core -> metropolis

Smalltown is now called Metropolis!

This is the first commit in a series of cleanup commits that prepare us
for an open source release. This one just some Bazel packages around to
follow a stricter directory layout.

All of Metropolis now lives in `//metropolis`.

All of Metropolis Node code now lives in `//metropolis/node`.

All of the main /init now lives in `//m/n/core`.

All of the Kubernetes functionality/glue now lives in `//m/n/kubernetes`.

Next steps:
     - hunt down all references to Smalltown and replace them appropriately
     - narrow down visibility rules
     - document new code organization
     - move `//build/toolchain` to `//monogon/build/toolchain`
     - do another cleanup pass between `//golibs` and
       `//monogon/node/{core,common}`.
     - remove `//delta` and `//anubis`

Fixes T799.

Test Plan: Just a very large refactor. CI should help us out here.

Bug: T799

X-Origin-Diff: phab/D667
GitOrigin-RevId: 6029b8d4edc42325d50042596b639e8b122d0ded
diff --git a/metropolis/cli/dbg/main.go b/metropolis/cli/dbg/main.go
new file mode 100644
index 0000000..1bb6185
--- /dev/null
+++ b/metropolis/cli/dbg/main.go
@@ -0,0 +1,171 @@
+// Copyright 2020 The Monogon Project Authors.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// 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 main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"math/rand"
+	"os"
+	"time"
+
+	"github.com/spf13/pflag"
+	"google.golang.org/grpc"
+	cliflag "k8s.io/component-base/cli/flag"
+	"k8s.io/kubectl/pkg/cmd/plugin"
+	"k8s.io/kubectl/pkg/util/logs"
+	"k8s.io/kubernetes/pkg/kubectl/cmd"
+
+	"git.monogon.dev/source/nexantic.git/metropolis/node/core/logtree"
+	apb "git.monogon.dev/source/nexantic.git/metropolis/proto/api"
+)
+
+func main() {
+	ctx := context.Background()
+	// Hardcode localhost since this should never be used to interface with a production node because of missing
+	// encryption & authentication
+	grpcClient, err := grpc.Dial("localhost:7837", grpc.WithInsecure())
+	if err != nil {
+		fmt.Printf("Failed to dial debug service (is it running): %v\n", err)
+	}
+	debugClient := apb.NewNodeDebugServiceClient(grpcClient)
+	if len(os.Args) < 2 {
+		fmt.Println("Please specify a subcommand")
+		os.Exit(1)
+	}
+
+	logsCmd := flag.NewFlagSet("logs", flag.ExitOnError)
+	logsTailN := logsCmd.Int("tail", -1, "Get last n lines (-1 = whole buffer, 0 = disable)")
+	logsStream := logsCmd.Bool("follow", false, "Stream log entries live from the system")
+	logsRecursive := logsCmd.Bool("recursive", false, "Get entries from entire DN subtree")
+	logsCmd.Usage = func() {
+		fmt.Fprintf(os.Stderr, "Usage: %s %s [options] dn\n", os.Args[0], os.Args[1])
+		flag.PrintDefaults()
+
+		fmt.Fprintf(os.Stderr, "Example:\n  %s %s --tail 5 --follow init\n", os.Args[0], os.Args[1])
+	}
+	goldenticketCmd := flag.NewFlagSet("goldenticket", flag.ExitOnError)
+	conditionCmd := flag.NewFlagSet("condition", flag.ExitOnError)
+	conditionCmd.Usage = func() {
+		fmt.Fprintf(os.Stderr, "Usage: %s %s [options] component_path\n", os.Args[0], os.Args[1])
+		flag.PrintDefaults()
+
+		fmt.Fprintf(os.Stderr, "Example:\n  %s %s IPAssigned\n", os.Args[0], os.Args[1])
+	}
+
+	switch os.Args[1] {
+	case "logs":
+		logsCmd.Parse(os.Args[2:])
+		dn := logsCmd.Arg(0)
+		req := &apb.GetLogsRequest{
+			Dn:          dn,
+			BacklogMode: apb.GetLogsRequest_BACKLOG_DISABLE,
+			StreamMode:  apb.GetLogsRequest_STREAM_DISABLE,
+			Filters:     nil,
+		}
+
+		switch *logsTailN {
+		case 0:
+		case -1:
+			req.BacklogMode = apb.GetLogsRequest_BACKLOG_ALL
+		default:
+			req.BacklogMode = apb.GetLogsRequest_BACKLOG_COUNT
+			req.BacklogCount = int64(*logsTailN)
+		}
+
+		if *logsStream {
+			req.StreamMode = apb.GetLogsRequest_STREAM_UNBUFFERED
+		}
+
+		if *logsRecursive {
+			req.Filters = append(req.Filters, &apb.LogFilter{
+				Filter: &apb.LogFilter_WithChildren_{WithChildren: &apb.LogFilter_WithChildren{}},
+			})
+		}
+
+		stream, err := debugClient.GetLogs(ctx, req)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to get logs: %v\n", err)
+			os.Exit(1)
+		}
+		for {
+			res, err := stream.Recv()
+			if err != nil {
+				if err == io.EOF {
+					os.Exit(0)
+				}
+				fmt.Fprintf(os.Stderr, "Failed to stream logs: %v\n", err)
+				os.Exit(1)
+			}
+			for _, entry := range res.BacklogEntries {
+				entry, err := logtree.LogEntryFromProto(entry)
+				if err != nil {
+					fmt.Printf("error decoding entry: %v", err)
+					continue
+				}
+				fmt.Println(entry.String())
+			}
+		}
+	case "goldenticket":
+		goldenticketCmd.Parse(os.Args[2:])
+		ip := goldenticketCmd.Arg(0)
+		res, err := debugClient.GetGoldenTicket(ctx, &apb.GetGoldenTicketRequest{ExternalIp: ip})
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to get golden ticket: %v\n", err)
+			os.Exit(1)
+		}
+		fmt.Println(res.Ticket)
+	case "kubectl":
+		// Always get a kubeconfig with cluster-admin (group system:masters), kubectl itself can impersonate
+		kubeconfigFile, err := ioutil.TempFile("", "dbg_kubeconfig")
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to create kubeconfig temp file: %v\n", err)
+			os.Exit(1)
+		}
+		defer kubeconfigFile.Close()
+		defer os.Remove(kubeconfigFile.Name())
+
+		res, err := debugClient.GetDebugKubeconfig(ctx, &apb.GetDebugKubeconfigRequest{Id: "debug-user", Groups: []string{"system:masters"}})
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to get kubeconfig: %v\n", err)
+			os.Exit(1)
+		}
+		if _, err := kubeconfigFile.WriteString(res.DebugKubeconfig); err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to write kubeconfig: %v\n", err)
+			os.Exit(1)
+		}
+
+		// This magic sets up everything as if this was just the kubectl binary. It sets the KUBECONFIG environment
+		// variable so that it knows where the Kubeconfig is located and forcibly overwrites the arguments so that
+		// the "wrapper" arguments are not visible to its flags parser. The base code is straight from
+		// https://github.com/kubernetes/kubernetes/blob/master/cmd/kubectl/kubectl.go
+		os.Setenv("KUBECONFIG", kubeconfigFile.Name())
+		rand.Seed(time.Now().UnixNano())
+		pflag.CommandLine.SetNormalizeFunc(cliflag.WordSepNormalizeFunc)
+		pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
+		logs.InitLogs()
+		defer logs.FlushLogs()
+		command := cmd.NewDefaultKubectlCommandWithArgs(cmd.NewDefaultPluginHandler(plugin.ValidPluginFilenamePrefixes), os.Args[2:], os.Stdin, os.Stdout, os.Stderr)
+		command.SetArgs(os.Args[2:])
+		if err := command.Execute(); err != nil {
+			os.Exit(1)
+		}
+	}
+}