// NewClient is used to create a new client from the given configuration
func NewClient(cfg *config.Config, consulSyncer *consul.Syncer, logger *log.Logger) (*Client, error) {
// Create the client
c := &Client{
config: cfg,
consulSyncer: consulSyncer,
start: time.Now(),
connPool: nomad.NewPool(cfg.LogOutput, clientRPCCache, clientMaxStreams, nil),
logger: logger,
hostStatsCollector: stats.NewHostStatsCollector(),
allocs: make(map[string]*AllocRunner),
allocUpdates: make(chan *structs.Allocation, 64),
shutdownCh: make(chan struct{}),
}
// Initialize the client
if err := c.init(); err != nil {
return nil, fmt.Errorf("failed to initialize client: %v", err)
}
// Setup the node
if err := c.setupNode(); err != nil {
return nil, fmt.Errorf("node setup failed: %v", err)
}
// Fingerprint the node
if err := c.fingerprint(); err != nil {
return nil, fmt.Errorf("fingerprinting failed: %v", err)
}
// Scan for drivers
if err := c.setupDrivers(); err != nil {
return nil, fmt.Errorf("driver setup failed: %v", err)
}
// Setup the reserved resources
c.reservePorts()
// Store the config copy before restoring state but after it has been
// initialized.
c.configLock.Lock()
c.configCopy = c.config.Copy()
c.configLock.Unlock()
// Create the RPC Proxy and bootstrap with the preconfigured list of
// static servers
c.configLock.RLock()
c.rpcProxy = rpcproxy.NewRPCProxy(c.logger, c.shutdownCh, c, c.connPool)
for _, serverAddr := range c.configCopy.Servers {
c.rpcProxy.AddPrimaryServer(serverAddr)
}
c.configLock.RUnlock()
// Restore the state
if err := c.restoreState(); err != nil {
return nil, fmt.Errorf("failed to restore state: %v", err)
}
// Setup the Consul syncer
if err := c.setupConsulSyncer(); err != nil {
return nil, fmt.Errorf("failed to create client Consul syncer: %v")
}
// Register and then start heartbeating to the servers.
go c.registerAndHeartbeat()
// Begin periodic snapshotting of state.
go c.periodicSnapshot()
// Begin syncing allocations to the server
go c.allocSync()
// Start the client!
go c.run()
// Start collecting stats
go c.collectHostStats()
// Start the RPCProxy maintenance task. This task periodically
// shuffles the list of Nomad Server Endpoints this Client will use
// when communicating with Nomad Servers via RPC. This is done in
// order to prevent server fixation in stable Nomad clusters. This
// task actively populates the active list of Nomad Server Endpoints
// from information from the Nomad Client heartbeats. If a heartbeat
// times out and there are no Nomad servers available, this data is
// populated by periodically polling Consul, if available.
go c.rpcProxy.Run()
return c, nil
}
// NewClient is used to create a new client from the given configuration
func NewClient(cfg *config.Config) (*Client, error) {
// Create a logger
logger := log.New(cfg.LogOutput, "", log.LstdFlags)
resourceUsage, err := stats.NewRingBuff(cfg.StatsDataPoints)
if err != nil {
return nil, err
}
// Create the client
c := &Client{
config: cfg,
start: time.Now(),
connPool: nomad.NewPool(cfg.LogOutput, clientRPCCache, clientMaxStreams, nil),
logger: logger,
hostStatsCollector: stats.NewHostStatsCollector(),
resourceUsage: resourceUsage,
allocs: make(map[string]*AllocRunner),
allocUpdates: make(chan *structs.Allocation, 64),
shutdownCh: make(chan struct{}),
}
// Initialize the client
if err := c.init(); err != nil {
return nil, fmt.Errorf("failed to initialize client: %v", err)
}
// Setup the node
if err := c.setupNode(); err != nil {
return nil, fmt.Errorf("node setup failed: %v", err)
}
// Fingerprint the node
if err := c.fingerprint(); err != nil {
return nil, fmt.Errorf("fingerprinting failed: %v", err)
}
// Scan for drivers
if err := c.setupDrivers(); err != nil {
return nil, fmt.Errorf("driver setup failed: %v", err)
}
// Setup the reserved resources
c.reservePorts()
// Set up the known servers list
c.SetServers(c.config.Servers)
// Store the config copy before restoring state but after it has been
// initialized.
c.configCopy = c.config.Copy()
// Restore the state
if err := c.restoreState(); err != nil {
return nil, fmt.Errorf("failed to restore state: %v", err)
}
// Setup the consul client
if err := c.setupConsulClient(); err != nil {
return nil, fmt.Errorf("failed to create consul client: %v")
}
// Register and then start heartbeating to the servers.
go c.registerAndHeartbeat()
// Begin periodic snapshotting of state.
go c.periodicSnapshot()
// Begin syncing allocations to the server
go c.allocSync()
// Start the client!
go c.run()
// Start collecting stats
go c.collectHostStats()
// Start the consul sync
go c.syncConsul()
return c, nil
}