terraform/config/config.go

559 lines
12 KiB
Go

// The config package is responsible for loading and validating the
// configuration.
package config
import (
"fmt"
"strconv"
"strings"
"github.com/hashicorp/terraform/flatmap"
"github.com/hashicorp/terraform/helper/multierror"
"github.com/mitchellh/mapstructure"
"github.com/mitchellh/reflectwalk"
)
// Config is the configuration that comes from loading a collection
// of Terraform templates.
type Config struct {
// Dir is the path to the directory where this configuration was
// loaded from. If it is blank, this configuration wasn't loaded from
// any meaningful directory.
Dir string
Modules []*Module
ProviderConfigs []*ProviderConfig
Resources []*Resource
Variables []*Variable
Outputs []*Output
// The fields below can be filled in by loaders for validation
// purposes.
unknownKeys []string
}
// Module is a module used within a configuration.
//
// This does not represent a module itself, this represents a module
// call-site within an existing configuration.
type Module struct {
Name string
Source string
RawConfig *RawConfig
}
// ProviderConfig is the configuration for a resource provider.
//
// For example, Terraform needs to set the AWS access keys for the AWS
// resource provider.
type ProviderConfig struct {
Name string
RawConfig *RawConfig
}
// A resource represents a single Terraform resource in the configuration.
// A Terraform resource is something that represents some component that
// can be created and managed, and has some properties associated with it.
type Resource struct {
Name string
Type string
RawCount *RawConfig
RawConfig *RawConfig
Provisioners []*Provisioner
DependsOn []string
Lifecycle ResourceLifecycle
}
// ResourceLifecycle is used to store the lifecycle tuning parameters
// to allow customized behavior
type ResourceLifecycle struct {
CreateBeforeDestroy bool `hcl:"create_before_destroy"`
}
// Provisioner is a configured provisioner step on a resource.
type Provisioner struct {
Type string
RawConfig *RawConfig
ConnInfo *RawConfig
}
// Variable is a variable defined within the configuration.
type Variable struct {
Name string
Default interface{}
Description string
}
// Output is an output defined within the configuration. An output is
// resulting data that is highlighted by Terraform when finished.
type Output struct {
Name string
RawConfig *RawConfig
}
// VariableType is the type of value a variable is holding, and returned
// by the Type() function on variables.
type VariableType byte
const (
VariableTypeUnknown VariableType = iota
VariableTypeString
VariableTypeMap
)
// ProviderConfigName returns the name of the provider configuration in
// the given mapping that maps to the proper provider configuration
// for this resource.
func ProviderConfigName(t string, pcs []*ProviderConfig) string {
lk := ""
for _, v := range pcs {
k := v.Name
if strings.HasPrefix(t, k) && len(k) > len(lk) {
lk = k
}
}
return lk
}
// A unique identifier for this module.
func (r *Module) Id() string {
return fmt.Sprintf("%s", r.Name)
}
// Count returns the count of this resource.
func (r *Resource) Count() (int, error) {
v, err := strconv.ParseInt(r.RawCount.Value().(string), 0, 0)
if err != nil {
return 0, err
}
return int(v), nil
}
// A unique identifier for this resource.
func (r *Resource) Id() string {
return fmt.Sprintf("%s.%s", r.Type, r.Name)
}
// Validate does some basic semantic checking of the configuration.
func (c *Config) Validate() error {
if c == nil {
return nil
}
var errs []error
for _, k := range c.unknownKeys {
errs = append(errs, fmt.Errorf(
"Unknown root level key: %s", k))
}
vars := c.InterpolatedVariables()
varMap := make(map[string]*Variable)
for _, v := range c.Variables {
varMap[v.Name] = v
}
for _, v := range c.Variables {
if v.Type() == VariableTypeUnknown {
errs = append(errs, fmt.Errorf(
"Variable '%s': must be string or mapping",
v.Name))
continue
}
interp := false
fn := func(i Interpolation) (string, error) {
interp = true
return "", nil
}
w := &interpolationWalker{F: fn}
if v.Default != nil {
if err := reflectwalk.Walk(v.Default, w); err == nil {
if interp {
errs = append(errs, fmt.Errorf(
"Variable '%s': cannot contain interpolations",
v.Name))
}
}
}
}
// Check for references to user variables that do not actually
// exist and record those errors.
for source, vs := range vars {
for _, v := range vs {
uv, ok := v.(*UserVariable)
if !ok {
continue
}
if _, ok := varMap[uv.Name]; !ok {
errs = append(errs, fmt.Errorf(
"%s: unknown variable referenced: %s",
source,
uv.Name))
}
}
}
// Check that all count variables are valid.
for source, vs := range vars {
for _, rawV := range vs {
switch v := rawV.(type) {
case *CountVariable:
if v.Type == CountValueInvalid {
errs = append(errs, fmt.Errorf(
"%s: invalid count variable: %s",
source,
v.FullKey()))
}
case *PathVariable:
if v.Type == PathValueInvalid {
errs = append(errs, fmt.Errorf(
"%s: invalid path variable: %s",
source,
v.FullKey()))
}
}
}
}
// Check that all references to modules are valid
modules := make(map[string]*Module)
dupped := make(map[string]struct{})
for _, m := range c.Modules {
// Check for duplicates
if _, ok := modules[m.Id()]; ok {
if _, ok := dupped[m.Id()]; !ok {
dupped[m.Id()] = struct{}{}
errs = append(errs, fmt.Errorf(
"%s: module repeated multiple times",
m.Id()))
}
}
// If we haven't seen this module before, check that the
// source has no interpolations.
if _, ok := modules[m.Id()]; !ok {
rc, err := NewRawConfig(map[string]interface{}{
"root": m.Source,
})
if err != nil {
errs = append(errs, fmt.Errorf(
"%s: module source error: %s",
m.Id(), err))
} else if len(rc.Interpolations) > 0 {
errs = append(errs, fmt.Errorf(
"%s: module source cannot contain interpolations",
m.Id()))
}
}
modules[m.Id()] = m
}
dupped = nil
// Check that all variables for modules reference modules that
// exist.
for source, vs := range vars {
for _, v := range vs {
mv, ok := v.(*ModuleVariable)
if !ok {
continue
}
if _, ok := modules[mv.Name]; !ok {
errs = append(errs, fmt.Errorf(
"%s: unknown module referenced: %s",
source,
mv.Name))
}
}
}
// Check that all references to resources are valid
resources := make(map[string]*Resource)
dupped = make(map[string]struct{})
for _, r := range c.Resources {
if _, ok := resources[r.Id()]; ok {
if _, ok := dupped[r.Id()]; !ok {
dupped[r.Id()] = struct{}{}
errs = append(errs, fmt.Errorf(
"%s: resource repeated multiple times",
r.Id()))
}
}
resources[r.Id()] = r
}
dupped = nil
// Validate resources
for n, r := range resources {
// Verify count variables
for _, v := range r.RawCount.Variables {
switch v.(type) {
case *CountVariable:
errs = append(errs, fmt.Errorf(
"%s: resource count can't reference count variable: %s",
n,
v.FullKey()))
case *ModuleVariable:
errs = append(errs, fmt.Errorf(
"%s: resource count can't reference module variable: %s",
n,
v.FullKey()))
case *ResourceVariable:
errs = append(errs, fmt.Errorf(
"%s: resource count can't reference resource variable: %s",
n,
v.FullKey()))
case *UserVariable:
// Good
default:
panic("Unknown type in count var: " + n)
}
}
// Interpolate with a fixed number to verify that its a number
r.RawCount.interpolate(func(Interpolation) (string, error) {
return "5", nil
})
_, err := strconv.ParseInt(r.RawCount.Value().(string), 0, 0)
if err != nil {
errs = append(errs, fmt.Errorf(
"%s: resource count must be an integer",
n))
}
r.RawCount.init()
for _, d := range r.DependsOn {
if _, ok := resources[d]; !ok {
errs = append(errs, fmt.Errorf(
"%s: resource depends on non-existent resource '%s'",
n, d))
}
}
}
for source, vs := range vars {
for _, v := range vs {
rv, ok := v.(*ResourceVariable)
if !ok {
continue
}
id := fmt.Sprintf("%s.%s", rv.Type, rv.Name)
if _, ok := resources[id]; !ok {
errs = append(errs, fmt.Errorf(
"%s: unknown resource '%s' referenced in variable %s",
source,
id,
rv.FullKey()))
continue
}
}
}
// Check that all outputs are valid
for _, o := range c.Outputs {
invalid := false
for k, _ := range o.RawConfig.Raw {
if k != "value" {
invalid = true
break
}
}
if invalid {
errs = append(errs, fmt.Errorf(
"%s: output should only have 'value' field", o.Name))
}
}
if len(errs) > 0 {
return &multierror.Error{Errors: errs}
}
return nil
}
// InterpolatedVariables is a helper that returns a mapping of all the interpolated
// variables within the configuration. This is used to verify references
// are valid in the Validate step.
func (c *Config) InterpolatedVariables() map[string][]InterpolatedVariable {
result := make(map[string][]InterpolatedVariable)
for _, pc := range c.ProviderConfigs {
source := fmt.Sprintf("provider config '%s'", pc.Name)
for _, v := range pc.RawConfig.Variables {
result[source] = append(result[source], v)
}
}
for _, rc := range c.Resources {
source := fmt.Sprintf("resource '%s'", rc.Id())
for _, v := range rc.RawCount.Variables {
result[source] = append(result[source], v)
}
for _, v := range rc.RawConfig.Variables {
result[source] = append(result[source], v)
}
}
for _, o := range c.Outputs {
source := fmt.Sprintf("output '%s'", o.Name)
for _, v := range o.RawConfig.Variables {
result[source] = append(result[source], v)
}
}
return result
}
func (m *Module) mergerName() string {
return m.Id()
}
func (m *Module) mergerMerge(other merger) merger {
m2 := other.(*Module)
result := *m
result.Name = m2.Name
result.RawConfig = result.RawConfig.merge(m2.RawConfig)
if m2.Source != "" {
result.Source = m2.Source
}
return &result
}
func (o *Output) mergerName() string {
return o.Name
}
func (o *Output) mergerMerge(m merger) merger {
o2 := m.(*Output)
result := *o
result.Name = o2.Name
result.RawConfig = result.RawConfig.merge(o2.RawConfig)
return &result
}
func (c *ProviderConfig) mergerName() string {
return c.Name
}
func (c *ProviderConfig) mergerMerge(m merger) merger {
c2 := m.(*ProviderConfig)
result := *c
result.Name = c2.Name
result.RawConfig = result.RawConfig.merge(c2.RawConfig)
return &result
}
func (r *Resource) mergerName() string {
return fmt.Sprintf("%s.%s", r.Type, r.Name)
}
func (r *Resource) mergerMerge(m merger) merger {
r2 := m.(*Resource)
result := *r
result.Name = r2.Name
result.Type = r2.Type
result.RawConfig = result.RawConfig.merge(r2.RawConfig)
if r2.RawCount.Value() != "1" {
result.RawCount = r2.RawCount
}
if len(r2.Provisioners) > 0 {
result.Provisioners = r2.Provisioners
}
return &result
}
// DefaultsMap returns a map of default values for this variable.
func (v *Variable) DefaultsMap() map[string]string {
if v.Default == nil {
return nil
}
n := fmt.Sprintf("var.%s", v.Name)
switch v.Type() {
case VariableTypeString:
return map[string]string{n: v.Default.(string)}
case VariableTypeMap:
result := flatmap.Flatten(map[string]interface{}{
n: v.Default.(map[string]string),
})
result[n] = v.Name
return result
default:
return nil
}
}
// Merge merges two variables to create a new third variable.
func (v *Variable) Merge(v2 *Variable) *Variable {
// Shallow copy the variable
result := *v
// The names should be the same, but the second name always wins.
result.Name = v2.Name
if v2.Default != nil {
result.Default = v2.Default
}
if v2.Description != "" {
result.Description = v2.Description
}
return &result
}
// Type returns the type of varialbe this is.
func (v *Variable) Type() VariableType {
if v.Default == nil {
return VariableTypeString
}
var strVal string
if err := mapstructure.WeakDecode(v.Default, &strVal); err == nil {
v.Default = strVal
return VariableTypeString
}
var m map[string]string
if err := mapstructure.WeakDecode(v.Default, &m); err == nil {
v.Default = m
return VariableTypeMap
}
return VariableTypeUnknown
}
func (v *Variable) mergerName() string {
return v.Name
}
func (v *Variable) mergerMerge(m merger) merger {
return v.Merge(m.(*Variable))
}
// Required tests whether a variable is required or not.
func (v *Variable) Required() bool {
return v.Default == nil
}