terraform/registry/client.go

236 lines
6.1 KiB
Go

package registry
import (
"encoding/json"
"fmt"
"io/ioutil"
"log"
"net/http"
"net/url"
"path"
"strings"
"time"
cleanhttp "github.com/hashicorp/go-cleanhttp"
"github.com/hashicorp/terraform/registry/regsrc"
"github.com/hashicorp/terraform/registry/response"
"github.com/hashicorp/terraform/svchost"
"github.com/hashicorp/terraform/svchost/auth"
"github.com/hashicorp/terraform/svchost/disco"
"github.com/hashicorp/terraform/version"
)
const (
xTerraformGet = "X-Terraform-Get"
xTerraformVersion = "X-Terraform-Version"
requestTimeout = 10 * time.Second
serviceID = "modules.v1"
)
var tfVersion = version.String()
// Client provides methods to query Terraform Registries.
type Client struct {
// this is the client to be used for all requests.
client *http.Client
// services is a required *disco.Disco, which may have services and
// credentials pre-loaded.
services *disco.Disco
// Creds optionally provides credentials for communicating with service
// providers.
creds auth.CredentialsSource
}
func NewClient(services *disco.Disco, creds auth.CredentialsSource, client *http.Client) *Client {
if services == nil {
services = disco.NewDisco()
}
services.SetCredentialsSource(creds)
if client == nil {
client = cleanhttp.DefaultPooledClient()
client.Timeout = requestTimeout
}
services.Transport = client.Transport.(*http.Transport)
return &Client{
client: client,
services: services,
creds: creds,
}
}
// Discover qeuries the host, and returns the url for the registry.
func (c *Client) Discover(host svchost.Hostname) *url.URL {
service := c.services.DiscoverServiceURL(host, serviceID)
if !strings.HasSuffix(service.Path, "/") {
service.Path += "/"
}
return service
}
// Versions queries the registry for a module, and returns the available versions.
func (c *Client) Versions(module *regsrc.Module) (*response.ModuleVersions, error) {
host, err := module.SvcHost()
if err != nil {
return nil, err
}
service := c.Discover(host)
if service == nil {
return nil, fmt.Errorf("host %s does not provide Terraform modules", host)
}
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 := http.NewRequest("GET", service.String(), nil)
if err != nil {
return nil, err
}
c.addRequestCreds(host, req)
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, fmt.Errorf("module %q not found", module.String())
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) {
if c.creds == nil {
return
}
creds, err := c.creds.ForHost(host)
if err != nil {
log.Printf("[WARN] Failed to get credentials for %s: %s (ignoring)", host, err)
return
}
if creds != nil {
creds.PrepareRequest(req)
}
}
// Location 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) Location(module *regsrc.Module, version string) (string, error) {
host, err := module.SvcHost()
if err != nil {
return "", err
}
service := c.Discover(host)
if service == nil {
return "", fmt.Errorf("host %s does not provide Terraform modules", host.ForDisplay())
}
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 := http.NewRequest("GET", download.String(), nil)
if err != nil {
return "", err
}
c.addRequestCreds(host, req)
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
}