metropolis/node/core/cluster/cluster_bootstrap.go

// 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 cluster

import (
	"context"
	"crypto/ed25519"
	"crypto/rand"
	"crypto/subtle"
	"encoding/hex"
	"fmt"

	"source.monogon.dev/metropolis/node/core/consensus"
	"source.monogon.dev/metropolis/node/core/curator"
	"source.monogon.dev/metropolis/pkg/supervisor"
	apb "source.monogon.dev/metropolis/proto/api"
	cpb "source.monogon.dev/metropolis/proto/common"
	ppb "source.monogon.dev/metropolis/proto/private"
)

func (m *Manager) bootstrap(ctx context.Context, bootstrap *apb.NodeParameters_ClusterBootstrap) error {
	supervisor.Logger(ctx).Infof("Bootstrapping new cluster, owner public key: %s", hex.EncodeToString(bootstrap.OwnerPublicKey))
	state, unlock := m.lock()
	defer unlock()

	state.configuration = &ppb.SealedConfiguration{}

	// Mount new storage with generated CUK, and save LUK into sealed config proto.
	supervisor.Logger(ctx).Infof("Bootstrapping: mounting new storage...")
	cuk, err := m.storageRoot.Data.MountNew(state.configuration)
	if err != nil {
		return fmt.Errorf("could not make and mount data partition: %w", err)
	}

	pub, priv, err := ed25519.GenerateKey(rand.Reader)
	if err != nil {
		return fmt.Errorf("could not generate node keypair: %w", err)
	}
	supervisor.Logger(ctx).Infof("Bootstrapping: node public key: %s", hex.EncodeToString([]byte(pub)))

	node := curator.NewNodeForBootstrap(cuk, pub)

	// Run worker to keep updating /ephemeral/hosts (and thus, /etc/hosts) with
	// our own IP address. This ensures that the node's ID always resolves to
	// its current external IP address.
	// TODO(q3k): move this out into roleserver.
	supervisor.Run(ctx, "hostsfile", func(ctx context.Context) error {
		supervisor.Signal(ctx, supervisor.SignalHealthy)
		watcher := m.networkService.Watch()
		for {
			status, err := watcher.Get(ctx)
			if err != nil {
				return err
			}
			err = node.ConfigureLocalHostname(ctx, &m.storageRoot.Ephemeral, status.ExternalAddress)
			if err != nil {
				return fmt.Errorf("could not configure hostname: %w", err)
			}
		}
	})

	// Bring up consensus with this node as the only member.
	m.consensus = consensus.New(consensus.Config{
		Data:       &m.storageRoot.Data.Etcd,
		Ephemeral:  &m.storageRoot.Ephemeral.Consensus,
		NewCluster: true,
		Name:       node.ID(),
	})

	supervisor.Logger(ctx).Infof("Bootstrapping: starting consensus...")
	if err := supervisor.Run(ctx, "consensus", m.consensus.Run); err != nil {
		return fmt.Errorf("when starting consensus: %w", err)
	}

	supervisor.Logger(ctx).Info("Bootstrapping: waiting for consensus...")
	if err := m.consensus.WaitReady(ctx); err != nil {
		return fmt.Errorf("consensus service failed to become ready: %w", err)
	}
	supervisor.Logger(ctx).Info("Bootstrapping: consensus ready.")

	metropolisKV, err := m.consensus.Client().Sub("metropolis")
	if err != nil {
		return fmt.Errorf("when retrieving application etcd subclient: %w", err)
	}

	status := Status{
		State:             cpb.ClusterState_CLUSTER_STATE_HOME,
		hasLocalConsensus: true,
		consensusClient:   metropolisKV,
		// Credentials are set further down once created through a curator
		// short-circuit bootstrap function.
		Credentials: nil,
	}

	// Short circuit curator into storing the new node.
	ckv, err := status.ConsensusClient(ConsensusUserCurator)
	if err != nil {
		return fmt.Errorf("when retrieving consensus user for curator: %w", err)
	}

	if err := node.BootstrapStore(ctx, ckv); err != nil {
		return fmt.Errorf("failed to store new node in etcd: %w", err)
	}

	// And short-circuit creating the curator CA and node certificate.
	caCert, nodeCert, err := curator.BootstrapNodeCredentials(ctx, ckv, priv, pub)
	if err != nil {
		return fmt.Errorf("failed to bootstrap node credentials: %w", err)
	}

	// Using the short-circuited credentials from the curator, build our
	// NodeCredentials. That, and the public part of the credentials
	// (NodeCertificate) are the primary output of the cluster manager.
	creds, err := NewNodeCredentials(priv, nodeCert, caCert)
	if err != nil {
		return fmt.Errorf("failed to use newly bootstrapped node credentials: %w", err)
	}

	// Overly cautious check: ensure that the credentials are for the public key
	// we've generated.
	if want, got := pub, []byte(creds.PublicKey()); subtle.ConstantTimeCompare(want, got) != 1 {
		return fmt.Errorf("newly bootstrapped node credentials emitted for wrong public key")
	}

	if err := creds.Save(&m.storageRoot.Data.Node.Credentials); err != nil {
		return fmt.Errorf("failed to write node credentials: %w", err)
	}

	status.Credentials = creds
	m.status.Set(status)

	supervisor.Signal(ctx, supervisor.SignalHealthy)
	supervisor.Signal(ctx, supervisor.SignalDone)
	return nil
}