From 56d427dc244036356ea38650a2014fdd551792ef Mon Sep 17 00:00:00 2001
From: fujiwara <fujiwara.shunichiro@gmail.com>
Date: Tue, 3 Sep 2024 13:21:24 +0900
Subject: [PATCH] add -dump flag and Dump() method.

---
 README.md              | 32 ++++++++++++++++++++++++++++++--
 tfstate/lookup.go      | 18 ++++++++++++++++--
 tfstate/lookup_test.go | 40 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 86 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index 6e8c088..dd8bedb 100644
--- a/README.md
+++ b/README.md
@@ -16,12 +16,14 @@ $ brew install fujiwara/tap/tfstate-lookup
 
 ```
 Usage of tfstate-lookup:
+  -dump
+        dump all resources
   -i    interactive mode
   -j    run jid after selecting an item
   -s string
-        tfstate file path or URL (default "terraform.tfstate")
+        tfstate file path or URL (default ".terraform/terraform.tfstate")
   -state string
-        tfstate file path or URL (default "terraform.tfstate")
+        tfstate file path or URL (default ".terraform/terraform.tfstate")
   -timeout duration
         timeout for reading tfstate
 ```
@@ -90,6 +92,32 @@ tfstate-lookup integrates jid as a library, so you don't need to install jid com
 
 See also [simiji/jid](https://github.com/simeji/jid).
 
+### Dump all resources, outputs, and data sources in tfstate
+
+You can dump all resources, outputs, and data sources in tfstate with `-dump` option.
+
+```console
+$ tfstate-lookup -dump
+```
+
+The output is a JSON object. The keys are the address of the resource, output, or data source. The values are the same as the lookup result.
+
+```jsonnet
+{
+  "aws_vpc.main": {
+    "arn": "arn:aws:ec2:ap-northeast-1:123456789012:vpc/vpc-1a2b3c4d",
+    "assign_generated_ipv6_cidr_block": false,
+    // ...
+  },
+  "data.aws_ami.foo": {
+    "arn": "arn:aws:ec2:ap-northeast-1:123456789012:ami/ami-1a2b3c4d",
+    // ...
+  },
+  "output.foo": "bar",
+  // ...
+}
+```
+
 ## Usage (Go package)
 
 See details in [godoc](https://pkg.go.dev/github.com/fujiwara/tfstate-lookup/tfstate).
diff --git a/tfstate/lookup.go b/tfstate/lookup.go
index 591bfe9..92dec34 100644
--- a/tfstate/lookup.go
+++ b/tfstate/lookup.go
@@ -28,7 +28,11 @@ type Object struct {
 	Value interface{}
 }
 
-func (a Object) Bytes() []byte {
+func (a *Object) MarshalJSON() ([]byte, error) {
+	return json.Marshal(a.Value)
+}
+
+func (a *Object) Bytes() []byte {
 	switch v := (a.Value).(type) {
 	case string:
 		return []byte(v)
@@ -38,7 +42,7 @@ func (a Object) Bytes() []byte {
 	}
 }
 
-func (a Object) String() string {
+func (a *Object) String() string {
 	return string(a.Bytes())
 }
 
@@ -271,6 +275,16 @@ func (s *TFState) List() ([]string, error) {
 	return names, nil
 }
 
+// Dump dumps all resources, outputs, and data sources in tfstate
+func (s *TFState) Dump() (map[string]*Object, error) {
+	s.once.Do(s.scan)
+	res := make(map[string]*Object, len(s.scanned))
+	for key, ins := range s.scanned {
+		res[key] = &Object{noneNil(ins.data, ins.Attributes, ins.AttributesFlat)}
+	}
+	return res, nil
+}
+
 func (s *TFState) scan() {
 	s.scanned = make(map[string]instance, len(s.state.Resources))
 	for key, value := range s.state.Outputs {
diff --git a/tfstate/lookup_test.go b/tfstate/lookup_test.go
index 0b2bda7..6cbce7b 100644
--- a/tfstate/lookup_test.go
+++ b/tfstate/lookup_test.go
@@ -251,3 +251,43 @@ func TestList(t *testing.T) {
 		t.Errorf("unexpected list names %s", diff)
 	}
 }
+
+func TestDump(t *testing.T) {
+	f, err := os.Open("test/terraform.tfstate")
+	if err != nil {
+		t.Error(err)
+	}
+	state, err := tfstate.Read(context.Background(), f)
+	if err != nil {
+		t.Error(err)
+	}
+	dump, _ := state.Dump()
+	if len(dump) != len(TestNames) {
+		t.Errorf("unexpected dump length %d", len(dump))
+	}
+
+	t.Run("compare dump keys with List()", func(t *testing.T) {
+		dumpKeys := make([]string, 0, len(dump))
+		for key := range dump {
+			dumpKeys = append(dumpKeys, key)
+		}
+		listKeys, _ := state.List()
+		sort.Strings(dumpKeys)
+		sort.Strings(listKeys)
+		if diff := cmp.Diff(dumpKeys, listKeys); diff != "" {
+			t.Errorf("unexpected dump keys %s", diff)
+		}
+	})
+
+	t.Run("compare dump values with Lookup()", func(t *testing.T) {
+		for key, dv := range dump {
+			lv, err := state.Lookup(key)
+			if err != nil {
+				t.Error(err)
+			}
+			if diff := cmp.Diff(dv, lv); diff != "" {
+				t.Errorf("unexpected dump value %s", diff)
+			}
+		}
+	})
+}