Report how a config reload went: failures, restarts required, and the keys that need one (#1935)

ssh_reload_test.go

@@ -0,0 +1,83 @@
+package nebula
+
+import (
+	"errors"
+	"io"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/slackhq/nebula/config"
+	"github.com/slackhq/nebula/test"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+type lineWriter struct {
+	lines []string
+	err   error
+}
+
+func (w *lineWriter) WriteLine(s string) error {
+	w.lines = append(w.lines, s)
+	return w.err
+}
+func (w *lineWriter) Write(s string) error      { return w.WriteLine(s) }
+func (w *lineWriter) WriteBytes(b []byte) error { return w.WriteLine(string(b)) }
+func (w *lineWriter) GetWriter() io.Writer      { return io.Discard }
+
+func TestSSHReloadReportsTheResult(t *testing.T) {
+	dir := t.TempDir()
+	write := func(body string) {
+		require.NoError(t, os.WriteFile(filepath.Join(dir, "config.yml"), []byte(body), 0o600))
+	}
+	write("a: 1\nb: 1")
+	l := test.NewLogger()
+	c := config.NewC(l)
+	require.NoError(t, c.Load(dir))
+	fail := false
+	c.RegisterReloadCallback(func(c *config.C, r *config.Reload) {
+		r.RestartRequiredIfChanged("b")
+		if fail {
+			r.Failed()
+		}
+	})
+
+	reload := func() []string {
+		w := &lineWriter{}
+		require.NoError(t, sshReload(l, c, w))
+		return w.lines
+	}
+
+	write("a: 2\nb: 1")
+	assert.Equal(t, []string{"Reloading config", "Config reload complete"}, reload())
+
+	fail = true
+	write("a: 3\nb: 1")
+	assert.Equal(t, []string{"Reloading config", "Config reload completed with errors, review the logs"}, reload())
+
+	fail = false
+	write("a: 3\nb: 2")
+	assert.Equal(t, []string{"Reloading config", "Config reload was completed but requires a restart to fully apply, keys [b]"}, reload())
+
+	write("a: [")
+	lines := reload()
+	require.Len(t, lines, 2)
+	assert.Contains(t, lines[1], "Config reload failed, the new config did not load")
+	assert.Contains(t, lines[1], dir, "names the config that did not load")
+}
+
+// A client that went away still gets the reload it asked for
+func TestSSHReloadReloadsWhenTheClientIsGone(t *testing.T) {
+	dir := t.TempDir()
+	require.NoError(t, os.WriteFile(filepath.Join(dir, "config.yml"), []byte("a: 1"), 0o600))
+	l := test.NewLogger()
+	c := config.NewC(l)
+	require.NoError(t, c.Load(dir))
+	reloaded := false
+	c.RegisterReloadCallback(func(*config.C, *config.Reload) { reloaded = true })
+
+	gone := errors.New("client is gone")
+	require.ErrorIs(t, sshReload(l, c, &lineWriter{err: gone}), gone)
+	assert.True(t, reloaded)
+}