feature: allow multiple --var-file to be parsed

README.md

@@ -84,6 +84,18 @@ variable "docker_ports" {
     image_id                = "xyz"
     ```
 
+- Multiple files can be specified via providing more `--var-file` options, variables overrides as for `terraform` command.
+    ```
+    $ cat my.tfvars
+    image_id = "xyz"
+
+    $ cat other.tfvars
+    image_id = "abc"
+
+    $ tfvar . --var-file my.tfvars --var-file other.tfvars
+    image_id = "abc"
+  ```
+
 For more info, checkout the `--help` page:
 
 ```
@@ -99,6 +111,7 @@ Flags:
                          variable definitions files e.g. terraform.tfvars[.json] *.auto.tfvars[.json]
   -d, --debug            Print debug log on stderr
   -e, --env-var          Print output in export TF_VAR_image_id=ami-abc123 format
+  --var-file             Reads variable file, multiple files can be provided
   -h, --help             help for tfvar
       --ignore-default   Do not use defined default values
       --version          version for tfvar

cmd/cmd.go

@@ -52,7 +52,7 @@ variable definitions files e.g. terraform.tfvars[.json] *.auto.tfvars[.json]`)
 	rootCmd.PersistentFlags().Bool(flagNoDefault, false, "Do not use defined default values")
 	rootCmd.PersistentFlags().StringArray(flagVar, []string{}, `Set a variable in the generated definitions.
 This flag can be set multiple times.`)
-	rootCmd.PersistentFlags().String(flagVarFile, "", `Set variables from a file.`)
+	rootCmd.PersistentFlags().StringArray(flagVarFile, []string{}, `Set variables from a file.`)
 
 	return rootCmd, func() {
 		if r.log != nil {
@@ -148,13 +148,13 @@ func (r *runner) rootRunE(cmd *cobra.Command, args []string) error {
 		}
 	}
 
-	fromFile, err := cmd.PersistentFlags().GetString(flagVarFile)
+	fromFiles, err := cmd.PersistentFlags().GetStringArray(flagVarFile)
 	if err != nil {
 		return errors.Wrap(err, "cmd: get flag --var-file")
 	}
 
-	if fromFile != "" {
-		if err := tfvar.CollectFromFile(fromFile, unparseds); err != nil {
+	for _, fv := range fromFiles {
+		if err := tfvar.CollectFromFile(fv, unparseds); err != nil {
 			return err
 		}
 	}

cmd/cmd_test.go

@@ -122,6 +122,25 @@ image_id = "xyz"
 `, actual.String())
 }
 
+func TestMultipleVarFiles(t *testing.T) {
+	os.Args = strings.Fields("tfvar testdata --var-file testdata/my.tfvars --var-file testdata/other.tfvars")
+
+	var actual bytes.Buffer
+	cmd, sync := New(&actual, "dev")
+	defer sync()
+
+	require.NoError(t, cmd.Execute())
+	assert.Equal(t, `availability_zone_names = ["us-west-1a"]
+docker_ports = [{
+  external = 8300
+  internal = 8300
+  protocol = "tcp"
+}]
+image_id = "abc"
+`, actual.String())
+}
+
+
 func TestVarFileError(t *testing.T) {
 	os.Args = strings.Fields("tfvar testdata --var-file testdata/bad.tfvars")
 

cmd/testdata/other.tfvars

@@ -0,0 +1 @@
+image_id = "abc"