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| -rw-r--r-- | .gitignore | 5 | ||||
| -rw-r--r-- | LICENSE | 674 | ||||
| -rw-r--r-- | cmd/cmd.go | 101 | ||||
| -rw-r--r-- | config/client.go | 43 | ||||
| -rw-r--r-- | go.mod | 18 | ||||
| -rw-r--r-- | go.sum | 36 | ||||
| -rw-r--r-- | observatory/client.go | 266 | ||||
| -rw-r--r-- | observatory/server.go | 261 | ||||
| -rw-r--r-- | observatory/server_test.go | 33 | ||||
| -rw-r--r-- | protocol/handshake.go | 14 | ||||
| -rw-r--r-- | protocol/messages.go | 29 | ||||
| -rw-r--r-- | protocol/observe.go | 14 | ||||
| -rw-r--r-- | protocol/publish.go | 8 |
13 files changed, 1502 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..75b89fc --- /dev/null +++ b/.gitignore @@ -0,0 +1,5 @@ +.idea/ +.code/ +.vscode/ + +run/
\ No newline at end of file @@ -0,0 +1,674 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/> + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. By contrast, +the GNU General Public License is intended to guarantee your freedom to +share and change all versions of a program--to make sure it remains free +software for all its users. We, the Free Software Foundation, use the +GNU General Public License for most of our software; it applies also to +any other work released this way by its authors. You can apply it to +your programs, too. + + When we speak of free software, we are referring to freedom, not +price. Our General Public Licenses are designed to make sure that you +have the freedom to distribute copies of free software (and charge for +them if you wish), that you receive source code or can get it if you +want it, that you can change the software or use pieces of it in new +free programs, and that you know you can do these things. + + To protect your rights, we need to prevent others from denying you +these rights or asking you to surrender the rights. Therefore, you have +certain responsibilities if you distribute copies of the software, or if +you modify it: responsibilities to respect the freedom of others. + + For example, if you distribute copies of such a program, whether +gratis or for a fee, you must pass on to the recipients the same +freedoms that you received. You must make sure that they, too, receive +or can get the source code. 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If the +Program specifies that a certain numbered version of the GNU General +Public License "or any later version" applies to it, you have the +option of following the terms and conditions either of that numbered +version or of any later version published by the Free Software +Foundation. If the Program does not specify a version number of the +GNU General Public License, you may choose any version ever published +by the Free Software Foundation. + + If the Program specifies that a proxy can decide which future +versions of the GNU General Public License can be used, that proxy's +public statement of acceptance of a version permanently authorizes you +to choose that version for the Program. + + Later license versions may give you additional or different +permissions. However, no additional obligations are imposed on any +author or copyright holder as a result of your choosing to follow a +later version. + + 15. Disclaimer of Warranty. + + THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY +APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT +HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY +OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, +THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM +IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF +ALL NECESSARY SERVICING, REPAIR OR CORRECTION. + + 16. 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Interpretation of Sections 15 and 16. + + If the disclaimer of warranty and limitation of liability provided +above cannot be given local legal effect according to their terms, +reviewing courts shall apply local law that most closely approximates +an absolute waiver of all civil liability in connection with the +Program, unless a warranty or assumption of liability accompanies a +copy of the Program in return for a fee. + + END OF TERMS AND CONDITIONS + + How to Apply These Terms to Your New Programs + + If you develop a new program, and you want it to be of the greatest +possible use to the public, the best way to achieve this is to make it +free software which everyone can redistribute and change under these terms. + + To do so, attach the following notices to the program. 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If not, see <https://www.gnu.org/licenses/>. + +Also add information on how to contact you by electronic and paper mail. + + If the program does terminal interaction, make it output a short +notice like this when it starts in an interactive mode: + + <program> Copyright (C) <year> <name of author> + This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, your program's commands +might be different; for a GUI interface, you would use an "about box". + + You should also get your employer (if you work as a programmer) or school, +if any, to sign a "copyright disclaimer" for the program, if necessary. +For more information on this, and how to apply and follow the GNU GPL, see +<https://www.gnu.org/licenses/>. + + The GNU General Public License does not permit incorporating your program +into proprietary programs. If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +<https://www.gnu.org/licenses/why-not-lgpl.html>. diff --git a/cmd/cmd.go b/cmd/cmd.go new file mode 100644 index 0000000..8374124 --- /dev/null +++ b/cmd/cmd.go @@ -0,0 +1,101 @@ +package main + +import ( + "context" + "errors" + "fmt" + "github.com/akamensky/argparse" + "github.com/bombsimon/logrusr/v4" + "github.com/go-logr/logr" + "github.com/hit-mc/observatory/config" + "github.com/hit-mc/observatory/observatory" + "github.com/sirupsen/logrus" + "net/http" + "os" + "os/signal" + "time" +) + +func main() { + parser := argparse.NewParser("observatory", "Minecraft tunnel observatory") + configFile := parser.String("c", "config", &argparse.Options{ + Required: true, + Help: "Config file to use", + Default: "config.toml", + }) + isServer := parser.Flag("", "server", &argparse.Options{ + Required: false, + Help: "Run program as server (stats collector)", + Default: false, + }) + isClient := parser.Flag("", "client", &argparse.Options{ + Required: false, + Help: "Run program as client (stats observer&reporter)", + Default: false, + }) + err := parser.Parse(os.Args) + if err != nil { + fmt.Print(parser.Usage(err)) + return + } + if !*isServer && !*isClient { + fmt.Println("You must specify either --server or --client in CLI arguments.") + os.Exit(1) + } + + ctx, cancel := context.WithCancel(context.Background()) + + logger := logrusr.New(logrus.New()) + go func() { + logger := logger.WithName("SignalHandler") + c := make(chan os.Signal, 1) + signal.Notify(c, os.Interrupt) + <-c + logger.Info("stopping") + cancel() + }() + + if *isServer { + runCollector(ctx, *configFile, logger) + } else { + runObserver(ctx, *configFile, logger) + } +} + +func runCollector(ctx context.Context, configFile string, logger logr.Logger) { + cfg, err := config.Read[config.Server](configFile) + if err != nil { + panic(fmt.Errorf("error reading config file `%v`: %w", configFile, err)) + } + + handshakeTimeout := time.Duration(cfg.HandshakeTimeout) * time.Millisecond + s := observatory.NewCollector(cfg.Listen, handshakeTimeout, logger, cfg.Token, cfg.Targets) + err = s.Run(ctx) + if err != nil && !errors.Is(err, http.ErrServerClosed) { + panic(err) + } +} + +func runObserver(ctx context.Context, configFile string, logger logr.Logger) { + cfg, err := config.Read[config.Client](configFile) + if err != nil { + panic(fmt.Errorf("error reading config file `%v`: %w", configFile, err)) + } + + sendBuf := cfg.SendBuffer + if sendBuf < 0 { + sendBuf = 0 + } + + reconnInterval := cfg.ReconnectInterval + if reconnInterval < 0 { + reconnInterval = 0 + } + + reportConnTimeout := cfg.ReportConnectTimeout + if reportConnTimeout < 0 { + reportConnTimeout = 0 + } + + observatory.RunClient(ctx, cfg, logger) +} diff --git a/config/client.go b/config/client.go new file mode 100644 index 0000000..a2d1500 --- /dev/null +++ b/config/client.go @@ -0,0 +1,43 @@ +package config + +import ( + "fmt" + "github.com/pelletier/go-toml/v2" + "os" +) + +type Server struct { + Listen string `toml:"listen"` + HandshakeTimeout int `toml:"handshake_timeout"` + Token string `toml:"token"` + Targets []Target `toml:"targets"` +} + +type Client struct { + ObserverID string `toml:"observer_id"` + ReportServer string `toml:"report_server"` + CheckInterval int `toml:"check_interval"` + SendBuffer int `toml:"send_buffer"` + ReconnectInterval int `toml:"reconnect_interval"` + ReportConnectTimeout int `toml:"report_connect_timeout"` + Token string `toml:"token"` +} + +type Target struct { + Host string `toml:"host"` + Port int `toml:"port"` +} + +func Read[T any](path string) (ret *T, err error) { + f, err := os.Open(path) + if err != nil { + return nil, fmt.Errorf("open: %w", err) + } + defer func() { + _ = f.Close() + }() + dec := toml.NewDecoder(f) + ret = new(T) + err = dec.Decode(ret) + return ret, err +} @@ -0,0 +1,18 @@ +module github.com/hit-mc/observatory + +go 1.18 + +require ( + github.com/akamensky/argparse v1.4.0 + github.com/bombsimon/logrusr/v4 v4.1.0 + github.com/go-logr/logr v1.4.1 + github.com/gorilla/websocket v1.5.1 + github.com/pelletier/go-toml/v2 v2.1.1 + github.com/sirupsen/logrus v1.9.0 + github.com/xrjr/mcutils v1.5.1 +) + +require ( + golang.org/x/net v0.17.0 // indirect + golang.org/x/sys v0.13.0 // indirect +) @@ -0,0 +1,36 @@ +github.com/akamensky/argparse v1.4.0 h1:YGzvsTqCvbEZhL8zZu2AiA5nq805NZh75JNj4ajn1xc= +github.com/akamensky/argparse v1.4.0/go.mod h1:S5kwC7IuDcEr5VeXtGPRVZ5o/FdhcMlQz4IZQuw64xA= +github.com/bombsimon/logrusr/v4 v4.1.0 h1:uZNPbwusB0eUXlO8hIUwStE6Lr5bLN6IgYgG+75kuh4= +github.com/bombsimon/logrusr/v4 v4.1.0/go.mod h1:pjfHC5e59CvjTBIU3V3sGhFWFAnsnhOR03TRc6im0l8= +github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38= +github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c= +github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38= +github.com/go-logr/logr v1.4.1 h1:pKouT5E8xu9zeFC39JXRDukb6JFQPXM5p5I91188VAQ= +github.com/go-logr/logr v1.4.1/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY= +github.com/gorilla/websocket v1.5.1 h1:gmztn0JnHVt9JZquRuzLw3g4wouNVzKL15iLr/zn/QY= +github.com/gorilla/websocket v1.5.1/go.mod h1:x3kM2JMyaluk02fnUJpQuwD2dCS5NDG2ZHL0uE0tcaY= +github.com/pelletier/go-toml/v2 v2.1.1 h1:LWAJwfNvjQZCFIDKWYQaM62NcYeYViCmWIwmOStowAI= +github.com/pelletier/go-toml/v2 v2.1.1/go.mod h1:tJU2Z3ZkXwnxa4DPO899bsyIoywizdUvyaeZurnPPDc= +github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM= +github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4= +github.com/sirupsen/logrus v1.9.0 h1:trlNQbNUG3OdDrDil03MCb1H2o9nJ1x4/5LYw7byDE0= +github.com/sirupsen/logrus v1.9.0/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ= +github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME= +github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw= +github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo= +github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg= +github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg= +github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU= +github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk= +github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo= +github.com/xrjr/mcutils v1.5.1 h1:E4ScafEH+joxWVgRCGpJBJfxWX/vaNJDcoS40V91rVo= +github.com/xrjr/mcutils v1.5.1/go.mod h1:43n8cyMIHYjiRM2LFZLVH5Ppz2+RvWppz6OgkLP8Lsk= +golang.org/x/net v0.17.0 h1:pVaXccu2ozPjCXewfr1S7xza/zcXTity9cCdXQYSjIM= +golang.org/x/net v0.17.0/go.mod h1:NxSsAGuq816PNPmqtQdLE42eU2Fs7NoRIZrHJAlaCOE= +golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= +golang.org/x/sys v0.13.0 h1:Af8nKPmuFypiUBjVoU9V20FiaFXOcuZI21p0ycVYYGE= +golang.org/x/sys v0.13.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= +gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0= +gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM= +gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA= +gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM= diff --git a/observatory/client.go b/observatory/client.go new file mode 100644 index 0000000..fc4d2b6 --- /dev/null +++ b/observatory/client.go @@ -0,0 +1,266 @@ +package observatory + +import ( + "context" + "encoding/json" + "fmt" + "github.com/go-logr/logr" + "github.com/gorilla/websocket" + "github.com/hit-mc/observatory/config" + "github.com/hit-mc/observatory/protocol" + "github.com/xrjr/mcutils/pkg/ping" + "net/http" + "slices" + "sync" + "time" +) + +func RunClient(ctx context.Context, cfg *config.Client, logger logr.Logger) { + + // [Communicator] -> [intermediate goroutine] -> [Pinger] + configUpdates := make(chan *protocol.ServerPushInfo, 8) + // [Pinger] -> [Communicator] + pingResults := make(chan *protocol.Observation, cfg.SendBuffer) + + pinger := Pinger{ + Logger: logger.WithName("pinger"), + Output: pingResults, + Interval: time.Duration(cfg.CheckInterval) * time.Millisecond, + } + comm := Communicator{ + ServerAddr: cfg.ReportServer, + ConnectTimeout: time.Duration(cfg.ReportConnectTimeout) * time.Millisecond, + ReconnectInterval: time.Duration(cfg.ReconnectInterval) * time.Millisecond, + Token: cfg.Token, + ObserverID: cfg.ObserverID, + Logger: logger.WithName("communicator"), + ConfigUpdate: configUpdates, + StateReport: pingResults, + } + + wg := &sync.WaitGroup{} + + wg.Add(1) + go func() { + defer wg.Done() + defer close(configUpdates) + comm.Run(ctx) + }() + + wg.Add(1) + go func() { + defer wg.Done() + for cu := range configUpdates { + // apply config updates to pinger + pinger.UpdateTargets(cu.Targets) + } + }() + + wg.Add(1) + go func() { + defer wg.Done() + defer close(pingResults) + pinger.Run(ctx) + }() + + wg.Wait() +} + +type Observer struct { + serverAddr string + interval time.Duration + observations chan *protocol.Observation + logger logr.Logger + reconnectInterval time.Duration + reportConnectTimeout time.Duration + token string + id string +} + +func readServerPushInfo(c *websocket.Conn) (*protocol.ServerPushInfo, error) { + for { + typ, data, err := c.ReadMessage() + if err != nil { + return nil, fmt.Errorf("read websocket message: %w", err) + } + if typ != websocket.BinaryMessage { + continue + } + var info protocol.ServerPushInfo + err = json.Unmarshal(data, &info) + if err != nil { + return nil, fmt.Errorf("unmarshal ServerPushInfo: %w", err) + } + if info.Version != protocol.CurrentServerPushInfoVersion { + return nil, fmt.Errorf("invalid ServerPushInfo version `%v`, raw data: `%v`", + info.Version, string(data)) + } + return &info, nil + } +} + +type Pinger struct { + targets []protocol.Target + mu sync.RWMutex + Logger logr.Logger + Output chan<- *protocol.Observation + Interval time.Duration +} + +func (p *Pinger) Run(ctx context.Context) { + tk := time.NewTicker(p.Interval) + defer tk.Stop() + for { + select { + case <-ctx.Done(): + return + case <-tk.C: + p.ping() + } + } +} + +func (p *Pinger) ping() { + var targets []protocol.Target + func() { + p.mu.RLock() + defer p.mu.RUnlock() + targets = slices.Clone(p.targets) + }() + var wg sync.WaitGroup + defer wg.Wait() + for i := range targets { + wg.Add(1) + i := i + go func() { + defer wg.Done() + p.Output <- ping0(targets[i], p.Logger) + }() + } +} + +func ping0(target protocol.Target, log logr.Logger) *protocol.Observation { + t := time.Now() + _, latency, err := ping.Ping(target.Host, int(target.Port)) + if err != nil { + log.Error(err, "ping failed", "target", target.String()) + return &protocol.Observation{ + Time: protocol.TimeStamp(t), + Target: target, + Online: false, + } + } + return &protocol.Observation{ + Time: protocol.TimeStamp(t), + Target: target, + Online: true, + Latency: uint32(latency), + } +} + +func (p *Pinger) UpdateTargets(targets []protocol.Target) { + p.mu.Lock() + defer p.mu.Unlock() + p.targets = slices.Clone(targets) +} + +type Communicator struct { + ServerAddr string + ConnectTimeout time.Duration + ReconnectInterval time.Duration + Token string + ObserverID string + Logger logr.Logger + ConfigUpdate chan<- *protocol.ServerPushInfo + StateReport <-chan *protocol.Observation + sendBuffer []*protocol.Observation // states that are taken out but not sent +} + +// Run blocks until StateReport or ctx is closed +func (c *Communicator) Run(ctx context.Context) { + for { + if ctx.Err() != nil { + return + } + err := c.run(ctx) + if err != nil { + if ctx.Err() != nil { + return + } + c.Logger.Error(err, "waiting for reconnect") + sleep(ctx, c.ReconnectInterval) + continue + } + return + } +} + +func (c *Communicator) run(ctx context.Context) error { + dialer := websocket.Dialer{ + Proxy: http.ProxyFromEnvironment, + HandshakeTimeout: c.ConnectTimeout, + } + headers := http.Header{ + protocol.TokenHeader: []string{c.Token}, + protocol.ObserverIDHeader: []string{c.ObserverID}, + } + conn, _, err := dialer.Dial(c.ServerAddr, headers) + if err != nil { + return fmt.Errorf("dial websocket: %w", err) + } + defer func() { + _ = conn.Close() + }() + + serverConfig, err := readServerPushInfo(conn) + if err != nil { + return fmt.Errorf("error reading server side config: %w", err) + } + c.Logger.Info("received observe targets from server", "targets", serverConfig.Targets) + + c.ConfigUpdate <- serverConfig + + sendData := func(ob *protocol.Observation) error { + data, err := json.Marshal(*ob) + if err != nil { + c.Logger.Error(err, "error marshalling observation result, drop") + return nil + } + return conn.WriteMessage(websocket.BinaryMessage, data) + } + + for len(c.sendBuffer) > 0 { + err := sendData(c.sendBuffer[0]) + if err != nil { + c.Logger.Error(err, "error writing websocket message, try reconnect") + return err + } + c.sendBuffer = c.sendBuffer[1:] + } + + for { + select { + case <-ctx.Done(): + return ctx.Err() + case ob, ok := <-c.StateReport: + if !ok { + return nil + } + err := sendData(ob) + if err != nil { + c.Logger.Error(err, "error writing websocket message, try reconnect") + c.sendBuffer = append(c.sendBuffer, ob) // store unsent messages to queue + return err + } + } + } +} + +func sleep(ctx context.Context, d time.Duration) { + tm := time.NewTimer(d) + defer tm.Stop() + select { + case <-ctx.Done(): + case <-tm.C: + } +} diff --git a/observatory/server.go b/observatory/server.go new file mode 100644 index 0000000..ea338f0 --- /dev/null +++ b/observatory/server.go @@ -0,0 +1,261 @@ +package observatory + +import ( + "cmp" + "context" + "encoding/json" + "fmt" + "github.com/go-logr/logr" + "github.com/gorilla/websocket" + "github.com/hit-mc/observatory/config" + "github.com/hit-mc/observatory/protocol" + "io" + "net" + "net/http" + "slices" + "sync" + "time" +) + +func NewCollector( + listen string, + handshakeTimeout time.Duration, + logger logr.Logger, + token string, + targets []config.Target, +) *Collector { + targets2 := make([]protocol.Target, len(targets)) + for i := range targets { + targets2[i] = protocol.Target{ + Host: targets[i].Host, + Port: uint16(targets[i].Port), + } + } + return &Collector{ + listen: listen, + handshakeTimeout: handshakeTimeout, + logger: logger, + stats: newServerStatus(), + token: token, + targets: targets2, + } +} + +type Collector struct { + listen string + handshakeTimeout time.Duration + logger logr.Logger + stats serverStatus + token string + targets []protocol.Target +} + +func (c *Collector) Run(ctx context.Context) error { + ssc, err := json.Marshal(protocol.ServerPushInfo{ + Version: protocol.CurrentServerPushInfoVersion, + Targets: c.targets, + }) + if err != nil { + return fmt.Errorf("error marshalling ServerPushInfo: %w", err) + } + + up := websocket.Upgrader{ + HandshakeTimeout: c.handshakeTimeout, + } + mux := http.NewServeMux() + mux.HandleFunc("/stats", func(w http.ResponseWriter, r *http.Request) { + if r.Method != "GET" { + w.WriteHeader(405) + return + } + stats := c.stats.GetStats() + data, err := json.Marshal(stats) + if err != nil { + w.WriteHeader(500) + _, _ = io.WriteString(w, fmt.Sprintf("error marshalling JSON: %v", err)) + return + } + w.Header().Set("Content-Type", "application/json") + _, _ = w.Write(data) + }) + mux.HandleFunc("/collect", func(w http.ResponseWriter, r *http.Request) { + conn, err := up.Upgrade(w, r, nil) + if err != nil { + c.logger.Error(err, "error upgrading connection protocol to websocket") + return + } + defer func() { + _ = conn.Close() + }() + token := r.Header.Get(protocol.TokenHeader) + if token != c.token { + c.logger.Error(nil, "reject connection with invalid token", "token", token) + return + } + observerID := r.Header.Get(protocol.ObserverIDHeader) + if observerID == "" { + return + } + c.logger.Info("observer connected successfully", + "endpoint", r.RemoteAddr, "observer_id", observerID) + + const pingInterval = 10 * time.Second + const maxPingWait = 20 * time.Second + conn.SetPongHandler(func(string) error { + _ = conn.SetReadDeadline(time.Now().Add(pingInterval + maxPingWait)) + return nil + }) + + writeMu := &sync.Mutex{} + writeMessage := func(typ int, data []byte) error { + writeMu.Lock() + defer writeMu.Unlock() + return conn.WriteMessage(websocket.BinaryMessage, ssc) + } + + wg := &sync.WaitGroup{} + // send keepalive packets periodically + wg.Add(1) + go func() { + for { + err := writeMessage(websocket.PingMessage, nil) + if err != nil { + c.logger.Error(err, "error pinging client, disconnect", + "observer_id", observerID) + _ = conn.Close() + return + } + sleep(r.Context(), pingInterval) + } + }() + defer wg.Wait() + + // send server-side config + err = writeMessage(websocket.BinaryMessage, ssc) + if err != nil { + c.logger.Error(err, "error writing server-side-config") + return + } + + for { + typ, data, err := conn.ReadMessage() + if err != nil { + c.logger.Error(err, "error reading websocket message") + return + } + if typ != websocket.BinaryMessage { + continue + } + var observation protocol.Observation + err = json.Unmarshal(data, &observation) + if err != nil { + c.logger.Error(err, "error unmarshalling message from client") + return + } + c.stats.Put(&observation, observerID) + } + }) + server := http.Server{ + Addr: c.listen, + Handler: mux, + ReadTimeout: 10 * time.Second, + ReadHeaderTimeout: 10 * time.Second, + WriteTimeout: 10 * time.Second, + IdleTimeout: 300 * time.Second, + BaseContext: func(net.Listener) context.Context { + return ctx + }, + } + go func() { + <-ctx.Done() + _ = server.Close() + }() + err = server.ListenAndServe() + if err != nil { + return fmt.Errorf("error starting HTTP server: %w", err) + } + return nil +} + +func newServerStatus() serverStatus { + return serverStatus{ + status: make(map[protocol.Target][]protocol.SourcedObservation), + } +} + +type serverStatus struct { + mu sync.RWMutex + status map[protocol.Target][]protocol.SourcedObservation +} + +func (s *serverStatus) Put(observation *protocol.Observation, source string) { + entry := protocol.SourcedObservation{ + Observation: *observation, + Source: source, + } + + s.mu.Lock() + defer s.mu.Unlock() + // replace existing entry with the same observer + for i, ob := range s.status[observation.Target] { + if ob.Source == source { + s.status[observation.Target][i] = entry + goto done + } + } + // add new entry if not exist + s.status[observation.Target] = append(s.status[observation.Target], entry) + slices.SortFunc(s.status[observation.Target], func(a, b protocol.SourcedObservation) int { + return cmp.Compare(a.Source, b.Source) + }) +done: + s.purge() +} + +// purge removes state entries lived longer than 180s +// Note: caller should hold write lock +func (s *serverStatus) purge() { + const ttl = 180 * time.Second + t0 := time.Now().Add(-ttl) + for target := range s.status { + ss := s.status[target] + purged := false + for i := range ss { + if time.Time(ss[i].Time).Before(t0) { + ss[i].Time = protocol.TimeStamp{} + purged = true + } + } + if purged { + s.status[target] = shrink(ss) + } + } +} + +func shrink(s []protocol.SourcedObservation) []protocol.SourcedObservation { + i := 0 // slow pointer + j := 0 // fast pointer + for j < len(s) { + if !time.Time(s[j].Time).IsZero() { + i++ + } + j++ + if j < len(s) { + s[i] = s[j] + } + } + if i != j { + return s[:i] + } + return s +} + +func (s *serverStatus) GetStats() protocol.TargetStats { + s.mu.RLock() + defer s.mu.RUnlock() + ret := make(protocol.TargetStats, len(s.status)) + for t, os := range s.status { + ret[t.String()] = os + } + return ret +} diff --git a/observatory/server_test.go b/observatory/server_test.go new file mode 100644 index 0000000..453da7a --- /dev/null +++ b/observatory/server_test.go @@ -0,0 +1,33 @@ +package observatory + +import ( + "github.com/hit-mc/observatory/protocol" + "math/rand" + "testing" + "time" +) + +func Fuzz_shrink(f *testing.F) { + f.Fuzz(func(t *testing.T, seed int64) { + s := rand.NewSource(seed) + n := s.Int63() % 1023 + ss := make([]protocol.SourcedObservation, n) + nonzero := protocol.TimeStamp(time.Unix(10000, 10000)) + n2 := 0 + for i := int64(0); i < n; i++ { + if s.Int63()%17 < 12 { + ss[i].Time = nonzero + n2++ + } + } + ss2 := shrink(ss) + if len(ss2) != n2 { + t.Fatal("invalid length ", len(ss2), " expected", n2) + } + for i := range ss2 { + if time.Time(ss2[i].Time).IsZero() { + t.Fatal("invalid time at ", i) + } + } + }) +} diff --git a/protocol/handshake.go b/protocol/handshake.go new file mode 100644 index 0000000..02e3f0d --- /dev/null +++ b/protocol/handshake.go @@ -0,0 +1,14 @@ +package protocol + +const ( + TokenHeader = "X-Observatory-Token" + ObserverIDHeader = "X-Observatory-Observer-ID" +) + +// ServerPushInfo is the first server->client packet, applying configs to observers +type ServerPushInfo struct { + Version uint64 `json:"server_push_info_version"` + Targets []Target `json:"targets"` +} + +const CurrentServerPushInfoVersion uint64 = 240308 diff --git a/protocol/messages.go b/protocol/messages.go new file mode 100644 index 0000000..d8f5697 --- /dev/null +++ b/protocol/messages.go @@ -0,0 +1,29 @@ +package protocol + +import ( + "encoding/json" + "time" +) + +type TimeStamp time.Time + +func (t *TimeStamp) UnmarshalJSON(data []byte) error { + var ts int64 + err := json.Unmarshal(data, &ts) + if err != nil { + return err + } + *t = TimeStamp(time.UnixMilli(ts)) + return nil +} + +func (t TimeStamp) MarshalJSON() ([]byte, error) { + return json.Marshal(time.Time(t).UnixMilli()) +} + +type Observation struct { + Time TimeStamp `json:"time"` + Target Target `json:"target"` + Online bool `json:"online"` + Latency uint32 `json:"latency"` +} diff --git a/protocol/observe.go b/protocol/observe.go new file mode 100644 index 0000000..48d052a --- /dev/null +++ b/protocol/observe.go @@ -0,0 +1,14 @@ +package protocol + +import ( + "fmt" +) + +type Target struct { + Host string `json:"host"` + Port uint16 `json:"port"` +} + +func (t Target) String() string { + return fmt.Sprintf("%s:%d", t.Host, t.Port) +} diff --git a/protocol/publish.go b/protocol/publish.go new file mode 100644 index 0000000..13e6ee1 --- /dev/null +++ b/protocol/publish.go @@ -0,0 +1,8 @@ +package protocol + +type TargetStats map[string][]SourcedObservation + +type SourcedObservation struct { + Observation + Source string `json:"source,omitempty"` +} |