package config import ( "fmt" "path/filepath" "github.com/mitchellh/go-libucl" "github.com/mitchellh/reflectwalk" ) // Put the parse flags we use for libucl in a constant so we can get // equally behaving parsing everywhere. const libuclParseFlags = libucl.ParserKeyLowercase // libuclConfigurable is an implementation of configurable that knows // how to turn libucl configuration into a *Config object. type libuclConfigurable struct { Object *libucl.Object } func (t *libuclConfigurable) Close() error { return t.Object.Close() } func (t *libuclConfigurable) Config() (*Config, error) { type LibuclVariable struct { Default string Description string Fields []string `libucl:",decodedFields"` } var rawConfig struct { Variable map[string]*LibuclVariable } if err := t.Object.Decode(&rawConfig); err != nil { return nil, err } // Start building up the actual configuration. We start with // variables. config := new(Config) config.Variables = make(map[string]*Variable) for k, v := range rawConfig.Variable { defaultSet := false for _, f := range v.Fields { if f == "Default" { defaultSet = true break } } config.Variables[k] = &Variable{ Default: v.Default, Description: v.Description, defaultSet: defaultSet, } } // Build the provider configs providers := t.Object.Get("provider") if providers != nil { var err error config.ProviderConfigs, err = loadProvidersLibucl(providers) providers.Close() if err != nil { return nil, err } } // Build the resources resources := t.Object.Get("resource") if resources != nil { var err error config.Resources, err = loadResourcesLibucl(resources) resources.Close() if err != nil { return nil, err } } return config, nil } // loadFileLibucl is a fileLoaderFunc that knows how to read libucl // files and turn them into libuclConfigurables. func loadFileLibucl(root string) (configurable, []string, error) { var obj *libucl.Object = nil // Parse and store the object. We don't use a defer here so that // we clear resources right away rather than stack them up all the // way through our recursive calls. parser := libucl.NewParser(libuclParseFlags) err := parser.AddFile(root) if err == nil { obj = parser.Object() defer obj.Close() } parser.Close() // If there was an error, return early if err != nil { return nil, nil, err } // Start building the result result := &libuclConfigurable{ Object: obj, } // Otherwise, dive in, find the imports. imports := obj.Get("import") if imports == nil { result.Object.Ref() return result, nil, nil } if imports.Type() != libucl.ObjectTypeString { imports.Close() return nil, nil, fmt.Errorf( "Error in %s: all 'import' declarations should be in the format\n"+ "`import \"foo\"` (Got type %s)", root, imports.Type()) } // Gather all the import paths importPaths := make([]string, 0, imports.Len()) iter := imports.Iterate(false) for imp := iter.Next(); imp != nil; imp = iter.Next() { path := imp.ToString() if !filepath.IsAbs(path) { // Relative paths are relative to the Terraform file itself dir := filepath.Dir(root) path = filepath.Join(dir, path) } importPaths = append(importPaths, path) imp.Close() } iter.Close() imports.Close() result.Object.Ref() return result, importPaths, nil } // LoadProvidersLibucl recurses into the given libucl object and turns // it into a mapping of provider configs. func loadProvidersLibucl(o *libucl.Object) (map[string]*ProviderConfig, error) { objects := make(map[string]*libucl.Object) // Iterate over all the "provider" blocks and get the keys along with // their raw configuration objects. We'll parse those later. iter := o.Iterate(false) for o1 := iter.Next(); o1 != nil; o1 = iter.Next() { iter2 := o1.Iterate(true) for o2 := iter2.Next(); o2 != nil; o2 = iter2.Next() { objects[o2.Key()] = o2 defer o2.Close() } o1.Close() iter2.Close() } iter.Close() // Go through each object and turn it into an actual result. result := make(map[string]*ProviderConfig) for n, o := range objects { var config map[string]interface{} if err := o.Decode(&config); err != nil { return nil, err } walker := new(variableDetectWalker) if err := reflectwalk.Walk(config, walker); err != nil { return nil, fmt.Errorf( "Error reading config for provider config %s: %s", n, err) } result[n] = &ProviderConfig{ Config: config, Variables: walker.Variables, } } return result, nil } // Given a handle to a libucl object, this recurses into the structure // and pulls out a list of resources. // // The resulting resources may not be unique, but each resource // represents exactly one resource definition in the libucl configuration. // We leave it up to another pass to merge them together. func loadResourcesLibucl(o *libucl.Object) ([]*Resource, error) { var allTypes []*libucl.Object // Libucl object iteration is really nasty. Below is likely to make // no sense to anyone approaching this code. Luckily, it is very heavily // tested. If working on a bug fix or feature, we recommend writing a // test first then doing whatever you want to the code below. If you // break it, the tests will catch it. Likewise, if you change this, // MAKE SURE you write a test for your change, because its fairly impossible // to reason about this mess. // // Functionally, what the code does below is get the libucl.Objects // for all the TYPES, such as "aws_security_group". iter := o.Iterate(false) for o1 := iter.Next(); o1 != nil; o1 = iter.Next() { // Iterate the inner to get the list of types iter2 := o1.Iterate(true) for o2 := iter2.Next(); o2 != nil; o2 = iter2.Next() { // Iterate all of this type to get _all_ the types iter3 := o2.Iterate(false) for o3 := iter3.Next(); o3 != nil; o3 = iter3.Next() { allTypes = append(allTypes, o3) } o2.Close() iter3.Close() } o1.Close() iter2.Close() } iter.Close() // Where all the results will go var result []*Resource // Now go over all the types and their children in order to get // all of the actual resources. for _, t := range allTypes { // Release the resources for this raw type since we don't need it. // Note that this makes it unsafe now to use allTypes again. defer t.Close() iter := t.Iterate(true) defer iter.Close() for r := iter.Next(); r != nil; r = iter.Next() { defer r.Close() var config map[string]interface{} if err := r.Decode(&config); err != nil { return nil, fmt.Errorf( "Error reading config for %s[%s]: %s", t.Key(), r.Key(), err) } walker := new(variableDetectWalker) if err := reflectwalk.Walk(config, walker); err != nil { return nil, fmt.Errorf( "Error reading config for %s[%s]: %s", t.Key(), r.Key(), err) } result = append(result, &Resource{ Name: r.Key(), Type: t.Key(), Config: config, Variables: walker.Variables, }) } } return result, nil }