Settings: Expand variables in configuration (#25075)

pkg/setting/expanders_test.go

@@ -0,0 +1,96 @@
+package setting
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"math/rand"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestExpandVar_EnvSuccessful(t *testing.T) {
+	const key = "GF_TEST_SETTING_EXPANDER_ENV"
+	const expected = "aurora borealis"
+	os.Setenv(key, expected)
+
+	// expanded format
+	{
+		got, err := ExpandVar(fmt.Sprintf("$__env{%s}", key))
+		assert.NoError(t, err)
+		assert.Equal(t, expected, got)
+	}
+
+	// short format
+	{
+		got, err := ExpandVar(fmt.Sprintf("${%s}", key))
+		assert.NoError(t, err)
+		assert.Equal(t, expected, got)
+	}
+}
+
+func TestExpandVar_FileSuccessful(t *testing.T) {
+	f, err := ioutil.TempFile(os.TempDir(), "file expansion *")
+	require.NoError(t, err)
+	file := f.Name()
+
+	defer func() {
+		os.Remove(file)
+	}()
+
+	_, err = f.WriteString("hello, world")
+	require.NoError(t, err)
+	f.Close()
+
+	got, err := ExpandVar(fmt.Sprintf("$__file{%s}", file))
+	assert.NoError(t, err)
+	assert.Equal(t, "hello, world", got)
+}
+
+func TestExpandVar_FileDoesNotExist(t *testing.T) {
+	got, err := ExpandVar(
+		fmt.Sprintf("$__file{%s%sthisisnotarealfile_%d}",
+			os.TempDir(),
+			string(os.PathSeparator),
+			rand.Int63()),
+	)
+	assert.Error(t, err)
+	assert.True(t, errors.Is(err, os.ErrNotExist))
+	assert.Empty(t, got)
+}
+
+func TestExpanderRegex(t *testing.T) {
+	tests := map[string][][]string{
+		// we should not expand variables where there are none
+		"smoketest":                          {},
+		"Pa$$word{0}":                        {},
+		"$_almost{but not quite a variable}": {},
+		// args are required
+		"$__file{}": {},
+
+		// base cases
+		"${ENV}":             {{"", "ENV"}},
+		"$__env{ENV}":        {{"__env", "ENV"}},
+		"$__file{/dev/null}": {{"__file", "/dev/null"}},
+		"$__vault{item}":     {{"__vault", "item"}},
+		// contains a space in the argument
+		"$__file{C:\\Program Files\\grafana\\something}": {{"__file", "C:\\Program Files\\grafana\\something"}},
+
+		// complex cases
+		"get variable from $__env{ENV}ironment":               {{"__env", "ENV"}},
+		"$__env{VAR1} $__file{/var/lib/grafana/secrets/var1}": {{"__env", "VAR1"}, {"__file", "/var/lib/grafana/secrets/var1"}},
+		"$__env{$__file{this is invalid}}":                    {{"__env", "$__file{this is invalid"}},
+	}
+
+	for input, expected := range tests {
+		output := regex.FindAllStringSubmatch(input, -1)
+		require.Len(t, output, len(expected))
+		for i, variable := range output {
+			assert.Equal(t, expected[i], variable[1:])
+		}
+	}
+}