Internalize unnecessarily published plugin packages (#273)

Author: wata727

Makefile

@@ -5,5 +5,5 @@ prepare:
 	@echo 'export PATH="$${AQUA_ROOT_DIR:-$${XDG_DATA_HOME:-$$HOME/.local/share}/aquaproj-aqua}/bin:$$PATH"'
 
 proto:
-	cd plugin/proto; \
+	cd plugin/internal/proto; \
 	protoc --go_out=. --go_opt=paths=source_relative --go-grpc_out=. --go-grpc_opt=paths=source_relative tflint.proto

README.md

@@ -17,7 +17,7 @@ NOTE: This plugin system is experimental. This means that API compatibility is f
 
 Please refer to [tflint-ruleset-template](https://github.com/terraform-linters/tflint-ruleset-template) for an example plugin implementation using this SDK.
 
-For more details on the API, see [tflint](https://pkg.go.dev/github.com/terraform-linters/tflint-plugin-sdk/tflint) and [helper](https://pkg.go.dev/github.com/terraform-linters/tflint-plugin-sdk/helper) packages on pkg.go.dev.
+For more details on the API, see https://pkg.go.dev/github.com/terraform-linters/tflint-plugin-sdk.
 
 ## Developing
 
@@ -41,10 +41,8 @@ $ make proto
 
 ## Architecture
 
-![architecture](architecture.png)
-
-This plugin system uses [go-plugin](https://github.com/hashicorp/go-plugin). TFLint launches the plugin as a sub-process and communicates with the plugin over gRPC. The plugin acts as a server, while TFLint acts as a client that sends inspection requests to the plugin.
+This plugin system uses [go-plugin](https://github.com/hashicorp/go-plugin). TFLint launch plugins as sub-processes and communicates with plugins over gRPC. A plugin acts as a server, while TFLint acts as a client that sends inspection requests to the plugin.
 
 On the other hand, the plugin sends various requests to a server (TFLint) to get detailed runtime contexts (e.g. variables and expressions). This means that TFLint and plugins can act as both a server and a client.
 
-These implementations are included in the [plugin/host2plugin](https://pkg.go.dev/github.com/terraform-linters/tflint-plugin-sdk/plugin/host2plugin) and [plugin/plugin2host](https://pkg.go.dev/github.com/terraform-linters/tflint-plugin-sdk/plugin/plugin2host) packages.
+This SDK provides client, server and Protocol Buffers for these bi-directional communications. See [Architecture](https://github.com/terraform-linters/tflint/blob/master/docs/developer-guide/architecture.md) for more details.

architecture.png

@@ -4,5 +4,5 @@
 // A plugin is implemented as an gRPC server and the host acts
 // as the client, sending analysis requests to the plugin.
 //
-// See host2plugin for implementation details.
+// See internal/host2plugin for implementation details.
 package plugin

plugin/doc.go

@@ -1,12 +1,7 @@
-// Package host2plugin contains a gRPC server (plugin) and client (host).
+// Package host2plugin exposes a gRPC client for use on a host (TFLint).
 //
-// In the plugin system, this communication is the first thing that happens,
-// and a plugin must use this package to provide a gRPC server.
-// However, the detailed implementation is hidden in the tflint.RuleSet interface,
-// and plugin developers usually don't need to be aware of gRPC server behavior.
-//
-// When the host initializes a gRPC client, go-plugin starts a gRPC server
-// on the plugin side as another process. This package acts as a wrapper for go-plugin.
-// Separately, the Check function initializes a new gRPC client for plugin-to-host
-// communication. See the plugin2host package for details.
+// The implementation details are hidden in internal/host2plugin and
+// the exposed ones are minimal. They are not intended to be used by plugins.
+// For that reason, this package is subject to breaking changes without notice,
+// and the changes do not follow the SDK versioning policy.
 package host2plugin

plugin/host2plugin/doc.go

@@ -0,0 +1,12 @@
+package host2plugin
+
+import "github.com/terraform-linters/tflint-plugin-sdk/plugin/internal/host2plugin"
+
+// Client is a host-side implementation. Host can send requests through the client to plugin's gRPC server.
+type Client = host2plugin.GRPCClient
+
+// ClientOpts is an option for initializing a Client.
+type ClientOpts = host2plugin.ClientOpts
+
+// NewClient returns a new gRPC client for host-to-plugin communication.
+var NewClient = host2plugin.NewClient

plugin/host2plugin/host2plugin.go

@@ -6,7 +6,7 @@ import (
 
 	"github.com/hashicorp/hcl/v2"
 	"github.com/terraform-linters/tflint-plugin-sdk/hclext"
-	"github.com/terraform-linters/tflint-plugin-sdk/plugin/proto"
+	"github.com/terraform-linters/tflint-plugin-sdk/plugin/internal/proto"
 	"github.com/terraform-linters/tflint-plugin-sdk/terraform/lang/marks"
 	"github.com/terraform-linters/tflint-plugin-sdk/tflint"
 	"github.com/zclconf/go-cty/cty"

plugin/fromproto/doc.go renamed to plugin/internal/fromproto/doc.go

@@ -8,11 +8,11 @@ import (
 	"github.com/hashicorp/go-version"
 	"github.com/terraform-linters/tflint-plugin-sdk/hclext"
 	"github.com/terraform-linters/tflint-plugin-sdk/logger"
-	"github.com/terraform-linters/tflint-plugin-sdk/plugin/fromproto"
-	"github.com/terraform-linters/tflint-plugin-sdk/plugin/interceptor"
-	"github.com/terraform-linters/tflint-plugin-sdk/plugin/plugin2host"
-	"github.com/terraform-linters/tflint-plugin-sdk/plugin/proto"
-	"github.com/terraform-linters/tflint-plugin-sdk/plugin/toproto"
+	"github.com/terraform-linters/tflint-plugin-sdk/plugin/internal/fromproto"
+	"github.com/terraform-linters/tflint-plugin-sdk/plugin/internal/interceptor"
+	"github.com/terraform-linters/tflint-plugin-sdk/plugin/internal/plugin2host"
+	"github.com/terraform-linters/tflint-plugin-sdk/plugin/internal/proto"
+	"github.com/terraform-linters/tflint-plugin-sdk/plugin/internal/toproto"
 	"github.com/terraform-linters/tflint-plugin-sdk/tflint"
 	"google.golang.org/grpc"
 )

plugin/fromproto/fromproto.go renamed to plugin/internal/fromproto/fromproto.go

@@ -0,0 +1,12 @@
+// Package host2plugin contains a gRPC server (plugin) and client (host).
+//
+// In the plugin system, this communication is the first thing that happens,
+// and a plugin must use this package to provide a gRPC server.
+// However, the detailed implementation is hidden in the tflint.RuleSet interface,
+// and plugin developers usually don't need to be aware of gRPC server behavior.
+//
+// When the host initializes a gRPC client, go-plugin starts a gRPC server
+// on the plugin side as another process. This package acts as a wrapper for go-plugin.
+// Separately, the Check function initializes a new gRPC client for plugin-to-host
+// communication. See the plugin2host package for details.
+package host2plugin