Ensure that only valid args get passed to terraform apply

cmd/terraform.go

@@ -10,7 +10,7 @@ import (
 var terraformCmd = &cobra.Command{
 	Use:     "terraform",
 	GroupID: "iac",
-	Short:   "Run Terrafrom with Overmind's risk analysis and change tracking",
+	Short:   "Run Terraform with Overmind's risk analysis and change tracking",
 	Long: `By using 'overmind terraform plan/apply' in place of your normal
 'terraform plan/apply' commands, you can get a risk analysis and change
 tracking for your Terraform changes with no extra effort.
@@ -36,6 +36,11 @@ var applyOnlyArgs = []string{
 	"auto-approve",
 }
 
+var planOnlyArgs = []string{
+	"var",
+	"var-file",
+}
+
 // planArgsFromApplyArgs filters out all apply-specific arguments from arguments
 // to `terraform apply`, so that we can run the corresponding `terraform plan`
 // command
@@ -55,3 +60,21 @@ append:
 	}
 	return planArgs
 }
+
+// applyArgsFromApplyArgs filters out all plan-specific arguments from arguments to `terraform apply`, so that we can run the corresponding `terraform apply` command
+func applyArgsFromApplyArgs(args []string) []string {
+	applyArgs := []string{}
+append:
+	for _, arg := range args {
+		for _, planOnlyArg := range planOnlyArgs {
+			if strings.HasPrefix(arg, "-"+planOnlyArg) {
+				continue append
+			}
+			if strings.HasPrefix(arg, "--"+planOnlyArg) {
+				continue append
+			}
+		}
+		applyArgs = append(applyArgs, arg)
+	}
+	return applyArgs
+}

cmd/terraform_apply.go

@@ -186,7 +186,9 @@ func TerraformApplyImpl(ctx context.Context, cmd *cobra.Command, oi sdp.Overmind
 		return err
 	}
 
-	err = RunApply(ctx, args)
+	// apply the args filtering here, after providers have been configured above
+	// (which might still need --var and --var-file information)
+	err = RunApply(ctx, applyArgsFromApplyArgs(args))
 	if err != nil {
 		return err
 	}