An AreProcessesUp func was turned into a lambda func.

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2021-2023 Alexander "Arav" Andreev <me@arav.su>
+Copyright (c) 2021-2024 Alexander "Arav" Andreev <me@arav.su>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

Makefile

@@ -6,7 +6,7 @@ SYSDDIR=${SYSDDIR_:/%=%}
 DESTDIR:=
 PREFIX:=/usr/local
 
-VERSION:=3.0.0
+VERSION:=3.1.1
 
 FLAGS:=-buildmode=pie -modcacherw -mod=readonly -trimpath
 LDFLAGS=-ldflags "-s -w -X main.version=${VERSION}" -tags netgo
@@ -20,7 +20,7 @@ ${TARGET}: ${SOURCES}
 
 install:
 	install -Dm 0755 ${TARGET} ${DESTDIR}${PREFIX}/bin/${TARGET}
-	install -Dm 0644 configs/config.example.json ${DESTDIR}${PREFIX}/etc/${TARGET}.json
+	install -Dm 0644 configs/config.example.json ${DESTDIR}/etc/${TARGET}.json
 	install -Dm 0644 LICENSE ${DESTDIR}${PREFIX}/share/licenses/${TARGET}/LICENSE
 	install -Dm 0644 init/systemd.service ${DESTDIR}${SYSDDIR}/${TARGET}.service
 

build/PKGBUILD

@@ -1,6 +1,6 @@
 # Maintainer: Alexander "Arav" Andreev <me@arav.su>
 pkgname=httpprocprobed
-pkgver=3.0.0
+pkgver=3.1.1
 pkgrel=1
 pkgdesc="HTTPProcProbeD hands out an HTTP endpoint to get if processes are running."
 arch=('i686' 'x86_64' 'arm' 'armv6h' 'armv7h' 'aarch64')

configuration.go

@@ -1,27 +0,0 @@
-package main
-
-import (
-	"encoding/json"
-	"os"
-)
-
-type Configuration struct {
-	ListenAddress string    `json:"listen-address"`
-	Processes     []Process `json:"processes"`
-}
-
-func LoadConfiguration(path string) (conf *Configuration, err error) {
-	f, err := os.Open(path)
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-
-	conf = &Configuration{}
-
-	if err := json.NewDecoder(f).Decode(conf); err != nil {
-		return nil, err
-	}
-
-	return conf, nil
-}

main.go

@@ -18,12 +18,66 @@ var showVersion *bool = flag.Bool("v", false, "show version")
 
 var version string
 
+// Process contains an alias that will be returned when queried, and a process
+// name to look for.
+// A process is effectively a substring that is being looked in a cmdline file
+// in /proc/ dir on unix-like systems.
+type Process struct {
+	Alias   string `json:"alias"`
+	Process string `json:"process"`
+}
+
+// ProcessesState is a map of processes' aliases and its statuses.
+type ProcessesState map[string]bool
+
+func GetProcessesState(procs *[]Process) (ps ProcessesState) {
+	ps = make(ProcessesState)
+
+	for _, proc := range *procs {
+		pids, err := GetProcessPIDs(proc.Process)
+		ps[proc.Alias] = err == nil && len(pids) > 0
+	}
+
+	return
+}
+
+type Configuration struct {
+	ListenAddress string    `json:"listen-address"`
+	Processes     []Process `json:"processes"`
+}
+
+func LoadConfiguration(path string) (conf *Configuration, err error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	conf = &Configuration{}
+
+	if err := json.NewDecoder(f).Decode(conf); err != nil {
+		return nil, err
+	}
+
+	for i := 0; i < len(conf.Processes); i++ {
+		if conf.Processes[i].Process == "" {
+			return nil, fmt.Errorf("an empty process field found")
+		}
+
+		if conf.Processes[i].Alias == "" {
+			conf.Processes[i].Alias = conf.Processes[i].Process
+		}
+	}
+
+	return conf, nil
+}
+
 func main() {
 	log.SetFlags(0)
 	flag.Parse()
 
 	if *showVersion {
-		fmt.Println("httpprocprobed ver.", version, "Copyright (c) 2021-2023 Alexander \"Arav\" Andreev <me@arav.su>")
+		fmt.Fprintln(os.Stderr, "httpprocprobed ver.", version, "\nCopyright (c) 2021-2024 Alexander \"Arav\" Andreev <me@arav.su>")
 		os.Exit(0)
 	}
 
@@ -33,7 +87,19 @@ func main() {
 	}
 
 	router := http.NewServeMux()
-	router.HandleFunc("/processes", AreProcessesUp(&conf.Processes))
+	router.HandleFunc("/processes", func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet {
+			w.WriteHeader(http.StatusMethodNotAllowed)
+			w.Header().Add("Allow", "GET")
+			return
+		}
+
+		w.Header().Add("Content-Type", "application/json")
+		if err := json.NewEncoder(w).Encode(GetProcessesState(&conf.Processes)); err != nil {
+			w.WriteHeader(http.StatusInternalServerError)
+			log.Printf("Failed to encode a process list: %s\n", err)
+		}
+	})
 
 	srv := &http.Server{
 		Addr:         conf.ListenAddress,
@@ -48,47 +114,28 @@ func main() {
 			log.Fatalf("ListenAndServe: %s\n", err)
 		}
 	}()
+	defer func() {
+		srv.SetKeepAlivesEnabled(false)
+		if err := srv.Shutdown(context.Background()); err != nil {
+			log.Fatalf("%s\n", err)
+		}
+	}()
 
 	syssignal := make(chan os.Signal, 1)
 	signal.Notify(syssignal, os.Interrupt, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)
 
-	log.Printf("httpprocprobed is running on \"%s\".", conf.ListenAddress)
-
 	for {
 		switch <-syssignal {
 		case os.Interrupt:
 			fallthrough
 		case syscall.SIGINT | syscall.SIGTERM:
-			srv.SetKeepAlivesEnabled(false)
-			if err := srv.Shutdown(context.Background()); err != nil {
-				log.Fatalf("%s\n", err)
-			}
-			log.Println("Server shutted down.")
-			os.Exit(0)
+			return
 		case syscall.SIGHUP:
 			newconf, err := LoadConfiguration(*configPath)
 			if err != nil {
 				log.Fatalf("Failed to reload a list of processes from configuration: %s\n", err)
 			}
 			conf.Processes = newconf.Processes
-			log.Println("Successfully reloaded a list of watched processes.")
-		}
-	}
-}
-
-// AreProcessesUp sends back status of watched processes.
-func AreProcessesUp(processes *[]Process) func(http.ResponseWriter, *http.Request) {
-	return func(w http.ResponseWriter, r *http.Request) {
-		if r.Method != http.MethodGet {
-			w.WriteHeader(http.StatusMethodNotAllowed)
-			w.Header().Add("Allow", "GET")
-			return
-		}
-
-		w.Header().Add("Content-Type", "application/json")
-		if err := json.NewEncoder(w).Encode(GetProcessesState(processes)); err != nil {
-			w.WriteHeader(http.StatusInternalServerError)
-			log.Printf("Failed to encode a process list: %s\n", err)
 		}
 	}
 }

process.go

@@ -1,22 +0,0 @@
-package main
-
-// Process contains an alias that will be returned when queries, and a process
-// name to look for.
-type Process struct {
-	Alias   string `json:"alias"`
-	Process string `json:"process"`
-}
-
-// ProcessesState is a map of processes' aliases and its statuses.
-type ProcessesState map[string]bool
-
-func GetProcessesState(procs *[]Process) (ps ProcessesState) {
-	ps = make(ProcessesState)
-
-	for _, proc := range *procs {
-		pids, err := GetProcessPIDs(proc.Process)
-		ps[proc.Alias] = err == nil && len(pids) > 0
-	}
-
-	return
-}