fn: user friendly timeout handling changes (#1021)

* fn: user friendly timeout handling changes

Timeout setting in routes now means "maximum amount
of time a function can run in a container".

Total wait time for a given http request is now expected
to be handled by the client. As long as the client waits,
the LB, runner or agents will search for resources to
schedule it.

api/agent/lb_agent.go

@@ -7,7 +7,6 @@ import (
 	"io"
 	"io/ioutil"
 	"sync/atomic"
-	"time"
 
 	"github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
@@ -104,20 +103,18 @@ func (a *lbAgent) GetCall(opts ...CallOpt) (Call, error) {
 	if c.req == nil || c.Call == nil {
 		return nil, errors.New("no model or request provided for call")
 	}
+
 	err := setMaxBodyLimit(&a.cfg, &c)
 	if err != nil {
 		return nil, err
 	}
 
+	setupCtx(&c)
+
+	c.isLB = true
 	c.da = a.da
 	c.ct = a
 	c.stderr = &nullReadWriter{}
-
-	ctx, _ := common.LoggerWithFields(c.req.Context(),
-		logrus.Fields{"id": c.ID, "app_id": c.AppID, "route": c.Path})
-	c.req = c.req.WithContext(ctx)
-
-	c.lbDeadline = time.Now().Add(time.Duration(c.Call.Timeout) * time.Second)
 	c.slotHashId = getSlotQueueKey(&c)
 
 	return &c, nil
@@ -157,12 +154,7 @@ func (a *lbAgent) Submit(callI Call) error {
 	}
 
 	call := callI.(*call)
-
-	ctx, cancel := context.WithDeadline(call.req.Context(), call.lbDeadline)
-	call.req = call.req.WithContext(ctx)
-	defer cancel()
-
-	ctx, span := trace.StartSpan(ctx, "agent_submit")
+	ctx, span := trace.StartSpan(call.req.Context(), "agent_submit")
 	defer span.End()
 
 	statsEnqueue(ctx)