Provide backend config values to TF code (#22)

README.md

@@ -149,7 +149,7 @@ gcp-org:
 - `inventory_path` =  relative path to the folder with jsons
 - `cmd_to_exec` = name of the binary to execute (`tofu` or `terraform`)
 - `backend` = Config values for backend provider. All the child key:values will be provided to `init` and `$tofugu_state_path` will be replaced by generated path.
-For example, it will look like `tofu init -backend-config=bucket=gcp-tfstates -backend-config=prefix=account_free-tier/free_instance.tfstate`
+For example, when you will execute `tofugu cook ...... -- init`, TofuGu actually will execute `init -backend-config=bucket=gcp-tfstates -backend-config=prefix=account_free-tier/free_instance.tfstate`
 
 At least 
 ```yaml
@@ -185,9 +185,9 @@ Examples:
 - [Shared module for VPC creation](examples/tofies/shared-modules/create_vpc)
 - [Shared module for VPC creation used in code](examples/tofies/demo-org/vpc/main.tf#L3)
 
-## Remote state in S3
+## Remote state (Terraform Backend where state data files are stored)
 
-AWS, Google Cloud and some other backends are supported! You could configure any backend provider in `tofugu config file`
+AWS, Google Cloud and some other backends are supported! You could configure any backend provider in [TofuGu Config file](#hometofugu)
 
 [For AWS S3 your terraform code (`tofi`) should contains at least:](examples/tofies/demo-org/vpc/versions.tf#L4):
 ```
@@ -209,6 +209,35 @@ If for the `demo-org` config `bucket` is NOT set, then `$tofugu_state_path` will
 
 This could be useful, if you want to store by default tfstate for all the organisations in the same/default bucket `default-tfstates` but for some specific organisation you need to store tfstates in dedicated bucket `demo-org-tfstates`
 
+## Data Source Configuration (data "terraform_remote_state")
+
+To simplify "Data Source Configuration" (`data "terraform_remote_state" "tfstate" { }`) will be nice to have backend config values as tfvars.
+
+`var.tofugu_backend_config` will contain all the parameters from [TofuGu config (backend Section)](#hometofugu)
+
+[For example, for AWS S3](examples/tofies/demo-org/vpc/data.tf):
+```
+data "terraform_remote_state" "network" {
+  backend = "s3"
+  config = {
+    bucket = var.tofugu_backend_config.bucket
+    key    = "network/terraform.tfstate"
+    region = var.tofugu_backend_config.region
+  }
+}
+```
+[And for GCS](examples/tofies/gcp-org/free_instance/data.tf):
+```
+data "terraform_remote_state" "free_instance" {
+  backend = "gcs"
+  config = {
+    bucket  = var.tofugu_backend_config.bucket
+    prefix  = "account_free-tier/free_instance.tfstate"
+  }
+}
+```
+
+You will set `key/prefix` to another tofie's tfstate, which outputs you want to use.
 
 ## $HOME/.tofurc
 

cmd/cook.go

@@ -40,16 +40,21 @@ var cookCmd = &cobra.Command{
 		tofuguStruct.ParseTofiManifest("tofi_manifest.json")
 		tofuguStruct.ParseDimensions()
 
-		backendConfig := tofuguStruct.SetupBackendConfig()
+		backendTofuguConfig := tofuguStruct.SetupBackendConfig()
 
 		tofuguStruct.PrepareTemp()
 
 		tofuguStruct.GenerateVarsByDims()
 		tofuguStruct.GenerateVarsByDimOptional("defaults")
 		tofuguStruct.GenerateVarsByEnvVars()
+		tofuguStruct.GenerateVarsByDimAndData("config", "backend", backendTofuguConfig)
 
 		//Local variables for child execution
 		forceCleanTempDir, _ := cmd.Flags().GetBool("clean")
+		var backendConfig []string
+		for param, value := range backendTofuguConfig {
+			backendConfig = append(backendConfig, "-backend-config="+param+"="+value.(string))
+		}
 		cmdArgs := args
 		if args[0] == "init" {
 			cmdArgs = append(cmdArgs, backendConfig...)

examples/tofies/demo-org/vpc/data.tf

@@ -0,0 +1,8 @@
+# data "terraform_remote_state" "network" {
+#   backend = "s3"
+#   config = {
+#     bucket = var.tofugu_backend_config.bucket
+#     key    = "network/terraform.tfstate"
+#     region = var.tofugu_backend_config.region
+#   }
+# }

examples/tofies/gcp-org/free_instance/data.tf

@@ -0,0 +1,7 @@
+# data "terraform_remote_state" "free_instance" {
+#   backend = "gcs"
+#   config = {
+#     bucket  = var.tofugu_backend_config.bucket
+#     prefix  = "account_free-tier/free_instance.tfstate"
+#   }
+# }

utils/externals.go

@@ -35,9 +35,7 @@ func (tofuguStruct *Tofugu) GetObjectFromViperByOrgOrDefault(keyName string) map
 	}
 }
 
-func (tofuguStruct *Tofugu) SetupBackendConfig() []string {
-	var backendFinalConfig []string
-
+func (tofuguStruct *Tofugu) SetupBackendConfig() map[string]interface{} {
 	var stateS3Path string
 	if !viper.IsSet(tofuguStruct.OrgName + ".backend") {
 		stateS3Path = stateS3Path + "org_" + tofuguStruct.OrgName + "/"
@@ -52,12 +50,13 @@ func (tofuguStruct *Tofugu) SetupBackendConfig() []string {
 	if len(backendTofuguConfig) == 0 {
 		log.Println("Tofugu: no backend config provied!")
 	}
+
+	var backendTofuguConfigMap = make(map[string]interface{}, len(backendTofuguConfig))
 	for param, value := range backendTofuguConfig {
-		replacedVar := strings.Replace(value.(string), "$tofugu_state_path", tofuguStruct.StateS3Path, 1)
-		backendFinalConfig = append(backendFinalConfig, "-backend-config="+param+"="+replacedVar)
+		backendTofuguConfigMap[param] = strings.Replace(value.(string), "$tofugu_state_path", tofuguStruct.StateS3Path, 1)
 	}
 
-	return backendFinalConfig
+	return backendTofuguConfigMap
 }
 
 func (tofuguStruct *Tofugu) GetDimData(dimensionKey string, dimensionValue string, skipOnNotFound bool) map[string]interface{} {

utils/generatevars.go

@@ -36,6 +36,14 @@ func (tofuguStruct *Tofugu) GenerateVarsByDimOptional(optionType string) {
 	}
 }
 
+func (tofuguStruct *Tofugu) GenerateVarsByDimAndData(optionType string, dimKey string, dimensionJsonMap map[string]interface{}) {
+	targetAutoTfvarMap := map[string]interface{}{
+		"tofugu_" + dimKey + "_" + optionType: dimensionJsonMap,
+	}
+	writeTfvarsMaps(targetAutoTfvarMap, dimKey+"_"+optionType, tofuguStruct.CmdWorkTempDir)
+	log.Println("TofuGu attached " + optionType + " in var.tofugu_" + dimKey + "_" + optionType)
+}
+
 func (tofuguStruct *Tofugu) GenerateVarsByEnvVars() {
 	targetAutoTfvarMap := make(map[string]interface{})
 

utils/preparetemp.go

@@ -7,6 +7,10 @@ import (
 )
 
 func (tofuguStruct *Tofugu) PrepareTemp() {
+	if tofuguStruct.StateS3Path == "" {
+		log.Fatalf("StateS3Path is empty \n")
+	}
+
 	tmpFolderNameSuffix := tofuguStruct.OrgName + tofuguStruct.StateS3Path + tofuguStruct.TofiName
 	cmdTempDirFullPath := os.TempDir() + "/tofugu-" + GetMD5Hash(tmpFolderNameSuffix)