mirror of https://github.com/grafana/grafana
Settings: Expand variables in configuration (#25075)
Emil Tullstedt
6 years ago
committed by
GitHub
parent
55f304f15d
commit
e8b5f2330d
@ -0,0 +1,147 @@ |
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package setting |
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|
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import ( |
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"fmt" |
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"io/ioutil" |
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"os" |
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"regexp" |
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"sort" |
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"strings" |
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|
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"gopkg.in/ini.v1" |
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) |
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type Expander interface { |
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SetupExpander(file *ini.File) error |
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Expand(string) (string, error) |
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} |
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type registeredExpander struct { |
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name string |
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priority int64 |
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expander Expander |
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} |
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|
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var expanders = []registeredExpander{ |
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{ |
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name: "env", |
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priority: -10, |
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expander: envExpander{}, |
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}, |
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{ |
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name: "file", |
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priority: -5, |
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expander: fileExpander{}, |
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}, |
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} |
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func AddExpander(name string, priority int64, e Expander) { |
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expanders = append(expanders, registeredExpander{ |
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name: name, |
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priority: priority, |
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expander: e, |
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}) |
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} |
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var regex = regexp.MustCompile(`\$(|__\w+){([^}]+)}`) |
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func expandConfig(file *ini.File) error { |
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sort.Slice(expanders, func(i, j int) bool { |
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return expanders[i].priority < expanders[j].priority |
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}) |
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for _, expander := range expanders { |
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err := expander.expander.SetupExpander(file) |
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if err != nil { |
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return fmt.Errorf("got error during initilazation of expander '%s': %w", expander.name, err) |
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} |
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for _, section := range file.Sections() { |
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for _, key := range section.Keys() { |
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updated, err := applyExpander(key.Value(), expander) |
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if err != nil { |
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return fmt.Errorf("got error while expanding %s.%s with expander '%s': %w", |
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section.Name(), |
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key.Name(), |
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expander.name, |
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err) |
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} |
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key.SetValue(updated) |
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} |
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} |
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} |
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return nil |
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} |
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func ExpandVar(s string) (string, error) { |
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for _, expander := range expanders { |
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var err error |
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s, err = applyExpander(s, expander) |
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if err != nil { |
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return "", fmt.Errorf("got error while expanding expander %s: %w", expander.name, err) |
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} |
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} |
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return s, nil |
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} |
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func applyExpander(s string, e registeredExpander) (string, error) { |
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matches := regex.FindAllStringSubmatch(s, -1) |
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for _, match := range matches { |
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if len(match) < 3 { |
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return "", fmt.Errorf("regex error, got %d results back for match, expected 3", len(match)) |
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} |
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_, isEnv := e.expander.(envExpander) |
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if match[1] == "__"+e.name || (match[1] == "" && isEnv) { |
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updated, err := e.expander.Expand(match[2]) |
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if err != nil { |
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return "", err |
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} |
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s = strings.Replace(s, match[0], updated, 1) |
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} |
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} |
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return s, nil |
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} |
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type envExpander struct { |
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} |
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func (e envExpander) SetupExpander(file *ini.File) error { |
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return nil |
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} |
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func (e envExpander) Expand(s string) (string, error) { |
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envValue := os.Getenv(s) |
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// if env variable is hostname and it is empty use os.Hostname as default
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if s == "HOSTNAME" && envValue == "" { |
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return os.Hostname() |
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} |
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return os.Getenv(s), nil |
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} |
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type fileExpander struct { |
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} |
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func (e fileExpander) SetupExpander(file *ini.File) error { |
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return nil |
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} |
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func (e fileExpander) Expand(s string) (string, error) { |
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_, err := os.Stat(s) |
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if err != nil { |
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return "", err |
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} |
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f, err := ioutil.ReadFile(s) |
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if err != nil { |
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return "", err |
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} |
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return strings.TrimSpace(string(f)), nil |
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} |
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@ -0,0 +1,96 @@ |
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package setting |
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import ( |
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"errors" |
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"fmt" |
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"io/ioutil" |
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"math/rand" |
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"os" |
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"testing" |
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"github.com/stretchr/testify/require" |
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"github.com/stretchr/testify/assert" |
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) |
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func TestExpandVar_EnvSuccessful(t *testing.T) { |
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const key = "GF_TEST_SETTING_EXPANDER_ENV" |
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const expected = "aurora borealis" |
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os.Setenv(key, expected) |
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// expanded format
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{ |
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got, err := ExpandVar(fmt.Sprintf("$__env{%s}", key)) |
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assert.NoError(t, err) |
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assert.Equal(t, expected, got) |
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} |
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// short format
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{ |
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got, err := ExpandVar(fmt.Sprintf("${%s}", key)) |
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assert.NoError(t, err) |
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assert.Equal(t, expected, got) |
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} |
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} |
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func TestExpandVar_FileSuccessful(t *testing.T) { |
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f, err := ioutil.TempFile(os.TempDir(), "file expansion *") |
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require.NoError(t, err) |
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file := f.Name() |
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defer func() { |
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os.Remove(file) |
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}() |
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_, err = f.WriteString("hello, world") |
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require.NoError(t, err) |
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f.Close() |
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got, err := ExpandVar(fmt.Sprintf("$__file{%s}", file)) |
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assert.NoError(t, err) |
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assert.Equal(t, "hello, world", got) |
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} |
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func TestExpandVar_FileDoesNotExist(t *testing.T) { |
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got, err := ExpandVar( |
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fmt.Sprintf("$__file{%s%sthisisnotarealfile_%d}", |
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os.TempDir(), |
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string(os.PathSeparator), |
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rand.Int63()), |
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) |
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assert.Error(t, err) |
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assert.True(t, errors.Is(err, os.ErrNotExist)) |
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assert.Empty(t, got) |
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} |
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func TestExpanderRegex(t *testing.T) { |
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tests := map[string][][]string{ |
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// we should not expand variables where there are none
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"smoketest": {}, |
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"Pa$$word{0}": {}, |
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"$_almost{but not quite a variable}": {}, |
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// args are required
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"$__file{}": {}, |
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// base cases
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"${ENV}": {{"", "ENV"}}, |
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"$__env{ENV}": {{"__env", "ENV"}}, |
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"$__file{/dev/null}": {{"__file", "/dev/null"}}, |
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"$__vault{item}": {{"__vault", "item"}}, |
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// contains a space in the argument
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"$__file{C:\\Program Files\\grafana\\something}": {{"__file", "C:\\Program Files\\grafana\\something"}}, |
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// complex cases
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"get variable from $__env{ENV}ironment": {{"__env", "ENV"}}, |
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"$__env{VAR1} $__file{/var/lib/grafana/secrets/var1}": {{"__env", "VAR1"}, {"__file", "/var/lib/grafana/secrets/var1"}}, |
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"$__env{$__file{this is invalid}}": {{"__env", "$__file{this is invalid"}}, |
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} |
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for input, expected := range tests { |
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output := regex.FindAllStringSubmatch(input, -1) |
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require.Len(t, output, len(expected)) |
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for i, variable := range output { |
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assert.Equal(t, expected[i], variable[1:]) |
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} |
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} |
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} |
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