Newdeploy backend (#387)

A newdeploy backend which uses new deployment to serve requests. This is the second phase of #193 and builds on top of changes in #384 .

* Executor layer added on top of pool manager

* Removed the external server for executor

* Minor changes to keep existing semantics as much possible

* Separating the executor vs. poolmgr backend functionality and associated data members

* Executor logic separated from Poolmgr backend completely, placeholder for new backend

* Changed references to poolmgr in tests

* Moved poolmgr to it's package, as a side effect moved Cache to its's package (was causing cyclical dependency) and had to make some data structures exposed outside package

* Rebased from master and changed references to tpr -> crd

* Executor layer added on top of pool manager

* Executor logic separated from Poolmgr backend completely, placeholder for new backend

* Changed podName to a generic objectReference in fscache (#391)

Changed podName to a generic objectReference in function service cache implementation.

* Moved poolmgr to it's package, as a side effect moved Cache to its's package (was causing cyclical dependency) and had to make some data structures exposed outside package

* Rebased from master and changed references to tpr -> crd

* Merged from master with latest changes

* Executor layer added on top of pool manager

* Removed the external server for executor

* Minor changes to keep existing semantics as much possible

* Separating the executor vs. poolmgr backend functionality and associated data members

* Executor logic separated from Poolmgr backend completely, placeholder for new backend

* Changed references to poolmgr in tests

* update compiling.md to use helm

* Compile instructions: changed pullPolicy to IfNotPresent (#378)

Containers will get stuck in ErrImagePull/ImagePullBackOff state otherwise

* Moved poolmgr to it's package, as a side effect moved Cache to its's package (was causing cyclical dependency) and had to make some data structures exposed outside package

* Fetcher called when pod is created for newDeploy backend but also supports older way, this is WIP and still needs pod specialization and creating & exposing a service so the URL can be hit by end user

* WIP Specializing the POD as part of startup along with fetching

* Working specialization of a new deployment. Needs some work on caching, cleanup etc.

* Switched to service based address instead of POD address

* Minor formating issue fixed

* Added logging to pods and a readiness check, the readiness check is flaky though ATM

* Fixed some rebase issues that were failing build

* Better names for K8S objects and methods

* Switched usage of FuncSvc in backends from pod to api.ObjectReference

* Adding retry to fetcher request, for now just using default retry client which might need tweaking in future

* Switching to plain old retry, some issue in getting retryablehttp with glide import

* Removed stale executor service & deployment from previous merge

* Addressed review comments, still testing some areas

* Added types in FunctionSpec

* Resolved conflicts due to merge from executor_abstraction branch

* Added backend type on EnvironmentSpec along with operations for create/list/update, the pools are created/destroyed based on change in backend type

* Backend from types and a minor err return issue fixed

* Draft version of CPU and memory parameters added to environment

* Added resourceReq to newDeploy, though it has some issues

* Issue with resourceName fixed, now newdeploy pods also pick up resources from the environment config

* Adding scale params, removing validation on CPU params for now

* Fixed a formatting issue

* Checking if slight more delay helps in the test which is currently failing for internal routes

* The resourceList newly added in Env can not be compared by compiler, hence must use breakdown comparison instead

* Added strategy selection on client side

* Added caching, informers, delete operations for newdeploy backend functions

* Deleted a stale directory

* A simple HPA based on scale parameters, testing still WIP

* Fixed a small issue in delete function, added HPA delete too when deleting a function

* Previous merge missed the pkg flag for update fn command somehow, fixed that

* Fixed comments from review

* Changed poolmgr cleanup to be generic cleanup and moved to executor, added instanceID labels to newdeploy so that cleanup works

* Moved instanceIdLabel to types to avoid cyclic dependency

* More review fixes

* Tweaking sleep to see results

* If user does not provide poolsize, then it should not default to zero

* Switched to naming convention for now, fixed default poolsize if not provided

* Changed error return behaviour in delete fn, also changed cleanup to look based on obj type though support for additional type will need more work

* Changed check location so avoid false logging

* Test for newdeploy backend

* Adding tests for poolmgr backend

* Fixed an issue with glide dependency version, already fixed in master

* Added instanceId for NewDeploy, Initial cleanup now cleans older objects of newdeploy backend, removed eagercreate flag and instead using minScale to drive eager creation

* Moved cleanup to executor layer with cleanup for newDeploy backend, changes to use the new Cache impl

* Cleaning up pod & rs along with deployment for newdeploy backend

* Enhanced fn and env listing to show min/maxscale and resuorces respectively

* Added conditional heapster deployment and fixed a small issue with resources for fetcher container in function pod

* Addressed review comments from previous change

* Addressed some more review comments - majorly create only on NotFoundError

* Added TargetCPU as an input for scaling

* Bumped target CPU to be greater than 0 and added a default value

* Min replicas should be 1 even if the minScale is 0 when creating deployment

* Changed name from 'backend' to executorType, added additional test for minscale 0 case, changed TargetCPU to TargetCPUPercent

executor/fscache/functionServiceCache.go

@@ -29,7 +29,7 @@ import (
 )
 
 type fscRequestType int
-type backendType int
+type executorType int
 
 const (
 	TOUCH fscRequestType = iota
@@ -38,17 +38,18 @@ const (
 )
 
 const (
-	POOLMGR backendType = iota
+	POOLMGR executorType = iota
 	NEWDEPLOY
 )
 
 type (
 	FuncSvc struct {
+		Name              string                // Name of object
 		Function          *metav1.ObjectMeta    // function this pod/service is for
 		Environment       *crd.Environment      // function's environment
 		Address           string                // Host:Port or IP:Port that the function's service can be reached at.
 		KubernetesObjects []api.ObjectReference // Kubernetes Objects (within the function namespace)
-		Backend           backendType
+		Executor          executorType
 
 		Ctime time.Time
 		Atime time.Time
@@ -135,20 +136,19 @@ func (fsc *FunctionServiceCache) GetByFunction(m *metav1.ObjectMeta) (*FuncSvc,
 	return &fsvcCopy, nil
 }
 
-// TODO: error should be second return
-func (fsc *FunctionServiceCache) Add(fsvc FuncSvc) (error, *FuncSvc) {
+func (fsc *FunctionServiceCache) Add(fsvc FuncSvc) (*FuncSvc, error) {
 	err, existing := fsc.byFunction.Set(crd.CacheKey(fsvc.Function), &fsvc)
 	if err != nil {
 		if existing != nil {
 			f := existing.(*FuncSvc)
 			err2 := fsc.TouchByAddress(f.Address)
 			if err2 != nil {
-				return err2, nil
+				return nil, err2
 			}
 			fCopy := *f
-			return err, &fCopy
+			return &fCopy, err
 		}
-		return err, nil
+		return nil, err
 	}
 	now := time.Now()
 	fsvc.Ctime = now
@@ -164,7 +164,7 @@ func (fsc *FunctionServiceCache) Add(fsvc FuncSvc) (error, *FuncSvc) {
 			}
 		}
 		log.Printf("error caching fsvc: %v", err)
-		return err, nil
+		return nil, err
 	}
 	return nil, nil
 }