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Add EndpointSlice API support for Kubernetes 1.33+ #1

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49 changes: 49 additions & 0 deletions lib/strategy/kubernetes.ex
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Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,7 @@ defmodule Cluster.Strategy.Kubernetes do
Available values:

+ `:endpoints` (default)
+ `:endpoint_slices`
+ `:pods`

#### :endpoints
Expand All @@ -61,6 +62,22 @@ defmodule Cluster.Strategy.Kubernetes do
Then, this strategy will fetch the addresses of all endpoints with that label and attempt to
connect.

> **Note**: The Endpoints API is deprecated in Kubernetes 1.33. For clusters running
> Kubernetes 1.33+, use `:endpoint_slices` instead.

#### :endpoint_slices

When setting this value, this strategy will lookup IP from endpoint slices using the
`discovery.k8s.io/v1` API. This is the recommended mode for Kubernetes 1.33+ clusters
where the legacy Endpoints API is deprecated.

In order for your endpoint slices to be found they should be returned when you run:

kubectl get endpointslices -l app=myapp

Then, this strategy will fetch the addresses of all endpoint slices with that label and
attempt to connect.

#### :pods

When setting this value, this strategy will lookup IP from pods directly.
Expand Down Expand Up @@ -400,6 +417,9 @@ defmodule Cluster.Strategy.Kubernetes do
:endpoints ->
"api/v1/namespaces/#{namespace}/endpoints?#{query_params}"

:endpoint_slices ->
"apis/discovery.k8s.io/v1/namespaces/#{namespace}/endpointslices?#{query_params}"

:pods ->
"api/v1/namespaces/#{namespace}/pods?#{query_params}"
end
Expand Down Expand Up @@ -490,6 +510,35 @@ defmodule Cluster.Strategy.Kubernetes do
end
end

defp parse_response(:endpoint_slices, resp) do
case resp do
%{"items" => items} when is_list(items) ->
Enum.reduce(items, [], fn
%{"endpoints" => endpoints} = _slice, acc when is_list(endpoints) ->
addrs =
Enum.flat_map(endpoints, fn
%{"addresses" => addresses, "targetRef" => %{"namespace" => namespace}} =
endpoint
when is_list(addresses) ->
Enum.map(addresses, fn ip ->
%{ip: ip, namespace: namespace, hostname: endpoint["hostname"]}
end)

_ ->
[]
end)

acc ++ addrs

_, acc ->
acc
end)

_ ->
[]
end
end

defp parse_response(:pods, resp) do
case resp do
%{"items" => items} when is_list(items) ->
Expand Down
66 changes: 66 additions & 0 deletions test/fixtures/vcr_cassettes/kubernetes_endpoint_slices.json
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Original file line number Diff line number Diff line change
@@ -0,0 +1,66 @@
[
{
"request": {
"body": "",
"headers": {
"authorization": "***"
},
"method": "get",
"options": {
"httpc_options": [],
"http_options": {
"ssl": "[verify: :verify_none]"
}
},
"request_body": "",
"url": "https://cluster.localhost./apis/discovery.k8s.io/v1/namespaces/__libcluster_test/endpointslices?labelSelector=app=test_selector"
},
"response": {
"binary": false,
"body": "{\"kind\":\"EndpointSliceList\",\"apiVersion\":\"discovery.k8s.io/v1\",\"metadata\":{\"resourceVersion\":\"17042410\"},\"items\":[{\"metadata\":{\"name\":\"development-development-abc12\",\"namespace\":\"airatel-service-localization\",\"uid\":\"7e3faf1e-0294-11e8-bcad-42010a9c01cc\",\"resourceVersion\":\"17037787\",\"creationTimestamp\":\"2018-01-26T12:29:03Z\",\"labels\":{\"app\":\"development\",\"kubernetes.io/service-name\":\"development-development\"}},\"addressType\":\"IPv4\",\"endpoints\":[{\"addresses\":[\"10.48.33.136\"],\"hostname\":\"my-hostname-0\",\"conditions\":{\"ready\":true,\"serving\":true,\"terminating\":false},\"targetRef\":{\"kind\":\"Pod\",\"namespace\":\"airatel-service-localization\",\"name\":\"development-4292695165-mgq9f\",\"uid\":\"eb0f3e80-0295-11e8-bcad-42010a9c01cc\"}}],\"ports\":[{\"name\":\"web\",\"port\":8443,\"protocol\":\"TCP\"}]}]}\n",
"headers": {
"date": "Fri, 26 Jan 2018 13:18:46 GMT",
"content-length": "877",
"content-type": "application/json"
},
"status_code": [
"HTTP/1.1",
200,
"OK"
],
"type": "ok"
}
},
{
"request": {
"body": "",
"headers": {
"authorization": "***"
},
"method": "get",
"options": {
"httpc_options": [],
"http_options": {
"ssl": "[verify: :verify_none]"
}
},
"request_body": "",
"url": "https://cluster.localhost./apis/discovery.k8s.io/v1/namespaces/__libcluster_test/endpointslices?labelSelector=app=test_selector&resourceVersion=0"
},
"response": {
"binary": false,
"body": "{\"kind\":\"EndpointSliceList\",\"apiVersion\":\"discovery.k8s.io/v1\",\"metadata\":{\"resourceVersion\":\"17042410\"},\"items\":[{\"metadata\":{\"name\":\"development-development-abc12\",\"namespace\":\"airatel-service-localization\",\"uid\":\"7e3faf1e-0294-11e8-bcad-42010a9c01cc\",\"resourceVersion\":\"17037787\",\"creationTimestamp\":\"2018-01-26T12:29:03Z\",\"labels\":{\"app\":\"development\",\"kubernetes.io/service-name\":\"development-development\"}},\"addressType\":\"IPv4\",\"endpoints\":[{\"addresses\":[\"10.48.33.136\"],\"hostname\":\"my-hostname-0\",\"conditions\":{\"ready\":true,\"serving\":true,\"terminating\":false},\"targetRef\":{\"kind\":\"Pod\",\"namespace\":\"airatel-service-localization\",\"name\":\"development-4292695165-mgq9f\",\"uid\":\"eb0f3e80-0295-11e8-bcad-42010a9c01cc\"}}],\"ports\":[{\"name\":\"web\",\"port\":8443,\"protocol\":\"TCP\"}]}]}\n",
"headers": {
"date": "Fri, 26 Jan 2018 13:18:46 GMT",
"content-length": "877",
"content-type": "application/json"
},
"status_code": [
"HTTP/1.1",
200,
"OK"
],
"type": "ok"
}
}
]
118 changes: 118 additions & 0 deletions test/kubernetes_test.exs
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Original file line number Diff line number Diff line change
Expand Up @@ -228,6 +228,124 @@ defmodule Cluster.Strategy.KubernetesTest do
end
end

test "works with endpoint_slices" do
use_cassette "kubernetes_endpoint_slices", custom: true do
capture_log(fn ->
start_supervised!({Kubernetes,
[
%Cluster.Strategy.State{
topology: :name,
config: [
kubernetes_node_basename: "test_basename",
kubernetes_selector: "app=test_selector",
kubernetes_ip_lookup_mode: :endpoint_slices,
# If you want to run the test freshly, you'll need to create a DNS Entry
kubernetes_master: "cluster.localhost.",
kubernetes_service_account_path:
Path.join([__DIR__, "fixtures", "kubernetes", "service_account"])
],
connect: {Nodes, :connect, [self()]},
disconnect: {Nodes, :disconnect, [self()]},
list_nodes: {Nodes, :list_nodes, [[]]}
}
]})

assert_receive {:connect, :"test_basename@10.48.33.136"}, 5_000
end)
end
end

test "works with endpoint_slices and cached resources" do
use_cassette "kubernetes_endpoint_slices", custom: true do
capture_log(fn ->
start_supervised!({Kubernetes,
[
%Cluster.Strategy.State{
topology: :name,
config: [
kubernetes_node_basename: "test_basename",
kubernetes_selector: "app=test_selector",
kubernetes_ip_lookup_mode: :endpoint_slices,
kubernetes_use_cached_resources: true,
# If you want to run the test freshly, you'll need to create a DNS Entry
kubernetes_master: "cluster.localhost.",
kubernetes_service_account_path:
Path.join([__DIR__, "fixtures", "kubernetes", "service_account"])
],
connect: {Nodes, :connect, [self()]},
disconnect: {Nodes, :disconnect, [self()]},
list_nodes: {Nodes, :list_nodes, [[]]}
}
]})

assert_receive {:connect, :"test_basename@10.48.33.136"}, 5_000
end)
end
end

test "works with endpoint_slices and hostname mode" do
use_cassette "kubernetes_endpoint_slices", custom: true do
capture_log(fn ->
start_supervised!({Kubernetes,
[
%Cluster.Strategy.State{
topology: :name,
config: [
kubernetes_node_basename: "test_basename",
kubernetes_cluster_name: "my_cluster",
kubernetes_ip_lookup_mode: :endpoint_slices,
mode: :hostname,
kubernetes_selector: "app=test_selector",
kubernetes_service_name: "my_service",
# If you want to run the test freshly, you'll need to create a DNS Entry
kubernetes_master: "cluster.localhost.",
kubernetes_service_account_path:
Path.join([__DIR__, "fixtures", "kubernetes", "service_account"])
],
connect: {Nodes, :connect, [self()]},
disconnect: {Nodes, :disconnect, [self()]},
list_nodes: {Nodes, :list_nodes, [[]]}
}
]})

assert_receive {:connect,
:"test_basename@my-hostname-0.my_service.airatel-service-localization.svc.my_cluster.local"},
5_000
end)
end
end

test "works with endpoint_slices and dns mode" do
use_cassette "kubernetes_endpoint_slices", custom: true do
capture_log(fn ->
start_supervised!({Kubernetes,
[
%Cluster.Strategy.State{
topology: :name,
config: [
kubernetes_node_basename: "test_basename",
kubernetes_cluster_name: "my_cluster",
kubernetes_ip_lookup_mode: :endpoint_slices,
mode: :dns,
kubernetes_selector: "app=test_selector",
# If you want to run the test freshly, you'll need to create a DNS Entry
kubernetes_master: "cluster.localhost.",
kubernetes_service_account_path:
Path.join([__DIR__, "fixtures", "kubernetes", "service_account"])
],
connect: {Nodes, :connect, [self()]},
disconnect: {Nodes, :disconnect, [self()]},
list_nodes: {Nodes, :list_nodes, [[]]}
}
]})

assert_receive {:connect,
:"test_basename@10-48-33-136.airatel-service-localization.pod.my_cluster.local"},
5_000
end)
end
end

test "works with pods" do
use_cassette "kubernetes_pods", custom: true do
capture_log(fn ->
Expand Down