Merge pull request #1 from janritter/feat/multi-backend

Feat/multi backend

README.md

@@ -1,8 +1,58 @@
 # Terrastate
 
 [![Build Status](https://travis-ci.com/janritter/terrastate.svg?token=fPhMwJC3SnTkQrfzte44&branch=master)](https://travis-ci.com/janritter/terrastate)
+[![Maintainability](https://api.codeclimate.com/v1/badges/235b50a37a1d73929d5c/maintainability)](https://codeclimate.com/github/janritter/terrastate/maintainability)
 
-## Commands
+> Tool to manage multiple states in Terraform - Allows Multi account setups
+
+## Use case
+
+> TODO
+
+## Usage
+
+### Generate statefile in the current directory
+
+``` bash
+terrastate --var-file ../../dev.tfvars
+```
+
+This generates a statefile called terrastate.tf
+
+It will also replace an exisiting terrastate.tf file with the new infromation.
+
+#### Required Terraform variables
+
+Some variables must be set in the varfile used by terrastate. Some of these variables are used by terrastate and others are depending on the backend.
+
+The state_backend var defines the backend type and therefore which backend implementation should be used by terrastate. If the given backend is not supported terrastate returns an error.
+In this example s3 is configured as backend.
+
+```bash
+state_backend = "s3"
+```
+
+The currently supported backends are:
+
+- [S3](docs/s3-backend.md)
+
+Feel free to add a new backend and create a pull request - [How to create a new backend?](docs/own-backend.md)
+
+For more information about the backend specific variables click the backend in the list above.
+
+### Version
+
+``` bash
+terrastate version
+```
+
+### Help
+
+``` bash
+terrastate help
+```
+
+## Development
 
 ### Resolve dependencies
 

backend/iface/interface.go

@@ -0,0 +1,5 @@
+package iface
+
+type BackendAPI interface {
+	GenerateStatefileForBackend(in interface{}) error
+}

backend/mapper.go

@@ -0,0 +1,20 @@
+package backend
+
+import (
+	"errors"
+	"log"
+
+	"github.com/janritter/terrastate/backend/iface"
+	"github.com/janritter/terrastate/backend/s3"
+)
+
+func GetBackendInterface(backendType string) (iface.BackendAPI, error) {
+	switch backendType {
+	case "s3":
+		return s3.NewS3Backend(), nil
+	}
+
+	err := errors.New("Backend " + backendType + " is currently not supported")
+	log.Println(err)
+	return nil, err
+}

backend/s3/api.go

@@ -0,0 +1,11 @@
+package s3
+
+type S3BackendAPI interface {
+	GenerateStatefileForBackend(in interface{}) error
+}
+
+type S3Backend struct{}
+
+func NewS3Backend() *S3Backend {
+	return &S3Backend{}
+}

backend/s3/create.go

@@ -0,0 +1,32 @@
+package s3
+
+import (
+	"io/ioutil"
+	"log"
+
+	"github.com/fatih/color"
+)
+
+func createStateFile(in stateConfig) error {
+	fileContent :=
+		`terraform {
+  backend "s3" {
+	encrypt        = true
+	bucket         = "` + in.Bucket + `"
+	region         = "` + in.Region + `"
+	key            = "` + in.Key + `"
+	dynamodb_table = "` + in.DynamoDBTable + `"
+  }
+}
+`
+
+	data := []byte(fileContent)
+	err := ioutil.WriteFile("terrastate.tf", data, 0644)
+	if err != nil {
+		log.Println(err)
+		return err
+	}
+
+	color.Green("Successfully created terrastate.tf")
+	return nil
+}

backend/s3/generate.go

@@ -0,0 +1,18 @@
+package s3
+
+import (
+	"github.com/janritter/terrastate/helper"
+)
+
+func (backend *S3Backend) GenerateStatefileForBackend(in interface{}) error {
+	stateParams := stateConfig{}
+	err := parseBackendParameter(in, &stateParams)
+	if err != nil {
+		return err
+	}
+
+	helper.PrintStateValues(stateParams)
+
+	err = createStateFile(stateParams)
+	return err
+}

backend/s3/parse.go

@@ -0,0 +1,93 @@
+package s3
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"reflect"
+	"strings"
+)
+
+func parseBackendParameter(in interface{}, out *stateConfig) error {
+	switch in.(type) {
+	case map[string]interface{}:
+		mapped := in.(map[string]interface{})
+
+		if mapped["state_bucket"] == nil {
+			err := errors.New("state_bucket must be defined")
+			log.Println(err)
+			return err
+		}
+		if reflect.TypeOf(mapped["state_bucket"]).String() != "string" {
+			err := errors.New("state_bucket must be of type string, was " + reflect.TypeOf(mapped["state_bucket"]).String())
+			log.Println(err)
+			return err
+		}
+		out.Bucket = mapped["state_bucket"].(string)
+
+		if mapped["state_dynamodb_table"] == nil {
+			err := errors.New("state_dynamodb_table must be defined")
+			log.Println(err)
+			return err
+		}
+		if reflect.TypeOf(mapped["state_dynamodb_table"]).String() != "string" {
+			err := errors.New("state_dynamodb_table must be of type string, was " + reflect.TypeOf(mapped["state_dynamodb_table"]).String())
+			log.Println(err)
+			return err
+		}
+		out.DynamoDBTable = mapped["state_dynamodb_table"].(string)
+
+		if mapped["state_key"] == nil {
+			err := errors.New("state_key must be defined")
+			log.Println(err)
+			return err
+		}
+		if reflect.TypeOf(mapped["state_key"]).String() != "string" {
+			err := errors.New("state_key must be of type string, was " + reflect.TypeOf(mapped["state_key"]).String())
+			log.Println(err)
+			return err
+		}
+
+		// Remove all spaces
+		key := strings.ReplaceAll(mapped["state_key"].(string), " ", "")
+
+		// Check if the key string contains current.dir
+		if !strings.Contains(key, "{{current.dir}}") {
+			err := errors.New("{{current.dir}} is missing the state_key string")
+			log.Println(err)
+			return err
+		}
+
+		// Replace placeholder with current dir
+		path, err := os.Getwd()
+		if err != nil {
+			log.Fatal(err)
+		}
+		dir := filepath.Base(path)
+		fmt.Println("Current Directory = " + dir)
+		key = strings.ReplaceAll(key, "{{current.dir}}", dir)
+
+		out.Key = key
+
+		if mapped["region"] == nil {
+			err := errors.New("region must be defined")
+			log.Println(err)
+			return err
+		}
+		if reflect.TypeOf(mapped["region"]).String() != "string" {
+			err := errors.New("region must be of type string, was " + reflect.TypeOf(mapped["region"]).String())
+			log.Println(err)
+			return err
+		}
+		out.Region = mapped["region"].(string)
+
+	default:
+		err := errors.New("Unknown var-file format")
+		log.Println(err)
+		return err
+	}
+
+	return nil
+}

backend/s3/types.go

@@ -0,0 +1,8 @@
+package s3
+
+type stateConfig struct {
+	Bucket        string
+	DynamoDBTable string
+	Key           string
+	Region        string
+}