🌱 Fix indexes

.golangci.yaml

@@ -25,6 +25,7 @@ linters:
     - errchkjson
     - errorlint
     - exhaustive
+    - gci
     - ginkgolinter
     - goconst
     - gocritic
@@ -53,6 +54,18 @@ linters:
     - whitespace
 
 linters-settings:
+  gci:
+    custom-order: true
+    sections:
+    - standard
+    - default
+    - prefix(k8s.io,sigs.k8s.io)
+    - prefix(github.com/kcp-dev)
+    - prefix(github.com/multicluster-runtime)
+    - prefix(github.com/kcp-dev/multicluster-provider)
+    - blank
+    - dot
+    skip-generated: true
   govet:
     enable-all: true
     disable:

Makefile

@@ -37,16 +37,6 @@ $(GOLANGCI_LINT):
 	  golangci-lint \
 	  ${GOLANGCI_LINT_VERSION}
 
-GIMPS = _tools/gimps
-GIMPS_VERSION = 0.6.0
-
-.PHONY: $(GIMPS)
-$(GIMPS):
-	@hack/download-tool.sh \
-	  https://github.com/xrstf/gimps/releases/download/v${GIMPS_VERSION}/gimps_${GIMPS_VERSION}_${GOOS}_${GOARCH}.tar.gz \
-	  gimps \
-	  ${GIMPS_VERSION}
-
 WWHRD = _tools/wwhrd
 WWHRD_VERSION = 0.4.0
 
@@ -100,8 +90,15 @@ lint: $(GOLANGCI_LINT)
 		./...
 
 .PHONY: imports
-imports: $(GIMPS)
-	$(GIMPS) .
+imports: WHAT ?=
+imports: $(GOLANGCI_LINT)
+	@if [ -n "$(WHAT)" ]; then \
+	  $(GOLANGCI_LINT) run --enable-only=gci --fix --fast $(WHAT); \
+	else \
+	  for MOD in . $$(git ls-files '**/go.mod' | sed 's,/go.mod,,'); do \
+		(cd $$MOD; $(GOLANGCI_LINT) run --enable-only=gci --fix --fast); \
+	  done; \
+	fi
 
 .PHONY: verify
 verify:

client/client.go

@@ -0,0 +1,67 @@
+package client
+
+import (
+	"sync"
+
+	"github.com/hashicorp/golang-lru/v2"
+
+	"k8s.io/client-go/rest"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	"github.com/kcp-dev/logicalcluster/v3"
+)
+
+// ClusterClient is a cluster-aware client.
+type ClusterClient interface {
+	// Cluster returns the client for the given cluster.
+	Cluster(cluster logicalcluster.Path) (client.Client, error)
+}
+
+// clusterClient is a multi-cluster-aware client.
+type clusterClient struct {
+	baseConfig *rest.Config
+	opts       client.Options
+
+	lock  sync.RWMutex
+	cache *lru.Cache[logicalcluster.Path, client.Client]
+}
+
+// New creates a new cluster-aware client.
+func New(cfg *rest.Config, options client.Options) (ClusterClient, error) {
+	ca, err := lru.New[logicalcluster.Path, client.Client](100)
+	if err != nil {
+		return nil, err
+	}
+	return &clusterClient{
+		opts:       options,
+		baseConfig: cfg,
+		cache:      ca,
+	}, nil
+}
+
+func (c *clusterClient) Cluster(cluster logicalcluster.Path) (client.Client, error) {
+	// quick path
+	c.lock.RLock()
+	cli, ok := c.cache.Get(cluster)
+	c.lock.RUnlock()
+	if ok {
+		return cli, nil
+	}
+
+	// slow path
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	if cli, ok := c.cache.Get(cluster); ok {
+		return cli, nil
+	}
+
+	// cache miss
+	cfg := rest.CopyConfig(c.baseConfig)
+	cfg.Host = cfg.Host + cluster.RequestPath()
+	cli, err := client.New(cfg, c.opts)
+	if err != nil {
+		return nil, err
+	}
+	c.cache.Add(cluster, cli)
+	return cli, nil
+}

envtest/doc.go

@@ -0,0 +1,3 @@
+// Package envtest provides a test environment for testing code against a
+// kcp control plane.
+package envtest

envtest/internal/addr/addr_suite_test.go

@@ -0,0 +1,30 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+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 addr_test
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestAddr(t *testing.T) {
+	t.Parallel()
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Addr Suite")
+}

envtest/internal/addr/manager.go

@@ -0,0 +1,142 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+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 addr
+
+import (
+	"errors"
+	"fmt"
+	"io/fs"
+	"net"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/kcp-dev/multicluster-provider/envtest/internal/flock"
+)
+
+// TODO(directxman12): interface / release functionality for external port managers
+
+const (
+	portReserveTime   = 2 * time.Minute
+	portConflictRetry = 100
+	portFilePrefix    = "port-"
+)
+
+var (
+	cacheDir string
+)
+
+func init() {
+	baseDir, err := os.UserCacheDir()
+	if err == nil {
+		cacheDir = filepath.Join(baseDir, "kubebuilder-envtest")
+		err = os.MkdirAll(cacheDir, 0o750)
+	}
+	if err != nil {
+		// Either we didn't get a cache directory, or we can't use it
+		baseDir = os.TempDir()
+		cacheDir = filepath.Join(baseDir, "kubebuilder-envtest")
+		err = os.MkdirAll(cacheDir, 0o750)
+	}
+	if err != nil {
+		panic(err)
+	}
+}
+
+type portCache struct{}
+
+func (c *portCache) add(port int) (bool, error) {
+	// Remove outdated ports.
+	if err := fs.WalkDir(os.DirFS(cacheDir), ".", func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if d.IsDir() || !d.Type().IsRegular() || !strings.HasPrefix(path, portFilePrefix) {
+			return nil
+		}
+		info, err := d.Info()
+		if err != nil {
+			// No-op if file no longer exists; may have been deleted by another
+			// process/thread trying to allocate ports.
+			if errors.Is(err, fs.ErrNotExist) {
+				return nil
+			}
+			return err
+		}
+		if time.Since(info.ModTime()) > portReserveTime {
+			if err := os.Remove(filepath.Join(cacheDir, path)); err != nil {
+				// No-op if file no longer exists; may have been deleted by another
+				// process/thread trying to allocate ports.
+				if os.IsNotExist(err) {
+					return nil
+				}
+				return err
+			}
+		}
+		return nil
+	}); err != nil {
+		return false, err
+	}
+	// Try allocating new port, by acquiring a file.
+	path := fmt.Sprintf("%s/%s%d", cacheDir, portFilePrefix, port)
+	if err := flock.Acquire(path); errors.Is(err, flock.ErrAlreadyLocked) {
+		return false, nil
+	} else if err != nil {
+		return false, err
+	}
+	return true, nil
+}
+
+var cache = &portCache{}
+
+func suggest(listenHost string) (*net.TCPListener, int, string, error) {
+	if listenHost == "" {
+		listenHost = "localhost"
+	}
+	addr, err := net.ResolveTCPAddr("tcp", net.JoinHostPort(listenHost, "0"))
+	if err != nil {
+		return nil, -1, "", err
+	}
+	l, err := net.ListenTCP("tcp", addr)
+	if err != nil {
+		return nil, -1, "", err
+	}
+	return l, l.Addr().(*net.TCPAddr).Port,
+		addr.IP.String(),
+		nil
+}
+
+// Suggest suggests an address a process can listen on. It returns
+// a tuple consisting of a free port and the hostname resolved to its IP.
+// It makes sure that new port allocated does not conflict with old ports
+// allocated within 1 minute.
+func Suggest(listenHost string) (int, string, error) {
+	for i := 0; i < portConflictRetry; i++ {
+		listener, port, resolvedHost, err := suggest(listenHost)
+		if err != nil {
+			return -1, "", err
+		}
+		defer listener.Close()
+		if ok, err := cache.add(port); ok {
+			return port, resolvedHost, nil
+		} else if err != nil {
+			return -1, "", err
+		}
+	}
+	return -1, "", fmt.Errorf("no free ports found after %d retries", portConflictRetry)
+}

envtest/internal/addr/manager_test.go

@@ -0,0 +1,77 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+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 addr_test
+
+import (
+	"net"
+	"strconv"
+
+	"github.com/kcp-dev/multicluster-provider/envtest/internal/addr"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("SuggestAddress", func() {
+	It("returns a free port and an address to bind to", func() {
+		port, host, err := addr.Suggest("")
+
+		Expect(err).NotTo(HaveOccurred())
+		Expect(host).To(Or(Equal("127.0.0.1"), Equal("::1")))
+		Expect(port).NotTo(Equal(0))
+
+		addr, err := net.ResolveTCPAddr("tcp", net.JoinHostPort(host, strconv.Itoa(port)))
+		Expect(err).NotTo(HaveOccurred())
+		l, err := net.ListenTCP("tcp", addr)
+		defer func() {
+			Expect(l.Close()).To(Succeed())
+		}()
+		Expect(err).NotTo(HaveOccurred())
+	})
+
+	It("supports an explicit listenHost", func() {
+		port, host, err := addr.Suggest("localhost")
+
+		Expect(err).NotTo(HaveOccurred())
+		Expect(host).To(Or(Equal("127.0.0.1"), Equal("::1")))
+		Expect(port).NotTo(Equal(0))
+
+		addr, err := net.ResolveTCPAddr("tcp", net.JoinHostPort(host, strconv.Itoa(port)))
+		Expect(err).NotTo(HaveOccurred())
+		l, err := net.ListenTCP("tcp", addr)
+		defer func() {
+			Expect(l.Close()).To(Succeed())
+		}()
+		Expect(err).NotTo(HaveOccurred())
+	})
+
+	It("supports a 0.0.0.0 listenHost", func() {
+		port, host, err := addr.Suggest("0.0.0.0")
+
+		Expect(err).NotTo(HaveOccurred())
+		Expect(host).To(Equal("0.0.0.0"))
+		Expect(port).NotTo(Equal(0))
+
+		addr, err := net.ResolveTCPAddr("tcp", net.JoinHostPort(host, strconv.Itoa(port)))
+		Expect(err).NotTo(HaveOccurred())
+		l, err := net.ListenTCP("tcp", addr)
+		defer func() {
+			Expect(l.Close()).To(Succeed())
+		}()
+		Expect(err).NotTo(HaveOccurred())
+	})
+})