add nginx plugin (#156)

* add nginx plugin

* update nginx.toml for nginx plugin

* Update nginx.go

Co-authored-by: ulricqin <ulricqin@qq.com>

agent/agent.go

@@ -31,6 +31,7 @@ import (
 	_ "flashcat.cloud/categraf/inputs/net_response"
 	_ "flashcat.cloud/categraf/inputs/netstat"
 	_ "flashcat.cloud/categraf/inputs/nfsclient"
+	_ "flashcat.cloud/categraf/inputs/nginx"
 	_ "flashcat.cloud/categraf/inputs/nginx_upstream_check"
 	_ "flashcat.cloud/categraf/inputs/ntp"
 	_ "flashcat.cloud/categraf/inputs/nvidia_smi"

conf/input.nginx/nginx.toml

@@ -0,0 +1,36 @@
+# # collect interval
+# interval = 15
+
+[[instances]]
+## An array of Nginx stub_status URI to gather stats.
+urls = [
+#    "http://192.168.0.216:8000/nginx_status",
+#    "https://www.baidu.com/ngx_status"
+]
+
+## append some labels for series
+# labels = { region="cloud", product="n9e" }
+
+## interval = global.interval * interval_times
+# interval_times = 1
+
+## Set response_timeout (default 5 seconds)
+response_timeout = "5s"
+
+## Whether to follow redirects from the server (defaults to false)
+# follow_redirects = false
+
+## Optional HTTP Basic Auth Credentials
+#username = "admin"
+#password = "admin"
+
+## Optional headers
+# headers = ["X-From", "categraf", "X-Xyz", "abc"]
+
+## Optional TLS Config
+# use_tls = false
+# tls_ca = "/etc/categraf/ca.pem"
+# tls_cert = "/etc/categraf/cert.pem"
+# tls_key = "/etc/categraf/key.pem"
+## Use TLS but skip chain & host verification
+# insecure_skip_verify = false

inputs/nginx/README.md

@@ -0,0 +1,25 @@
+# nginx
+
+nginx 监控采集插件，由telegraf改造而来。
+
+该插件依赖**nginx**的 **http_stub_status_module**
+
+在**nginx**中添加如下配置：
+```nginx
+server{
+    listen 8000;
+    server_name _;
+    
+    location /nginx_status {
+        stub_status on;
+        access_log off;
+    }
+}
+```
+## Configuration
+
+请参考配置[示例](../../conf/input.nginx/nginx.toml)
+
+## 监控大盘和告警规则
+
+待更新...

inputs/nginx/nginx.go

@@ -0,0 +1,264 @@
+package nginx
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"flashcat.cloud/categraf/config"
+	"flashcat.cloud/categraf/inputs"
+	"flashcat.cloud/categraf/pkg/tls"
+	"flashcat.cloud/categraf/types"
+)
+
+const inputName = "nginx"
+
+type Nginx struct {
+	config.PluginConfig
+	Instances []*Instance `toml:"instances"`
+}
+
+func init() {
+	inputs.Add(inputName, func() inputs.Input {
+		return &Nginx{}
+	})
+}
+
+func (ngx *Nginx) GetInstances() []inputs.Instance {
+	ret := make([]inputs.Instance, len(ngx.Instances))
+	for i := 0; i < len(ngx.Instances); i++ {
+		ret[i] = ngx.Instances[i]
+	}
+	return ret
+}
+
+type Instance struct {
+	config.InstanceConfig
+
+	Urls []string `toml:"urls"`
+
+	ResponseTimeout config.Duration `toml:"response_timeout"`
+	FollowRedirects bool            `toml:"follow_redirects"`
+	Username        string          `toml:"username"`
+	Password        string          `toml:"password"`
+	Headers         []string        `toml:"headers"`
+
+	tls.ClientConfig
+
+	client *http.Client
+}
+
+func (ins *Instance) Init() error {
+	if len(ins.Urls) == 0 {
+		return types.ErrInstancesEmpty
+	}
+
+	if ins.ResponseTimeout < config.Duration(time.Second) {
+		ins.ResponseTimeout = config.Duration(time.Second * 5)
+	}
+
+	client, err := ins.createHTTPClient()
+	if err != nil {
+		return fmt.Errorf("failed to create http client: %v", err)
+	}
+	ins.client = client
+
+	for _, u := range ins.Urls {
+		addr, err := url.Parse(u)
+		if err != nil {
+			return fmt.Errorf("failed to parse the url: %s, error: %v", u, err)
+		}
+
+		if addr.Scheme != "http" && addr.Scheme != "https" {
+			return fmt.Errorf("only http and https are supported, url: %s", u)
+		}
+	}
+
+	return nil
+}
+
+func (ins *Instance) Gather(slist *types.SampleList) {
+	var wg sync.WaitGroup
+
+	if len(ins.Urls) == 0 {
+		return
+	}
+
+	for _, u := range ins.Urls {
+		addr, err := url.Parse(u)
+		if err != nil {
+			log.Println("E! failed to parse the url:", u, "error:", err)
+			continue
+		}
+		wg.Add(1)
+		go func(addr *url.URL) {
+			defer wg.Done()
+			if err := ins.gather(addr, slist); err != nil {
+				log.Println("E!", err)
+			}
+		}(addr)
+	}
+
+	wg.Wait()
+}
+
+func (ins *Instance) createHTTPClient() (*http.Client, error) {
+	tlsCfg, err := ins.ClientConfig.TLSConfig()
+	if err != nil {
+		return nil, err
+	}
+
+	trans := &http.Transport{
+		DisableKeepAlives: true,
+	}
+	if ins.UseTLS {
+		trans.TLSClientConfig = tlsCfg
+	}
+
+	client := &http.Client{
+		Transport: trans,
+		Timeout:   time.Duration(ins.ResponseTimeout),
+	}
+
+	if !ins.FollowRedirects {
+		client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
+			return http.ErrUseLastResponse
+		}
+	}
+
+	return client, nil
+}
+
+func (ins *Instance) gather(addr *url.URL, slist *types.SampleList) error {
+	if config.Config.DebugMode {
+		log.Println("D! nginx... url:", addr)
+	}
+
+	var body io.Reader
+	request, err := http.NewRequest("GET", addr.String(), body)
+	if err != nil {
+		return fmt.Errorf("failed to create an HTTP request, url: %s, error: %s", addr.String(), err)
+	}
+
+	for i := 0; i < len(ins.Headers); i += 2 {
+		request.Header.Add(ins.Headers[i], ins.Headers[i+1])
+		if ins.Headers[i] == "Host" {
+			request.Host = ins.Headers[i+1]
+		}
+	}
+
+	if ins.Username != "" || ins.Password != "" {
+		request.SetBasicAuth(ins.Username, ins.Password)
+	}
+
+	resp, err := ins.client.Do(request)
+	if err != nil {
+		return fmt.Errorf("failed to request the url: %s, error: %s", addr.String(), err)
+	}
+
+	defer func(Body io.ReadCloser) {
+		err := Body.Close()
+		if err != nil {
+			log.Println("E! failed to close the body of client:", err)
+		}
+	}(resp.Body)
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("the HTTP response status exception, url: %s, status: %s", addr.String(), resp.Status)
+	}
+	r := bufio.NewReader(resp.Body)
+
+	// Active connections
+	_, err = r.ReadString(':')
+	if err != nil {
+		return fmt.Errorf("failed to parse the response, error: %s", err)
+	}
+	line, err := r.ReadString('\n')
+	if err != nil {
+		return fmt.Errorf("failed to parse the response, error: %s", err)
+	}
+	active, err := strconv.ParseUint(strings.TrimSpace(line), 10, 64)
+	if err != nil {
+		return fmt.Errorf("failed to parse the response, error: %s", err)
+	}
+
+	// Server accepts handled requests
+	_, err = r.ReadString('\n')
+	if err != nil {
+		return fmt.Errorf("failed to parse the response, error: %s", err)
+	}
+	line, err = r.ReadString('\n')
+	if err != nil {
+		return fmt.Errorf("failed to parse the response, error: %s", err)
+	}
+	data := strings.Fields(line)
+	accepts, err := strconv.ParseUint(data[0], 10, 64)
+	if err != nil {
+		return fmt.Errorf("failed to parse the response, error: %s", err)
+	}
+
+	handled, err := strconv.ParseUint(data[1], 10, 64)
+	if err != nil {
+		return fmt.Errorf("failed to parse the response, error: %s", err)
+	}
+	requests, err := strconv.ParseUint(data[2], 10, 64)
+	if err != nil {
+		return fmt.Errorf("failed to parse the response, error: %s", err)
+	}
+
+	// Reading/Writing/Waiting
+	line, err = r.ReadString('\n')
+	if err != nil {
+		return fmt.Errorf("failed to parse the response, error: %s", err)
+	}
+	data = strings.Fields(line)
+	reading, err := strconv.ParseUint(data[1], 10, 64)
+	if err != nil {
+		return fmt.Errorf("failed to parse the response, error: %s", err)
+	}
+	writing, err := strconv.ParseUint(data[3], 10, 64)
+	if err != nil {
+		return fmt.Errorf("failed to parse the response, error: %s", err)
+	}
+	waiting, err := strconv.ParseUint(data[5], 10, 64)
+	if err != nil {
+		return fmt.Errorf("failed to parse the response, error: %s", err)
+	}
+
+	host, port, err := net.SplitHostPort(addr.Host)
+	if err != nil {
+		host = addr.Host
+		if addr.Scheme == "http" {
+			port = "80"
+		} else if addr.Scheme == "https" {
+			port = "443"
+		} else {
+			port = ""
+		}
+	}
+	fields := map[string]interface{}{
+		"active":   active,
+		"accepts":  accepts,
+		"handled":  handled,
+		"requests": requests,
+		"reading":  reading,
+		"writing":  writing,
+		"waiting":  waiting,
+	}
+	tags := map[string]string{
+		"server": host,
+		"port":   port,
+	}
+
+	slist.PushSamples("nginx", fields, tags)
+
+	return nil
+}