Add testing

Extract webserver functions to allow testing and introduce first unit
tests for the webserver.

.gitignore

@@ -25,3 +25,7 @@ vendor/
 # Go workspace file
 go.work
 
+# Possible key and cert files
+*.key
+*.pem
+*.cert

Taskfile.yml

@@ -33,3 +33,8 @@ tasks:
   vet:
     cmds:
       - go vet ./...
+  certs:
+    cmds:
+      - openssl genrsa -out weblug.key 2048
+      - openssl req -new -x509 -sha256 -key weblug.key -subj "/C=XX/ST=None/L=Nirwana/O=Adeptus Mechanicus/OU=Cult Mechanicus/CN=example1.local" -addext "subjectAltName = DNS:example1.local" -out weblug1.pem -days 365
+      - openssl req -new -x509 -sha256 -key weblug.key -subj "/C=XX/ST=None/L=Nirwana/O=Adeptus Mechanicus/OU=Cult Mechanicus/CN=example1.local" -addext "subjectAltName = DNS:example1.local" -out weblug2.pem -days 365

cmd/weblug/config.go

@@ -1,24 +1,42 @@
 package main
 
 import (
+	"crypto/tls"
 	"fmt"
 	"io/ioutil"
 
 	"gopkg.in/yaml.v2"
 )
 
+var cf Config
+
 type Config struct {
 	Settings ConfigSettings `yaml:"settings"`
 	Hooks    []Hook         `yaml:"hooks"`
 }
 
 type ConfigSettings struct {
-	BindAddress    string `yaml:"bind"`          // Bind address for the webserver
-	UID            int    `yaml:"uid"`           // Custom user ID or 0, if not being used
-	GID            int    `yaml:"gid"`           // Custom group ID or 0, if not being used
-	ReadTimeout    int    `yaml:"readtimeout"`   // Timeout for reading the whole request
-	WriteTimeout   int    `yaml:"writetimeout"`  // Timeout for writing the whole response
-	MaxHeaderBytes int    `yaml:"maxheadersize"` // Maximum size of the receive body
+	BindAddress    string      `yaml:"bind"`          // Bind address for the webserver
+	UID            int         `yaml:"uid"`           // Custom user ID or 0, if not being used
+	GID            int         `yaml:"gid"`           // Custom group ID or 0, if not being used
+	ReadTimeout    int         `yaml:"readtimeout"`   // Timeout for reading the whole request
+	WriteTimeout   int         `yaml:"writetimeout"`  // Timeout for writing the whole response
+	MaxHeaderBytes int         `yaml:"maxheadersize"` // Maximum size of the receive body
+	TLS            TLSSettings `yaml:"tls"`
+}
+
+type TLSSettings struct {
+	Enabled      bool          `yaml:"enabled"`
+	MinVersion   string        `yaml:"minversion"`
+	MaxVersion   string        `yaml:"maxversion"`
+	Keypairs     []TLSKeypairs `yaml:"keypairs"`
+	Keyfile      string        `yaml:"keyfile"`
+	Certificates []string      `yaml:"certificates"`
+}
+
+type TLSKeypairs struct {
+	Keyfile     string `yaml:"keyfile"`
+	Certificate string `yaml:"certificate"`
 }
 
 func (cf *Config) SetDefaults() {
@@ -63,3 +81,19 @@ func (cf *Config) LoadYAML(filename string) error {
 	}
 	return cf.Check()
 }
+
+func ParseTLSVersion(version string) (uint16, error) {
+	if version == "" {
+		return tls.VersionTLS12, nil
+	} else if version == "1.0" {
+		return tls.VersionTLS10, nil
+	} else if version == "1.1" {
+		return tls.VersionTLS11, nil
+	} else if version == "1.2" {
+		return tls.VersionTLS12, nil
+	} else if version == "1.3" {
+		return tls.VersionTLS13, nil
+	} else {
+		return 0, fmt.Errorf("invalid tls version string")
+	}
+}

cmd/weblug/hook.go

@@ -12,6 +12,7 @@ import (
 type Hook struct {
 	Name             string            `yaml:"name"`        // name of the hook
 	Route            string            `yaml:"route"`       // http route
+	Hosts            []string          `yaml:"hosts"`       // allowed remote hosts
 	Command          string            `yaml:"command"`     // Actual command to execute
 	Background       bool              `yaml:"background"`  // Run in background
 	Concurrency      int               `yaml:"concurrency"` // Number of allowed concurrent runs
@@ -80,6 +81,10 @@ func cmdSplit(command string) []string {
 
 // Run executes the given command and return it's return code. It also respects the given concurrency number and will block until resources are free
 func (hook *Hook) Run() error {
+	if hook.Command == "" {
+		return nil
+	}
+
 	split := cmdSplit(hook.Command)
 	args := make([]string, 0)
 	if len(split) > 1 {

cmd/weblug/weblug.go

@@ -4,8 +4,10 @@
 package main
 
 import (
+	"crypto/tls"
 	"fmt"
 	"log"
+	"net"
 	"net/http"
 	"os"
 	"os/signal"
@@ -13,8 +15,6 @@ import (
 	"time"
 )
 
-var cf Config
-
 type Handler func(http.ResponseWriter, *http.Request)
 
 func usage() {
@@ -100,36 +100,118 @@ func main() {
 		}
 	}
 
-	// Create default handlers
-	http.HandleFunc("/", createDefaultHandler())
-	http.HandleFunc("/health", createHealthHandler())
-	http.HandleFunc("/health.json", createHealthHandler())
-	http.HandleFunc("/robots.txt", createRobotsHandler())
-
-	// Register hooks
+	server := CreateWebserver(cf)
+	mux := http.NewServeMux()
+	server.Handler = mux
+	if err := RegisterHandlers(cf, mux); err != nil {
+		fmt.Fprintf(os.Stderr, "error: %s\n", err)
+		os.Exit(1)
+	}
 	for i, hook := range cf.Hooks {
-		if hook.Route == "" {
-			fmt.Fprintf(os.Stderr, "Invalid hook %s: No route defined\n", hook.Name)
-		}
-		if hook.Concurrency < 1 {
-			hook.Concurrency = 1
-		}
 		log.Printf("Webhook %d: '%s' [%s] \"%s\"\n", i, hook.Name, hook.Route, hook.Command)
-		http.HandleFunc(hook.Route, createHandler(hook))
 	}
 
 	awaitTerminationSignal()
 
-	log.Printf("Launching webserver on %s", cf.Settings.BindAddress)
+	var listener net.Listener
+	var err error
+	if cf.Settings.TLS.Enabled {
+		log.Printf("Launching tls webserver on %s", cf.Settings.BindAddress)
+		listener, err = CreateTLSListener(cf)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error: %s\n", err)
+			os.Exit(1)
+		}
+	} else {
+		log.Printf("Launching webserver on %s", cf.Settings.BindAddress)
+		listener, err = CreateListener(cf)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error: %s\n", err)
+			os.Exit(1)
+		}
+	}
+	server.Serve(listener)
+
+	// read guard, should never ever ever be called.
+	// If we end up here, the only safe thing we can do is terminate the program
+	panic("unexpected end of main loop")
+}
+
+func CreateListener(cf Config) (net.Listener, error) {
+	return net.Listen("tcp", cf.Settings.BindAddress)
+}
+
+func CreateTLSListener(cf Config) (net.Listener, error) {
+	var err error
+	tlsConfig := &tls.Config{
+		MinVersion: tls.VersionTLS12,
+	}
+	if cf.Settings.TLS.MinVersion != "" {
+		tlsConfig.MinVersion, err = ParseTLSVersion(cf.Settings.TLS.MinVersion)
+		if err != nil {
+			return nil, fmt.Errorf("invalid tls min version")
+		}
+	}
+	if cf.Settings.TLS.MaxVersion != "" {
+		tlsConfig.MaxVersion, err = ParseTLSVersion(cf.Settings.TLS.MinVersion)
+		if err != nil {
+			return nil, fmt.Errorf("invalid tls max version")
+		}
+	}
+	if tlsConfig.MinVersion == tls.VersionTLS10 || tlsConfig.MinVersion == tls.VersionTLS11 {
+		fmt.Fprintf(os.Stderr, "warning: using of a deprecated TLS version (< 1.2) is not recommended\n")
+	}
+
+	// Create self-signed certificate, when no keyfile and no certificates are present
+	if len(cf.Settings.TLS.Keypairs) == 0 {
+		// TODO
+		return nil, fmt.Errorf("creating self-signed certificates is not yet supported")
+	} else {
+		// Load key/certificates keypairs
+		tlsConfig.Certificates = make([]tls.Certificate, len(cf.Settings.TLS.Keypairs))
+		for i, keypair := range cf.Settings.TLS.Keypairs {
+			tlsConfig.Certificates[i], err = tls.LoadX509KeyPair(keypair.Certificate, keypair.Keyfile)
+			if err != nil {
+				return nil, fmt.Errorf("invalid tls keypair '%s,%s' - %s", keypair.Certificate, keypair.Keyfile, err)
+			}
+		}
+
+		if len(tlsConfig.Certificates) == 1 {
+			log.Printf("Loaded 1 tls certificate")
+		} else {
+			log.Printf("Loaded %d tls certificates", len(tlsConfig.Certificates))
+		}
+	}
+	return tls.Listen("tcp", cf.Settings.BindAddress, tlsConfig)
+}
+
+func CreateWebserver(cf Config) *http.Server {
 	server := &http.Server{
 		Addr:           cf.Settings.BindAddress,
 		ReadTimeout:    time.Duration(cf.Settings.ReadTimeout) * time.Second,
 		WriteTimeout:   time.Duration(cf.Settings.WriteTimeout) * time.Second,
 		MaxHeaderBytes: cf.Settings.MaxHeaderBytes,
 	}
-	err := server.ListenAndServe()
-	log.Fatal(err)
-	os.Exit(1)
+	return server
+}
+
+func RegisterHandlers(cf Config, mux *http.ServeMux) error {
+	mux.HandleFunc("/", createDefaultHandler())
+	mux.HandleFunc("/health", createHealthHandler())
+	mux.HandleFunc("/health.json", createHealthHandler())
+	mux.HandleFunc("/robots.txt", createRobotsHandler())
+
+	// Register hooks
+	for _, hook := range cf.Hooks {
+		if hook.Route == "" {
+			return fmt.Errorf("no route defined in hook %s", hook.Name)
+		}
+		if hook.Concurrency < 1 {
+			hook.Concurrency = 1
+		}
+		mux.HandleFunc(hook.Route, createHandler(hook))
+	}
+	return nil
 }
 
 // create a http handler function from the given hook
@@ -137,6 +219,23 @@ func createHandler(hook Hook) Handler {
 	return func(w http.ResponseWriter, r *http.Request) {
 		log.Printf("GET %s %s", r.RemoteAddr, hook.Name)
 
+		// Check if this hook is remote-host limited
+		if len(hook.Hosts) > 0 {
+			allowed := false
+			for _, host := range hook.Hosts {
+				if r.RemoteAddr == host {
+					allowed = true
+					break
+				}
+			}
+
+			if !allowed {
+				// Hook doesn't exist for this host.
+				respondNotFound(w, r)
+				return
+			}
+		}
+
 		// Check if adresses are allowed or blocked
 		allowed, err := hook.IsAddressAllowed(r.RemoteAddr)
 		if err != nil {
@@ -228,8 +327,7 @@ func createDefaultHandler() Handler {
 			w.WriteHeader(200)
 			fmt.Fprintf(w, "<!DOCTYPE html><html><head><title>weblug</title></head>\n<body><p><a href=\"https://codeberg.org/grisu48/weblug\">weblug</a> - webhook receiver program</p>\n</body></html>")
 		} else {
-			w.WriteHeader(404)
-			fmt.Fprintf(w, "not found\n")
+			respondNotFound(w, r)
 		}
 	}
 }
@@ -240,3 +338,9 @@ func createRobotsHandler() Handler {
 		fmt.Fprintf(w, "User-agent: *\nDisallow: /")
 	}
 }
+
+func respondNotFound(w http.ResponseWriter, r *http.Request) error {
+	w.WriteHeader(404)
+	_, err := fmt.Fprintf(w, "not found\n")
+	return err
+}

cmd/weblug/weblug_test.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"os"
+	"testing"
+)
+
+func TestMain(m *testing.M) {
+	// Run tests
+	ret := m.Run()
+	os.Exit(ret)
+}
+
+// Test the general webserver functionalities
+func TestWebserver(t *testing.T) {
+	var cf Config
+
+	cf.Settings.BindAddress = "127.0.0.1:2088"
+	cf.Hooks = make([]Hook, 0)
+	cf.Hooks = append(cf.Hooks, Hook{Route: "/test1", Name: "test1", Command: ""})
+	cf.Hooks = append(cf.Hooks, Hook{Route: "/test2", Name: "test2", Command: ""})
+
+	listener, err := CreateListener(cf)
+	if err != nil {
+		t.Fatalf("error creating listener: %s", err)
+		return
+	}
+	server := CreateWebserver(cf)
+	mux := http.NewServeMux()
+	server.Handler = mux
+	if err := RegisterHandlers(cf, mux); err != nil {
+		t.Fatalf("error registering handlers: %s", err)
+		return
+	}
+	go server.Serve(listener)
+
+	assertStatusCode := func(url string, statusCode int) {
+		resp, err := http.Get(url)
+		if err != nil {
+			t.Fatalf("%s", err)
+			return
+		}
+		if resp.StatusCode != statusCode {
+			t.Fatalf("GET / returns status code %d != %d", resp.StatusCode, statusCode)
+		}
+	}
+
+	// Check default sites
+	assertStatusCode(fmt.Sprintf("http://%s/", cf.Settings.BindAddress), http.StatusOK)
+	assertStatusCode(fmt.Sprintf("http://%s/health", cf.Settings.BindAddress), http.StatusOK)
+	assertStatusCode(fmt.Sprintf("http://%s/health.json", cf.Settings.BindAddress), http.StatusOK)
+	assertStatusCode(fmt.Sprintf("http://%s/robots.txt", cf.Settings.BindAddress), http.StatusOK)
+	// Check for a 404 page
+	assertStatusCode(fmt.Sprintf("http://%s/404", cf.Settings.BindAddress), http.StatusNotFound)
+	assertStatusCode(fmt.Sprintf("http://%s/test3", cf.Settings.BindAddress), http.StatusNotFound)
+	// Test registered hooks
+	assertStatusCode(fmt.Sprintf("http://%s/test1", cf.Settings.BindAddress), http.StatusOK)
+	assertStatusCode(fmt.Sprintf("http://%s/test2", cf.Settings.BindAddress), http.StatusOK)
+
+	if err := server.Shutdown(context.Background()); err != nil {
+		t.Fatalf("error while server shutdown: %s", err)
+		return
+	}
+}

doc/weblug.8

@@ -50,6 +50,29 @@ See the following example configuration file:
 .br
 .B "  gid: 0                     # run under specified group id
 .br
+.B "  # Enable TLS here here
+.br
+.B "  tls:
+.br
+.B "    enabled: true
+.br
+.B "    # Minimum and maximum required TLS version. By default TLS1.2 is the minimum
+.br
+.B "    minversion: '1.2'
+.br
+.B "    maxversion: ''
+.br
+.B "    keypairs:
+.br
+.B "      - keyfile: 'weblug.key'
+.br
+.B "        certificate: 'weblug1.pem'
+.br
+.B "      - keyfile: 'weblug.key'
+.br
+.B "        certificate: 'weblug2.pem'
+.br
+.br
 .B "# hook definitions. A hook needs to define the HTTP endpoint ("route") and the command
 .br
 .B "# See the following examples for more possible options.
@@ -60,6 +83,16 @@ See the following example configuration file:
 .br
 .B "    route: "/webhooks/1"
 .br
+.B "    # if hosts is present, then limit the incoming requests to the given remote host(s)
+.br
+.B "    # Currently multiplexing the same route to different hosts does not work
+.br
+.B "    hosts:
+.br
+.B "      - example1.local
+.br
+.B "      - example2.local
+.br
 .B "    command: "sleep 5"
 .br
 .B "    background: True         # Terminate http request immediately

weblug.yml

@@ -11,12 +11,30 @@ settings:
   readtimeout: 10            # if set, maximum number of seconds to receive the full request
   writetimeout: 10           # if set, maximum number of seconds to send the full response
   maxheadersize: 4096        # maximum header size
+  # Enable TLS here here
+  tls:
+    enabled: true
+    # Minimum and maximum required TLS version. By default TLS1.2 is the minimum
+    minversion: '1.2'
+    maxversion: ''
+    keypairs:
+      - keyfile: 'weblug.key'
+        certificate: 'weblug1.pem'
+      - keyfile: 'weblug.key'
+        certificate: 'weblug2.pem'
 
 # hook definitions. A hook needs to define the HTTP endpoint ("route") and the command
 # See the following examples for more possible options.
 hooks:
   - name: 'hook one'
     route: "/webhooks/1"
+
+    # if hosts is present, then limit the incoming requests to the given remote host(s)
+    # Currently multiplexing the same route to different hosts does not work
+    hosts:
+      - example1.local
+      - example2.local
+    
     command: "sleep 5"
     background: True         # Terminate http request immediately
     concurrency: 2           # At most 2 parallel processes are allowed