Simplify JSON execs

hashicorp · Sep 1, 2020 · 3a3bbe7 · 3a3bbe7
1 parent 821c81e
commit 3a3bbe7
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Showing 4 changed files with 26 additions and 51 deletions.
diff --git a/tfexec/cmd.go b/tfexec/cmd.go
@@ -1,7 +1,9 @@
 package tfexec
 
 import (
+	"bytes"
 	"context"
+	"encoding/json"
 	"fmt"
 	"io"
 	"os"
@@ -115,6 +117,25 @@ func (tf *Terraform) buildTerraformCmd(ctx context.Context, args ...string) *exe
 	return cmd
 }
 
+func (tf *Terraform) runTerraformCmdJSON(cmd *exec.Cmd, v interface{}) error {
+	var outbuf = bytes.Buffer{}
+
+	{
+		var stdout io.Writer = &outbuf
+		if cmd.Stdout != nil {
+			stdout = io.MultiWriter(cmd.Stdout, stdout)
+		}
+		cmd.Stdout = stdout
+	}
+
+	err := tf.runTerraformCmd(cmd)
+	if err != nil {
+		return err
+	}
+
+	return json.Unmarshal(outbuf.Bytes(), v)
+}
+
 func (tf *Terraform) runTerraformCmd(cmd *exec.Cmd) error {
 	var errBuf strings.Builder
 

diff --git a/tfexec/output.go b/tfexec/output.go
@@ -1,7 +1,6 @@
 package tfexec
 
 import (
-	"bytes"
 	"context"
 	"encoding/json"
 	"os/exec"
@@ -35,17 +34,8 @@ type OutputMeta struct {
 func (tf *Terraform) Output(ctx context.Context, opts ...OutputOption) (map[string]OutputMeta, error) {
 	outputCmd := tf.outputCmd(ctx, opts...)
 
-	var outBuf bytes.Buffer
-	outputCmd.Stdout = &outBuf
-
 	outputs := map[string]OutputMeta{}
-
-	err := tf.runTerraformCmd(outputCmd)
-	if err != nil {
-		return nil, err
-	}
-
-	err = json.Unmarshal(outBuf.Bytes(), &outputs)
+	err := tf.runTerraformCmdJSON(outputCmd, &outputs)
 	if err != nil {
 		return nil, err
 	}

diff --git a/tfexec/providers_schema.go b/tfexec/providers_schema.go
@@ -1,9 +1,7 @@
 package tfexec
 
 import (
-	"bytes"
 	"context"
-	"encoding/json"
 	"os/exec"
 
 	tfjson "github.com/hashicorp/terraform-json"
@@ -13,15 +11,7 @@ func (tf *Terraform) ProvidersSchema(ctx context.Context) (*tfjson.ProviderSchem
 	schemaCmd := tf.providersSchemaCmd(ctx)
 
 	var ret tfjson.ProviderSchemas
-	var outBuf bytes.Buffer
-	schemaCmd.Stdout = &outBuf
-
-	err := tf.runTerraformCmd(schemaCmd)
-	if err != nil {
-		return nil, err
-	}
-
-	err = json.Unmarshal(outBuf.Bytes(), &ret)
+	err := tf.runTerraformCmdJSON(schemaCmd, &ret)
 	if err != nil {
 		return nil, err
 	}

diff --git a/tfexec/show.go b/tfexec/show.go
@@ -1,9 +1,7 @@
 package tfexec
 
 import (
-	"bytes"
 	"context"
-	"encoding/json"
 	"fmt"
 	"os/exec"
 
@@ -21,15 +19,7 @@ func (tf *Terraform) Show(ctx context.Context) (*tfjson.State, error) {
 	showCmd := tf.showCmd(ctx)
 
 	var ret tfjson.State
-	var outBuf bytes.Buffer
-	showCmd.Stdout = &outBuf
-
-	err = tf.runTerraformCmd(showCmd)
-	if err != nil {
-		return nil, err
-	}
-
-	err = json.Unmarshal(outBuf.Bytes(), &ret)
+	err = tf.runTerraformCmdJSON(showCmd, &ret)
 	if err != nil {
 		return nil, err
 	}
@@ -56,15 +46,7 @@ func (tf *Terraform) ShowStateFile(ctx context.Context, statePath string) (*tfjs
 	showCmd := tf.showCmd(ctx, statePath)
 
 	var ret tfjson.State
-	var outBuf bytes.Buffer
-	showCmd.Stdout = &outBuf
-
-	err = tf.runTerraformCmd(showCmd)
-	if err != nil {
-		return nil, err
-	}
-
-	err = json.Unmarshal(outBuf.Bytes(), &ret)
+	err = tf.runTerraformCmdJSON(showCmd, &ret)
 	if err != nil {
 		return nil, err
 	}
@@ -91,15 +73,7 @@ func (tf *Terraform) ShowPlanFile(ctx context.Context, planPath string) (*tfjson
 	showCmd := tf.showCmd(ctx, planPath)
 
 	var ret tfjson.Plan
-	var outBuf bytes.Buffer
-	showCmd.Stdout = &outBuf
-
-	err = tf.runTerraformCmd(showCmd)
-	if err != nil {
-		return nil, err
-	}
-
-	err = json.Unmarshal(outBuf.Bytes(), &ret)
+	err = tf.runTerraformCmdJSON(showCmd, &ret)
 	if err != nil {
 		return nil, err
 	}