terraform/config/loader.go

166 lines
3.3 KiB
Go

package config
import (
"fmt"
"io"
"os"
"path/filepath"
"sort"
"strings"
)
// Load loads the Terraform configuration from a given file.
//
// This file can be any format that Terraform recognizes, and import any
// other format that Terraform recognizes.
func Load(path string) (*Config, error) {
importTree, err := loadTree(path)
if err != nil {
return nil, err
}
configTree, err := importTree.ConfigTree()
// Close the importTree now so that we can clear resources as quickly
// as possible.
importTree.Close()
if err != nil {
return nil, err
}
return configTree.Flatten()
}
// LoadDir loads all the Terraform configuration files in a single
// directory and appends them together.
//
// Special files known as "override files" can also be present, which
// are merged into the loaded configuration. That is, the non-override
// files are loaded first to create the configuration. Then, the overrides
// are merged into the configuration to create the final configuration.
//
// Files are loaded in lexical order.
func LoadDir(root string) (*Config, error) {
var files, overrides []string
f, err := os.Open(root)
if err != nil {
return nil, err
}
fi, err := f.Stat()
if err != nil {
return nil, err
}
if !fi.IsDir() {
return nil, fmt.Errorf(
"configuration path must be a directory: %s",
root)
}
err = nil
for err != io.EOF {
var fis []os.FileInfo
fis, err = f.Readdir(128)
if err != nil && err != io.EOF {
f.Close()
return nil, err
}
for _, fi := range fis {
// Ignore directories
if fi.IsDir() {
continue
}
// Only care about files that are valid to load
name := fi.Name()
extValue := ext(name)
if extValue == "" {
continue
}
// Determine if we're dealing with an override
nameNoExt := name[:len(name)-len(extValue)]
override := nameNoExt == "override" ||
strings.HasSuffix(nameNoExt, "_override")
path := filepath.Join(root, name)
if override {
overrides = append(overrides, path)
} else {
files = append(files, path)
}
}
}
// Close the directory, we're done with it
f.Close()
if len(files) == 0 {
return nil, fmt.Errorf(
"No Terraform configuration files found in directory: %s",
root)
}
// Determine the absolute path to the directory.
rootAbs, err := filepath.Abs(root)
if err != nil {
return nil, err
}
var result *Config
// Sort the files and overrides so we have a deterministic order
sort.Strings(files)
sort.Strings(overrides)
// Load all the regular files, append them to each other.
for _, f := range files {
c, err := Load(f)
if err != nil {
return nil, err
}
if result != nil {
result, err = Append(result, c)
if err != nil {
return nil, err
}
} else {
result = c
}
}
// Load all the overrides, and merge them into the config
for _, f := range overrides {
c, err := Load(f)
if err != nil {
return nil, err
}
result, err = Merge(result, c)
if err != nil {
return nil, err
}
}
// Mark the directory
result.Dir = rootAbs
return result, nil
}
// Ext returns the Terraform configuration extension of the given
// path, or a blank string if it is an invalid function.
func ext(path string) string {
if strings.HasSuffix(path, ".tf") {
return ".tf"
} else if strings.HasSuffix(path, ".tf.json") {
return ".tf.json"
} else {
return ""
}
}