feat(server): add prometheus stats server

go.mod

@@ -4,7 +4,6 @@ go 1.17
 
 require (
 	github.com/alecthomas/chroma v0.10.0
-	github.com/caarlos0/env/v6 v6.10.1
 	github.com/charmbracelet/bubbles v0.15.0
 	github.com/charmbracelet/bubbletea v0.23.2
 	github.com/charmbracelet/glamour v0.6.0
@@ -20,6 +19,7 @@ require (
 
 require (
 	github.com/aymanbagabas/go-osc52 v1.2.2
+	github.com/caarlos0/env/v7 v7.1.0
 	github.com/charmbracelet/keygen v0.3.0
 	github.com/charmbracelet/log v0.2.1
 	github.com/charmbracelet/ssh v0.0.0-20221117183211-483d43d97103
@@ -28,6 +28,8 @@ require (
 	github.com/lrstanley/bubblezone v0.0.0-20220716194435-3cb8c52f6a8f
 	github.com/muesli/mango-cobra v1.2.0
 	github.com/muesli/roff v0.1.0
+	github.com/prometheus/client_golang v1.14.0
+	github.com/robfig/cron/v3 v3.0.1
 	github.com/spf13/cobra v1.6.1
 	goji.io v2.0.2+incompatible
 	golang.org/x/crypto v0.7.0
@@ -40,16 +42,20 @@ require (
 	github.com/atotto/clipboard v0.1.4 // indirect
 	github.com/aymanbagabas/go-osc52/v2 v2.0.1 // indirect
 	github.com/aymerick/douceur v0.2.0 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/caarlos0/sshmarshal v0.1.0 // indirect
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/containerd/console v1.0.3 // indirect
 	github.com/dlclark/regexp2 v1.4.0 // indirect
 	github.com/go-logfmt/logfmt v0.6.0 // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/gorilla/css v1.0.0 // indirect
 	github.com/inconshreveable/mousetrap v1.0.1 // indirect
 	github.com/lucasb-eyer/go-colorful v1.2.0 // indirect
 	github.com/mattn/go-isatty v0.0.18 // indirect
 	github.com/mattn/go-localereader v0.0.1 // indirect
 	github.com/mattn/go-runewidth v0.0.14 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
 	github.com/mcuadros/go-version v0.0.0-20190308113854-92cdf37c5b75 // indirect
 	github.com/microcosm-cc/bluemonday v1.0.21 // indirect
 	github.com/mitchellh/go-homedir v1.1.0 // indirect
@@ -58,6 +64,9 @@ require (
 	github.com/muesli/mango v0.1.0 // indirect
 	github.com/muesli/mango-pflag v0.1.0 // indirect
 	github.com/olekukonko/tablewriter v0.0.5 // indirect
+	github.com/prometheus/client_model v0.3.0 // indirect
+	github.com/prometheus/common v0.37.0 // indirect
+	github.com/prometheus/procfs v0.8.0 // indirect
 	github.com/rivo/uniseg v0.2.0 // indirect
 	github.com/sahilm/fuzzy v0.1.0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
@@ -67,4 +76,5 @@ require (
 	golang.org/x/sys v0.6.0 // indirect
 	golang.org/x/term v0.6.0 // indirect
 	golang.org/x/text v0.8.0 // indirect
+	google.golang.org/protobuf v1.28.1 // indirect
 )

server/config/config.go

@@ -4,7 +4,7 @@ import (
 	"os"
 	"path/filepath"
 
-	"github.com/caarlos0/env/v6"
+	"github.com/caarlos0/env/v7"
 	"github.com/charmbracelet/log"
 	"github.com/charmbracelet/soft-serve/server/backend"
 	"gopkg.in/yaml.v3"
@@ -61,6 +61,12 @@ type HTTPConfig struct {
 	PublicURL string `env:"PUBLIC_URL" yaml:"public_url"`
 }
 
+// StatsConfig is the configuration for the stats server.
+type StatsConfig struct {
+	// ListenAddr is the address on which the stats server will listen.
+	ListenAddr string `env:"LISTEN_ADDR" yaml:"listen_addr"`
+}
+
 // Config is the configuration for Soft Serve.
 type Config struct {
 	// Name is the name of the server.
@@ -75,6 +81,9 @@ type Config struct {
 	// HTTP is the configuration for the HTTP server.
 	HTTP HTTPConfig `envPrefix:"HTTP_" yaml:"http"`
 
+	// Stats is the configuration for the stats server.
+	Stats StatsConfig `envPrefix:"STATS_" yaml:"stats"`
+
 	// InitialAdminKeys is a list of public keys that will be added to the list of admins.
 	InitialAdminKeys []string `env:"INITIAL_ADMIN_KEY" envSeparator:"\n" yaml:"initial_admin_keys"`
 
@@ -92,7 +101,7 @@ func ParseConfig(path string) (*Config, error) {
 	if err != nil {
 		return nil, err
 	}
-	defer f.Close()
+	defer f.Close() // nolint: errcheck
 	if err := yaml.NewDecoder(f).Decode(cfg); err != nil {
 		return nil, err
 	}
@@ -129,11 +138,14 @@ func DefaultConfig() *Config {
 			ListenAddr: ":8080",
 			PublicURL:  "http://localhost:8080",
 		},
+		Stats: StatsConfig{
+			ListenAddr: ":8081",
+		},
 	}
 	cp := filepath.Join(cfg.DataPath, "config.yaml")
 	f, err := os.Open(cp)
 	if err == nil {
-		defer f.Close()
+		defer f.Close() // nolint: errcheck
 		if err := yaml.NewDecoder(f).Decode(cfg); err != nil {
 			log.Error("failed to decode config", "err", err)
 		}

server/config/file.go

@@ -64,6 +64,11 @@ http:
   # This is the address will be used to clone repositories.
   public_url: "{{ .HTTP.PublicURL }}"
 
+# The stats server configuration.
+stats:
+  # The address on which the stats server will listen.
+  listen_addr: "{{ .Stats.ListenAddr }}"
+
 `))
 )
 

server/daemon.go

@@ -13,6 +13,24 @@ import (
 	"github.com/charmbracelet/soft-serve/server/config"
 	"github.com/charmbracelet/soft-serve/server/utils"
 	"github.com/go-git/go-git/v5/plumbing/format/pktline"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var (
+	uploadPackGitCounter = promauto.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "soft_serve",
+		Subsystem: "git",
+		Name:      "git_upload_pack_total",
+		Help:      "The total number of git-upload-pack requests",
+	}, []string{"repo"})
+
+	uploadArchiveGitCounter = promauto.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "soft_serve",
+		Subsystem: "git",
+		Name:      "git_upload_archive_total",
+		Help:      "The total number of git-upload-archive requests",
+	}, []string{"repo"})
 )
 
 // ErrServerClosed indicates that the server has been closed.
@@ -184,12 +202,14 @@ func (d *GitDaemon) handleClient(conn net.Conn) {
 		}
 
 		gitPack := uploadPack
+		counter := uploadPackGitCounter
 		cmd := string(split[0])
 		switch cmd {
 		case uploadPackBin:
 			gitPack = uploadPack
 		case uploadArchiveBin:
 			gitPack = uploadArchive
+			counter = uploadArchiveGitCounter
 		default:
 			fatal(c, ErrInvalidRequest)
 			return
@@ -223,6 +243,8 @@ func (d *GitDaemon) handleClient(conn net.Conn) {
 			fatal(c, err)
 			return
 		}
+
+		counter.WithLabelValues(name)
 	}
 }
 

server/http.go

@@ -15,11 +15,29 @@ import (
 	"github.com/charmbracelet/soft-serve/server/config"
 	"github.com/charmbracelet/soft-serve/server/utils"
 	"github.com/dustin/go-humanize"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	"goji.io"
 	"goji.io/pat"
 	"goji.io/pattern"
 )
 
+var (
+	gitHttpCounter = promauto.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "soft_serve",
+		Subsystem: "http",
+		Name:      "git_fetch_pull_total",
+		Help:      "The total number of git fetch/pull requests",
+	}, []string{"repo", "file"})
+
+	goGetCounter = promauto.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "soft_serve",
+		Subsystem: "http",
+		Name:      "go_get_total",
+		Help:      "The total number of go get requests",
+	}, []string{"repo"})
+)
+
 // logWriter is a wrapper around http.ResponseWriter that allows us to capture
 // the HTTP status code and bytes written to the response.
 type logWriter struct {
@@ -179,12 +197,12 @@ var (
 		return findStringSubmatch(u.Path, getLooseObjectRegexp)
 	}
 
-	getPackFileRegexp = regexp.MustCompile(".*?(/objects/pack/pack-[0-9a-f]{40}\\.pack)$")
+	getPackFileRegexp = regexp.MustCompile(`.*?(/objects/pack/pack-[0-9a-f]{40}\.pack)$`)
 	getPackFile       = func(u *url.URL) *Match {
 		return findStringSubmatch(u.Path, getPackFileRegexp)
 	}
 
-	getIdxFileRegexp = regexp.MustCompile(".*?(/objects/pack/pack-[0-9a-f]{40}\\.idx)$")
+	getIdxFileRegexp = regexp.MustCompile(`.*?(/objects/pack/pack-[0-9a-f]{40}\.idx)$`)
 	getIdxFile       = func(u *url.URL) *Match {
 		return findStringSubmatch(u.Path, getIdxFileRegexp)
 	}
@@ -264,6 +282,8 @@ func (s *HTTPServer) handleIndex(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
+
+	goGetCounter.WithLabelValues(repo).Inc()
 }
 
 func (s *HTTPServer) handleGit(w http.ResponseWriter, r *http.Request) {
@@ -287,6 +307,7 @@ func (s *HTTPServer) handleGit(w http.ResponseWriter, r *http.Request) {
 	}
 
 	file := pat.Param(r, "file")
+	gitHttpCounter.WithLabelValues(repo, file).Inc()
 	r.URL.Path = fmt.Sprintf("/%s/%s", repo, file)
 	s.dirHandler.ServeHTTP(w, r)
 }

server/server.go

@@ -21,11 +21,12 @@ var (
 
 // Server is the Soft Serve server.
 type Server struct {
-	SSHServer  *SSHServer
-	GitDaemon  *GitDaemon
-	HTTPServer *HTTPServer
-	Config     *config.Config
-	Backend    backend.Backend
+	SSHServer   *SSHServer
+	GitDaemon   *GitDaemon
+	HTTPServer  *HTTPServer
+	StatsServer *StatsServer
+	Config      *config.Config
+	Backend     backend.Backend
 }
 
 // NewServer returns a new *ssh.Server configured to serve Soft Serve. The SSH
@@ -74,6 +75,11 @@ func NewServer(cfg *config.Config) (*Server, error) {
 		return nil, err
 	}
 
+	srv.StatsServer, err = NewStatsServer(cfg)
+	if err != nil {
+		return nil, err
+	}
+
 	return srv, nil
 }
 
@@ -101,6 +107,13 @@ func (s *Server) Start() error {
 		}
 		return nil
 	})
+	errg.Go(func() error {
+		log.Print("Starting Stats server", "addr", s.Config.Stats.ListenAddr)
+		if err := s.StatsServer.ListenAndServe(); err != http.ErrServerClosed {
+			return err
+		}
+		return nil
+	})
 	return errg.Wait()
 }
 
@@ -116,6 +129,9 @@ func (s *Server) Shutdown(ctx context.Context) error {
 	errg.Go(func() error {
 		return s.SSHServer.Shutdown(ctx)
 	})
+	errg.Go(func() error {
+		return s.StatsServer.Shutdown(ctx)
+	})
 	return errg.Wait()
 }
 
@@ -125,5 +141,6 @@ func (s *Server) Close() error {
 	errg.Go(s.GitDaemon.Close)
 	errg.Go(s.HTTPServer.Close)
 	errg.Go(s.SSHServer.Close)
+	errg.Go(s.StatsServer.Close)
 	return errg.Wait()
 }

server/session.go

@@ -13,15 +13,28 @@ import (
 	"github.com/charmbracelet/ssh"
 	"github.com/charmbracelet/wish"
 	bm "github.com/charmbracelet/wish/bubbletea"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var (
+	tuiSessionCounter = promauto.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "soft_serve",
+		Subsystem: "ssh",
+		Name:      "tui_session_total",
+		Help:      "The total number of TUI sessions",
+	}, []string{"key", "user", "repo", "term"})
 )
 
 // SessionHandler is the soft-serve bubbletea ssh session handler.
 func SessionHandler(cfg *config.Config) bm.ProgramHandler {
 	return func(s ssh.Session) *tea.Program {
+		ak := backend.MarshalAuthorizedKey(s.PublicKey())
 		pty, _, active := s.Pty()
 		if !active {
 			return nil
 		}
+
 		cmd := s.Command()
 		initialRepo := ""
 		if len(cmd) == 1 {
@@ -32,6 +45,7 @@ func SessionHandler(cfg *config.Config) bm.ProgramHandler {
 				return nil
 			}
 		}
+
 		envs := s.Environ()
 		envs = append(envs, fmt.Sprintf("TERM=%s", pty.Term))
 		output := osc52.NewOutput(s, envs)
@@ -45,6 +59,9 @@ func SessionHandler(cfg *config.Config) bm.ProgramHandler {
 			tea.WithoutCatchPanics(),
 			tea.WithMouseCellMotion(),
 		)
+
+		tuiSessionCounter.WithLabelValues(ak, s.User(), initialRepo, pty.Term).Inc()
+
 		return p
 	}
 }