This was initially added to avoid restarts if poolmgr starts before
fission api; but we don't really need that since k8s will restart
it. Also, poolmgr now talks to the k8s api directly instead of the
fission api.
This changes the core fission function, environment and trigger types. It also changes Fission's storage to use ThirdPartyResources.
- Functions are now specified by packages. Functions can also have both source and deployment packages. A package can be specified by a literal, or by a URL.
- Environments have a build and runtime component.
- Triggers reference functions by a FunctionReference. This is a layer of indirection between triggers and functions, and will allow things like incremental function upgrades in future releases.
See Documentation/wip/env-v2.md for design discussion about points 1 and 2.
Changes:
* V2 Types
All types now have a spec, following the pattern of K8s objects.
Functions now have source and deployment packages. A Package can be
specified by literal, or by URL.
Environments now have a builder and runtime component.
All triggers use a new FunctionReference to specify the function. This
for now only uses a function name, but in the future can be extended
to be more flexible.
A new FunctionLoadRequest type is added for specialization requests to
the environment runtime.
* TPR types, TPR init code, and a "fission client"
Implements TPR types using the spec types in fission/types.go.
Adds code for adding creating TPR types, and convenient types for crud
operations on each of our resource types.
Adds code for connecting to K8s API and configuring a REST client with
fission types set up.
* Change old stateful controller into a thin apiserver
This apiserver is now simply a stateless api layer on top of the TPR
types. At the moment it doesn't do anything that couldn't be done by
simply talking to the TPR types. In the future we can have better
validation and potentially some higher level APIs (like versioning for
example) in here.
* Split controller client into files and update for v2 types.
* Update CLI for v2 types.
As far as possible we keep the CLI flags the same. We'll have to add
flags for source/deploy packages and builder/runtime
environments. That will come in the next change.
* Update poolmgr and fetcher for v2 types.
Also adds a poolmgr_test.
* Update router for new types.
Also adds a function reference resolver, which separates out the job
of resolving a FunctionReference to a function.
* Update kubewatcher and timer for v2 types.
* Update Message Queue trigger type for v2 types.
* Minor odds and ends.
* Fission bundle CLI updates
Remove controllerUrl flag, since we don't need it any more.
* Remove etcd deployment (replaced by storing state in TPR)
Also update the poolmgr commandline, and use an env var for the
fetcher image URL.
* Explicit ChecksumType and consts
* Clarify separation of environment interface types
The generic pool manager creates a generic pool with the reference of environment metadata. Since the reference is address of loop variable, so the content of metadata will be replaced with the last element of envs. So pool manager sets up logging with wrong env.
Label all poolmgr-created resources with an id that's unique to a
running poolmgr instance. On poolmgr start up, clean up resources
created by old instances. Resources that are idle are killed
immediately; resources that could be running a user function are
killed after the maximum function timeout.
Move separate caches to one cache -- functionServiceCache. It can be
looked up by function, can update atime by address, and can be deleted
by podname. This removes the other caches. Some of the concurrency
logic is still a bit hairy; it might be better not to use fission.Cache.
:= attempts to declare as many of the variables on its left side as it
can, instead of re-using as many as it can. Consider this code:
a, ok := foo()
if !ok {
a, err := bar()
...
}
The inner 'a' is a different var from the outer one, and goes out of
scope at the }. The outer 'a' is left with whatever value foo()
returned.
Switch to client-go package instead of pulling the from kubernetes.
Use a versioned client with sensible compatiblity.
This change breaks 'go get'. For now you have to manually checkout
the 'release-1.4' branch of the client-go package after 'go get'
fetches it. TODO: use one of the build tools to fix this.
GenericPool is a pool of generic containers for an environment.
GenericPoolManager keeps track of all GenericPools, creating them
on-demand.
The pool manager API is simply a "lookup" for the service URL of a
function. If one exists it is returned immediately; otherwise, a
generic pool is created, and then a pod is specialized from that pool.
poolmgr is designed to run from within the cluster, since it connects
to pod IP addresses directly.
This is a first cut with many pieces missing.
TODO:
* Use versioned kubernetes clients instead of the unversioned one
* Unit tests for GenericPoolMgr; improve unit test for GenericPool;
test for API.
* Handle cases where a service exists but pod backing it has failed.
* On start up, use existing deployments/pods/services if they exist;
in other words don't orphan resources on restart.
* Kill idle resources (services, pods, even generic pools)
* Autoscale generic pool (for example, by watching num ready pods)
Soam Vasani