// Interpolate uses the given mapping of variable values and uses
// those as the values to replace any variables in this raw
// configuration.
//
// Any prior calls to Interpolate are replaced with this one.
//
// If a variable key is missing, this will panic.
func (r *RawConfig) Interpolate(vs map[string]ast.Variable) error {
config := langEvalConfig(vs)
return r.interpolate(func(root ast.Node) (string, error) {
// We detect the variables again and check if the value of any
// of the variables is the computed value. If it is, then we
// treat this entire value as computed.
//
// We have to do this here before the `lang.Eval` because
// if any of the variables it depends on are computed, then
// the interpolation can fail at runtime for other reasons. Example:
// `${count.index+1}`: in a world where `count.index` is computed,
// this would fail a type check since the computed placeholder is
// a string, but realistically the whole value is just computed.
vars, err := DetectVariables(root)
if err != nil {
return "", err
}
for _, v := range vars {
varVal, ok := vs[v.FullKey()]
if ok && varVal.Value == UnknownVariableValue {
return UnknownVariableValue, nil
}
}
// None of the variables we need are computed, meaning we should
// be able to properly evaluate.
out, _, err := lang.Eval(root, config)
if err != nil {
return "", err
}
return out.(string), nil
})
}
func testFunction(t *testing.T, config testFunctionConfig) {
for i, tc := range config.Cases {
ast, err := lang.Parse(tc.Input)
if err != nil {
t.Fatalf("Case #%d: input: %#v\nerr: %s", i, tc.Input, err)
}
out, _, err := lang.Eval(ast, langEvalConfig(config.Vars))
if err != nil != tc.Error {
t.Fatalf("Case #%d:\ninput: %#v\nerr: %s", i, tc.Input, err)
}
if !reflect.DeepEqual(out, tc.Result) {
t.Fatalf(
"%d: bad output for input: %s\n\nOutput: %#v\nExpected: %#v",
i, tc.Input, out, tc.Result)
}
}
}
// execute parses and executes a template using vars.
func execute(s string, vars map[string]interface{}) (string, error) {
root, err := lang.Parse(s)
if err != nil {
return "", err
}
varmap := make(map[string]ast.Variable)
for k, v := range vars {
// As far as I can tell, v is always a string.
// If it's not, tell the user gracefully.
s, ok := v.(string)
if !ok {
return "", fmt.Errorf("unexpected type for variable %q: %T", k, v)
}
varmap[k] = ast.Variable{
Value: s,
Type: ast.TypeString,
}
}
cfg := lang.EvalConfig{
GlobalScope: &ast.BasicScope{
VarMap: varmap,
FuncMap: config.Funcs(),
},
}
out, typ, err := lang.Eval(root, &cfg)
if err != nil {
return "", err
}
if typ != ast.TypeString {
return "", fmt.Errorf("unexpected output ast.Type: %v", typ)
}
return out.(string), nil
}
// 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(ast.Node) (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'. define it with 'variable' blocks",
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 providers aren't declared multiple times.
providerSet := make(map[string]struct{})
for _, p := range c.ProviderConfigs {
name := p.FullName()
if _, ok := providerSet[name]; ok {
errs = append(errs, fmt.Errorf(
"provider.%s: declared multiple times, you can only declare a provider once",
name))
continue
}
providerSet[name] = struct{}{}
}
// 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()))
}
// Already seen this module, just skip it
continue
}
modules[m.Id()] = m
// Check that the source has no interpolations
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()))
}
// Check that the name matches our regexp
if !NameRegexp.Match([]byte(m.Name)) {
errs = append(errs, fmt.Errorf(
"%s: module name can only contain letters, numbers, "+
"dashes, and underscores",
m.Id()))
}
// Check that the configuration can all be strings
raw := make(map[string]interface{})
for k, v := range m.RawConfig.Raw {
var strVal string
if err := mapstructure.WeakDecode(v, &strVal); err != nil {
errs = append(errs, fmt.Errorf(
"%s: variable %s must be a string value",
m.Id(), k))
}
raw[k] = strVal
}
// Check for invalid count variables
for _, v := range m.RawConfig.Variables {
switch v.(type) {
case *CountVariable:
errs = append(errs, fmt.Errorf(
"%s: count variables are only valid within resources", m.Name))
case *SelfVariable:
errs = append(errs, fmt.Errorf(
"%s: self variables are only valid within resources", m.Name))
}
}
// Update the raw configuration to only contain the string values
m.RawConfig, err = NewRawConfig(raw)
if err != nil {
errs = append(errs, fmt.Errorf(
"%s: can't initialize configuration: %s",
m.Id(), err))
}
}
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(root ast.Node) (string, error) {
// Execute the node but transform the AST so that it returns
// a fixed value of "5" for all interpolations.
out, _, err := lang.Eval(
lang.FixedValueTransform(
root, &ast.LiteralNode{Value: "5", Typex: ast.TypeString}),
nil)
if err != nil {
return "", err
}
return out.(string), 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()
// Verify depends on points to resources that all exist
for _, d := range r.DependsOn {
// Check if we contain interpolations
rc, err := NewRawConfig(map[string]interface{}{
"value": d,
})
if err == nil && len(rc.Variables) > 0 {
errs = append(errs, fmt.Errorf(
"%s: depends on value cannot contain interpolations: %s",
n, d))
continue
}
if _, ok := resources[d]; !ok {
errs = append(errs, fmt.Errorf(
"%s: resource depends on non-existent resource '%s'",
n, d))
}
}
// Verify provider points to a provider that is configured
if r.Provider != "" {
if _, ok := providerSet[r.Provider]; !ok {
errs = append(errs, fmt.Errorf(
"%s: resource depends on non-configured provider '%s'",
n, r.Provider))
}
}
// Verify provisioners don't contain any splats
for _, p := range r.Provisioners {
// This validation checks that there are now splat variables
// referencing ourself. This currently is not allowed.
for _, v := range p.ConnInfo.Variables {
rv, ok := v.(*ResourceVariable)
if !ok {
continue
}
if rv.Multi && rv.Index == -1 && rv.Type == r.Type && rv.Name == r.Name {
errs = append(errs, fmt.Errorf(
"%s: connection info cannot contain splat variable "+
"referencing itself", n))
break
}
}
for _, v := range p.RawConfig.Variables {
rv, ok := v.(*ResourceVariable)
if !ok {
continue
}
if rv.Multi && rv.Index == -1 && rv.Type == r.Type && rv.Name == r.Name {
errs = append(errs, fmt.Errorf(
"%s: connection info cannot contain splat variable "+
"referencing itself", n))
break
}
}
}
}
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))
}
for _, v := range o.RawConfig.Variables {
if _, ok := v.(*CountVariable); ok {
errs = append(errs, fmt.Errorf(
"%s: count variables are only valid within resources", o.Name))
}
}
}
// Check that all variables are in the proper context
for source, rc := range c.rawConfigs() {
walker := &interpolationWalker{
ContextF: c.validateVarContextFn(source, &errs),
}
if err := reflectwalk.Walk(rc.Raw, walker); err != nil {
errs = append(errs, fmt.Errorf(
"%s: error reading config: %s", source, err))
}
}
// Validate the self variable
for source, rc := range c.rawConfigs() {
// Ignore provisioners. This is a pretty brittle way to do this,
// but better than also repeating all the resources.
if strings.Contains(source, "provision") {
continue
}
for _, v := range rc.Variables {
if _, ok := v.(*SelfVariable); ok {
errs = append(errs, fmt.Errorf(
"%s: cannot contain self-reference %s", source, v.FullKey()))
}
}
}
if len(errs) > 0 {
return &multierror.Error{Errors: errs}
}
return nil
}