("The web-page 'rebuild' button was pressed by "
                       "'%s': %s\n" % (name, comments))
+            msg = ""
             extraProperties = getAndCheckProperties(req)
             if not bc or not b.isFinished() or extraProperties is None:
-                log.msg("could not rebuild: bc=%s, isFinished=%s"
-                        % (bc, b.isFinished()))
-                # TODO: indicate an error
+                msg = "could not rebuild: "
+                if b.isFinished():
+                    msg += "build still not finished "
+                if bc:
+                    msg += "could not get builder control"
             else:
                 d = bc.rebuildBuild(b, reason, extraProperties)
                 wfd = defer.waitForDeferred(d)
                 yield wfd
                 tup = wfd.getResult()
                 # check that (bsid, brids) were properly stored
-                if not isinstance(tup, (int, dict)):
-                    log.err("while rebuilding a build")
+                if not (isinstance(tup, tuple) and 
+                        isinstance(tup[0], int) and
+                        isinstance(tup[1], dict)):
+                    msg = "rebuilding a build failed "+ str(tup)
             # we're at
             # http://localhost:8080/builders/NAME/builds/5/rebuild?[args]
             # Where should we send them?
@@ -82,7 +87,7 @@ def performAction(self, req):
             # evidence of their build starting (or to see the reason that it
             # didn't start). This should be the Builder page.
 
-            url = path_to_builder(req, self.builder)
+            url = path_to_builder(req, self.builder), msg
         yield url
 
 

master/buildbot/status/web/templates/layout.html

@@ -51,6 +51,12 @@
 
     {%- block barecontent -%}
     <hr/>
+
+    {% if alert_msg != "" %}
+    <div class="alert">    
+    {{ alert_msg }}
+    </div>
+    {% endif %}
 
     <div class="content">
       {%- block content -%}