Zabbix API refactoring

pkg/zabbixapi/models.go

@@ -0,0 +1,8 @@
+package zabbixapi
+
+type ZabbixAPIRequest struct {
+	Method string          `json:"method"`
+	Params ZabbixAPIParams `json:"params,omitempty"`
+}
+
+type ZabbixAPIParams = map[string]interface{}

pkg/zabbixapi/zabbix_api.go

@@ -0,0 +1,199 @@
+package zabbixapi
+
+import (
+	"bytes"
+	"context"
+	"crypto/tls"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"time"
+
+	"github.com/bitly/go-simplejson"
+	"github.com/grafana/grafana-plugin-sdk-go/backend/log"
+	"golang.org/x/net/context/ctxhttp"
+)
+
+var (
+	ErrNotAuthenticated = errors.New("zabbix api: not authenticated")
+)
+
+type ZabbixAPI struct {
+	url        *url.URL
+	httpClient *http.Client
+	logger     log.Logger
+	auth       string
+}
+
+func newHttpClient() *http.Client {
+	return &http.Client{
+		Transport: &http.Transport{
+			TLSClientConfig: &tls.Config{
+				Renegotiation: tls.RenegotiateFreelyAsClient,
+			},
+			Proxy: http.ProxyFromEnvironment,
+			Dial: (&net.Dialer{
+				Timeout:   30 * time.Second,
+				KeepAlive: 30 * time.Second,
+			}).Dial,
+			TLSHandshakeTimeout:   10 * time.Second,
+			ExpectContinueTimeout: 1 * time.Second,
+			MaxIdleConns:          100,
+			IdleConnTimeout:       90 * time.Second,
+		},
+		Timeout: time.Duration(time.Second * 30),
+	}
+}
+
+// New returns new ZabbixAPI instance initialized with given URL or error.
+func New(api_url string) (*ZabbixAPI, error) {
+	apiLogger := log.New()
+	zabbixURL, err := url.Parse(api_url)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ZabbixAPI{
+		url:        zabbixURL,
+		logger:     apiLogger,
+		httpClient: newHttpClient(),
+	}, nil
+}
+
+// GetUrl gets new API URL
+func (api *ZabbixAPI) GetUrl() *url.URL {
+	return api.url
+}
+
+// SetUrl sets new API URL
+func (api *ZabbixAPI) SetUrl(api_url string) error {
+	zabbixURL, err := url.Parse(api_url)
+	if err != nil {
+		return err
+	}
+
+	api.url = zabbixURL
+	return nil
+}
+
+// SetAuth sets API authentication token
+func (api *ZabbixAPI) SetAuth(auth string) {
+	api.auth = auth
+}
+
+// Request performs API request
+func (api *ZabbixAPI) Request(ctx context.Context, method string, params ZabbixAPIParams) (*simplejson.Json, error) {
+	if api.auth == "" {
+		return nil, ErrNotAuthenticated
+	}
+
+	return api.request(ctx, method, params, api.auth)
+}
+
+// Request performs API request without authentication token
+func (api *ZabbixAPI) RequestUnauthenticated(ctx context.Context, method string, params ZabbixAPIParams) (*simplejson.Json, error) {
+	return api.request(ctx, method, params, "")
+}
+
+func (api *ZabbixAPI) request(ctx context.Context, method string, params ZabbixAPIParams, auth string) (*simplejson.Json, error) {
+	apiRequest := map[string]interface{}{
+		"jsonrpc": "2.0",
+		"id":      2,
+		"method":  method,
+		"params":  params,
+	}
+
+	if auth != "" {
+		apiRequest["auth"] = auth
+	}
+
+	reqBodyJSON, err := json.Marshal(apiRequest)
+	if err != nil {
+		return nil, err
+	}
+
+	var body io.Reader
+	body = bytes.NewReader(reqBodyJSON)
+	rc, ok := body.(io.ReadCloser)
+	if !ok && body != nil {
+		rc = ioutil.NopCloser(body)
+	}
+
+	req := &http.Request{
+		Method: "POST",
+		URL:    api.url,
+		Header: map[string][]string{
+			"Content-Type": {"application/json"},
+		},
+		Body: rc,
+	}
+
+	response, err := makeHTTPRequest(ctx, api.httpClient, req)
+	if err != nil {
+		return nil, err
+	}
+
+	return handleAPIResult(response)
+}
+
+// Login performs API authentication and returns authentication token.
+func (api *ZabbixAPI) Login(ctx context.Context, username string, password string) (string, error) {
+	params := ZabbixAPIParams{
+		"user":     username,
+		"password": password,
+	}
+
+	auth, err := api.request(ctx, "user.login", params, "")
+	if err != nil {
+		return "", err
+	}
+
+	return auth.MustString(), nil
+}
+
+// Authenticate performs API authentication and sets authentication token.
+func (api *ZabbixAPI) Authenticate(ctx context.Context, username string, password string) error {
+	auth, err := api.Login(ctx, username, password)
+	if err != nil {
+		return err
+	}
+
+	api.SetAuth(auth)
+	return nil
+}
+
+func handleAPIResult(response []byte) (*simplejson.Json, error) {
+	jsonResp, err := simplejson.NewJson([]byte(response))
+	if err != nil {
+		return nil, err
+	}
+	if errJSON, isError := jsonResp.CheckGet("error"); isError {
+		errMessage := fmt.Sprintf("%s %s", errJSON.Get("message").MustString(), errJSON.Get("data").MustString())
+		return nil, errors.New(errMessage)
+	}
+	jsonResult := jsonResp.Get("result")
+	return jsonResult, nil
+}
+
+func makeHTTPRequest(ctx context.Context, httpClient *http.Client, req *http.Request) ([]byte, error) {
+	res, err := ctxhttp.Do(ctx, httpClient, req)
+	if err != nil {
+		return nil, err
+	}
+	defer res.Body.Close()
+
+	if res.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("invalid status code. status: %v", res.Status)
+	}
+
+	body, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		return nil, err
+	}
+	return body, nil
+}