terraform/internal/getproviders/didyoumean.go

254 lines
9.2 KiB
Go

package getproviders
import (
"context"
"encoding/json"
"errors"
"fmt"
"net/http"
"net/url"
"path"
"github.com/hashicorp/go-retryablehttp"
svchost "github.com/hashicorp/terraform-svchost"
"github.com/hashicorp/terraform/addrs"
)
// MissingProviderSuggestion takes a provider address that failed installation
// due to the remote registry reporting that it didn't exist, and attempts
// to find another provider that the user might have meant to select.
//
// If the result is equal to the given address then that indicates that there
// is no suggested alternative to offer, either because the function
// successfully determined there is no recorded alternative or because the
// lookup failed somehow. We don't consider a failure to find a suggestion
// as an installation failure, because the caller should already be reporting
// that the provider didn't exist anyway and this is only extra context for
// that error message.
//
// The result of this is a best effort, so any UI presenting it should be
// careful to give it only as a possibility and not necessarily a suitable
// replacement for the given provider.
//
// In practice today this function only knows how to suggest alternatives for
// "default" providers, which is to say ones that are in the hashicorp
// namespace in the Terraform registry. It will always return no result for
// any other provider. That might change in future if we introduce other ways
// to discover provider suggestions.
//
// If the given context is cancelled then this function might not return a
// renaming suggestion even if one would've been available for a completed
// request.
func MissingProviderSuggestion(ctx context.Context, addr addrs.Provider, source Source) addrs.Provider {
if !addr.IsDefault() {
return addr
}
// Our strategy here, for a default provider, is to use the default
// registry's special API for looking up "legacy" providers and try looking
// for a legacy provider whose type name matches the type of the given
// provider. This should then find a suitable answer for any provider
// that was originally auto-installable in v0.12 and earlier but moved
// into a non-default namespace as part of introducing the hierarchical
// provider namespace.
//
// To achieve that, we need to find the direct registry client in
// particular from the given source, because that is the only Source
// implementation that can actually handle a legacy provider lookup.
regSource := findLegacyProviderLookupSource(addr.Hostname, source)
if regSource == nil {
// If there's no direct registry source in the installation config
// then we can't provide a renaming suggestion.
return addr
}
defaultNS, redirectNS, err := regSource.lookupLegacyProviderNamespace(ctx, addr.Hostname, addr.Type)
if err != nil {
return addr
}
switch {
case redirectNS != "":
return addrs.Provider{
Hostname: addr.Hostname,
Namespace: redirectNS,
Type: addr.Type,
}
default:
return addrs.Provider{
Hostname: addr.Hostname,
Namespace: defaultNS,
Type: addr.Type,
}
}
}
// findLegacyProviderLookupSource tries to find a *RegistrySource that can talk
// to the given registry host in the given Source. It might be given directly,
// or it might be given indirectly via a MultiSource where the selector
// includes a wildcard for registry.terraform.io.
//
// Returns nil if the given source does not have any configured way to talk
// directly to the given host.
//
// If the given source contains multiple sources that can talk to the given
// host directly, the first one in the sequence takes preference. In practice
// it's pointless to have two direct installation sources that match the same
// hostname anyway, so this shouldn't arise in normal use.
func findLegacyProviderLookupSource(host svchost.Hostname, source Source) *RegistrySource {
switch source := source.(type) {
case *RegistrySource:
// Easy case: the source is a registry source directly, and so we'll
// just use it.
return source
case *MemoizeSource:
// Also easy: the source is a memoize wrapper, so defer to its
// underlying source.
return findLegacyProviderLookupSource(host, source.underlying)
case MultiSource:
// Trickier case: if it's a multisource then we need to scan over
// its selectors until we find one that is a *RegistrySource _and_
// that is configured to accept arbitrary providers from the
// given hostname.
// For our matching purposes we'll use an address that would not be
// valid as a real provider FQN and thus can only match a selector
// that has no filters at all or a selector that wildcards everything
// except the hostname, like "registry.terraform.io/*/*"
matchAddr := addrs.Provider{
Hostname: host,
// Other fields are intentionally left empty, to make this invalid
// as a specific provider address.
}
for _, selector := range source {
// If this source has suitable matching patterns to install from
// the given hostname then we'll recursively search inside it
// for *RegistrySource objects.
if selector.CanHandleProvider(matchAddr) {
ret := findLegacyProviderLookupSource(host, selector.Source)
if ret != nil {
return ret
}
}
}
// If we get here then there were no selectors that are both configured
// to handle modules from the given hostname and that are registry
// sources, so we fail.
return nil
default:
// This source cannot be and cannot contain a *RegistrySource, so
// we fail.
return nil
}
}
// lookupLegacyProviderNamespace is a special method available only on
// RegistrySource which can deal with legacy provider addresses that contain
// only a type and leave the namespace implied.
//
// It asks the registry at the given hostname to provide a default namespace
// for the given provider type, which can be combined with the given hostname
// and type name to produce a fully-qualified provider address.
//
// Not all unqualified type names can be resolved to a default namespace. If
// the request fails, this method returns an error describing the failure.
//
// This method exists only to allow compatibility with unqualified names
// in older configurations. New configurations should be written so as not to
// depend on it, and this fallback mechanism will likely be removed altogether
// in a future Terraform version.
func (s *RegistrySource) lookupLegacyProviderNamespace(ctx context.Context, hostname svchost.Hostname, typeName string) (string, string, error) {
client, err := s.registryClient(hostname)
if err != nil {
return "", "", err
}
return client.legacyProviderDefaultNamespace(ctx, typeName)
}
// legacyProviderDefaultNamespace returns the raw address strings produced by
// the registry when asked about the given unqualified provider type name.
// The returned namespace string is taken verbatim from the registry's response.
//
// This method exists only to allow compatibility with unqualified names
// in older configurations. New configurations should be written so as not to
// depend on it.
func (c *registryClient) legacyProviderDefaultNamespace(ctx context.Context, typeName string) (string, string, error) {
endpointPath, err := url.Parse(path.Join("-", typeName, "versions"))
if err != nil {
// Should never happen because we're constructing this from
// already-validated components.
return "", "", err
}
endpointURL := c.baseURL.ResolveReference(endpointPath)
req, err := retryablehttp.NewRequest("GET", endpointURL.String(), nil)
if err != nil {
return "", "", err
}
req = req.WithContext(ctx)
c.addHeadersToRequest(req.Request)
// This is just to give us something to return in error messages. It's
// not a proper provider address.
placeholderProviderAddr := addrs.NewLegacyProvider(typeName)
resp, err := c.httpClient.Do(req)
if err != nil {
return "", "", c.errQueryFailed(placeholderProviderAddr, err)
}
defer resp.Body.Close()
switch resp.StatusCode {
case http.StatusOK:
// Great!
case http.StatusNotFound:
return "", "", ErrProviderNotFound{
Provider: placeholderProviderAddr,
}
case http.StatusUnauthorized, http.StatusForbidden:
return "", "", c.errUnauthorized(placeholderProviderAddr.Hostname)
default:
return "", "", c.errQueryFailed(placeholderProviderAddr, errors.New(resp.Status))
}
type ResponseBody struct {
Id string `json:"id"`
MovedTo string `json:"moved_to"`
}
var body ResponseBody
dec := json.NewDecoder(resp.Body)
if err := dec.Decode(&body); err != nil {
return "", "", c.errQueryFailed(placeholderProviderAddr, err)
}
provider, diags := addrs.ParseProviderSourceString(body.Id)
if diags.HasErrors() {
return "", "", fmt.Errorf("Error parsing provider ID from Registry: %s", diags.Err())
}
if provider.Type != typeName {
return "", "", fmt.Errorf("Registry returned provider with type %q, expected %q", provider.Type, typeName)
}
var movedTo addrs.Provider
if body.MovedTo != "" {
movedTo, diags = addrs.ParseProviderSourceString(body.MovedTo)
if diags.HasErrors() {
return "", "", fmt.Errorf("Error parsing provider ID from Registry: %s", diags.Err())
}
if movedTo.Type != typeName {
return "", "", fmt.Errorf("Registry returned provider with type %q, expected %q", movedTo.Type, typeName)
}
}
return provider.Namespace, movedTo.Namespace, nil
}