Execute the command after passing tests (#22)

README.md

@@ -41,10 +41,11 @@ interval time.
 - **CI/CD Friendly:** Well-suited to be part of a CI/CD pipeline step
 - **Cross Platform:** One single pre-built binary for Linux, Mac OSX, and Windows
 - **Importable:** Beside the CLI tool, Wait4X can be imported as a pkg in your Go app
+- **Command execution:** Execute your desired command after a successful wait
 
 ## Installation
 
-There are many different ways to install **Wait4X**
+There are many ways to install **Wait4X**
 
 ### with Docker
 
@@ -235,3 +236,38 @@ wait4x rabbitmq 'amqp://127.0.0.1:5672'
 # Checking RabbitMQ connection with credentials and vhost
 wait4x rabbitmq 'amqp://guest:guest@127.0.0.1:5672/vhost'
 ```
+
+### Command Execution
+
+We need to wait for something in order to execute something else. This feature is also supported by using `--` after a feature parameter.
+
+Let's have some scenarios:
+
+* As soon as the MySQL server becomes ready, run a Django migration:
+
+```shell
+wait4x mysql username:password@unix(/tmp/mysql.sock)/myDatabase -- django migrate
+```
+
+* As soon as the new version of the website becomes ready, send an email to the support team:
+
+```shell
+wait4x http https://www.kernel.org/ --expect-body-xpath "//*[@id="website-logo"]" -- mail -s "The new version of the website has just been released" support@company < /dev/null
+```
+
+* Chain type: when PostgreSQL becomes ready, then wait for RabbitMQ, when it becomes ready, then run the integration tests:
+
+```shell
+wait4x postgresql 'postgres://bob:secret@/mydb?host=/var/run/postgresql' -t 1m -- wait4x rabbitmq 'amqp://guest:guest@127.0.0.1:5672/vhost' -t 30s -- ./integration-tests.sh
+```
+
+* Using an environment variable in the command:
+
+```shell
+EMAIL="support@company" wait4x http https://www.kernel.org/ --expect-body-xpath "//*[@id="website-logo"]" -- mail -s "New version of the website has just released" $EMAIL < /dev/null
+
+# Or
+
+export EMAIL="support@company"
+wait4x http https://www.kernel.org/ --expect-body-xpath "//*[@id="website-logo"]" -- mail -s "New version of the website has just released" $EMAIL < /dev/null
+```

internal/app/wait4x/cmd/http.go

@@ -28,7 +28,7 @@ import (
 // NewHTTPCommand creates the http sub-command
 func NewHTTPCommand() *cobra.Command {
 	httpCommand := &cobra.Command{
-		Use:   "http ADDRESS",
+		Use:   "http ADDRESS [flags] [-- command [args...]]",
 		Short: "Check HTTP connection.",
 		Long:  "",
 		Args: func(cmd *cobra.Command, args []string) error {

internal/app/wait4x/cmd/influxdb.go

@@ -24,7 +24,7 @@ import (
 // NewInfluxDBCommand creates the influxdb sub-command
 func NewInfluxDBCommand() *cobra.Command {
 	influxdbCommand := &cobra.Command{
-		Use:   "influxdb SERVER_URL",
+		Use:   "influxdb SERVER_URL [flags] [-- command [args...]]",
 		Short: "Check InfluxDB connection",
 		Args: func(cmd *cobra.Command, args []string) error {
 			if len(args) < 1 {

internal/app/wait4x/cmd/mongodb.go

@@ -24,7 +24,7 @@ import (
 // NewMongoDBCommand creates the mongodb sub-command
 func NewMongoDBCommand() *cobra.Command {
 	mongodbCommand := &cobra.Command{
-		Use:   "mongodb DSN",
+		Use:   "mongodb DSN [flags] [-- command [args...]]",
 		Short: "Check MongoDB connection",
 		Args: func(cmd *cobra.Command, args []string) error {
 			if len(args) < 1 {

internal/app/wait4x/cmd/mysql.go

@@ -24,7 +24,7 @@ import (
 // NewMysqlCommand creates the mysql sub-command
 func NewMysqlCommand() *cobra.Command {
 	mysqlCommand := &cobra.Command{
-		Use:   "mysql DSN",
+		Use:   "mysql DSN [flags] [-- command [args...]]",
 		Short: "Check MySQL connection.",
 		Args: func(cmd *cobra.Command, args []string) error {
 			if len(args) < 1 {

internal/app/wait4x/cmd/postgresql.go

@@ -24,7 +24,7 @@ import (
 // NewPostgresqlCommand creates the postgresql sub-command
 func NewPostgresqlCommand() *cobra.Command {
 	postgresqlCommand := &cobra.Command{
-		Use:     "postgresql DSN",
+		Use:     "postgresql DSN [flags] [-- command [args...]]",
 		Aliases: []string{"postgres", "postgre"},
 		Short:   "Check PostgreSQL connection.",
 		Args: func(cmd *cobra.Command, args []string) error {

internal/app/wait4x/cmd/rabbitmq.go

@@ -24,7 +24,7 @@ import (
 // NewRabbitMQCommand creates the rabbitmq sub-command
 func NewRabbitMQCommand() *cobra.Command {
 	rabbitmqCommand := &cobra.Command{
-		Use:   "rabbitmq DSN",
+		Use:   "rabbitmq DSN [flags] [-- command [args...]]",
 		Short: "Check RabbitMQ connection.",
 		Args: func(cmd *cobra.Command, args []string) error {
 			if len(args) < 1 {

internal/app/wait4x/cmd/redis.go

@@ -26,7 +26,7 @@ import (
 // NewRedisCommand creates the redis sub-command
 func NewRedisCommand() *cobra.Command {
 	redisCommand := &cobra.Command{
-		Use:   "redis ADDRESS",
+		Use:   "redis ADDRESS [flags] [-- command [args...]]",
 		Short: "Check Redis connection or key existence.",
 		Args: func(cmd *cobra.Command, args []string) error {
 			if len(args) < 1 {

internal/app/wait4x/cmd/root.go

@@ -20,6 +20,7 @@ import (
 	"github.com/go-logr/logr"
 	"github.com/go-logr/zerologr"
 	"os"
+	"os/exec"
 	"os/signal"
 	"time"
 
@@ -67,6 +68,23 @@ func NewRootCommand() *cobra.Command {
 				Logger()
 			Logger = zerologr.New(&zl)
 
+			return nil
+		},
+		PersistentPostRunE: func(cmd *cobra.Command, args []string) error {
+			if cmd.ArgsLenAtDash() != -1 && (len(args)-cmd.ArgsLenAtDash()) > 0 {
+				command := args[cmd.ArgsLenAtDash():][0]
+				arguments := args[cmd.ArgsLenAtDash():][1:]
+				for i, arg := range arguments {
+					arguments[i] = os.ExpandEnv(arg)
+				}
+
+				c := exec.CommandContext(cmd.Context(), command, arguments...)
+				c.Stdout = os.Stdout
+				c.Stderr = os.Stderr
+
+				return c.Run()
+			}
+
 			return nil
 		},
 	}

internal/app/wait4x/cmd/tcp.go

@@ -26,7 +26,7 @@ import (
 // NewTCPCommand creates the tcp sub-command
 func NewTCPCommand() *cobra.Command {
 	tcpCommand := &cobra.Command{
-		Use:   "tcp ADDRESS",
+		Use:   "tcp ADDRESS [flags] [-- command [args...]]",
 		Short: "Check TCP connection.",
 		Args: func(cmd *cobra.Command, args []string) error {
 			if len(args) < 1 {