terraform/backend/remote-state/http/client.go

248 lines
5.6 KiB
Go

package http
import (
"bytes"
"crypto/md5"
"encoding/base64"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"net/http"
"net/url"
"github.com/hashicorp/go-retryablehttp"
"github.com/hashicorp/terraform/state"
"github.com/hashicorp/terraform/state/remote"
)
// httpClient is a remote client that stores data in Consul or HTTP REST.
type httpClient struct {
// Update & Retrieve
URL *url.URL
UpdateMethod string
// Locking
LockURL *url.URL
LockMethod string
UnlockURL *url.URL
UnlockMethod string
// HTTP
Client *retryablehttp.Client
Username string
Password string
lockID string
jsonLockInfo []byte
}
func (c *httpClient) httpRequest(method string, url *url.URL, data *[]byte, what string) (*http.Response, error) {
// If we have data we need a reader
var reader io.Reader = nil
if data != nil {
reader = bytes.NewReader(*data)
}
// Create the request
req, err := retryablehttp.NewRequest(method, url.String(), reader)
if err != nil {
return nil, fmt.Errorf("Failed to make %s HTTP request: %s", what, err)
}
// Setup basic auth
if c.Username != "" {
req.SetBasicAuth(c.Username, c.Password)
}
// Work with data/body
if data != nil {
req.Header.Set("Content-Type", "application/json")
req.ContentLength = int64(len(*data))
// Generate the MD5
hash := md5.Sum(*data)
b64 := base64.StdEncoding.EncodeToString(hash[:])
req.Header.Set("Content-MD5", b64)
}
// Make the request
resp, err := c.Client.Do(req)
if err != nil {
return nil, fmt.Errorf("Failed to %s: %v", what, err)
}
return resp, nil
}
func (c *httpClient) Lock(info *state.LockInfo) (string, error) {
if c.LockURL == nil {
return "", nil
}
c.lockID = ""
jsonLockInfo := info.Marshal()
resp, err := c.httpRequest(c.LockMethod, c.LockURL, &jsonLockInfo, "lock")
if err != nil {
return "", err
}
defer resp.Body.Close()
switch resp.StatusCode {
case http.StatusOK:
c.lockID = info.ID
c.jsonLockInfo = jsonLockInfo
return info.ID, nil
case http.StatusUnauthorized:
return "", fmt.Errorf("HTTP remote state endpoint requires auth")
case http.StatusForbidden:
return "", fmt.Errorf("HTTP remote state endpoint invalid auth")
case http.StatusConflict, http.StatusLocked:
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
return "", fmt.Errorf("HTTP remote state already locked, failed to read body")
}
existing := state.LockInfo{}
err = json.Unmarshal(body, &existing)
if err != nil {
return "", fmt.Errorf("HTTP remote state already locked, failed to unmarshal body")
}
return "", fmt.Errorf("HTTP remote state already locked: ID=%s", existing.ID)
default:
return "", fmt.Errorf("Unexpected HTTP response code %d", resp.StatusCode)
}
}
func (c *httpClient) Unlock(id string) error {
if c.UnlockURL == nil {
return nil
}
resp, err := c.httpRequest(c.UnlockMethod, c.UnlockURL, &c.jsonLockInfo, "unlock")
if err != nil {
return err
}
defer resp.Body.Close()
switch resp.StatusCode {
case http.StatusOK:
return nil
default:
return fmt.Errorf("Unexpected HTTP response code %d", resp.StatusCode)
}
}
func (c *httpClient) Get() (*remote.Payload, error) {
resp, err := c.httpRequest("GET", c.URL, nil, "get state")
if err != nil {
return nil, err
}
defer resp.Body.Close()
// Handle the common status codes
switch resp.StatusCode {
case http.StatusOK:
// Handled after
case http.StatusNoContent:
return nil, nil
case http.StatusNotFound:
return nil, nil
case http.StatusUnauthorized:
return nil, fmt.Errorf("HTTP remote state endpoint requires auth")
case http.StatusForbidden:
return nil, fmt.Errorf("HTTP remote state endpoint invalid auth")
case http.StatusInternalServerError:
return nil, fmt.Errorf("HTTP remote state internal server error")
default:
return nil, fmt.Errorf("Unexpected HTTP response code %d", resp.StatusCode)
}
// Read in the body
buf := bytes.NewBuffer(nil)
if _, err := io.Copy(buf, resp.Body); err != nil {
return nil, fmt.Errorf("Failed to read remote state: %s", err)
}
// Create the payload
payload := &remote.Payload{
Data: buf.Bytes(),
}
// If there was no data, then return nil
if len(payload.Data) == 0 {
return nil, nil
}
// Check for the MD5
if raw := resp.Header.Get("Content-MD5"); raw != "" {
md5, err := base64.StdEncoding.DecodeString(raw)
if err != nil {
return nil, fmt.Errorf(
"Failed to decode Content-MD5 '%s': %s", raw, err)
}
payload.MD5 = md5
} else {
// Generate the MD5
hash := md5.Sum(payload.Data)
payload.MD5 = hash[:]
}
return payload, nil
}
func (c *httpClient) Put(data []byte) error {
// Copy the target URL
base := *c.URL
if c.lockID != "" {
query := base.Query()
query.Set("ID", c.lockID)
base.RawQuery = query.Encode()
}
/*
// Set the force query parameter if needed
if force {
values := base.Query()
values.Set("force", "true")
base.RawQuery = values.Encode()
}
*/
var method string = "POST"
if c.UpdateMethod != "" {
method = c.UpdateMethod
}
resp, err := c.httpRequest(method, &base, &data, "upload state")
if err != nil {
return err
}
defer resp.Body.Close()
// Handle the error codes
switch resp.StatusCode {
case http.StatusOK, http.StatusCreated, http.StatusNoContent:
return nil
default:
return fmt.Errorf("HTTP error: %d", resp.StatusCode)
}
}
func (c *httpClient) Delete() error {
// Make the request
resp, err := c.httpRequest("DELETE", c.URL, nil, "delete state")
if err != nil {
return err
}
defer resp.Body.Close()
// Handle the error codes
switch resp.StatusCode {
case http.StatusOK:
return nil
default:
return fmt.Errorf("HTTP error: %d", resp.StatusCode)
}
}