Merge pull request #94 from netlify/add-ban-list

add banlist and tests

Author: rybit

http/banlist/banlist.go

@@ -0,0 +1,119 @@
+package banlist
+
+import (
+	"encoding/json"
+	"net/http"
+	"os"
+	"os/signal"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"syscall"
+
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+type Config struct {
+	Domains []string
+	URLs    []string
+}
+
+type Banlist struct {
+	domainHolder atomic.Value
+	urlHolder    atomic.Value
+	mtx          sync.Mutex
+	ch           chan os.Signal
+	log          logrus.FieldLogger
+	path         string
+}
+
+func New(log logrus.FieldLogger, filepath string) *Banlist {
+	bl := newBanlist(log, filepath)
+	bl.listen()
+	bl.runUpdate()
+	return bl
+}
+
+func newBanlist(log logrus.FieldLogger, path string) *Banlist {
+	bl := &Banlist{log: log, path: path}
+	bl.domainHolder.Store(make(map[string]struct{}))
+	bl.urlHolder.Store(make(map[string]struct{}))
+	return bl
+}
+
+func (b *Banlist) listen() {
+	b.ch = make(chan os.Signal, 1)
+	signal.Notify(b.ch, syscall.SIGHUP)
+	go func() {
+		for range b.ch {
+			b.runUpdate()
+		}
+		b.log.Info("No longer listening for SIGHUP")
+	}()
+}
+
+func (b *Banlist) runUpdate() {
+	if err := b.update(); err != nil {
+		b.log.WithError(err).Warn("error updating banlist")
+	} else {
+		b.log.Info("banlist updated")
+	}
+}
+
+func (b *Banlist) update() error {
+	b.mtx.Lock()
+	defer b.mtx.Unlock()
+
+	f, err := os.Open(b.path)
+	if err != nil {
+		return errors.Wrap(err, "error opening banlist config")
+	}
+	defer f.Close()
+
+	c := new(Config)
+	if err := json.NewDecoder(f).Decode(c); err != nil {
+		return errors.Wrap(err, "error decoding banlist config")
+	}
+
+	domains := make(map[string]struct{})
+	urls := make(map[string]struct{})
+	for _, el := range c.Domains {
+		domains[strings.ToLower(el)] = struct{}{}
+	}
+	for _, el := range c.URLs {
+		urls[strings.ToLower(el)] = struct{}{}
+	}
+
+	b.domainHolder.Store(domains)
+	b.urlHolder.Store(urls)
+	return nil
+}
+
+// CheckRequest will check if the domain is blocked or the path is blocked
+func (b *Banlist) CheckRequest(r *http.Request) bool {
+	domain := strings.SplitN(r.Host, ":", 2)[0]
+	if _, ok := b.domains()[strings.ToLower(domain)]; ok {
+		return true
+	}
+
+	url := domain + r.URL.Path
+	if _, ok := b.urls()[strings.ToLower(url)]; ok {
+		return true
+	}
+
+	return false
+}
+
+func (b *Banlist) Close() {
+	signal.Stop(b.ch)
+	close(b.ch)
+}
+
+func (b *Banlist) domains() map[string]struct{} {
+	return b.domainHolder.Load().(map[string]struct{})
+}
+
+func (b *Banlist) urls() map[string]struct{} {
+	return b.urlHolder.Load().(map[string]struct{})
+}

http/banlist/banlist_test.go

@@ -0,0 +1,101 @@
+package banlist
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+
+	"github.com/sirupsen/logrus"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBanlistMissingFile(t *testing.T) {
+	bl := newBanlist(tl(t), "not a path")
+	require.Error(t, bl.update())
+}
+
+func TestBanlistInvalidFileContents(t *testing.T) {
+	path, err := ioutil.TempFile("", "")
+	require.NoError(t, err)
+	defer os.Remove(path.Name())
+
+	_, err = path.WriteString("this isn't valid json")
+	require.NoError(t, err)
+
+	bl := newBanlist(tl(t), path.Name())
+	require.Error(t, bl.update())
+}
+
+func TestBanlistNoPaths(t *testing.T) {
+	bl := testList(t, &Config{
+		Domains: []string{"something.com"},
+	})
+
+	assert.Empty(t, bl.urls())
+	domains := bl.domains()
+	assert.Len(t, domains, 1)
+	_, ok := domains["something.com"]
+	assert.True(t, ok)
+}
+
+func TestBanlistNoDomains(t *testing.T) {
+	bl := testList(t, &Config{
+		URLs: []string{"something.com/path/to/thing"},
+	})
+
+	urls := bl.urls()
+	assert.Len(t, urls, 1)
+	_, ok := urls["something.com/path/to/thing"]
+	assert.True(t, ok)
+
+	assert.Empty(t, bl.domains())
+}
+func TestBanlistBanning(t *testing.T) {
+	bl := testList(t, &Config{
+		URLs:    []string{"villians.com/the/joker"},
+		Domains: []string{"sick.com"},
+	})
+
+	tests := []struct {
+		url      string
+		isBanned bool
+		name     string
+	}{
+		{"http://heros.com", false, "completely unbanned"},
+		{"http://sick.com:12345", true, "banned domain with port"},
+		{"http://sick.com", true, "banned domain without port"},
+		{"http://siCK.com", true, "banned domain mixed case"},
+		{"http://villians.com:12354/the/joker", true, "banned path with port"},
+		{"http://villians.com/the/joker", true, "banned path without port"},
+		{"http://villians.com/the/Joker", true, "banned path mixed case"},
+		{"http://villians.com/the/joker?query=param", true, "banned path with query params"},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			req := httptest.NewRequest(http.MethodGet, test.url, nil)
+			assert.Equal(t, test.isBanned, bl.CheckRequest(req))
+		})
+	}
+}
+
+func tl(t *testing.T) logrus.FieldLogger {
+	l := logrus.New()
+	l.SetLevel(logrus.DebugLevel)
+	return l.WithField("test", t.Name())
+}
+
+func testList(t *testing.T, config *Config) *Banlist {
+	path, err := ioutil.TempFile("", "")
+	require.NoError(t, err)
+	defer os.Remove(path.Name())
+
+	require.NoError(t, json.NewEncoder(path).Encode(config))
+
+	bl := newBanlist(tl(t), path.Name())
+	require.NoError(t, bl.update())
+	return bl
+}