Merge pull request #7 from ph4r5h4d/http-support

Add Http support

README.md

@@ -1,15 +1,19 @@
 # wait4it
-A simple go application to test whether a port is ready to accept a connection, and also you can check whether your 
-MySQL or PostgresQL server is ready or not.
+
+![LICENSE](https://img.shields.io/github/workflow/status/ph4r5h4d/wait4it/Wait4it CI?style=for-the-badge) [![Docker Pull](https://img.shields.io/docker/pulls/ph4r5h4d/wait4it?style=for-the-badge)](https://hub.docker.com/r/ph4r5h4d/wait4it)  ![GO Version](https://img.shields.io/github/go-mod/go-version/ph4r5h4d/wait4it?style=for-the-badge) ![TAG](https://img.shields.io/github/v/tag/ph4r5h4d/wait4it?style=for-the-badge) ![LICENSE](https://img.shields.io/github/license/ph4r5h4d/wait4it?style=for-the-badge)
+
+A simple go application to test whether a port is ready to accept a connection or check 
+MySQL or PostgreSQL server is ready or not, Also you can do Http call and check the response code and text in response.  
 It also supports **timeout** so it can wait for a particular time and then fail.
 
 ## Supported Modules
 * TCP port
 * MySQL
 * PostgresQL
+* Http
 
 ## Install
-You can download the latest release, or you can build it yourself.
+You can download the latest [release](https://github.com/ph4r5h4d/wait4it/releases), or you can build it yourself.
 To build just run `go build -o wait4it`
 
 ## Command Line Args
@@ -21,6 +25,9 @@ The following command-line flags are supported
 * u (username for the services that needs username)
 * P (password for the services that needs password)
 * n (currently this param is used to identify database name for MySQL)  
+* ssl (whether to enable or disable ssl-mode for Postgres)  
+* http-status (for Http check, which status code to expect)  
+* http-text (for Http check, find substring inside the response)  
 
 ### Sample
 Check a TCP port  
@@ -37,6 +44,11 @@ Check a PostgresQL instance
 ./wait4it -type=postgres -h=127.0.0.1 -p=5432 -t=60 -u=postgres -P=secret -ssl=disable
 ```
 
+Check HTTP response and text
+```bash
+-type=http -h=https://farshad.nematdoust.com -t=60 -status-code=200 -http-text="Software Engineer" 
+```
+
 ### Docker
 You can run this `wait4it` inside a docker container, and it's possible to run this container as init container inside
 K8s and Openshift.  
@@ -61,8 +73,20 @@ Check a PostgresQL instance
 docker run ph4r5h4d/wait4it -type=postgres -h=127.0.0.1 -p=5432 -t=60 -u=postgres -P=secret -ssl=disable
 ```
 
+Check HTTP response and text
+```bash
+docker run ph4r5h4d/wait4it -type=http -h=https://farshad.nematdoust.com -t=60 -status-code=200 -http-text="Software Engineer" 
+```
+
 ## Notes
 #### Exit codes
 * 0: connection established successfully
 * 1: timed out
 * 2: mostly means a validation error or something wrong with the input data
+
+#### Http check
+* for the Http check if you do not define status code it will check for 200 status code
+* if `http-text` is not defined then wait4it will check the status code
+
+#### Postgres check
+* if `ssl` is not defined then it's `disable` by default

cmd/check-module-list.go

@@ -4,10 +4,12 @@ import (
 	"wait4it/MySQLChecker"
 	"wait4it/PostgreSQLChecker"
 	"wait4it/TcpChecker"
+	"wait4it/httpChecker"
 )
 
 var cm = map[string]interface{}{
 	"tcp":      &TcpChecker.Tcp{},
 	"mysql":    &MySQLChecker.MySQLConnection{},
 	"postgres": &PostgreSQLChecker.PostgresSQLConnection{},
+	"http":     &httpChecker.HttpCheck{},
 }

httpChecker/helpers.go

@@ -0,0 +1,25 @@
+package httpChecker
+
+import "net/url"
+
+func (h *HttpCheck) validateUrl() bool {
+	_, err := url.ParseRequestURI(h.Url)
+	if err != nil {
+		return false
+	}
+
+	u, err := url.Parse(h.Url)
+	if err != nil || u.Scheme == "" || u.Host == "" {
+		return false
+	}
+
+	return true
+}
+
+func (h *HttpCheck) validateStatusCode() bool {
+	// check against common status code
+	if h.Status < 100 || h.Status > 599 {
+		return false
+	}
+	return true
+}

httpChecker/httpChecker.go

@@ -0,0 +1,54 @@
+package httpChecker
+
+import (
+	"errors"
+	"io/ioutil"
+	"net/http"
+	"strings"
+	"wait4it/model"
+)
+
+func (h *HttpCheck) BuildContext(cx model.CheckContext) {
+	h.Url = cx.Host
+	h.Status = cx.HttpConf.StatusCode
+	if len(cx.HttpConf.Text) > 0 {
+		h.Text = cx.HttpConf.Text
+	}
+}
+
+func (h *HttpCheck) Validate() (bool, error) {
+	if !h.validateUrl() {
+		return false, errors.New("invalid URL provided")
+	}
+
+	if !h.validateStatusCode() {
+		return false, errors.New("invalid status code provided")
+	}
+
+	return true, nil
+}
+
+func (h *HttpCheck) Check() (bool, bool, error) {
+	resp, err := http.Get(h.Url)
+
+	if err != nil {
+		return false, true, err
+	}
+
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return false, true, err
+	}
+
+	if resp.StatusCode != h.Status {
+		return false, false, errors.New("invalid status code")
+	}
+
+	if len(h.Text) > 0 {
+		if !strings.Contains(string(body), h.Text) {
+			return false, false, errors.New("can't find substring in response")
+		}
+	}
+
+	return true, false, nil
+}

httpChecker/structs.go

@@ -0,0 +1,7 @@
+package httpChecker
+
+type HttpCheck struct {
+	Url    string
+	Status int
+	Text   string
+}

inputParser/input-parser.go

@@ -14,6 +14,8 @@ func GetInput() model.CheckContext {
 	password := flag.String("P", "", "Password of the service")
 	databaseName := flag.String("n", "", "Name of the database")
 	sslMode := flag.String("ssl", "disable", "Enable or Disable ssl mode (for some database or services)")
+	httpCode := flag.Int("status-code", 200, "Status code to be expected from http call")
+	httpText := flag.String("http-text", "", "Text to check inside http response")
 	flag.Parse()
 
 	c := model.CheckContext{
@@ -29,6 +31,10 @@ func GetInput() model.CheckContext {
 		DBConf: model.DatabaseSpecificConf{
 			SSLMode: *sslMode,
 		},
+		HttpConf: model.HttpSpecificConf{
+			StatusCode: *httpCode,
+			Text:       *httpText,
+		},
 	}
 	return c
 }

model/check-context-struct.go

@@ -8,6 +8,7 @@ type CheckContext struct {
 	Password     string
 	DatabaseName string
 	DBConf       DatabaseSpecificConf
+	HttpConf     HttpSpecificConf
 }
 
 type ConfigurationContext struct {
@@ -18,3 +19,7 @@ type ConfigurationContext struct {
 type DatabaseSpecificConf struct {
 	SSLMode string
 }
+type HttpSpecificConf struct {
+	StatusCode int
+	Text       string
+}