Adds a first cut at initial CLI setup

cmd/root.go

@@ -0,0 +1,167 @@
+/*
+Copyright © 2020 Matt Gowie <matt@masterpoint.io>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/credentials"
+	"github.com/aws/aws-sdk-go/aws/session"
+
+	"github.com/sirupsen/logrus"
+
+	homedir "github.com/mitchellh/go-homedir"
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+)
+
+var cfgFile string
+var awsSession *session.Session
+
+var log = logrus.New()
+
+var rootCmd = &cobra.Command{
+	Use:   "escrun",
+	Short: "Easily run one-off tasks against a ECS Cluster",
+	Long: `
+ecsrun is a CLI tool that allows users to run one-off administrative tasks
+using their existing ECS Cluster and Task Definitions.
+TODO: Supply more info here.`,
+
+	Run: func(cmd *cobra.Command, args []string) {},
+}
+
+// Execute adds all child commands to the root command and sets flags appropriately.
+// This is called by main.main(). It only needs to happen once to the rootCmd.
+func Execute() {
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}
+
+func init() {
+	cobra.OnInitialize(initConfig)
+
+	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.escrun.yaml)")
+	rootCmd.PersistentFlags().StringP("cred", "c", "", "aws credentials file (default is $HOME/.aws/.credentials)")
+	rootCmd.PersistentFlags().StringP("profile", "p", "", "aws profile to target (default is AWS_PROFILE or 'default')")
+	rootCmd.PersistentFlags().StringP("region", "r", "", `aws region to target (default is AWS_REGION or pulled from $HOME/.aws/.credentials)`)
+
+	viper.BindPFlag("profile", rootCmd.PersistentFlags().Lookup("profile"))
+	viper.BindPFlag("region", rootCmd.PersistentFlags().Lookup("region"))
+
+	cred, profile, region := initAws()
+
+	viper.Set("profile", profile)
+	viper.Set("region", region)
+	viper.Set("accesskey", cred.AccessKeyID)
+	viper.Set("secretkey", cred.SecretAccessKey)
+}
+
+// initConfig reads in config file and ENV variables if set.
+func initConfig() {
+	if cfgFile != "" {
+		// Use config file from the flag.
+		viper.SetConfigFile(cfgFile)
+	} else {
+		// Find home directory.
+		home, err := homedir.Dir()
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+
+		// Search config in home directory with name ".escrun" (without extension).
+		viper.AddConfigPath(home)
+		viper.SetConfigName(".escrun")
+	}
+
+	viper.AutomaticEnv() // read in environment variables that match
+
+	// If a config file is found, read it in.
+	if err := viper.ReadInConfig(); err == nil {
+		fmt.Println("Using config file:", viper.ConfigFileUsed())
+	}
+}
+
+func initAws() (credentials.Value, string, string) {
+	profile := getProfile()
+
+	// Create our AWS session object for AWS API Usage
+	sesh, err := initAwsSession(profile)
+	if err != nil {
+		log.Fatal("Unable to init AWS Session. Check your credentials and profile.")
+		log.Fatal(err)
+		os.Exit(1)
+	}
+
+	cred, err := sesh.Config.Credentials.Get()
+	if err != nil {
+		log.Fatal("Unable to get credentials from Session. Check your credentials and profile.")
+		log.Fatal(err)
+		os.Exit(1)
+	}
+
+	region := viper.GetString("region")
+	if region == "" {
+		region = *awsSession.Config.Region
+	}
+	// Override our Session's region in case it was set.
+	sesh.Config.WithRegion(region)
+
+	return cred, profile, region
+}
+
+func getProfile() string {
+	profile := viper.GetString("profile")
+	if profile == "" {
+		profile = "default"
+		if os.Getenv("AWS_PROFILE") != "" {
+			profile = os.Getenv("AWS_PROFILE")
+		}
+	}
+	return profile
+}
+
+func initAwsSession(profile string) (*session.Session, error) {
+	credFile, err := rootCmd.Flags().GetString("cred")
+	if err != nil {
+		log.Fatal(err)
+		os.Exit(1)
+	}
+
+	if credFile != "" {
+		sesh, err := session.NewSession(&aws.Config{
+			Credentials: credentials.NewSharedCredentials(credFile, profile),
+		})
+		return sesh, err
+	} else {
+		sesh, err := session.NewSessionWithOptions(session.Options{
+			Profile:           profile,
+			SharedConfigState: session.SharedConfigEnable,
+		})
+		return sesh, err
+	}
+}

main.go

@@ -0,0 +1,28 @@
+/*
+Copyright © 2020 Matt Gowie <matt@masterpoint.io>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+package main
+
+import "github.com/masterpointio/escrun/cmd"
+
+func main() {
+	cmd.Execute()
+}