From 14a345504f03c02a70b9323d157deccab236d86a Mon Sep 17 00:00:00 2001
From: Bo-Yi Wu <appleboy.tw@gmail.com>
Date: Sat, 13 Aug 2022 14:30:05 +0800
Subject: [PATCH] refactor: docker engine with options

---
 cmd/damon.go      |  5 ++---
 engine/docker.go  | 28 +++++++++++++---------------
 engine/options.go | 30 ++++++++++++++++++++++++++++++
 3 files changed, 45 insertions(+), 18 deletions(-)
 create mode 100644 engine/options.go

diff --git a/cmd/damon.go b/cmd/damon.go
index 2067ff2..d739c45 100644
--- a/cmd/damon.go
+++ b/cmd/damon.go
@@ -137,8 +137,7 @@ func runDaemon(ctx context.Context, input *Input) func(cmd *cobra.Command, args
 
 		initLogging(cfg)
 
-		opts := engine.Opts{}
-		engine, err := engine.NewEnv(opts)
+		engine, err := engine.New()
 		if err != nil {
 			log.WithError(err).
 				Fatalln("cannot load the docker engine")
@@ -161,7 +160,7 @@ func runDaemon(ctx context.Context, input *Input) func(cmd *cobra.Command, args
 				count++
 				if count == 5 {
 					log.WithError(err).
-						Fatalln("retry count reached")
+						Fatalf("retry count reached: %d", count)
 				}
 				time.Sleep(time.Second)
 			} else {
diff --git a/engine/docker.go b/engine/docker.go
index 9aee014..c3017e9 100644
--- a/engine/docker.go
+++ b/engine/docker.go
@@ -6,30 +6,28 @@ import (
 	"github.com/docker/docker/client"
 )
 
-// Opts configures the Docker engine.
-type Opts struct {
-	HidePull bool
-}
-
 type Docker struct {
 	client   client.APIClient
 	hidePull bool
 }
 
-func New(client client.APIClient, opts Opts) *Docker {
-	return &Docker{
-		client:   client,
-		hidePull: opts.HidePull,
-	}
-}
-
-// NewEnv returns a new Engine from the environment.
-func NewEnv(opts Opts) (*Docker, error) {
+func New(opts ...Option) (*Docker, error) {
 	cli, err := client.NewClientWithOpts(client.FromEnv)
 	if err != nil {
 		return nil, err
 	}
-	return New(cli, opts), nil
+
+	srv := &Docker{
+		client: cli,
+	}
+
+	// Loop through each option
+	for _, opt := range opts {
+		// Call the option giving the instantiated
+		opt.Apply(srv)
+	}
+
+	return srv, nil
 }
 
 // Ping pings the Docker daemon.
diff --git a/engine/options.go b/engine/options.go
new file mode 100644
index 0000000..791c6b1
--- /dev/null
+++ b/engine/options.go
@@ -0,0 +1,30 @@
+package engine
+
+import "github.com/docker/docker/client"
+
+// An Option configures a mutex.
+type Option interface {
+	Apply(*Docker)
+}
+
+// OptionFunc is a function that configure a value.
+type OptionFunc func(*Docker)
+
+// Apply calls f(option)
+func (f OptionFunc) Apply(docker *Docker) {
+	f(docker)
+}
+
+// WithClient set custom client
+func WithClient(c client.APIClient) Option {
+	return OptionFunc(func(q *Docker) {
+		q.client = c
+	})
+}
+
+// WithHidePull set custom client
+func WithHidePull(v bool) Option {
+	return OptionFunc(func(q *Docker) {
+		q.hidePull = v
+	})
+}