Move admin APIs to new path and add redesigned heal APIs (#5351)

- Changes related to moving admin APIs
   - admin APIs now have an endpoint under /minio/admin
   - admin APIs are now versioned - a new API to server the version is
     added at "GET /minio/admin/version" and all API operations have the
     path prefix /minio/admin/v1/<operation>
   - new service stop API added
   - credentials change API is moved to /minio/admin/v1/config/credential
   - credentials change API and configuration get/set API now require TLS
     so that credentials are protected
   - all API requests now receive JSON
   - heal APIs are disabled as they will be changed substantially

- Heal API changes
   Heal API is now provided at a single endpoint with the ability for a
   client to start a heal sequence on all the data in the server, a
   single bucket, or under a prefix within a bucket.

   When a heal sequence is started, the server returns a unique token
   that needs to be used for subsequent 'status' requests to fetch heal
   results.

   On each status request from the client, the server returns heal result
   records that it has accumulated since the previous status request. The
   server accumulates upto 1000 records and pauses healing further
   objects until the client requests for status. If the client does not
   request any further records for a long time, the server aborts the
   heal sequence automatically.

   A heal result record is returned for each entity healed on the server,
   such as system metadata, object metadata, buckets and objects, and has
   information about the before and after states on each disk.

   A client may request to force restart a heal sequence - this causes
   the running heal sequence to be aborted at the next safe spot and
   starts a new heal sequence.

pkg/madmin/config-commands.go

@@ -20,14 +20,10 @@ package madmin
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"net/http"
-	"net/url"
-)
-
-const (
-	configQueryParam = "config"
 )
 
 // NodeSummary - represents the result of an operation part of
@@ -47,20 +43,14 @@ type SetConfigResult struct {
 
 // GetConfig - returns the config.json of a minio setup.
 func (adm *AdminClient) GetConfig() ([]byte, error) {
-	queryVal := make(url.Values)
-	queryVal.Set(configQueryParam, "")
-
-	hdrs := make(http.Header)
-	hdrs.Set(minioAdminOpHeader, "get")
-
-	reqData := requestData{
-		queryValues:   queryVal,
-		customHeaders: hdrs,
+	// No TLS?
+	if !adm.secure {
+		return nil, fmt.Errorf("credentials/configuration cannot be retrieved over an insecure connection")
 	}
 
-	// Execute GET on /?config to get config of a setup.
-	resp, err := adm.executeMethod("GET", reqData)
-
+	// Execute GET on /minio/admin/v1/config to get config of a setup.
+	resp, err := adm.executeMethod("GET",
+		requestData{relPath: "/v1/config"})
 	defer closeResponse(resp)
 	if err != nil {
 		return nil, err
@@ -75,50 +65,42 @@ func (adm *AdminClient) GetConfig() ([]byte, error) {
 }
 
 // SetConfig - set config supplied as config.json for the setup.
-func (adm *AdminClient) SetConfig(config io.Reader) (SetConfigResult, error) {
-	queryVal := url.Values{}
-	queryVal.Set(configQueryParam, "")
-
-	// Set x-minio-operation to set.
-	hdrs := make(http.Header)
-	hdrs.Set(minioAdminOpHeader, "set")
+func (adm *AdminClient) SetConfig(config io.Reader) (r SetConfigResult, err error) {
+	// No TLS?
+	if !adm.secure {
+		return r, fmt.Errorf("credentials/configuration cannot be updated over an insecure connection")
+	}
 
 	// Read config bytes to calculate MD5, SHA256 and content length.
 	configBytes, err := ioutil.ReadAll(config)
 	if err != nil {
-		return SetConfigResult{}, err
+		return r, err
 	}
 
 	reqData := requestData{
-		queryValues:        queryVal,
-		customHeaders:      hdrs,
+		relPath:            "/v1/config",
 		contentBody:        bytes.NewReader(configBytes),
 		contentMD5Bytes:    sumMD5(configBytes),
 		contentSHA256Bytes: sum256(configBytes),
 	}
 
-	// Execute PUT on /?config to set config.
+	// Execute PUT on /minio/admin/v1/config to set config.
 	resp, err := adm.executeMethod("PUT", reqData)
 
 	defer closeResponse(resp)
 	if err != nil {
-		return SetConfigResult{}, err
+		return r, err
 	}
 
 	if resp.StatusCode != http.StatusOK {
-		return SetConfigResult{}, httpRespToErrorResponse(resp)
+		return r, httpRespToErrorResponse(resp)
 	}
 
-	var result SetConfigResult
 	jsonBytes, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
-		return SetConfigResult{}, err
+		return r, err
 	}
 
-	err = json.Unmarshal(jsonBytes, &result)
-	if err != nil {
-		return SetConfigResult{}, err
-	}
-
-	return result, nil
+	err = json.Unmarshal(jsonBytes, &r)
+	return r, err
 }