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/node/kubernetes/controller-manager.go b/metropolis/node/kubernetes/controller-manager.go
new file mode 100644
index 0000000..487511f
--- /dev/null
+++ b/metropolis/node/kubernetes/controller-manager.go
@@ -0,0 +1,93 @@
+// 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 kubernetes
+
+import (
+	"context"
+	"encoding/pem"
+	"fmt"
+	"net"
+	"os/exec"
+
+	"git.monogon.dev/source/nexantic.git/metropolis/node/common/fileargs"
+	"git.monogon.dev/source/nexantic.git/metropolis/node/common/supervisor"
+	"git.monogon.dev/source/nexantic.git/metropolis/node/kubernetes/pki"
+)
+
+type controllerManagerConfig struct {
+	clusterNet net.IPNet
+	// All PKI-related things are in DER
+	kubeConfig            []byte
+	rootCA                []byte
+	serviceAccountPrivKey []byte // In PKCS#8 form
+	serverCert            []byte
+	serverKey             []byte
+}
+
+func getPKIControllerManagerConfig(ctx context.Context, kpki *pki.KubernetesPKI) (*controllerManagerConfig, error) {
+	var config controllerManagerConfig
+	var err error
+	config.rootCA, _, err = kpki.Certificate(ctx, pki.IdCA)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get ID root CA: %w", err)
+	}
+	config.serverCert, config.serverKey, err = kpki.Certificate(ctx, pki.ControllerManager)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get controller-manager serving certificate: %w", err)
+	}
+	config.serviceAccountPrivKey, err = kpki.ServiceAccountKey(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get serviceaccount privkey: %w", err)
+	}
+	config.kubeConfig, err = kpki.Kubeconfig(ctx, pki.ControllerManagerClient)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get controller-manager kubeconfig: %w", err)
+	}
+	return &config, nil
+}
+
+func runControllerManager(config controllerManagerConfig) supervisor.Runnable {
+	return func(ctx context.Context) error {
+		args, err := fileargs.New()
+		if err != nil {
+			panic(err) // If this fails, something is very wrong. Just crash.
+		}
+		defer args.Close()
+
+		cmd := exec.CommandContext(ctx, "/kubernetes/bin/kube", "kube-controller-manager",
+			args.FileOpt("--kubeconfig", "kubeconfig", config.kubeConfig),
+			args.FileOpt("--service-account-private-key-file", "service-account-privkey.pem",
+				pem.EncodeToMemory(&pem.Block{Type: "PRIVATE KEY", Bytes: config.serviceAccountPrivKey})),
+			args.FileOpt("--root-ca-file", "root-ca.pem",
+				pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: config.rootCA})),
+			"--port=0",                               // Kill insecure serving
+			"--use-service-account-credentials=true", // Enables things like PSP enforcement
+			fmt.Sprintf("--cluster-cidr=%v", config.clusterNet.String()),
+			args.FileOpt("--tls-cert-file", "server-cert.pem",
+				pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: config.serverCert})),
+			args.FileOpt("--tls-private-key-file", "server-key.pem",
+				pem.EncodeToMemory(&pem.Block{Type: "PRIVATE KEY", Bytes: config.serverKey})),
+			"--allocate-node-cidrs",
+			"--cluster-cidr="+config.clusterNet.String(),
+		)
+
+		if args.Error() != nil {
+			return fmt.Errorf("failed to use fileargs: %w", err)
+		}
+		return supervisor.RunCommand(ctx, cmd)
+	}
+}