Support building an allow-list of providers (#527)

* Add providers subcommand to verify providers

Allows users to check what providers are available

* Fix version output to add new line

This command was totally broken until we moved around the call to
`initConfig()`, this just fixes the output now that it works.

* Flip boolean of provider include tags

All providers are still included by default and fix tags using the old
format.

Makefile

@@ -4,10 +4,11 @@ DOCKER_IMAGE := virtual-kubelet
 exec := $(DOCKER_IMAGE)
 github_repo := virtual-kubelet/virtual-kubelet
 binary := virtual-kubelet
-build_tags := "netgo osusergo $(VK_BUILD_TAGS)"
+build_tags := netgo osusergo $(VK_BUILD_TAGS)
+
 
 # comment this line out for quieter things
-#V := 1 # When V is set, print commands and build progress.
+# V := 1 # When V is set, print commands and build progress.
 
 # Space separated patterns of packages to skip in list, test, format.
 IGNORED_PACKAGES := /vendor/
@@ -22,9 +23,10 @@ safebuild:
 	$Q docker build --build-arg BUILD_TAGS=$(build_tags) -t $(DOCKER_IMAGE):$(VERSION) .
 
 .PHONY: build
+build: build_tags_actual := $(shell scripts/process_build_tags.sh $(build_tags))
 build: authors
 	@echo "Building..."
-	$Q CGO_ENABLED=0 go build -a --tags $(build_tags) -ldflags '-extldflags "-static"' -o bin/$(binary) $(if $V,-v) $(VERSION_FLAGS) $(IMPORT_PATH)
+	$Q CGO_ENABLED=0 go build -a --tags '$(build_tags_actual)' -ldflags '-extldflags "-static"' -o bin/$(binary) $(if $V,-v) $(VERSION_FLAGS) $(IMPORT_PATH)
 
 .PHONY: tags
 tags:
@@ -117,20 +119,26 @@ format: $(GOPATH)/bin/goimports
 	$Q find . -iname \*.go | grep -v \
         -e "^$$" $(addprefix -e ,$(IGNORED_PACKAGES)) | xargs goimports -w
 
+.PHONY: skaffold-validate
+skaffold-validate:
+	@if [[ ! "minikube,docker-for-desktop" =~ .*"$(kubectl_context)".* ]]; then \
+		echo current-context is [$(kubectl_context)]. Must be one of [minikube,docker-for-desktop]; false; \
+	fi
+
+.PHONY: skaffold-build
+skaffold-build: tags_with_mock := $(VK_BUILD_TAGS) mock_provider
+skaffold-build:
+	@if [[ ! "$(MODE)" == "delete" ]]; then \
+		GOOS=linux GOARCH=amd64 $(MAKE) VK_BUILD_TAGS="$(tags_with_mock)" build; \
+	fi
+
 # skaffold deploys the virtual-kubelet to the Kubernetes cluster targeted by the current kubeconfig using skaffold.
 # The current context (as indicated by "kubectl config current-context") must be one of "minikube" or "docker-for-desktop".
 # MODE must be set to one of "dev" (default), "delete" or "run", and is used as the skaffold command to be run.
 .PHONY: skaffold
 skaffold: MODE ?= dev
 skaffold: PROFILE := local
-skaffold: VK_BUILD_TAGS ?= no_alibabacloud_provider no_aws_provider no_azure_provider no_azurebatch_provider no_cri_provider no_huawei_provider no_vic_provider no_web_provider
-skaffold:
-	@if [[ ! "minikube,docker-for-desktop" =~ .*"$(kubectl_context)".* ]]; then \
-		echo current-context is [$(kubectl_context)]. Must be one of [minikube,docker-for-desktop]; false; \
-	fi
-	@if [[ ! "$(MODE)" == "delete" ]]; then \
-		GOOS=linux GOARCH=amd64 VK_BUILD_TAGS="$(VK_BUILD_TAGS)" $(MAKE) build; \
-	fi
+skaffold: skaffold-validate skaffold-build
 	@skaffold $(MODE) \
 		-f $(PWD)/hack/skaffold/virtual-kubelet/skaffold.yml \
 		-p $(PROFILE)

cmd/providers.go

@@ -0,0 +1,55 @@
+// Copyright © 2017 NAME HERE <EMAIL ADDRESS>
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+	"github.com/virtual-kubelet/virtual-kubelet/providers/register"
+)
+
+// versionCmd represents the version command
+var providersCmd = &cobra.Command{
+	Use:   "providers",
+	Short: "Show the list of supported providers",
+	Long:  "Show the list of supported providers",
+	Args:  cobra.MaximumNArgs(2),
+	Run: func(cmd *cobra.Command, args []string) {
+		switch len(args) {
+		case 0:
+			ls := register.List()
+			for _, p := range ls {
+				fmt.Fprintln(cmd.OutOrStdout(), p)
+			}
+		case 1:
+			if !register.Exists(args[0]) {
+				fmt.Fprintln(cmd.OutOrStderr(), "no such provider", args[0])
+
+				// TODO(@cpuuy83): would be nice to not short-circuit the exit here
+				// But at the momemt this seems to be the only way to exit non-zero and
+				// handle our own error output
+				os.Exit(1)
+			}
+			fmt.Fprintln(cmd.OutOrStdout(), args[0])
+		}
+		return
+	},
+}
+
+func init() {
+	RootCmd.AddCommand(providersCmd)
+}

cmd/root.go

@@ -90,6 +90,8 @@ var RootCmd = &cobra.Command{
 backend implementation allowing users to create kubernetes nodes without running the kubelet.
 This allows users to schedule kubernetes workloads on nodes that aren't running Kubernetes.`,
 	Run: func(cmd *cobra.Command, args []string) {
+		initConfig()
+
 		defer rootContextCancel()
 
 		vk := vkubelet.New(vkubelet.Config{
@@ -167,8 +169,6 @@ func init() {
 	log.L = logruslogger.FromLogrus(logrus.NewEntry(logrus.StandardLogger()))
 	trace.T = opencensus.Adapter{}
 
-	cobra.OnInitialize(initConfig)
-
 	// read default node name from environment variable.
 	// it can be overwritten by cli flags if specified.
 	defaultNodeName := os.Getenv("DEFAULT_NODE_NAME")

cmd/version.go

@@ -27,7 +27,7 @@ var versionCmd = &cobra.Command{
 	Short: "Show the version of the program",
 	Long:  `Show the version of the program`,
 	Run: func(cmd *cobra.Command, args []string) {
-		fmt.Printf("Version: %s, Built: %s", version.Version, version.BuildTime)
+		fmt.Printf("Version: %s, Built: %s\n", version.Version, version.BuildTime)
 	},
 }
 

providers/register/provider_alibabacloud.go

@@ -1,4 +1,4 @@
-// +build !no_alibabacloud_provider
+// +build alibabacloud_provider
 
 package register
 

providers/register/provider_aws.go

@@ -1,4 +1,4 @@
-// +build !no_aws_provider
+// +build aws_provider
 
 package register
 

providers/register/provider_azure.go

@@ -1,4 +1,4 @@
-// +build !no_azure_provider
+// +build azure_provider
 
 package register
 

providers/register/provider_azurebatch.go

@@ -1,4 +1,4 @@
-// +build !no_azurebatch_provider
+// +build azurebatch_provider
 
 package register
 

providers/register/provider_cri.go

@@ -1,4 +1,4 @@
-// +build linux,!no_cri_provider
+// +build linux,cri_provider
 
 package register
 

providers/register/provider_huawei.go

@@ -1,4 +1,4 @@
-// +build !no_huawei_provider
+// +build huawei_provider
 
 package register
 

providers/register/provider_mock.go

@@ -1,4 +1,4 @@
-// +build !no_mock_provider
+// +build mock_provider
 
 package register
 

providers/register/provider_nomad.go

@@ -1,4 +1,4 @@
-// +build !no_nomad_provider
+// +build nomad_provider
 
 package register
 

providers/register/provider_sfmesh.go

@@ -1,4 +1,4 @@
-// +build !no_sfmesh_provider
+// +build sfmesh_provider
 
 package register
 

providers/register/provider_vic.go

@@ -1,4 +1,4 @@
-// +build linux,!no_vic_provider
+// +build linux,vic_provider
 
 package register
 

providers/register/provider_web.go

@@ -1,4 +1,4 @@
-// +build !no_web_provider
+// +build web_provider
 
 package register
 

providers/register/register.go

@@ -1,6 +1,8 @@
 package register
 
 import (
+	"sort"
+
 	"github.com/cpuguy83/strongerrors"
 	"github.com/pkg/errors"
 	"github.com/virtual-kubelet/virtual-kubelet/manager"
@@ -30,6 +32,22 @@ func GetProvider(name string, cfg InitConfig) (providers.Provider, error) {
 	return f(cfg)
 }
 
+// Exists checks if a provider is regstered
+func Exists(name string) bool {
+	_, ok := providerInits[name]
+	return ok
+}
+
+// List gets the list of all provider names
+func List() []string {
+	ls := make([]string, 0, len(providerInits))
+	for name := range providerInits {
+		ls = append(ls, name)
+	}
+	sort.Strings(ls)
+	return ls
+}
+
 func register(name string, f initFunc) {
 	providerInits[name] = f
 }

scripts/process_build_tags.sh

@@ -0,0 +1,56 @@
+#!/bin/bash
+
+# set -e -o pipefail
+
+orig_tags=(${@})
+new_tags=()
+omit_providers=()
+
+let found_provider=0
+
+function debug() {
+	if [ "${V}" = "1" ]; then
+		(>&2 echo "$@")
+	fi
+}
+
+for tag in ${orig_tags[@]}; do
+	case "${tag}" in
+	no_*_provider)
+		# filtered
+		debug "filtered old, invalid ${tag} from tag list, provider is already excluded"
+
+		# store just in case no "proper" provider tags were provided
+		# In such cases we'd build everything, but we don't want to build these
+		p="${tag#no_}"
+		p="${p%_*}"
+		omit_providers+=("${p}")
+		;;
+	*_provider)
+		found_provider+=1
+		new_tags+=("${tag}")
+		;;
+	*)
+		new_tags+=("${tag}")
+		;;
+	esac
+done
+
+if [ ${found_provider} -eq 0 ]; then
+	# include all providers
+	for i in $(ls providers/register/provider_*.go); do
+		p="${i#*provider_}"
+		p="${p%.*}"
+
+		if [[ ! "${omit_providers[*]}" =~ "${p}"  ]]; then
+			debug "including provider ${p}"
+			new_tags+=("${p}_provider")
+		else
+			debug "excluding provider ${p}"
+		fi
+	done
+fi
+
+
+
+echo "${new_tags[@]}"