opentofu/internal/configs/named_values.go
Martin Atkins 31349a9c3a Move configs/ to internal/configs/
This is part of a general effort to move all of Terraform's non-library
package surface under internal in order to reinforce that these are for
internal use within Terraform only.

If you were previously importing packages under this prefix into an
external codebase, you could pin to an earlier release tag as an interim
solution until you've make a plan to achieve the same functionality some
other way.
2021-05-17 14:09:07 -07:00

589 lines
19 KiB
Go

package configs
import (
"fmt"
"unicode"
"github.com/hashicorp/hcl/v2"
"github.com/hashicorp/hcl/v2/gohcl"
"github.com/hashicorp/hcl/v2/hclsyntax"
"github.com/zclconf/go-cty/cty"
"github.com/zclconf/go-cty/cty/convert"
"github.com/hashicorp/terraform/internal/addrs"
"github.com/hashicorp/terraform/internal/typeexpr"
)
// A consistent detail message for all "not a valid identifier" diagnostics.
const badIdentifierDetail = "A name must start with a letter or underscore and may contain only letters, digits, underscores, and dashes."
// Variable represents a "variable" block in a module or file.
type Variable struct {
Name string
Description string
Default cty.Value
Type cty.Type
ParsingMode VariableParsingMode
Validations []*VariableValidation
Sensitive bool
DescriptionSet bool
SensitiveSet bool
DeclRange hcl.Range
}
func decodeVariableBlock(block *hcl.Block, override bool) (*Variable, hcl.Diagnostics) {
v := &Variable{
Name: block.Labels[0],
DeclRange: block.DefRange,
}
// Unless we're building an override, we'll set some defaults
// which we might override with attributes below. We leave these
// as zero-value in the override case so we can recognize whether
// or not they are set when we merge.
if !override {
v.Type = cty.DynamicPseudoType
v.ParsingMode = VariableParseLiteral
}
content, diags := block.Body.Content(variableBlockSchema)
if !hclsyntax.ValidIdentifier(v.Name) {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid variable name",
Detail: badIdentifierDetail,
Subject: &block.LabelRanges[0],
})
}
// Don't allow declaration of variables that would conflict with the
// reserved attribute and block type names in a "module" block, since
// these won't be usable for child modules.
for _, attr := range moduleBlockSchema.Attributes {
if attr.Name == v.Name {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid variable name",
Detail: fmt.Sprintf("The variable name %q is reserved due to its special meaning inside module blocks.", attr.Name),
Subject: &block.LabelRanges[0],
})
}
}
for _, blockS := range moduleBlockSchema.Blocks {
if blockS.Type == v.Name {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid variable name",
Detail: fmt.Sprintf("The variable name %q is reserved due to its special meaning inside module blocks.", blockS.Type),
Subject: &block.LabelRanges[0],
})
}
}
if attr, exists := content.Attributes["description"]; exists {
valDiags := gohcl.DecodeExpression(attr.Expr, nil, &v.Description)
diags = append(diags, valDiags...)
v.DescriptionSet = true
}
if attr, exists := content.Attributes["type"]; exists {
ty, parseMode, tyDiags := decodeVariableType(attr.Expr)
diags = append(diags, tyDiags...)
v.Type = ty
v.ParsingMode = parseMode
}
if attr, exists := content.Attributes["sensitive"]; exists {
valDiags := gohcl.DecodeExpression(attr.Expr, nil, &v.Sensitive)
diags = append(diags, valDiags...)
v.SensitiveSet = true
}
if attr, exists := content.Attributes["default"]; exists {
val, valDiags := attr.Expr.Value(nil)
diags = append(diags, valDiags...)
// Convert the default to the expected type so we can catch invalid
// defaults early and allow later code to assume validity.
// Note that this depends on us having already processed any "type"
// attribute above.
// However, we can't do this if we're in an override file where
// the type might not be set; we'll catch that during merge.
if v.Type != cty.NilType {
var err error
val, err = convert.Convert(val, v.Type)
if err != nil {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid default value for variable",
Detail: fmt.Sprintf("This default value is not compatible with the variable's type constraint: %s.", err),
Subject: attr.Expr.Range().Ptr(),
})
val = cty.DynamicVal
}
}
v.Default = val
}
for _, block := range content.Blocks {
switch block.Type {
case "validation":
vv, moreDiags := decodeVariableValidationBlock(v.Name, block, override)
diags = append(diags, moreDiags...)
v.Validations = append(v.Validations, vv)
default:
// The above cases should be exhaustive for all block types
// defined in variableBlockSchema
panic(fmt.Sprintf("unhandled block type %q", block.Type))
}
}
return v, diags
}
func decodeVariableType(expr hcl.Expression) (cty.Type, VariableParsingMode, hcl.Diagnostics) {
if exprIsNativeQuotedString(expr) {
// If a user provides the pre-0.12 form of variable type argument where
// the string values "string", "list" and "map" are accepted, we
// provide an error to point the user towards using the type system
// correctly has a hint.
// Only the native syntax ends up in this codepath; we handle the
// JSON syntax (which is, of course, quoted within the type system)
// in the normal codepath below.
val, diags := expr.Value(nil)
if diags.HasErrors() {
return cty.DynamicPseudoType, VariableParseHCL, diags
}
str := val.AsString()
switch str {
case "string":
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid quoted type constraints",
Detail: "Terraform 0.11 and earlier required type constraints to be given in quotes, but that form is now deprecated and will be removed in a future version of Terraform. Remove the quotes around \"string\".",
Subject: expr.Range().Ptr(),
})
return cty.DynamicPseudoType, VariableParseLiteral, diags
case "list":
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid quoted type constraints",
Detail: "Terraform 0.11 and earlier required type constraints to be given in quotes, but that form is now deprecated and will be removed in a future version of Terraform. Remove the quotes around \"list\" and write list(string) instead to explicitly indicate that the list elements are strings.",
Subject: expr.Range().Ptr(),
})
return cty.DynamicPseudoType, VariableParseHCL, diags
case "map":
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid quoted type constraints",
Detail: "Terraform 0.11 and earlier required type constraints to be given in quotes, but that form is now deprecated and will be removed in a future version of Terraform. Remove the quotes around \"map\" and write map(string) instead to explicitly indicate that the map elements are strings.",
Subject: expr.Range().Ptr(),
})
return cty.DynamicPseudoType, VariableParseHCL, diags
default:
return cty.DynamicPseudoType, VariableParseHCL, hcl.Diagnostics{{
Severity: hcl.DiagError,
Summary: "Invalid legacy variable type hint",
Detail: `To provide a full type expression, remove the surrounding quotes and give the type expression directly.`,
Subject: expr.Range().Ptr(),
}}
}
}
// First we'll deal with some shorthand forms that the HCL-level type
// expression parser doesn't include. These both emulate pre-0.12 behavior
// of allowing a list or map of any element type as long as all of the
// elements are consistent. This is the same as list(any) or map(any).
switch hcl.ExprAsKeyword(expr) {
case "list":
return cty.List(cty.DynamicPseudoType), VariableParseHCL, nil
case "map":
return cty.Map(cty.DynamicPseudoType), VariableParseHCL, nil
}
ty, diags := typeexpr.TypeConstraint(expr)
if diags.HasErrors() {
return cty.DynamicPseudoType, VariableParseHCL, diags
}
switch {
case ty.IsPrimitiveType():
// Primitive types use literal parsing.
return ty, VariableParseLiteral, diags
default:
// Everything else uses HCL parsing
return ty, VariableParseHCL, diags
}
}
// Required returns true if this variable is required to be set by the caller,
// or false if there is a default value that will be used when it isn't set.
func (v *Variable) Required() bool {
return v.Default == cty.NilVal
}
// VariableParsingMode defines how values of a particular variable given by
// text-only mechanisms (command line arguments and environment variables)
// should be parsed to produce the final value.
type VariableParsingMode rune
// VariableParseLiteral is a variable parsing mode that just takes the given
// string directly as a cty.String value.
const VariableParseLiteral VariableParsingMode = 'L'
// VariableParseHCL is a variable parsing mode that attempts to parse the given
// string as an HCL expression and returns the result.
const VariableParseHCL VariableParsingMode = 'H'
// Parse uses the receiving parsing mode to process the given variable value
// string, returning the result along with any diagnostics.
//
// A VariableParsingMode does not know the expected type of the corresponding
// variable, so it's the caller's responsibility to attempt to convert the
// result to the appropriate type and return to the user any diagnostics that
// conversion may produce.
//
// The given name is used to create a synthetic filename in case any diagnostics
// must be generated about the given string value. This should be the name
// of the root module variable whose value will be populated from the given
// string.
//
// If the returned diagnostics has errors, the returned value may not be
// valid.
func (m VariableParsingMode) Parse(name, value string) (cty.Value, hcl.Diagnostics) {
switch m {
case VariableParseLiteral:
return cty.StringVal(value), nil
case VariableParseHCL:
fakeFilename := fmt.Sprintf("<value for var.%s>", name)
expr, diags := hclsyntax.ParseExpression([]byte(value), fakeFilename, hcl.Pos{Line: 1, Column: 1})
if diags.HasErrors() {
return cty.DynamicVal, diags
}
val, valDiags := expr.Value(nil)
diags = append(diags, valDiags...)
return val, diags
default:
// Should never happen
panic(fmt.Errorf("Parse called on invalid VariableParsingMode %#v", m))
}
}
// VariableValidation represents a configuration-defined validation rule
// for a particular input variable, given as a "validation" block inside
// a "variable" block.
type VariableValidation struct {
// Condition is an expression that refers to the variable being tested
// and contains no other references. The expression must return true
// to indicate that the value is valid or false to indicate that it is
// invalid. If the expression produces an error, that's considered a bug
// in the module defining the validation rule, not an error in the caller.
Condition hcl.Expression
// ErrorMessage is one or more full sentences, which would need to be in
// English for consistency with the rest of the error message output but
// can in practice be in any language as long as it ends with a period.
// The message should describe what is required for the condition to return
// true in a way that would make sense to a caller of the module.
ErrorMessage string
DeclRange hcl.Range
}
func decodeVariableValidationBlock(varName string, block *hcl.Block, override bool) (*VariableValidation, hcl.Diagnostics) {
var diags hcl.Diagnostics
vv := &VariableValidation{
DeclRange: block.DefRange,
}
if override {
// For now we'll just forbid overriding validation blocks, to simplify
// the initial design. If we can find a clear use-case for overriding
// validations in override files and there's a way to define it that
// isn't confusing then we could relax this.
diags = diags.Append(&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Can't override variable validation rules",
Detail: "Variable \"validation\" blocks cannot be used in override files.",
Subject: vv.DeclRange.Ptr(),
})
return vv, diags
}
content, moreDiags := block.Body.Content(variableValidationBlockSchema)
diags = append(diags, moreDiags...)
if attr, exists := content.Attributes["condition"]; exists {
vv.Condition = attr.Expr
// The validation condition can only refer to the variable itself,
// to ensure that the variable declaration can't create additional
// edges in the dependency graph.
goodRefs := 0
for _, traversal := range vv.Condition.Variables() {
ref, moreDiags := addrs.ParseRef(traversal)
if !moreDiags.HasErrors() {
if addr, ok := ref.Subject.(addrs.InputVariable); ok {
if addr.Name == varName {
goodRefs++
continue // Reference is valid
}
}
}
// If we fall out here then the reference is invalid.
diags = diags.Append(&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid reference in variable validation",
Detail: fmt.Sprintf("The condition for variable %q can only refer to the variable itself, using var.%s.", varName, varName),
Subject: traversal.SourceRange().Ptr(),
})
}
if goodRefs < 1 {
diags = diags.Append(&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid variable validation condition",
Detail: fmt.Sprintf("The condition for variable %q must refer to var.%s in order to test incoming values.", varName, varName),
Subject: attr.Expr.Range().Ptr(),
})
}
}
if attr, exists := content.Attributes["error_message"]; exists {
moreDiags := gohcl.DecodeExpression(attr.Expr, nil, &vv.ErrorMessage)
diags = append(diags, moreDiags...)
if !moreDiags.HasErrors() {
const errSummary = "Invalid validation error message"
switch {
case vv.ErrorMessage == "":
diags = diags.Append(&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: errSummary,
Detail: "An empty string is not a valid nor useful error message.",
Subject: attr.Expr.Range().Ptr(),
})
case !looksLikeSentences(vv.ErrorMessage):
// Because we're going to include this string verbatim as part
// of a bigger error message written in our usual style in
// English, we'll require the given error message to conform
// to that. We might relax this in future if e.g. we start
// presenting these error messages in a different way, or if
// Terraform starts supporting producing error messages in
// other human languages, etc.
// For pragmatism we also allow sentences ending with
// exclamation points, but we don't mention it explicitly here
// because that's not really consistent with the Terraform UI
// writing style.
diags = diags.Append(&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: errSummary,
Detail: "The validation error message must be at least one full sentence starting with an uppercase letter and ending with a period or question mark.\n\nYour given message will be included as part of a larger Terraform error message, written as English prose. For broadly-shared modules we suggest using a similar writing style so that the overall result will be consistent.",
Subject: attr.Expr.Range().Ptr(),
})
}
}
}
return vv, diags
}
// looksLikeSentence is a simple heuristic that encourages writing error
// messages that will be presentable when included as part of a larger
// Terraform error diagnostic whose other text is written in the Terraform
// UI writing style.
//
// This is intentionally not a very strong validation since we're assuming
// that module authors want to write good messages and might just need a nudge
// about Terraform's specific style, rather than that they are going to try
// to work around these rules to write a lower-quality message.
func looksLikeSentences(s string) bool {
if len(s) < 1 {
return false
}
runes := []rune(s) // HCL guarantees that all strings are valid UTF-8
first := runes[0]
last := runes[len(runes)-1]
// If the first rune is a letter then it must be an uppercase letter.
// (This will only see the first rune in a multi-rune combining sequence,
// but the first rune is generally the letter if any are, and if not then
// we'll just ignore it because we're primarily expecting English messages
// right now anyway, for consistency with all of Terraform's other output.)
if unicode.IsLetter(first) && !unicode.IsUpper(first) {
return false
}
// The string must be at least one full sentence, which implies having
// sentence-ending punctuation.
// (This assumes that if a sentence ends with quotes then the period
// will be outside the quotes, which is consistent with Terraform's UI
// writing style.)
return last == '.' || last == '?' || last == '!'
}
// Output represents an "output" block in a module or file.
type Output struct {
Name string
Description string
Expr hcl.Expression
DependsOn []hcl.Traversal
Sensitive bool
DescriptionSet bool
SensitiveSet bool
DeclRange hcl.Range
}
func decodeOutputBlock(block *hcl.Block, override bool) (*Output, hcl.Diagnostics) {
var diags hcl.Diagnostics
o := &Output{
Name: block.Labels[0],
DeclRange: block.DefRange,
}
schema := outputBlockSchema
if override {
schema = schemaForOverrides(schema)
}
content, moreDiags := block.Body.Content(schema)
diags = append(diags, moreDiags...)
if !hclsyntax.ValidIdentifier(o.Name) {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid output name",
Detail: badIdentifierDetail,
Subject: &block.LabelRanges[0],
})
}
if attr, exists := content.Attributes["description"]; exists {
valDiags := gohcl.DecodeExpression(attr.Expr, nil, &o.Description)
diags = append(diags, valDiags...)
o.DescriptionSet = true
}
if attr, exists := content.Attributes["value"]; exists {
o.Expr = attr.Expr
}
if attr, exists := content.Attributes["sensitive"]; exists {
valDiags := gohcl.DecodeExpression(attr.Expr, nil, &o.Sensitive)
diags = append(diags, valDiags...)
o.SensitiveSet = true
}
if attr, exists := content.Attributes["depends_on"]; exists {
deps, depsDiags := decodeDependsOn(attr)
diags = append(diags, depsDiags...)
o.DependsOn = append(o.DependsOn, deps...)
}
return o, diags
}
// Local represents a single entry from a "locals" block in a module or file.
// The "locals" block itself is not represented, because it serves only to
// provide context for us to interpret its contents.
type Local struct {
Name string
Expr hcl.Expression
DeclRange hcl.Range
}
func decodeLocalsBlock(block *hcl.Block) ([]*Local, hcl.Diagnostics) {
attrs, diags := block.Body.JustAttributes()
if len(attrs) == 0 {
return nil, diags
}
locals := make([]*Local, 0, len(attrs))
for name, attr := range attrs {
if !hclsyntax.ValidIdentifier(name) {
diags = append(diags, &hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid local value name",
Detail: badIdentifierDetail,
Subject: &attr.NameRange,
})
}
locals = append(locals, &Local{
Name: name,
Expr: attr.Expr,
DeclRange: attr.Range,
})
}
return locals, diags
}
// Addr returns the address of the local value declared by the receiver,
// relative to its containing module.
func (l *Local) Addr() addrs.LocalValue {
return addrs.LocalValue{
Name: l.Name,
}
}
var variableBlockSchema = &hcl.BodySchema{
Attributes: []hcl.AttributeSchema{
{
Name: "description",
},
{
Name: "default",
},
{
Name: "type",
},
{
Name: "sensitive",
},
},
Blocks: []hcl.BlockHeaderSchema{
{
Type: "validation",
},
},
}
var variableValidationBlockSchema = &hcl.BodySchema{
Attributes: []hcl.AttributeSchema{
{
Name: "condition",
Required: true,
},
{
Name: "error_message",
Required: true,
},
},
}
var outputBlockSchema = &hcl.BodySchema{
Attributes: []hcl.AttributeSchema{
{
Name: "description",
},
{
Name: "value",
Required: true,
},
{
Name: "depends_on",
},
{
Name: "sensitive",
},
},
}