package registry import ( "encoding/json" "fmt" "io/ioutil" "log" "net/http" "net/url" "os" "path" "strconv" "strings" "time" "github.com/hashicorp/go-retryablehttp" svchost "github.com/hashicorp/terraform-svchost" "github.com/hashicorp/terraform-svchost/disco" "github.com/hashicorp/terraform/httpclient" "github.com/hashicorp/terraform/internal/logging" "github.com/hashicorp/terraform/registry/regsrc" "github.com/hashicorp/terraform/registry/response" "github.com/hashicorp/terraform/version" ) const ( xTerraformGet = "X-Terraform-Get" xTerraformVersion = "X-Terraform-Version" modulesServiceID = "modules.v1" providersServiceID = "providers.v1" // 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 ( tfVersion = version.String() discoveryRetry int requestTimeout time.Duration ) func init() { configureDiscoveryRetry() configureRequestTimeout() } // Client provides methods to query Terraform Registries. type Client struct { // this is the client to be used for all requests. client *retryablehttp.Client // services is a required *disco.Disco, which may have services and // credentials pre-loaded. services *disco.Disco } // NewClient returns a new initialized registry client. func NewClient(services *disco.Disco, client *http.Client) *Client { if services == nil { services = disco.New() } if client == nil { client = httpclient.New() client.Timeout = requestTimeout } retryableClient := retryablehttp.NewClient() retryableClient.HTTPClient = client retryableClient.RetryMax = discoveryRetry retryableClient.RequestLogHook = requestLogHook retryableClient.ErrorHandler = maxRetryErrorHandler logOutput := logging.LogOutput() retryableClient.Logger = log.New(logOutput, "", log.Flags()) services.Transport = retryableClient.HTTPClient.Transport services.SetUserAgent(httpclient.TerraformUserAgent(version.String())) return &Client{ client: retryableClient, services: services, } } // Discover queries the host, and returns the url for the registry. func (c *Client) Discover(host svchost.Hostname, serviceID string) (*url.URL, error) { service, err := c.services.DiscoverServiceURL(host, serviceID) if err != nil { return nil, &ServiceUnreachableError{err} } if !strings.HasSuffix(service.Path, "/") { service.Path += "/" } return service, nil } // ModuleVersions queries the registry for a module, and returns the available versions. func (c *Client) ModuleVersions(module *regsrc.Module) (*response.ModuleVersions, error) { host, err := module.SvcHost() if err != nil { return nil, err } service, err := c.Discover(host, modulesServiceID) if err != nil { return nil, err } p, err := url.Parse(path.Join(module.Module(), "versions")) if err != nil { return nil, err } service = service.ResolveReference(p) log.Printf("[DEBUG] fetching module versions from %q", service) req, err := retryablehttp.NewRequest("GET", service.String(), nil) if err != nil { return nil, err } c.addRequestCreds(host, req.Request) req.Header.Set(xTerraformVersion, tfVersion) resp, err := c.client.Do(req) if err != nil { return nil, err } defer resp.Body.Close() switch resp.StatusCode { case http.StatusOK: // OK case http.StatusNotFound: return nil, &errModuleNotFound{addr: module} default: return nil, fmt.Errorf("error looking up module versions: %s", resp.Status) } var versions response.ModuleVersions dec := json.NewDecoder(resp.Body) if err := dec.Decode(&versions); err != nil { return nil, err } for _, mod := range versions.Modules { for _, v := range mod.Versions { log.Printf("[DEBUG] found available version %q for %s", v.Version, mod.Source) } } return &versions, nil } func (c *Client) addRequestCreds(host svchost.Hostname, req *http.Request) { creds, err := c.services.CredentialsForHost(host) if err != nil { log.Printf("[WARN] Failed to get credentials for %s: %s (ignoring)", host, err) return } if creds != nil { creds.PrepareRequest(req) } } // ModuleLocation find the download location for a specific version module. // This returns a string, because the final location may contain special go-getter syntax. func (c *Client) ModuleLocation(module *regsrc.Module, version string) (string, error) { host, err := module.SvcHost() if err != nil { return "", err } service, err := c.Discover(host, modulesServiceID) if err != nil { return "", err } var p *url.URL if version == "" { p, err = url.Parse(path.Join(module.Module(), "download")) } else { p, err = url.Parse(path.Join(module.Module(), version, "download")) } if err != nil { return "", err } download := service.ResolveReference(p) log.Printf("[DEBUG] looking up module location from %q", download) req, err := retryablehttp.NewRequest("GET", download.String(), nil) if err != nil { return "", err } c.addRequestCreds(host, req.Request) req.Header.Set(xTerraformVersion, tfVersion) resp, err := c.client.Do(req) if err != nil { return "", err } defer resp.Body.Close() // there should be no body, but save it for logging body, err := ioutil.ReadAll(resp.Body) if err != nil { return "", fmt.Errorf("error reading response body from registry: %s", err) } switch resp.StatusCode { case http.StatusOK, http.StatusNoContent: // OK case http.StatusNotFound: return "", fmt.Errorf("module %q version %q not found", module, version) default: // anything else is an error: return "", fmt.Errorf("error getting download location for %q: %s resp:%s", module, resp.Status, body) } // the download location is in the X-Terraform-Get header location := resp.Header.Get(xTerraformGet) if location == "" { return "", fmt.Errorf("failed to get download URL for %q: %s resp:%s", module, resp.Status, body) } // If location looks like it's trying to be a relative URL, treat it as // one. // // We don't do this for just _any_ location, since the X-Terraform-Get // header is a go-getter location rather than a URL, and so not all // possible values will parse reasonably as URLs.) // // When used in conjunction with go-getter we normally require this header // to be an absolute URL, but we are more liberal here because third-party // registry implementations may not "know" their own absolute URLs if // e.g. they are running behind a reverse proxy frontend, or such. if strings.HasPrefix(location, "/") || strings.HasPrefix(location, "./") || strings.HasPrefix(location, "../") { locationURL, err := url.Parse(location) if err != nil { return "", fmt.Errorf("invalid relative URL for %q: %s", module, err) } locationURL = download.ResolveReference(locationURL) location = locationURL.String() } return location, 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 } } }