terraform/remote/http.go

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package remote
import (
"bytes"
"crypto/md5"
"encoding/base64"
"fmt"
"io"
"net/http"
"net/url"
)
// HTTPRemoteClient implements the RemoteClient interface
// for an HTTP compatible server.
type HTTPRemoteClient struct {
// url is the URL that we GET / POST / DELETE to
url *url.URL
}
func NewHTTPRemoteClient(conf map[string]string) (*HTTPRemoteClient, error) {
client := &HTTPRemoteClient{}
if err := client.validateConfig(conf); err != nil {
return nil, err
}
return client, nil
}
func (c *HTTPRemoteClient) validateConfig(conf map[string]string) error {
urlRaw, ok := conf["url"]
if !ok || urlRaw == "" {
return fmt.Errorf("missing 'url' configuration")
}
url, err := url.Parse(urlRaw)
if err != nil {
return fmt.Errorf("failed to parse url: %v", err)
}
c.url = url
return nil
}
func (c *HTTPRemoteClient) GetState() (*RemoteStatePayload, error) {
// Request the url
resp, err := http.Get(c.url.String())
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
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case http.StatusUnauthorized:
return nil, ErrRequireAuth
case http.StatusForbidden:
return nil, ErrInvalidAuth
case http.StatusInternalServerError:
return nil, ErrRemoteInternal
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: %v", err)
}
// Create the payload
payload := &RemoteStatePayload{
State: buf.Bytes(),
}
// 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': %v", raw, err)
}
payload.MD5 = md5
} else {
// Generate the MD5
hash := md5.Sum(payload.State)
payload.MD5 = hash[:md5.Size]
}
return payload, nil
}
func (c *HTTPRemoteClient) PutState(state []byte, force bool) error {
// Copy the target URL
base := new(url.URL)
*base = *c.url
// Generate the MD5
hash := md5.Sum(state)
b64 := base64.StdEncoding.EncodeToString(hash[:md5.Size])
// Set the force query parameter if needed
if force {
values := base.Query()
values.Set("force", "true")
base.RawQuery = values.Encode()
}
// Make the HTTP client and request
req, err := http.NewRequest("POST", base.String(), bytes.NewReader(state))
if err != nil {
return fmt.Errorf("Failed to make HTTP request: %v", err)
}
// Prepare the request
req.Header.Set("Content-Type", "application/octet-stream")
req.Header.Set("Content-MD5", b64)
req.ContentLength = int64(len(state))
// Make the request
resp, err := http.DefaultClient.Do(req)
if err != nil {
return fmt.Errorf("Failed to upload state: %v", err)
}
defer resp.Body.Close()
// Handle the error codes
switch resp.StatusCode {
case http.StatusOK:
return nil
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case http.StatusConflict:
return ErrConflict
case http.StatusPreconditionFailed:
return ErrServerNewer
case http.StatusUnauthorized:
return ErrRequireAuth
case http.StatusForbidden:
return ErrInvalidAuth
case http.StatusInternalServerError:
return ErrRemoteInternal
default:
return fmt.Errorf("Unexpected HTTP response code %d", resp.StatusCode)
}
}
func (c *HTTPRemoteClient) DeleteState() error {
// Make the HTTP request
req, err := http.NewRequest("DELETE", c.url.String(), nil)
if err != nil {
return fmt.Errorf("Failed to make HTTP request: %v", err)
}
// Make the request
resp, err := http.DefaultClient.Do(req)
if err != nil {
return fmt.Errorf("Failed to delete state: %v", err)
}
defer resp.Body.Close()
// Handle the error codes
switch resp.StatusCode {
case http.StatusOK:
return nil
case http.StatusNoContent:
return nil
case http.StatusNotFound:
return nil
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case http.StatusUnauthorized:
return ErrRequireAuth
case http.StatusForbidden:
return ErrInvalidAuth
case http.StatusInternalServerError:
return ErrRemoteInternal
default:
return fmt.Errorf("Unexpected HTTP response code %d", resp.StatusCode)
}
}