terraform/addrs/provider.go

327 lines
12 KiB
Go

package addrs
import (
"fmt"
"strings"
"golang.org/x/net/idna"
"github.com/hashicorp/hcl/v2"
svchost "github.com/hashicorp/terraform-svchost"
"github.com/hashicorp/terraform/tfdiags"
)
// Provider encapsulates a single provider type. In the future this will be
// extended to include additional fields including Namespace and SourceHost
type Provider struct {
Type string
Namespace string
Hostname svchost.Hostname
}
// DefaultRegistryHost is the hostname used for provider addresses that do
// not have an explicit hostname.
const DefaultRegistryHost = svchost.Hostname("registry.terraform.io")
// LegacyProviderNamespace is the special string used in the Namespace field
// of type Provider to mark a legacy provider address. This special namespace
// value would normally be invalid, and can be used only when the hostname is
// DefaultRegistryHost because that host owns the mapping from legacy name to
// FQN.
const LegacyProviderNamespace = "-"
// String returns an FQN string, indended for use in output.
func (pt Provider) String() string {
if pt.IsZero() {
panic("called String on zero-value addrs.Provider")
}
return pt.Hostname.ForDisplay() + "/" + pt.Namespace + "/" + pt.Type
}
// NewProvider constructs a provider address from its parts, and normalizes
// the namespace and type parts to lowercase using unicode case folding rules
// so that resulting addrs.Provider values can be compared using standard
// Go equality rules (==).
//
// The hostname is given as a svchost.Hostname, which is required by the
// contract of that type to have already been normalized for equality testing.
//
// This function will panic if the given namespace or type name are not valid.
// When accepting namespace or type values from outside the program, use
// ParseProviderPart first to check that the given value is valid.
func NewProvider(hostname svchost.Hostname, namespace, typeName string) Provider {
if namespace == LegacyProviderNamespace {
// Legacy provider addresses must always be created via
// NewLegacyProvider so that we can use static analysis to find
// codepaths still working with those.
panic("attempt to create legacy provider address using NewProvider; use NewLegacyProvider instead")
}
return Provider{
Type: MustParseProviderPart(typeName),
Namespace: MustParseProviderPart(namespace),
Hostname: hostname,
}
}
// NewDefaultProvider returns the default address of a HashiCorp-maintained,
// Registry-hosted provider.
func NewDefaultProvider(name string) Provider {
return Provider{
Type: MustParseProviderPart(name),
Namespace: "hashicorp",
Hostname: DefaultRegistryHost,
}
}
// NewLegacyProvider returns a mock address for a provider.
// This will be removed when ProviderType is fully integrated.
func NewLegacyProvider(name string) Provider {
return Provider{
// We intentionally don't normalize and validate the legacy names,
// because existing code expects legacy provider names to pass through
// verbatim, even if not compliant with our new naming rules.
Type: name,
Namespace: LegacyProviderNamespace,
Hostname: DefaultRegistryHost,
}
}
// LegacyString returns the provider type, which is frequently used
// interchangeably with provider name. This function can and should be removed
// when provider type is fully integrated. As a safeguard for future
// refactoring, this function panics if the Provider is not a legacy provider.
func (pt Provider) LegacyString() string {
if pt.IsZero() {
panic("called LegacyString on zero-value addrs.Provider")
}
if pt.Namespace != LegacyProviderNamespace {
panic(pt.String() + " is not a legacy addrs.Provider")
}
return pt.Type
}
// IsZero returns true if the receiver is the zero value of addrs.Provider.
//
// The zero value is not a valid addrs.Provider and calling other methods on
// such a value is likely to either panic or otherwise misbehave.
func (pt Provider) IsZero() bool {
return pt == Provider{}
}
// LessThan returns true if the receiver should sort before the other given
// address in an ordered list of provider addresses.
//
// This ordering is an arbitrary one just to allow deterministic results from
// functions that would otherwise have no natural ordering. It's subject
// to change in future.
func (pt Provider) LessThan(other Provider) bool {
switch {
case pt.Hostname != other.Hostname:
return pt.Hostname < other.Hostname
case pt.Namespace != other.Namespace:
return pt.Namespace < other.Namespace
default:
return pt.Type < other.Type
}
}
// IsLegacy returns true if the provider is a legacy-style provider
func (pt Provider) IsLegacy() bool {
if pt.IsZero() {
panic("called IsLegacy() on zero-value addrs.Provider")
}
return pt.Hostname == DefaultRegistryHost && pt.Namespace == LegacyProviderNamespace
}
// IsDefault returns true if the provider is a default hashicorp provider
func (pt Provider) IsDefault() bool {
if pt.IsZero() {
panic("called IsDefault() on zero-value addrs.Provider")
}
return pt.Hostname == DefaultRegistryHost && pt.Namespace == "hashicorp"
}
// Equals returns true if the receiver and other provider have the same attributes.
func (pt Provider) Equals(other Provider) bool {
return pt == other
}
// ParseProviderSourceString parses the source attribute and returns a provider.
// This is intended primarily to parse the FQN-like strings returned by
// terraform-config-inspect.
//
// The following are valid source string formats:
// name
// namespace/name
// hostname/namespace/name
func ParseProviderSourceString(str string) (Provider, tfdiags.Diagnostics) {
var ret Provider
var diags tfdiags.Diagnostics
// split the source string into individual components
parts := strings.Split(str, "/")
if len(parts) == 0 || len(parts) > 3 {
diags = diags.Append(&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid provider source string",
Detail: `The "source" attribute must be in the format "[hostname/][namespace/]name"`,
})
return ret, diags
}
// check for an invalid empty string in any part
for i := range parts {
if parts[i] == "" {
diags = diags.Append(&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid provider source string",
Detail: `The "source" attribute must be in the format "[hostname/][namespace/]name"`,
})
return ret, diags
}
}
// check the 'name' portion, which is always the last part
givenName := parts[len(parts)-1]
name, err := ParseProviderPart(givenName)
if err != nil {
diags = diags.Append(&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid provider type",
Detail: fmt.Sprintf(`Invalid provider type %q in source %q: %s"`, name, str, err),
})
return ret, diags
}
ret.Type = name
ret.Hostname = DefaultRegistryHost
if len(parts) == 1 {
// FIXME: update this to NewDefaultProvider in the provider source release
return NewLegacyProvider(parts[0]), diags
}
if len(parts) >= 2 {
// the namespace is always the second-to-last part
givenNamespace := parts[len(parts)-2]
if givenNamespace == LegacyProviderNamespace {
// For now we're tolerating legacy provider addresses until we've
// finished updating the rest of the codebase to no longer use them,
// or else we'd get errors round-tripping through legacy subsystems.
ret.Namespace = LegacyProviderNamespace
} else {
namespace, err := ParseProviderPart(givenNamespace)
if err != nil {
diags = diags.Append(&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid provider namespace",
Detail: fmt.Sprintf(`Invalid provider namespace %q in source %q: %s"`, namespace, str, err),
})
return Provider{}, diags
}
ret.Namespace = namespace
}
}
// Final Case: 3 parts
if len(parts) == 3 {
// the namespace is always the first part in a three-part source string
hn, err := svchost.ForComparison(parts[0])
if err != nil {
diags = diags.Append(&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid provider source hostname",
Detail: fmt.Sprintf(`Invalid provider source hostname namespace %q in source %q: %s"`, hn, str, err),
})
return Provider{}, diags
}
ret.Hostname = hn
}
if ret.Namespace == LegacyProviderNamespace && ret.Hostname != DefaultRegistryHost {
// Legacy provider addresses must always be on the default registry
// host, because the default registry host decides what actual FQN
// each one maps to.
diags = diags.Append(&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Invalid provider namespace",
Detail: "The legacy provider namespace \"-\" can be used only with hostname " + DefaultRegistryHost.ForDisplay() + ".",
})
return Provider{}, diags
}
return ret, diags
}
// ParseProviderPart processes an addrs.Provider namespace or type string
// provided by an end-user, producing a normalized version if possible or
// an error if the string contains invalid characters.
//
// A provider part is processed in the same way as an individual label in a DNS
// domain name: it is transformed to lowercase per the usual DNS case mapping
// and normalization rules and may contain only letters, digits, and dashes.
// Additionally, dashes may not appear at the start or end of the string.
//
// These restrictions are intended to allow these names to appear in fussy
// contexts such as directory/file names on case-insensitive filesystems,
// repository names on GitHub, etc. We're using the DNS rules in particular,
// rather than some similar rules defined locally, because the hostname part
// of an addrs.Provider is already a hostname and it's ideal to use exactly
// the same case folding and normalization rules for all of the parts.
//
// In practice a provider type string conventionally does not contain dashes
// either. Such names are permitted, but providers with such type names will be
// hard to use because their resource type names will not be able to contain
// the provider type name and thus each resource will need an explicit provider
// address specified. (A real-world example of such a provider is the
// "google-beta" variant of the GCP provider, which has resource types that
// start with the "google_" prefix instead.)
//
// It's valid to pass the result of this function as the argument to a
// subsequent call, in which case the result will be identical.
func ParseProviderPart(given string) (string, error) {
if len(given) == 0 {
return "", fmt.Errorf("must have at least one character")
}
// We're going to process the given name using the same "IDNA" library we
// use for the hostname portion, since it already implements the case
// folding rules we want.
//
// The idna library doesn't expose individual label parsing directly, but
// once we've verified it doesn't contain any dots we can just treat it
// like a top-level domain for this library's purposes.
if strings.ContainsRune(given, '.') {
return "", fmt.Errorf("dots are not allowed")
}
// We don't allow names containing multiple consecutive dashes, just as
// a matter of preference: they look weird, confusing, or incorrect.
// This also, as a side-effect, prevents the use of the "punycode"
// indicator prefix "xn--" that would cause the IDNA library to interpret
// the given name as punycode, because that would be weird and unexpected.
if strings.Contains(given, "--") {
return "", fmt.Errorf("cannot use multiple consecutive dashes")
}
result, err := idna.Lookup.ToUnicode(given)
if err != nil {
return "", fmt.Errorf("must contain only letters, digits, and dashes, and may not use leading or trailing dashes")
}
return result, nil
}
// MustParseProviderPart is a wrapper around ParseProviderPart that panics if
// it returns an error.
func MustParseProviderPart(given string) string {
result, err := ParseProviderPart(given)
if err != nil {
panic(err.Error())
}
return result
}