terraform/internal/getproviders/registry_client.go

507 lines
15 KiB
Go

package getproviders
import (
"context"
"crypto/sha256"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"log"
"net/http"
"net/url"
"os"
"path"
"strconv"
"time"
"github.com/hashicorp/go-retryablehttp"
svchost "github.com/hashicorp/terraform-svchost"
svcauth "github.com/hashicorp/terraform-svchost/auth"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/internal/httpclient"
"github.com/hashicorp/terraform/internal/logging"
"github.com/hashicorp/terraform/version"
)
const (
terraformVersionHeader = "X-Terraform-Version"
// registryDiscoveryRetryEnvName is the name of the environment variable that
// can be configured to customize number of retries for module and provider
// discovery requests with the remote registry.
registryDiscoveryRetryEnvName = "TF_REGISTRY_DISCOVERY_RETRY"
defaultRetry = 1
// registryClientTimeoutEnvName is the name of the environment variable that
// can be configured to customize the timeout duration (seconds) for module
// and provider discovery with the remote registry.
registryClientTimeoutEnvName = "TF_REGISTRY_CLIENT_TIMEOUT"
// defaultRequestTimeout is the default timeout duration for requests to the
// remote registry.
defaultRequestTimeout = 10 * time.Second
)
var (
discoveryRetry int
requestTimeout time.Duration
)
func init() {
configureDiscoveryRetry()
configureRequestTimeout()
}
var SupportedPluginProtocols = MustParseVersionConstraints("~> 5")
// registryClient is a client for the provider registry protocol that is
// specialized only for the needs of this package. It's not intended as a
// general registry API client.
type registryClient struct {
baseURL *url.URL
creds svcauth.HostCredentials
httpClient *retryablehttp.Client
}
func newRegistryClient(baseURL *url.URL, creds svcauth.HostCredentials) *registryClient {
httpClient := httpclient.New()
httpClient.Timeout = requestTimeout
retryableClient := retryablehttp.NewClient()
retryableClient.HTTPClient = httpClient
retryableClient.RetryMax = discoveryRetry
retryableClient.RequestLogHook = requestLogHook
retryableClient.ErrorHandler = maxRetryErrorHandler
retryableClient.Logger = log.New(logging.LogOutput(), "", log.Flags())
return &registryClient{
baseURL: baseURL,
creds: creds,
httpClient: retryableClient,
}
}
// ProviderVersions returns the raw version and protocol strings produced by the
// registry for the given provider.
//
// The returned error will be ErrRegistryProviderNotKnown if the registry responds with
// 404 Not Found to indicate that the namespace or provider type are not known,
// ErrUnauthorized if the registry responds with 401 or 403 status codes, or
// ErrQueryFailed for any other protocol or operational problem.
func (c *registryClient) ProviderVersions(ctx context.Context, addr addrs.Provider) (map[string][]string, []string, error) {
endpointPath, err := url.Parse(path.Join(addr.Namespace, addr.Type, "versions"))
if err != nil {
// Should never happen because we're constructing this from
// already-validated components.
return nil, nil, err
}
endpointURL := c.baseURL.ResolveReference(endpointPath)
req, err := retryablehttp.NewRequest("GET", endpointURL.String(), nil)
if err != nil {
return nil, nil, err
}
req = req.WithContext(ctx)
c.addHeadersToRequest(req.Request)
resp, err := c.httpClient.Do(req)
if err != nil {
return nil, nil, c.errQueryFailed(addr, err)
}
defer resp.Body.Close()
switch resp.StatusCode {
case http.StatusOK:
// Great!
case http.StatusNotFound:
return nil, nil, ErrRegistryProviderNotKnown{
Provider: addr,
}
case http.StatusUnauthorized, http.StatusForbidden:
return nil, nil, c.errUnauthorized(addr.Hostname)
default:
return nil, nil, c.errQueryFailed(addr, errors.New(resp.Status))
}
// We ignore the platforms portion of the response body, because the
// installer verifies the platform compatibility after pulling a provider
// versions' metadata.
type ResponseBody struct {
Versions []struct {
Version string `json:"version"`
Protocols []string `json:"protocols"`
} `json:"versions"`
Warnings []string `json:"warnings"`
}
var body ResponseBody
dec := json.NewDecoder(resp.Body)
if err := dec.Decode(&body); err != nil {
return nil, nil, c.errQueryFailed(addr, err)
}
if len(body.Versions) == 0 {
return nil, body.Warnings, nil
}
ret := make(map[string][]string, len(body.Versions))
for _, v := range body.Versions {
ret[v.Version] = v.Protocols
}
return ret, body.Warnings, nil
}
// PackageMeta returns metadata about a distribution package for a provider.
//
// The returned error will be one of the following:
//
// - ErrPlatformNotSupported if the registry responds with 404 Not Found,
// under the assumption that the caller previously checked that the provider
// and version are valid.
// - ErrProtocolNotSupported if the requested provider version's protocols are not
// supported by this version of terraform.
// - ErrUnauthorized if the registry responds with 401 or 403 status codes
// - ErrQueryFailed for any other operational problem.
func (c *registryClient) PackageMeta(ctx context.Context, provider addrs.Provider, version Version, target Platform) (PackageMeta, error) {
endpointPath, err := url.Parse(path.Join(
provider.Namespace,
provider.Type,
version.String(),
"download",
target.OS,
target.Arch,
))
if err != nil {
// Should never happen because we're constructing this from
// already-validated components.
return PackageMeta{}, err
}
endpointURL := c.baseURL.ResolveReference(endpointPath)
req, err := retryablehttp.NewRequest("GET", endpointURL.String(), nil)
if err != nil {
return PackageMeta{}, err
}
req = req.WithContext(ctx)
c.addHeadersToRequest(req.Request)
resp, err := c.httpClient.Do(req)
if err != nil {
return PackageMeta{}, c.errQueryFailed(provider, err)
}
defer resp.Body.Close()
switch resp.StatusCode {
case http.StatusOK:
// Great!
case http.StatusNotFound:
return PackageMeta{}, ErrPlatformNotSupported{
Provider: provider,
Version: version,
Platform: target,
}
case http.StatusUnauthorized, http.StatusForbidden:
return PackageMeta{}, c.errUnauthorized(provider.Hostname)
default:
return PackageMeta{}, c.errQueryFailed(provider, errors.New(resp.Status))
}
type SigningKeyList struct {
GPGPublicKeys []*SigningKey `json:"gpg_public_keys"`
}
type ResponseBody struct {
Protocols []string `json:"protocols"`
OS string `json:"os"`
Arch string `json:"arch"`
Filename string `json:"filename"`
DownloadURL string `json:"download_url"`
SHA256Sum string `json:"shasum"`
SHA256SumsURL string `json:"shasums_url"`
SHA256SumsSignatureURL string `json:"shasums_signature_url"`
SigningKeys SigningKeyList `json:"signing_keys"`
}
var body ResponseBody
dec := json.NewDecoder(resp.Body)
if err := dec.Decode(&body); err != nil {
return PackageMeta{}, c.errQueryFailed(provider, err)
}
var protoVersions VersionList
for _, versionStr := range body.Protocols {
v, err := ParseVersion(versionStr)
if err != nil {
return PackageMeta{}, c.errQueryFailed(
provider,
fmt.Errorf("registry response includes invalid version string %q: %s", versionStr, err),
)
}
protoVersions = append(protoVersions, v)
}
protoVersions.Sort()
// Verify that this version of terraform supports the providers' protocol
// version(s)
if len(protoVersions) > 0 {
supportedProtos := MeetingConstraints(SupportedPluginProtocols)
protoErr := ErrProtocolNotSupported{
Provider: provider,
Version: version,
}
match := false
for _, version := range protoVersions {
if supportedProtos.Has(version) {
match = true
}
}
if !match {
// If the protocol version is not supported, try to find the closest
// matching version.
closest, err := c.findClosestProtocolCompatibleVersion(ctx, provider, version)
if err != nil {
return PackageMeta{}, err
}
protoErr.Suggestion = closest
return PackageMeta{}, protoErr
}
}
if body.OS != target.OS || body.Arch != target.Arch {
return PackageMeta{}, fmt.Errorf("registry response to request for %s archive has incorrect target %s", target, Platform{body.OS, body.Arch})
}
downloadURL, err := url.Parse(body.DownloadURL)
if err != nil {
return PackageMeta{}, fmt.Errorf("registry response includes invalid download URL: %s", err)
}
downloadURL = resp.Request.URL.ResolveReference(downloadURL)
if downloadURL.Scheme != "http" && downloadURL.Scheme != "https" {
return PackageMeta{}, fmt.Errorf("registry response includes invalid download URL: must use http or https scheme")
}
ret := PackageMeta{
Provider: provider,
Version: version,
ProtocolVersions: protoVersions,
TargetPlatform: Platform{
OS: body.OS,
Arch: body.Arch,
},
Filename: body.Filename,
Location: PackageHTTPURL(downloadURL.String()),
// "Authentication" is populated below
}
if len(body.SHA256Sum) != sha256.Size*2 { // *2 because it's hex-encoded
return PackageMeta{}, c.errQueryFailed(
provider,
fmt.Errorf("registry response includes invalid SHA256 hash %q: %s", body.SHA256Sum, err),
)
}
var checksum [sha256.Size]byte
_, err = hex.Decode(checksum[:], []byte(body.SHA256Sum))
if err != nil {
return PackageMeta{}, c.errQueryFailed(
provider,
fmt.Errorf("registry response includes invalid SHA256 hash %q: %s", body.SHA256Sum, err),
)
}
shasumsURL, err := url.Parse(body.SHA256SumsURL)
if err != nil {
return PackageMeta{}, fmt.Errorf("registry response includes invalid SHASUMS URL: %s", err)
}
shasumsURL = resp.Request.URL.ResolveReference(shasumsURL)
if shasumsURL.Scheme != "http" && shasumsURL.Scheme != "https" {
return PackageMeta{}, fmt.Errorf("registry response includes invalid SHASUMS URL: must use http or https scheme")
}
document, err := c.getFile(shasumsURL)
if err != nil {
return PackageMeta{}, c.errQueryFailed(
provider,
fmt.Errorf("failed to retrieve authentication checksums for provider: %s", err),
)
}
signatureURL, err := url.Parse(body.SHA256SumsSignatureURL)
if err != nil {
return PackageMeta{}, fmt.Errorf("registry response includes invalid SHASUMS signature URL: %s", err)
}
signatureURL = resp.Request.URL.ResolveReference(signatureURL)
if signatureURL.Scheme != "http" && signatureURL.Scheme != "https" {
return PackageMeta{}, fmt.Errorf("registry response includes invalid SHASUMS signature URL: must use http or https scheme")
}
signature, err := c.getFile(signatureURL)
if err != nil {
return PackageMeta{}, c.errQueryFailed(
provider,
fmt.Errorf("failed to retrieve cryptographic signature for provider: %s", err),
)
}
keys := make([]SigningKey, len(body.SigningKeys.GPGPublicKeys))
for i, key := range body.SigningKeys.GPGPublicKeys {
keys[i] = *key
}
ret.Authentication = PackageAuthenticationAll(
NewMatchingChecksumAuthentication(document, body.Filename, checksum),
NewArchiveChecksumAuthentication(ret.TargetPlatform, checksum),
NewSignatureAuthentication(document, signature, keys),
)
return ret, nil
}
// findClosestProtocolCompatibleVersion searches for the provider version with the closest protocol match.
func (c *registryClient) findClosestProtocolCompatibleVersion(ctx context.Context, provider addrs.Provider, version Version) (Version, error) {
var match Version
available, _, err := c.ProviderVersions(ctx, provider)
if err != nil {
return UnspecifiedVersion, err
}
// extract the maps keys so we can make a sorted list of available versions.
versionList := make(VersionList, 0, len(available))
for versionStr := range available {
v, err := ParseVersion(versionStr)
if err != nil {
return UnspecifiedVersion, ErrQueryFailed{
Provider: provider,
Wrapped: fmt.Errorf("registry response includes invalid version string %q: %s", versionStr, err),
}
}
versionList = append(versionList, v)
}
versionList.Sort() // lowest precedence first, preserving order when equal precedence
protoVersions := MeetingConstraints(SupportedPluginProtocols)
FindMatch:
// put the versions in increasing order of precedence
for index := len(versionList) - 1; index >= 0; index-- { // walk backwards to consider newer versions first
for _, protoStr := range available[versionList[index].String()] {
p, err := ParseVersion(protoStr)
if err != nil {
return UnspecifiedVersion, ErrQueryFailed{
Provider: provider,
Wrapped: fmt.Errorf("registry response includes invalid protocol string %q: %s", protoStr, err),
}
}
if protoVersions.Has(p) {
match = versionList[index]
break FindMatch
}
}
}
return match, nil
}
func (c *registryClient) addHeadersToRequest(req *http.Request) {
if c.creds != nil {
c.creds.PrepareRequest(req)
}
req.Header.Set(terraformVersionHeader, version.String())
}
func (c *registryClient) errQueryFailed(provider addrs.Provider, err error) error {
if err == context.Canceled {
// This one has a special error type so that callers can
// handle it in a different way.
return ErrRequestCanceled{}
}
return ErrQueryFailed{
Provider: provider,
Wrapped: err,
}
}
func (c *registryClient) errUnauthorized(hostname svchost.Hostname) error {
return ErrUnauthorized{
Hostname: hostname,
HaveCredentials: c.creds != nil,
}
}
func (c *registryClient) getFile(url *url.URL) ([]byte, error) {
resp, err := c.httpClient.Get(url.String())
if err != nil {
return nil, err
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return nil, fmt.Errorf("%s", resp.Status)
}
data, err := ioutil.ReadAll(resp.Body)
if err != nil {
return data, err
}
return data, nil
}
// configureDiscoveryRetry configures the number of retries the registry client
// will attempt for requests with retryable errors, like 502 status codes
func configureDiscoveryRetry() {
discoveryRetry = defaultRetry
if v := os.Getenv(registryDiscoveryRetryEnvName); v != "" {
retry, err := strconv.Atoi(v)
if err == nil && retry > 0 {
discoveryRetry = retry
}
}
}
func requestLogHook(logger retryablehttp.Logger, req *http.Request, i int) {
if i > 0 {
logger.Printf("[INFO] Previous request to the remote registry failed, attempting retry.")
}
}
func maxRetryErrorHandler(resp *http.Response, err error, numTries int) (*http.Response, error) {
// Close the body per library instructions
if resp != nil {
resp.Body.Close()
}
// Additional error detail: if we have a response, use the status code;
// if we have an error, use that; otherwise nothing. We will never have
// both response and error.
var errMsg string
if resp != nil {
errMsg = fmt.Sprintf(": %d", resp.StatusCode)
} else if err != nil {
errMsg = fmt.Sprintf(": %s", err)
}
// This function is always called with numTries=RetryMax+1. If we made any
// retry attempts, include that in the error message.
if numTries > 1 {
return resp, fmt.Errorf("the request failed after %d attempts, please try again later%s",
numTries, errMsg)
}
return resp, fmt.Errorf("the request failed, please try again later%s", errMsg)
}
// configureRequestTimeout configures the registry client request timeout from
// environment variables
func configureRequestTimeout() {
requestTimeout = defaultRequestTimeout
if v := os.Getenv(registryClientTimeoutEnvName); v != "" {
timeout, err := strconv.Atoi(v)
if err == nil && timeout > 0 {
requestTimeout = time.Duration(timeout) * time.Second
}
}
}