diff --git a/command/agent/agent.go b/command/agent/agent.go index afe247e1d0..b74a1dcf10 100644 --- a/command/agent/agent.go +++ b/command/agent/agent.go @@ -124,7 +124,7 @@ func Create(config *Config, logOutput io.Writer) (*Agent, error) { if config.Datacenter == "" { return nil, fmt.Errorf("Must configure a Datacenter") } - if config.DataDir == "" { + if config.DataDir == "" && !config.DevMode { return nil, fmt.Errorf("Must configure a DataDir") } @@ -227,6 +227,9 @@ func (a *Agent) consulConfig() *consul.Config { base = consul.DefaultConfig() } + // Apply dev mode + base.DevMode = a.config.DevMode + // Override with our config if a.config.Datacenter != "" { base.Datacenter = a.config.Datacenter @@ -748,7 +751,7 @@ func (a *Agent) AddService(service *structs.NodeService, chkTypes CheckTypes, pe a.state.AddService(service, token) // Persist the service to a file - if persist { + if persist && !a.config.DevMode { if err := a.persistService(service); err != nil { return err } @@ -958,7 +961,7 @@ func (a *Agent) AddCheck(check *structs.HealthCheck, chkType *CheckType, persist a.state.AddCheck(check, token) // Persist the check - if persist { + if persist && !a.config.DevMode { return a.persistCheck(check, chkType) } @@ -1022,6 +1025,10 @@ func (a *Agent) UpdateCheck(checkID, status, output string) error { // Set the status through CheckTTL to reset the TTL check.SetStatus(status, output) + if a.config.DevMode { + return nil + } + // Always persist the state for TTL checks if err := a.persistCheckState(check, status, output); err != nil { return fmt.Errorf("failed persisting state for check %q: %s", checkID, err) diff --git a/command/agent/command.go b/command/agent/command.go index 050be0d3c8..ffdfcef070 100644 --- a/command/agent/command.go +++ b/command/agent/command.go @@ -60,12 +60,14 @@ func (c *Command) readConfig() *Config { var retryInterval string var retryIntervalWan string var dnsRecursors []string + var dev bool cmdFlags := flag.NewFlagSet("agent", flag.ContinueOnError) cmdFlags.Usage = func() { c.Ui.Output(c.Help()) } cmdFlags.Var((*AppendSliceValue)(&configFiles), "config-file", "json file to read config from") cmdFlags.Var((*AppendSliceValue)(&configFiles), "config-dir", "directory of json files to read") cmdFlags.Var((*AppendSliceValue)(&dnsRecursors), "recursor", "address of an upstream DNS server") + cmdFlags.BoolVar(&dev, "dev", false, "development server mode") cmdFlags.StringVar(&cmdConfig.LogLevel, "log-level", "", "log level") cmdFlags.StringVar(&cmdConfig.NodeName, "node", "", "node name") @@ -137,7 +139,13 @@ func (c *Command) readConfig() *Config { cmdConfig.RetryIntervalWan = dur } - config := DefaultConfig() + var config *Config + if dev { + config = DevConfig() + } else { + config = DefaultConfig() + } + if len(configFiles) > 0 { fileConfig, err := ReadConfigPaths(configFiles) if err != nil { @@ -162,7 +170,7 @@ func (c *Command) readConfig() *Config { } // Ensure we have a data directory - if config.DataDir == "" { + if config.DataDir == "" && !dev { c.Ui.Error("Must specify data directory using -data-dir") return nil } diff --git a/command/agent/config.go b/command/agent/config.go index 79836f8811..2f18c2dc3e 100644 --- a/command/agent/config.go +++ b/command/agent/config.go @@ -94,6 +94,10 @@ type DNSConfig struct { // Some of this is configurable as CLI flags, but most must // be set using a configuration file. type Config struct { + // DevMode enables a fast-path mode of opertaion to bring up an in-memory + // server with minimal configuration. Useful for developing Consul. + DevMode bool `mapstructure:"-"` + // Bootstrap is used to bring up the first Consul server, and // permits that node to elect itself leader Bootstrap bool `mapstructure:"bootstrap"` @@ -521,6 +525,18 @@ func DefaultConfig() *Config { } } +// DevConfig is used to return a set of configuration to use for dev mode. +func DevConfig() *Config { + conf := DefaultConfig() + conf.DevMode = true + conf.LogLevel = "DEBUG" + conf.Server = true + conf.EnableDebug = true + conf.DisableAnonymousSignature = true + conf.EnableUi = true + return conf +} + // EncryptBytes returns the encryption key configured. func (c *Config) EncryptBytes() ([]byte, error) { return base64.StdEncoding.DecodeString(c.EncryptKey) diff --git a/consul/config.go b/consul/config.go index bfb3fa809b..78b3fc8753 100644 --- a/consul/config.go +++ b/consul/config.go @@ -54,6 +54,9 @@ type Config struct { // DataDir is the directory to store our state in DataDir string + // DevMode is used to enable a development server mode. + DevMode bool + // Node name is the name we use to advertise. Defaults to hostname. NodeName string diff --git a/consul/server.go b/consul/server.go index eec5802127..7a59cb5945 100644 --- a/consul/server.go +++ b/consul/server.go @@ -110,6 +110,7 @@ type Server struct { raftPeers raft.PeerStore raftStore *raftboltdb.BoltStore raftTransport *raft.NetworkTransport + raftInmem *raft.InmemStore // reconcileCh is used to pass events from the serf handler // into the leader manager, so that the strong state can be @@ -173,7 +174,7 @@ func NewServer(config *Config) (*Server, error) { } // Check for a data directory! - if config.DataDir == "" { + if config.DataDir == "" && !config.DevMode { return nil, fmt.Errorf("Config must provide a DataDir") } @@ -301,7 +302,9 @@ func (s *Server) setupSerf(conf *serf.Config, ch chan serf.Event, path string, w conf.MemberlistConfig.LogOutput = s.config.LogOutput conf.LogOutput = s.config.LogOutput conf.EventCh = ch - conf.SnapshotPath = filepath.Join(s.config.DataDir, path) + if !s.config.DevMode { + conf.SnapshotPath = filepath.Join(s.config.DataDir, path) + } conf.ProtocolVersion = protocolVersionMap[s.config.ProtocolVersion] conf.RejoinAfterLeave = s.config.RejoinAfterLeave if wan { @@ -327,7 +330,7 @@ func (s *Server) setupSerf(conf *serf.Config, ch chan serf.Event, path string, w // setupRaft is used to setup and initialize Raft func (s *Server) setupRaft() error { // If we are in bootstrap mode, enable a single node cluster - if s.config.Bootstrap { + if s.config.Bootstrap || s.config.DevMode { s.config.RaftConfig.EnableSingleNode = true } @@ -338,45 +341,66 @@ func (s *Server) setupRaft() error { return err } - // Create the base raft path - path := filepath.Join(s.config.DataDir, raftState) - if err := ensurePath(path, true); err != nil { - return err - } - - // Create the backend raft store for logs and stable storage - store, err := raftboltdb.NewBoltStore(filepath.Join(path, "raft.db")) - if err != nil { - return err - } - s.raftStore = store - - // Wrap the store in a LogCache to improve performance - cacheStore, err := raft.NewLogCache(raftLogCacheSize, store) - if err != nil { - store.Close() - return err - } - - // Create the snapshot store - snapshots, err := raft.NewFileSnapshotStore(path, snapshotsRetained, s.config.LogOutput) - if err != nil { - store.Close() - return err - } - // Create a transport layer trans := raft.NewNetworkTransport(s.raftLayer, 3, 10*time.Second, s.config.LogOutput) s.raftTransport = trans - // Setup the peer store - s.raftPeers = raft.NewJSONPeers(path, trans) + var log raft.LogStore + var stable raft.StableStore + var snap raft.SnapshotStore + var peers raft.PeerStore + + if s.config.DevMode { + store := raft.NewInmemStore() + s.raftInmem = store + stable = store + log = store + snap = raft.NewDiscardSnapshotStore() + peers = &raft.StaticPeers{} + s.raftPeers = peers + } else { + // Create the base raft path + path := filepath.Join(s.config.DataDir, raftState) + if err := ensurePath(path, true); err != nil { + return err + } + + // Create the backend raft store for logs and stable storage + store, err := raftboltdb.NewBoltStore(filepath.Join(path, "raft.db")) + if err != nil { + return err + } + s.raftStore = store + stable = store + + // Wrap the store in a LogCache to improve performance + cacheStore, err := raft.NewLogCache(raftLogCacheSize, store) + if err != nil { + store.Close() + return err + } + log = cacheStore + + // Create the snapshot store + snapshots, err := raft.NewFileSnapshotStore(path, snapshotsRetained, s.config.LogOutput) + if err != nil { + store.Close() + return err + } + snap = snapshots + + // Setup the peer store + s.raftPeers = raft.NewJSONPeers(path, trans) + peers = s.raftPeers + } // Ensure local host is always included if we are in bootstrap mode if s.config.Bootstrap { peers, err := s.raftPeers.Peers() if err != nil { - store.Close() + if s.raftStore != nil { + s.raftStore.Close() + } return err } if !raft.PeerContained(peers, trans.LocalAddr()) { @@ -388,10 +412,12 @@ func (s *Server) setupRaft() error { s.config.RaftConfig.LogOutput = s.config.LogOutput // Setup the Raft store - s.raft, err = raft.NewRaft(s.config.RaftConfig, s.fsm, cacheStore, store, - snapshots, s.raftPeers, trans) + s.raft, err = raft.NewRaft(s.config.RaftConfig, s.fsm, log, stable, + snap, s.raftPeers, trans) if err != nil { - store.Close() + if s.raftStore != nil { + s.raftStore.Close() + } trans.Close() return err } @@ -484,7 +510,9 @@ func (s *Server) Shutdown() error { if err := future.Error(); err != nil { s.logger.Printf("[WARN] consul: Error shutting down raft: %s", err) } - s.raftStore.Close() + if s.raftStore != nil { + s.raftStore.Close() + } // Clear the peer set on a graceful leave to avoid // triggering elections on a rejoin. diff --git a/website/source/docs/agent/options.html.markdown b/website/source/docs/agent/options.html.markdown index c2b85a2396..e7703cd290 100644 --- a/website/source/docs/agent/options.html.markdown +++ b/website/source/docs/agent/options.html.markdown @@ -124,6 +124,12 @@ The options below are all specified on the command-line. the use of filesystem locking, meaning some types of mounted folders (e.g. VirtualBox shared folders) may not be suitable. +* `-dev` - Enable development server + mode. This is useful for quickly starting a Consul agent with all persistence + options turned off, enabling an in-memory server which can be used for rapid + prototyping or developing against the API. This mode is **not** intended for + production use as it does not write any data to disk. + * `-dc` - This flag controls the datacenter in which the agent is running. If not provided, it defaults to "dc1". Consul has first-class support for multiple datacenters, but diff --git a/website/source/intro/getting-started/agent.html.markdown b/website/source/intro/getting-started/agent.html.markdown index 28ddff23db..920e0f6892 100644 --- a/website/source/intro/getting-started/agent.html.markdown +++ b/website/source/intro/getting-started/agent.html.markdown @@ -2,8 +2,11 @@ layout: "intro" page_title: "Run the Agent" sidebar_current: "gettingstarted-agent" -description: |- - After Consul is installed, the agent must be run. The agent can either run in server or client mode. Each datacenter must have at least one server, though a cluster of 3 or 5 servers is recommended. A single server deployment is highly discouraged as data loss is inevitable in a failure scenario. +description: > + The Consul agent can run in either server or client mode. Each datacenter + must have at least one server, though a cluster of 3 or 5 servers is + recommended. A single server deployment is highly discouraged in production + as data loss is inevitable in a failure scenario. --- # Run the Consul Agent @@ -22,34 +25,45 @@ For more detail on bootstrapping a datacenter, see ## Starting the Agent -For simplicity, we'll run a single Consul agent in server mode: +For simplicity, we'll start the Consul agent in development mode for now. This +mode is useful for bringing up a single-node Consul environment quickly and +easily. It is **not** intended to be used in production as it does not persist +any state. ```text -$ consul agent -server -bootstrap-expect 1 -data-dir /tmp/consul -==> WARNING: BootstrapExpect Mode is specified as 1; this is the same as Bootstrap mode. -==> WARNING: Bootstrap mode enabled! Do not enable unless necessary +$ consul agent -dev ==> Starting Consul agent... ==> Starting Consul agent RPC... ==> Consul agent running! - Node name: 'Armons-MacBook-Air' - Datacenter: 'dc1' - Server: true (bootstrap: true) - Client Addr: 127.0.0.1 (HTTP: 8500, DNS: 8600, RPC: 8400) - Cluster Addr: 10.1.10.38 (LAN: 8301, WAN: 8302) + Node name: 'Armons-MacBook-Air' + Datacenter: 'dc1' + Server: true (bootstrap: false) + Client Addr: 127.0.0.1 (HTTP: 8500, HTTPS: -1, DNS: 8600, RPC: 8400) + Cluster Addr: 172.20.20.11 (LAN: 8301, WAN: 8302) + Gossip encrypt: false, RPC-TLS: false, TLS-Incoming: false + Atlas: ==> Log data will now stream in as it occurs: -[INFO] serf: EventMemberJoin: Armons-MacBook-Air.local 10.1.10.38 -[INFO] raft: Node at 10.1.10.38:8300 [Follower] entering Follower state -[INFO] consul: adding server for datacenter: dc1, addr: 10.1.10.38:8300 -[ERR] agent: failed to sync remote state: rpc error: No cluster leader +[INFO] raft: Node at 172.20.20.11:8300 [Follower] entering Follower state +[INFO] serf: EventMemberJoin: Armons-MacBook-Air 172.20.20.11 +[INFO] consul: adding LAN server Armons-MacBook-Air (Addr: 172.20.20.11:8300) (DC: dc1) +[INFO] serf: EventMemberJoin: Armons-MacBook-Air.dc1 172.20.20.11 +[INFO] consul: adding WAN server Armons-MacBook-Air.dc1 (Addr: 172.20.20.11:8300) (DC: dc1) +[ERR] agent: failed to sync remote state: No cluster leader [WARN] raft: Heartbeat timeout reached, starting election -[INFO] raft: Node at 10.1.10.38:8300 [Candidate] entering Candidate state +[INFO] raft: Node at 172.20.20.11:8300 [Candidate] entering Candidate state +[DEBUG] raft: Votes needed: 1 +[DEBUG] raft: Vote granted. Tally: 1 [INFO] raft: Election won. Tally: 1 -[INFO] raft: Node at 10.1.10.38:8300 [Leader] entering Leader state +[INFO] raft: Node at 172.20.20.11:8300 [Leader] entering Leader state +[INFO] raft: Disabling EnableSingleNode (bootstrap) [INFO] consul: cluster leadership acquired +[DEBUG] raft: Node 172.20.20.11:8300 updated peer set (2): [172.20.20.11:8300] +[DEBUG] consul: reset tombstone GC to index 2 [INFO] consul: New leader elected: Armons-MacBook-Air [INFO] consul: member 'Armons-MacBook-Air' joined, marking health alive +[INFO] agent: Synced service 'consul' ``` As you can see, the Consul agent has started and has output some log @@ -70,8 +84,8 @@ section, but for now, you should only see one member (yourself): ```text $ consul members -Node Address Status Type Build Protocol -Armons-MacBook-Air 10.1.10.38:8301 alive server 0.5.1 2 +Node Address Status Type Build Protocol DC +Armons-MacBook-Air 172.20.20.11:8301 alive server 0.6.1dev 2 dc1 ``` The output shows our own node, the address it is running on, its @@ -87,7 +101,7 @@ request to the Consul servers: ```text $ curl localhost:8500/v1/catalog/nodes -[{"Node":"Armons-MacBook-Air","Address":"10.1.10.38"}] +[{"Node":"Armons-MacBook-Air","Address":"172.20.20.11","CreateIndex":3,"ModifyIndex":4}] ``` In addition to the HTTP API, the [DNS interface](/docs/agent/dns.html) can @@ -104,7 +118,7 @@ $ dig @127.0.0.1 -p 8600 Armons-MacBook-Air.node.consul ;Armons-MacBook-Air.node.consul. IN A ;; ANSWER SECTION: -Armons-MacBook-Air.node.consul. 0 IN A 10.1.10.38 +Armons-MacBook-Air.node.consul. 0 IN A 172.20.20.11 ``` ## Stopping the Agent diff --git a/website/source/intro/getting-started/consul.d/web.json b/website/source/intro/getting-started/consul.d/web.json new file mode 100644 index 0000000000..1dc4674f97 --- /dev/null +++ b/website/source/intro/getting-started/consul.d/web.json @@ -0,0 +1 @@ +{"service": {"name": "web", "tags": ["rails"], "port": 80}} diff --git a/website/source/intro/getting-started/join.html.markdown b/website/source/intro/getting-started/join.html.markdown index a4c3dc368a..d7a68d1cae 100644 --- a/website/source/intro/getting-started/join.html.markdown +++ b/website/source/intro/getting-started/join.html.markdown @@ -2,8 +2,11 @@ layout: "intro" page_title: "Consul Cluster" sidebar_current: "gettingstarted-join" -description: |- - We've started our first agent and registered and queried a service on that agent. This showed how easy it is to use Consul but didn't show how this could be extended to a scalable, production-grade service discovery infrastructure. In this step, we'll create our first real cluster with multiple members. +description: > + When a Consul agent is started, it begins as an isolated cluster of its own. + To learn about other cluster members, the agent must join one or more other + nodes using a provided join address. In this step, we will set up a two-node + cluster and join the nodes together. --- # Consul Cluster @@ -40,6 +43,12 @@ of our cluster. We start by logging in to the first node: $ vagrant ssh n1 ``` +In our previous examples, we used the [`-dev` +flag](/docs/agent/options.html#_dev) to quickly set up a development server. +However, this is not sufficient for use in a clustered environment. We will +omit the `-dev` flag from here on, and instead specify our clustering flags as +outlined below. + Each node in a cluster must have a unique name. By default, Consul uses the hostname of the machine, but we'll manually override it using the [`-node` command-line option](/docs/agent/options.html#_node). @@ -53,9 +62,17 @@ multiple interfaces, so specifying a `bind` address assures that you will never bind Consul to the wrong interface. The first node will act as our sole server in this cluster, and we indicate -this with the [`server` switch](/docs/agent/options.html#_server). Finally, we -add the [`config-dir` flag](/docs/agent/options.html#_config_dir), marking -where service and check definitions can be found. +this with the [`server` switch](/docs/agent/options.html#_server). + +The [`-bootstrap-expect` flag](/docs/agent/options.html#_bootstrap_expect) +hints to the Consul server the number of additional server nodes we are +expecting to join. The purpose of this flag is to delay the bootstrapping of +the replicated log until the expected number of servers has successfully joined. +You can read more about this in the [bootstrapping +guide](/docs/guides/bootstrapping.html). + +Finally, we add the [`config-dir` flag](/docs/agent/options.html#_config_dir), +marking where service and check definitions can be found. All together, these settings yield a [`consul agent`](/docs/commands/agent.html) command like this: diff --git a/website/source/intro/getting-started/services.html.markdown b/website/source/intro/getting-started/services.html.markdown index 38924a9abd..70f77c695b 100644 --- a/website/source/intro/getting-started/services.html.markdown +++ b/website/source/intro/getting-started/services.html.markdown @@ -2,8 +2,11 @@ layout: "intro" page_title: "Registering Services" sidebar_current: "gettingstarted-services" -description: |- - In the previous step, we ran our first agent, saw the cluster members (well, our cluster member), and queried that node. Now, we'll register our first service and query that service. +description: > + A service can be registered either by providing a service definition or by + making the appropriate calls to the HTTP API. A configuration file is the + most common, so we will use this approach to register a service, and then + query that service using the REST API and DNS interfaces. --- # Registering Services @@ -44,8 +47,7 @@ $ echo '{"service": {"name": "web", "tags": ["rails"], "port": 80}}' \ Now, restart the agent, providing the configuration directory: ```text -$ consul agent -server -bootstrap-expect 1 -data-dir /tmp/consul \ - -config-dir /etc/consul.d +$ consul agent -dev -config-dir /etc/consul.d ==> Starting Consul agent... ... [INFO] agent: Synced service 'web' @@ -53,7 +55,8 @@ $ consul agent -server -bootstrap-expect 1 -data-dir /tmp/consul \ ``` You'll notice in the output that it "synced" the web service. This means -that it loaded the information from the configuration. +that the agent loaded the service definition from the configuration file, +and has successfully registered it in the service catalog. If you wanted to register multiple services, you could create multiple service definition files in the Consul configuration directory. @@ -97,13 +100,13 @@ $ dig @127.0.0.1 -p 8600 web.service.consul SRV ... ;; QUESTION SECTION: -;web.service.consul. IN SRV +;web.service.consul. IN SRV ;; ANSWER SECTION: -web.service.consul. 0 IN SRV 1 1 80 agent-one.node.dc1.consul. +web.service.consul. 0 IN SRV 1 1 80 Armons-MacBook-Air.node.dc1.consul. ;; ADDITIONAL SECTION: -agent-one.node.dc1.consul. 0 IN A 172.20.20.11 +Armons-MacBook-Air.node.dc1.consul. 0 IN A 172.20.20.11 ``` The `SRV` record says that the web service is running on port 80 and exists on