Unified api and add session invalidation handling

* Move to backward compatible 3.x API
    * If you're using Quobyte 2.x refer to 2.x management API definitions, not supported fields by 2.x are ignored by API server.
* Add session cookies to improve API performance
   * Currently, each request is authenticated with username and password. The authentication is expensive and could block requests if there are many concurrent requests. With session cookies solves this problem.

Author: venkatsc

README.md

@@ -1,6 +1,59 @@
-# Quobyte API
+# Quobyte API Clients
 
-* User documentation
-  * [For 2.x API](./v2/README.md)
-  * [For 3.x API](./v3/README.md)
-* Developer documentation (./docs/)
+Get the Quobyte api client
+
+```bash
+go get github.com/quobyte/api
+```
+
+## Usage
+
+`Note:` Create below example in separate project outside of the api repository to avoid circular `go mod` dependencies.
+
+```go
+package main
+
+import (
+  "log"
+  quobyte_api "github.com/quobyte/api/quobyte"
+)
+
+func main() {
+    url := flag.String("url", "", "URL of Quobyte API")
+    username := flag.String("username", "", "username")
+    password := flag.String("password", "", "password")
+    flag.Parse()
+
+    if *url == "" || *username == "" || *password == "" {
+        flag.PrintDefaults()
+        os.Exit(1)
+    }
+
+    client := quobyte_api.NewQuobyteClient(*url, *username, *password)
+    client.SetAPIRetryPolicy(quobyte_api.RetryInfinitely) // Default quobyte_api.RetryInteractive
+    req := &quobyte_api.CreateVolumeRequest{
+        Name:              "MyVolume",
+        TenantId:          "32edb36d-badc-affe-b44a-4ab749af4d9a",
+        RootUserId:        "root",
+        RootGroupId:	   "root",
+        ConfigurationName: "BASE",
+        Label: []*quobyte_api.Label{
+            {Name: "label1", Value: "value1"},
+            {Name: "label2", Value: "value2"},
+        },
+    }
+
+    response, err := client.CreateVolume(req)
+    if err != nil {
+        log.Fatalf("Error: %v", err)
+    }
+
+    capactiy := int64(1024 * 1024 * 1024)
+    err = client.SetVolumeQuota(response.VolumeUuid, capactiy)
+    if err != nil {
+        log.Fatalf("Error: %v", err)
+    }
+
+    log.Printf("%s", response.VolumeUuid)
+}
+```

docs/README.md

@@ -0,0 +1,19 @@
+# Developer notes
+
+## Releasing new version
+
+* `go.mod` files must be present at the root level of the project
+* Each major release beyond V1 (such =v2[+].a.b) must provide unique import path such as `github.com/quobyte/api/vX`
+  * To get around this issue, we always use v1.x.x (**NEVER** make v2 release)
+  * Further, each `*.go` file must have a `package XYZ` statement as the first line and must be placed into `XZY`
+    directory. (It seems go mod ignores .go file that is not placed in declared package directory!!)
+* For local testing of edited module,
+  * Create a standalone project with the `testing or main.go` and `go mod init` inside the project root.
+      The `go mod init` fetches the depedencies required by code.
+  * Replace Quobyte API with updated API `go mod edit -replace github.com/quobyte/api=</path/to/local/quobyte/api>`
+* Publishing change must always have highest minor version of all the published tags (even if the tag is deleted,
+ the new version must have the higher version than deleted tag).
+
+Note: go mod updates dependency to the highest minor version available. Even if the version is deleted from the tags,
+go-git gets it from the deleted references (Uhhh!!). The only way out is to create a new higher minor
+version with the changes.

docs/Release-instructions.md

@@ -0,0 +1,3 @@
+module github.com/quobyte/api
+
+go 1.14

go.mod

@@ -0,0 +1 @@
+

go.sum

@@ -3,8 +3,9 @@ package quobyte
 import (
 	"log"
 	"net/http"
-	"regexp"
 	"net/http/cookiejar"
+	"net/url"
+	"regexp"
 )
 
 // retry policy codes
@@ -17,11 +18,15 @@ var UUIDValidator = regexp.MustCompile("^[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-4[a-fA-F0
 
 type QuobyteClient struct {
 	client         *http.Client
-	url            string
+	url            *url.URL
 	username       string
 	password       string
 	apiRetryPolicy string
-	hasCookies     bool
+	// hasCookies     bool
+}
+
+func (client *QuobyteClient) hasCookies() (bool, error) {
+	return client.client.Jar != nil && len(client.client.Jar.Cookies(client.url)) > 0, nil
 }
 
 func (client *QuobyteClient) SetAPIRetryPolicy(retry string) {
@@ -37,20 +42,22 @@ func (client *QuobyteClient) SetTransport(t http.RoundTripper) {
 }
 
 // NewQuobyteClient creates a new Quobyte API client
-func NewQuobyteClient(url string, username string, password string) *QuobyteClient {
+func NewQuobyteClient(urlStr string, username string, password string) *QuobyteClient {
+	url, err := url.Parse(urlStr)
+	if err != nil {
+		log.Fatalf("could not parse url due to %s", err.Error())
+	}
 	cookieJar, err := cookiejar.New(nil)
-	if err == nil {
-		return &QuobyteClient{
-			client:         &http.Client{Jar: cookieJar},
-			url:            url,
-			username:       username,
-			password:       password,
-			apiRetryPolicy: RetryInteractive,
-			hasCookies:     false,
-		}
-	} else {
+	if err != nil {
 		log.Fatalf("could not initialize cookie jar due to %s", err.Error())
 	}
+	return &QuobyteClient{
+		client:         &http.Client{Jar: cookieJar},
+		url:            url,
+		username:       username,
+		password:       password,
+		apiRetryPolicy: RetryInteractive,
+	}
 	return nil
 }
 

v3/quobyte.go quobyte/quobyte.gov3/quobyte.go renamed to quobyte/quobyte.go

@@ -103,39 +103,60 @@ func (client QuobyteClient) sendRequest(method string, request interface{}, resp
 	if err != nil {
 		return err
 	}
-	req, err := http.NewRequest("POST", client.url, bytes.NewBuffer(message))
+	req, err := http.NewRequest("POST", client.url.String(), bytes.NewBuffer(message))
 	if err != nil {
 		return err
 	}
 	req.Header.Set("Content-Type", "application/json")
 	// If no cookies, serialize requests such that first successful request sets the cookies
-	if !client.hasCookies {
+	for {
 		mux.Lock()
-		defer mux.Unlock()
-		req.SetBasicAuth(client.username, client.password)
-	}
-	resp, err := client.client.Do(req)
-	if err != nil {
-		return err
-	}
-	// log.Printf("response %v", resp)
-	defer resp.Body.Close()
-
-	if resp.StatusCode < 200 || resp.StatusCode > 299 {
-		if resp.StatusCode == 401 {
-			return errors.New("Unable to authenticate with Quobyte API service")
+		hasCookies, err := client.hasCookies()
+		if err != nil {
+			return err
+		}
+		if !hasCookies {
+			req.SetBasicAuth(client.username, client.password)
+			// no cookies available, must hold lock until request is completed and
+			// new cookies are created by server
+			defer mux.Unlock()
+		} else {
+			// let every thread/routine send request using the cookie
+			mux.Unlock()
 		}
-		body, err := ioutil.ReadAll(resp.Body)
+		resp, err := client.client.Do(req)
 		if err != nil {
-			return (err)
+			return err
 		}
-		return fmt.Errorf("JsonRPC failed with error (error code: %d) %s",
-			resp.StatusCode, string(body))
-	}
-	if len(resp.Cookies()) > 0 {
-		client.hasCookies = true
-	} else {
-		client.hasCookies = false
+		defer resp.Body.Close()
+
+		if resp.StatusCode < 200 || resp.StatusCode > 299 {
+			if resp.StatusCode == 401 {
+				_, ok := req.Header["Authorization"]
+				if ok {
+					return errors.New("Unable to authenticate with Quobyte API service")
+				}
+				// Session is not valid anymore (service restart, sesssion invalidated etc)!!
+				// resend basic auth and get new cookies
+				// invalidate session cookies
+				cookieJar := client.client.Jar
+				if cookieJar != nil {
+					cookies := cookieJar.Cookies(client.url)
+					for _, cookie := range cookies {
+						cookie.MaxAge = -1
+					}
+					cookieJar.SetCookies(client.url, cookies)
+				}
+				// retry request with authorization header
+				continue
+			}
+			body, err := ioutil.ReadAll(resp.Body)
+			if err != nil {
+				return (err)
+			}
+			return fmt.Errorf("JsonRPC failed with error (error code: %d) %s",
+				resp.StatusCode, string(body))
+		}
+		return decodeResponse(resp.Body, &response)
 	}
-	return decodeResponse(resp.Body, &response)
 }