package configs import ( "fmt" "strings" "github.com/hashicorp/hcl2/hcl" "github.com/hashicorp/hcl2/hclparse" "github.com/spf13/afero" ) // Parser is the main interface to read configuration files and other related // files from disk. // // It retains a cache of all files that are loaded so that they can be used // to create source code snippets in diagnostics, etc. type Parser struct { fs afero.Afero p *hclparse.Parser } // NewParser creates and returns a new Parser that reads files from the given // filesystem. If a nil filesystem is passed then the system's "real" filesystem // will be used, via afero.OsFs. func NewParser(fs afero.Fs) *Parser { if fs == nil { fs = afero.OsFs{} } return &Parser{ fs: afero.Afero{Fs: fs}, p: hclparse.NewParser(), } } // LoadHCLFile is a low-level method that reads the file at the given path, // parses it, and returns the hcl.Body representing its root. In many cases // it is better to use one of the other Load*File methods on this type, // which additionally decode the root body in some way and return a higher-level // construct. // // If the file cannot be read at all -- e.g. because it does not exist -- then // this method will return a nil body and error diagnostics. In this case // callers may wish to ignore the provided error diagnostics and produce // a more context-sensitive error instead. // // The file will be parsed using the HCL native syntax unless the filename // ends with ".json", in which case the HCL JSON syntax will be used. func (p *Parser) LoadHCLFile(path string) (hcl.Body, hcl.Diagnostics) { src, err := p.fs.ReadFile(path) if err != nil { return nil, hcl.Diagnostics{ { Severity: hcl.DiagError, Summary: "Failed to read file", Detail: fmt.Sprintf("The file %q could not be read.", path), }, } } var file *hcl.File var diags hcl.Diagnostics switch { case strings.HasSuffix(path, ".json"): file, diags = p.p.ParseJSON(src, path) default: file, diags = p.p.ParseHCL(src, path) } // If the returned file or body is nil, then we'll return a non-nil empty // body so we'll meet our contract that nil means an error reading the file. if file == nil || file.Body == nil { return hcl.EmptyBody(), diags } return file.Body, diags } // Sources returns a map of the cached source buffers for all files that // have been loaded through this parser, with source filenames (as requested // when each file was opened) as the keys. func (p *Parser) Sources() map[string][]byte { return p.p.Sources() } // ForceFileSource artificially adds source code to the cache of file sources, // as if it had been loaded from the given filename. // // This should be used only in special situations where configuration is loaded // some other way. Most callers should load configuration via methods of // Parser, which will update the sources cache automatically. func (p *Parser) ForceFileSource(filename string, src []byte) { // We'll make a synthetic hcl.File here just so we can reuse the // existing cache. p.p.AddFile(filename, &hcl.File{ Body: hcl.EmptyBody(), Bytes: src, }) }