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gateway.go
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gateway.go
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package cluster
import (
"bufio"
"context"
"crypto/tls"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"net"
"net/http"
"net/url"
"os"
"path/filepath"
"strconv"
"sync"
"time"
dqlite "github.com/canonical/go-dqlite"
client "github.com/canonical/go-dqlite/client"
"github.com/lxc/lxd/lxd/db"
"github.com/lxc/lxd/lxd/util"
"github.com/lxc/lxd/shared"
"github.com/lxc/lxd/shared/eagain"
"github.com/lxc/lxd/shared/logger"
"github.com/pkg/errors"
)
// NewGateway creates a new Gateway for managing access to the dqlite cluster.
//
// When a new gateway is created, the node-level database is queried to check
// what kind of role this node plays and if it's exposed over the network. It
// will initialize internal data structures accordingly, for example starting a
// local dqlite server if this node is a database node.
//
// After creation, the Daemon is expected to expose whatever http handlers the
// HandlerFuncs method returns and to access the dqlite cluster using the
// dialer returned by the DialFunc method.
func NewGateway(db *db.Node, cert *shared.CertInfo, options ...Option) (*Gateway, error) {
ctx, cancel := context.WithCancel(context.Background())
o := newOptions()
for _, option := range options {
option(o)
}
gateway := &Gateway{
db: db,
cert: cert,
options: o,
ctx: ctx,
cancel: cancel,
upgradeCh: make(chan struct{}, 0),
acceptCh: make(chan net.Conn),
store: &dqliteNodeStore{},
}
err := gateway.init()
if err != nil {
return nil, err
}
return gateway, nil
}
// Gateway mediates access to the dqlite cluster using a gRPC SQL client, and
// possibly runs a dqlite replica on this LXD node (if we're configured to do
// so).
type Gateway struct {
db *db.Node
cert *shared.CertInfo
options *options
// The raft instance to use for creating the dqlite driver. It's nil if
// this LXD node is not supposed to be part of the raft cluster.
info *db.RaftNode
// The gRPC server exposing the dqlite driver created by this
// gateway. It's nil if this LXD node is not supposed to be part of the
// raft cluster.
server *dqlite.Node
acceptCh chan net.Conn
// A dialer that will connect to the dqlite server using a loopback
// net.Conn. It's non-nil when clustering is not enabled on this LXD
// node, and so we don't expose any dqlite or raft network endpoint,
// but still we want to use dqlite as backend for the "cluster"
// database, to minimize the difference between code paths in
// clustering and non-clustering modes.
memoryDial client.DialFunc
// Used when shutting down the daemon to cancel any ongoing gRPC
// dialing attempt.
ctx context.Context
cancel context.CancelFunc
// Used to unblock nodes that are waiting for other nodes to upgrade
// their version.
upgradeCh chan struct{}
// Used to track whether we already triggered an upgrade because we
// detected a peer with an higher version.
upgradeTriggered bool
// Used for the heartbeat handler
Cluster *db.Cluster
HeartbeatNodeHook func(*APIHeartbeat)
// NodeStore wrapper.
store *dqliteNodeStore
lock sync.RWMutex
// Abstract unix socket that the local dqlite task is listening to.
bindAddress string
}
// Current dqlite protocol version.
const dqliteVersion = 1
// Set the dqlite version header.
func setDqliteVersionHeader(request *http.Request) {
request.Header.Set("X-Dqlite-Version", fmt.Sprintf("%d", dqliteVersion))
}
// HandlerFuncs returns the HTTP handlers that should be added to the REST API
// endpoint in order to handle database-related requests.
//
// There are two handlers, one for the /internal/raft endpoint and the other
// for /internal/db, which handle respectively raft and gRPC-SQL requests.
//
// These handlers might return 404, either because this LXD node is a
// non-clustered node not available over the network or because it is not a
// database node part of the dqlite cluster.
func (g *Gateway) HandlerFuncs(nodeRefreshTask func(*APIHeartbeat)) map[string]http.HandlerFunc {
database := func(w http.ResponseWriter, r *http.Request) {
g.lock.RLock()
defer g.lock.RUnlock()
if !tlsCheckCert(r, g.cert) {
http.Error(w, "403 invalid client certificate", http.StatusForbidden)
return
}
// Compare the dqlite version of the connecting client
// with our own one.
versionHeader := r.Header.Get("X-Dqlite-Version")
if versionHeader == "" {
// No version header means an old pre dqlite 1.0 client.
versionHeader = "0"
}
version, err := strconv.Atoi(versionHeader)
if err != nil {
http.Error(w, "400 invalid dqlite version", http.StatusBadRequest)
return
}
if version != dqliteVersion {
if version > dqliteVersion {
if !g.upgradeTriggered {
err = triggerUpdate()
if err == nil {
g.upgradeTriggered = true
}
}
http.Error(w, "503 unsupported dqlite version", http.StatusServiceUnavailable)
} else {
http.Error(w, "426 dqlite version too old ", http.StatusUpgradeRequired)
}
return
}
// Handle heatbeats (these normally come from leader, but can come from joining nodes too).
if r.Method == "PUT" {
var heartbeatData APIHeartbeat
err := json.NewDecoder(r.Body).Decode(&heartbeatData)
if err != nil {
logger.Errorf("Error decoding heartbeat body: %v", err)
http.Error(w, "400 invalid heartbeat payload", http.StatusBadRequest)
return
}
raftNodes := make([]db.RaftNode, 0)
for _, node := range heartbeatData.Members {
if node.RaftID > 0 {
raftNodes = append(raftNodes, db.RaftNode{
ID: node.RaftID,
Address: node.Address,
Role: db.RaftRole(node.RaftRole),
})
}
}
// Check we have been sent at least 1 raft node before wiping our set.
if len(raftNodes) > 0 {
// Accept Raft node updates from any node (joining nodes just send raft nodes heartbeat data).
logger.Debugf("Replace current raft nodes with %+v", raftNodes)
err = g.db.Transaction(func(tx *db.NodeTx) error {
return tx.RaftNodesReplace(raftNodes)
})
if err != nil {
logger.Errorf("Error updating raft nodes: %v", err)
http.Error(w, "500 failed to update raft nodes", http.StatusInternalServerError)
return
}
} else {
logger.Errorf("Empty raft node set received")
}
// Only perform node refresh task if we have received a full state list from leader.
if !heartbeatData.FullStateList {
logger.Debugf("Partial node list heartbeat received, skipping full update")
return
}
// If node refresh task is specified, run it async.
if nodeRefreshTask != nil {
go nodeRefreshTask(&heartbeatData)
}
return
}
// Handle database upgrade notifications.
if r.Method == "PATCH" {
select {
case g.upgradeCh <- struct{}{}:
default:
}
return
}
// From here on we require that this node is part of the raft
// cluster.
if g.server == nil || g.memoryDial != nil {
http.NotFound(w, r)
return
}
// Before actually establishing the connection, our dialer
// probes the node to see if it's currently the leader
// (otherwise it tries with another node or retry later).
if r.Method == "HEAD" {
// We can safely know about current leader only if we are a voter.
if g.info.Role != db.RaftVoter {
http.NotFound(w, r)
return
}
client, err := g.getClient()
if err != nil {
http.Error(w, "500 failed to get dqlite client", http.StatusInternalServerError)
return
}
defer client.Close()
leader, err := client.Leader(context.Background())
if err != nil {
http.Error(w, "500 failed to get leader address", http.StatusInternalServerError)
return
}
if leader == nil || leader.ID != g.info.ID {
http.Error(w, "503 not leader", http.StatusServiceUnavailable)
return
}
return
}
// Handle leader address requests.
if r.Method == "GET" {
leader, err := g.LeaderAddress()
if err != nil {
http.Error(w, "500 no elected leader", http.StatusInternalServerError)
return
}
util.WriteJSON(w, map[string]string{"leader": leader}, false)
return
}
if r.Header.Get("Upgrade") != "dqlite" {
http.Error(w, "Missing or invalid upgrade header", http.StatusBadRequest)
return
}
hijacker, ok := w.(http.Hijacker)
if !ok {
http.Error(w, "Webserver doesn't support hijacking", http.StatusInternalServerError)
return
}
conn, _, err := hijacker.Hijack()
if err != nil {
message := errors.Wrap(err, "Failed to hijack connection").Error()
http.Error(w, message, http.StatusInternalServerError)
return
}
// Write the status line and upgrade header by hand since w.WriteHeader()
// would fail after Hijack()
data := []byte("HTTP/1.1 101 Switching Protocols\r\nUpgrade: dqlite\r\n\r\n")
if n, err := conn.Write(data); err != nil || n != len(data) {
conn.Close()
return
}
g.acceptCh <- conn
}
return map[string]http.HandlerFunc{
databaseEndpoint: database,
}
}
// Snapshot can be used to manually trigger a RAFT snapshot
func (g *Gateway) Snapshot() error {
g.lock.RLock()
defer g.lock.RUnlock()
// TODO: implement support for forcing a snapshot in dqlite v1
return fmt.Errorf("Not supported")
}
// WaitUpgradeNotification waits for a notification from another node that all
// nodes in the cluster should now have been upgraded and have matching schema
// and API versions.
func (g *Gateway) WaitUpgradeNotification() {
select {
case <-g.upgradeCh:
case <-time.After(time.Minute):
}
}
// IsDqliteNode returns true if this gateway is running a dqlite node.
func (g *Gateway) IsDqliteNode() bool {
g.lock.RLock()
defer g.lock.RUnlock()
if g.info != nil {
if g.server == nil {
panic("gateway has node identity but no dqlite server")
}
return true
}
if g.server != nil {
panic("gateway dqlite server but no node identity")
}
return true
}
// DialFunc returns a dial function that can be used to connect to one of the
// dqlite nodes.
func (g *Gateway) DialFunc() client.DialFunc {
return func(ctx context.Context, address string) (net.Conn, error) {
g.lock.RLock()
defer g.lock.RUnlock()
// Memory connection.
if g.memoryDial != nil {
return g.memoryDial(ctx, address)
}
return dqliteNetworkDial(ctx, address, g, true)
}
}
// Dial function for establishing raft connections.
func (g *Gateway) raftDial() client.DialFunc {
return func(ctx context.Context, address string) (net.Conn, error) {
if address == "1" {
addr, err := g.raftAddress(1)
if err != nil {
return nil, err
}
address = string(addr)
}
return dqliteNetworkDial(ctx, address, g, false)
}
}
// Context returns a cancellation context to pass to dqlite.NewDriver as
// option.
//
// This context gets cancelled by Gateway.Kill() and at that point any
// connection failure won't be retried.
func (g *Gateway) Context() context.Context {
return g.ctx
}
// NodeStore returns a dqlite server store that can be used to lookup the
// addresses of known database nodes.
func (g *Gateway) NodeStore() client.NodeStore {
return g.store
}
// Kill is an API that the daemon calls before it actually shuts down and calls
// Shutdown(). It will abort any ongoing or new attempt to establish a SQL gRPC
// connection with the dialer (typically for running some pre-shutdown
// queries).
func (g *Gateway) Kill() {
logger.Debug("Cancel ongoing or future gRPC connection attempts")
g.cancel()
}
// Shutdown this gateway, stopping the gRPC server and possibly the raft factory.
func (g *Gateway) Shutdown() error {
logger.Debugf("Stop database gateway")
if g.server != nil {
if g.info.Role == db.RaftVoter {
g.Sync()
}
// If we are the cluster leader, let's try to transfer leadership.
isLeader, err := g.isLeader()
if err == nil && isLeader {
client, err := g.getClient()
if err == nil {
ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
client.Transfer(ctx, 0)
client.Close()
}
}
g.server.Close()
// Unset the memory dial, since Shutdown() is also called for
// switching between in-memory and network mode.
g.lock.Lock()
g.memoryDial = nil
g.lock.Unlock()
}
return nil
}
// Sync dumps the content of the database to disk. This is useful for
// inspection purposes, and it's also needed by the activateifneeded command so
// it can inspect the database in order to decide whether to activate the
// daemon or not.
func (g *Gateway) Sync() {
g.lock.RLock()
defer g.lock.RUnlock()
if g.server == nil || g.info.Role != db.RaftVoter {
return
}
client, err := g.getClient()
if err != nil {
logger.Warnf("Failed to get client: %v", err)
return
}
defer client.Close()
files, err := client.Dump(context.Background(), "db.bin")
if err != nil {
// Just log a warning, since this is not fatal.
logger.Warnf("Failed get database dump: %v", err)
return
}
dir := filepath.Join(g.db.Dir(), "global")
for _, file := range files {
path := filepath.Join(dir, file.Name)
err := ioutil.WriteFile(path, file.Data, 0600)
if err != nil {
logger.Warnf("Failed to dump database file %s: %v", file.Name, err)
}
}
}
func (g *Gateway) getClient() (*client.Client, error) {
return client.New(context.Background(), g.bindAddress)
}
// Reset the gateway, shutting it down and starting against from scratch using
// the given certificate.
//
// This is used when disabling clustering on a node.
func (g *Gateway) Reset(cert *shared.CertInfo) error {
err := g.Shutdown()
if err != nil {
return err
}
err = os.RemoveAll(filepath.Join(g.db.Dir(), "global"))
if err != nil {
return err
}
err = g.db.Transaction(func(tx *db.NodeTx) error {
return tx.RaftNodesReplace(nil)
})
if err != nil {
return err
}
g.cert = cert
return g.init()
}
// LeaderAddress returns the address of the current raft leader.
func (g *Gateway) LeaderAddress() (string, error) {
g.lock.RLock()
defer g.lock.RUnlock()
// If we aren't clustered, return an error.
if g.memoryDial != nil {
return "", fmt.Errorf("Node is not clustered")
}
ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
// If this is a voter node, return the address of the current leader, or
// wait a bit until one is elected.
if g.server != nil && g.info.Role == db.RaftVoter {
for ctx.Err() == nil {
client, err := g.getClient()
if err != nil {
return "", errors.Wrap(err, "Failed to get dqlite client")
}
defer client.Close()
leader, err := client.Leader(context.Background())
if err != nil {
return "", errors.Wrap(err, "Failed to get leader address")
}
if leader != nil {
return leader.Address, nil
}
time.Sleep(time.Second)
}
return "", ctx.Err()
}
// If this isn't a raft node, contact a raft node and ask for the
// address of the current leader.
config, err := tlsClientConfig(g.cert)
if err != nil {
return "", err
}
addresses := []string{}
err = g.db.Transaction(func(tx *db.NodeTx) error {
nodes, err := tx.RaftNodes()
if err != nil {
return err
}
for _, node := range nodes {
if node.Role != db.RaftVoter {
continue
}
addresses = append(addresses, node.Address)
}
return nil
})
if err != nil {
return "", errors.Wrap(err, "Failed to fetch raft nodes addresses")
}
if len(addresses) == 0 {
// This should never happen because the raft_nodes table should
// be never empty for a clustered node, but check it for good
// measure.
return "", fmt.Errorf("No raft node known")
}
transport, cleanup := tlsTransport(config)
defer cleanup()
for _, address := range addresses {
url := fmt.Sprintf("https://%s%s", address, databaseEndpoint)
request, err := http.NewRequest("GET", url, nil)
if err != nil {
return "", err
}
setDqliteVersionHeader(request)
request = request.WithContext(ctx)
client := &http.Client{Transport: transport}
response, err := client.Do(request)
if err != nil {
logger.Debugf("Failed to fetch leader address from %s", address)
continue
}
if response.StatusCode != http.StatusOK {
logger.Debugf("Request for leader address from %s failed", address)
continue
}
info := map[string]string{}
err = shared.ReadToJSON(response.Body, &info)
if err != nil {
logger.Debugf("Failed to parse leader address from %s", address)
continue
}
leader := info["leader"]
if leader == "" {
logger.Debugf("Raft node %s returned no leader address", address)
continue
}
return leader, nil
}
return "", fmt.Errorf("RAFT cluster is unavailable")
}
// Initialize the gateway, creating a new raft factory and gRPC server (if this
// node is a database node), and a gRPC dialer.
func (g *Gateway) init() error {
logger.Debugf("Initializing database gateway")
info, err := loadInfo(g.db, g.cert)
if err != nil {
return errors.Wrap(err, "Failed to create raft factory")
}
dir := filepath.Join(g.db.Dir(), "global")
if shared.PathExists(filepath.Join(dir, "logs.db")) {
err := shared.DirCopy(dir, dir+".bak")
if err != nil {
return errors.Wrap(err, "Failed to backup global database")
}
err = MigrateToDqlite10(dir)
if err != nil {
return errors.Wrap(err, "Failed to migrate to dqlite 1.0")
}
os.Remove(filepath.Join(dir, "logs.db"))
os.RemoveAll(filepath.Join(dir, "snapshots"))
}
// If the resulting raft instance is not nil, it means that this node
// should serve as database node, so create a dqlite driver possibly
// exposing it over the network.
if info != nil {
// Use the autobind feature of abstract unix sockets to get a
// random unused address.
listener, err := net.Listen("unix", "")
if err != nil {
return errors.Wrap(err, "Failed to autobind unix socket")
}
g.bindAddress = listener.Addr().String()
listener.Close()
options := []dqlite.Option{
dqlite.WithBindAddress(g.bindAddress),
}
if info.Address == "1" {
if info.ID != 1 {
panic("unexpected server ID")
}
g.memoryDial = dqliteMemoryDial(g.bindAddress)
g.store.inMemory = client.NewInmemNodeStore()
g.store.Set(context.Background(), []client.NodeInfo{*info})
} else {
go runDqliteProxy(g.bindAddress, g.acceptCh)
g.store.inMemory = nil
options = append(options, dqlite.WithDialFunc(g.raftDial()))
}
server, err := dqlite.New(
info.ID,
info.Address,
dir,
options...,
)
if err != nil {
return errors.Wrap(err, "Failed to create dqlite server")
}
err = server.Start()
if err != nil {
return errors.Wrap(err, "Failed to start dqlite server")
}
g.lock.Lock()
g.server = server
g.info = info
g.lock.Unlock()
} else {
g.lock.Lock()
g.server = nil
g.info = nil
g.store.inMemory = nil
g.lock.Unlock()
}
g.lock.Lock()
g.store.onDisk = client.NewNodeStore(
g.db.DB(), "main", "raft_nodes", "address",
client.WithNodeStoreWhereClause(fmt.Sprintf("role=%d", db.RaftVoter)))
g.lock.Unlock()
return nil
}
// Wait for the raft node to become leader. Should only be used by Bootstrap,
// since we know that we'll self elect.
func (g *Gateway) waitLeadership() error {
n := 80
sleep := 250 * time.Millisecond
for i := 0; i < n; i++ {
g.lock.RLock()
isLeader, err := g.isLeader()
if err != nil {
g.lock.RUnlock()
return err
}
if isLeader {
g.lock.RUnlock()
return nil
}
g.lock.RUnlock()
time.Sleep(sleep)
}
return fmt.Errorf("RAFT node did not self-elect within %s", time.Duration(n)*sleep)
}
func (g *Gateway) isLeader() (bool, error) {
if g.server == nil || g.info.Role != db.RaftVoter {
return false, nil
}
client, err := g.getClient()
if err != nil {
return false, errors.Wrap(err, "Failed to get dqlite client")
}
defer client.Close()
leader, err := client.Leader(context.Background())
if err != nil {
return false, errors.Wrap(err, "Failed to get leader address")
}
return leader != nil && leader.ID == g.info.ID, nil
}
// ErrNotLeader signals that a node not the leader.
var ErrNotLeader = fmt.Errorf("Not leader")
// Return information about the LXD nodes that a currently part of the raft
// cluster, as configured in the raft log. It returns an error if this node is
// not the leader.
func (g *Gateway) currentRaftNodes() ([]db.RaftNode, error) {
g.lock.RLock()
defer g.lock.RUnlock()
if g.info == nil || g.info.Role != db.RaftVoter {
return nil, ErrNotLeader
}
isLeader, err := g.isLeader()
if err != nil {
return nil, err
}
if !isLeader {
return nil, ErrNotLeader
}
client, err := g.getClient()
if err != nil {
return nil, err
}
defer client.Close()
servers, err := client.Cluster(context.Background())
if err != nil {
return nil, err
}
for i, server := range servers {
address, err := g.raftAddress(server.ID)
if err != nil {
if err != db.ErrNoSuchObject {
return nil, errors.Wrap(err, "Failed to fetch raft server address")
}
// Use the initial address as fallback. This is an edge
// case that happens when a new leader is elected and
// its raft_nodes table is not fully up-to-date yet.
address = server.Address
}
servers[i].Address = address
}
return servers, nil
}
// Look up a server address in the raft_nodes table.
func (g *Gateway) raftAddress(databaseID uint64) (string, error) {
var address string
err := g.db.Transaction(func(tx *db.NodeTx) error {
var err error
address, err = tx.RaftNodeAddress(int64(databaseID))
return err
})
if err != nil {
return "", err
}
return address, nil
}
func dqliteNetworkDial(ctx context.Context, addr string, g *Gateway, checkLeader bool) (net.Conn, error) {
config, err := tlsClientConfig(g.cert)
if err != nil {
return nil, err
}
path := fmt.Sprintf("https://%s%s", addr, databaseEndpoint)
if checkLeader {
// Make a probe HEAD request to check if the target node is the leader.
request, err := http.NewRequest("HEAD", path, nil)
if err != nil {
return nil, err
}
setDqliteVersionHeader(request)
request = request.WithContext(ctx)
transport, cleanup := tlsTransport(config)
defer cleanup()
client := &http.Client{Transport: transport}
response, err := client.Do(request)
if err != nil {
return nil, err
}
// If the remote server has detected that we are out of date, let's
// trigger an upgrade.
if response.StatusCode == http.StatusUpgradeRequired {
g.lock.Lock()
defer g.lock.Unlock()
if !g.upgradeTriggered {
err = triggerUpdate()
if err == nil {
g.upgradeTriggered = true
}
}
return nil, fmt.Errorf("Upgrade needed")
}
// If the endpoint does not exists, it means that the target node is
// running version 1 of dqlite protocol. In that case we simply behave
// as the node was at an older LXD version.
if response.StatusCode == http.StatusNotFound {
return nil, db.ErrSomeNodesAreBehind
}
if response.StatusCode != http.StatusOK {
return nil, fmt.Errorf(response.Status)
}
}
// Establish the connection
request := &http.Request{
Method: "POST",
Proto: "HTTP/1.1",
ProtoMajor: 1,
ProtoMinor: 1,
Header: make(http.Header),
Host: addr,
}
request.URL, err = url.Parse(path)
if err != nil {
return nil, err
}
request.Header.Set("Upgrade", "dqlite")
setDqliteVersionHeader(request)
request = request.WithContext(ctx)
deadline, _ := ctx.Deadline()
dialer := &net.Dialer{Timeout: time.Until(deadline)}
conn, err := tls.DialWithDialer(dialer, "tcp", addr, config)
if err != nil {
return nil, errors.Wrap(err, "Failed to connect to HTTP endpoint")
}
err = request.Write(conn)
if err != nil {
return nil, errors.Wrap(err, "Sending HTTP request failed")
}
response, err := http.ReadResponse(bufio.NewReader(conn), request)
if err != nil {
return nil, errors.Wrap(err, "Failed to read response")
}
if response.StatusCode != http.StatusSwitchingProtocols {
return nil, fmt.Errorf("Dialing failed: expected status code 101 got %d", response.StatusCode)
}
if response.Header.Get("Upgrade") != "dqlite" {
return nil, fmt.Errorf("Missing or unexpected Upgrade header in response")
}
listener, err := net.Listen("unix", "")
if err != nil {
return nil, errors.Wrap(err, "Failed to create unix listener")
}
goUnix, err := net.Dial("unix", listener.Addr().String())
if err != nil {
return nil, errors.Wrap(err, "Failed to connect to unix listener")
}
cUnix, err := listener.Accept()
if err != nil {
return nil, errors.Wrap(err, "Failed to connect to unix listener")
}
listener.Close()
go func() {
_, err := io.Copy(eagain.Writer{Writer: goUnix}, eagain.Reader{Reader: conn})
if err != nil {
logger.Warnf("Dqlite client proxy TLS -> Unix: %v", err)
}
goUnix.Close()
conn.Close()
}()
go func() {
_, err := io.Copy(eagain.Writer{Writer: conn}, eagain.Reader{Reader: goUnix})
if err != nil {
logger.Warnf("Dqlite client proxy Unix -> TLS: %v", err)
}
conn.Close()
goUnix.Close()
}()
// We successfully established a connection with the leader. Maybe the
// leader is ourselves, and we were recently elected. In that case
// trigger a full heartbeat now: it will be a no-op if we aren't
// actually leaders.
if checkLeader {
go g.heartbeat(g.ctx, true)
}
return cUnix, nil
}
// Create a dial function that connects to the local dqlite.
func dqliteMemoryDial(bindAddress string) client.DialFunc {
return func(ctx context.Context, address string) (net.Conn, error) {
return net.Dial("unix", bindAddress)
}
}
// The LXD API endpoint path that gets routed to a dqlite server handler for
// performing SQL queries against the dqlite server running on this node.
const databaseEndpoint = "/internal/database"
// DqliteLog redirects dqlite's logs to our own logger
func DqliteLog(l client.LogLevel, format string, a ...interface{}) {
format = fmt.Sprintf("Dqlite: %s", format)
switch l {
case client.LogDebug:
logger.Debugf(format, a...)
case client.LogInfo:
logger.Debugf(format, a...)
case client.LogWarn:
logger.Warnf(format, a...)
case client.LogError:
logger.Errorf(format, a...)
}
}
// Copy incoming TLS streams from upgraded HTTPS connections into Unix sockets
// connected to the dqlite task.
func runDqliteProxy(bindAddress string, acceptCh chan net.Conn) {
for {
src := <-acceptCh
dst, err := net.Dial("unix", bindAddress)
if err != nil {
continue
}
go func() {
_, err := io.Copy(eagain.Writer{Writer: dst}, eagain.Reader{Reader: src})
if err != nil {
logger.Warnf("Dqlite server proxy TLS -> Unix: %v", err)
}
src.Close()
dst.Close()
}()
go func() {
_, err := io.Copy(eagain.Writer{Writer: src}, eagain.Reader{Reader: dst})
if err != nil {
logger.Warnf("Dqlite server proxy Unix -> TLS: %v", err)
}
src.Close()
dst.Close()
}()
}
}
// Conditionally uses the in-memory or the on-disk server store.
type dqliteNodeStore struct {
inMemory client.NodeStore
onDisk client.NodeStore
}
func (s *dqliteNodeStore) Get(ctx context.Context) ([]client.NodeInfo, error) {
if s.inMemory != nil {
return s.inMemory.Get(ctx)
}
return s.onDisk.Get(ctx)
}
func (s *dqliteNodeStore) Set(ctx context.Context, servers []client.NodeInfo) error {