From c031d37b918ca838f121d1507012e5cb63ca8fde Mon Sep 17 00:00:00 2001
From: Dane Everitt <dane@daneeveritt.com>
Date: Sat, 17 Oct 2020 14:04:56 -0700
Subject: [PATCH] Use single call to create/return the docker client

---
 cmd/diagnostics.go                |  4 ++--
 environment/docker.go             | 21 ++++++++++++++++++++-
 environment/docker/environment.go |  2 +-
 server/install.go                 |  2 +-
 4 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/cmd/diagnostics.go b/cmd/diagnostics.go
index a6d0650..973fde9 100644
--- a/cmd/diagnostics.go
+++ b/cmd/diagnostics.go
@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"github.com/pterodactyl/wings/environment"
 	"io"
 	"io/ioutil"
 	"net/http"
@@ -19,7 +20,6 @@ import (
 	"github.com/AlecAivazis/survey/v2/terminal"
 	"github.com/docker/cli/components/engine/pkg/parsers/operatingsystem"
 	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/client"
 	"github.com/docker/docker/pkg/parsers/kernel"
 	"github.com/pterodactyl/wings/config"
 	"github.com/pterodactyl/wings/system"
@@ -187,7 +187,7 @@ func diagnosticsCmdRun(cmd *cobra.Command, args []string) {
 }
 
 func getDockerInfo() (types.Version, types.Info, error) {
-	cli, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
+	cli, err := environment.DockerClient()
 	if err != nil {
 		return types.Version{}, types.Info{}, err
 	}
diff --git a/environment/docker.go b/environment/docker.go
index b30bd8d..9165e37 100644
--- a/environment/docker.go
+++ b/environment/docker.go
@@ -3,6 +3,7 @@ package environment
 import (
 	"context"
 	"github.com/apex/log"
+	"sync"
 
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/network"
@@ -10,10 +11,28 @@ import (
 	"github.com/pterodactyl/wings/config"
 )
 
+var _cmu sync.Mutex
+var _client *client.Client
+
+// Return a Docker client to be used throughout the codebase. Once a client has been created it
+// will be returned for all subsequent calls to this function.
+func DockerClient() (*client.Client, error) {
+	_cmu.Lock()
+	defer _cmu.Unlock()
+
+	if _client != nil {
+		return _client, nil
+	}
+
+	_client, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation());
+
+	return _client, err
+}
+
 // Configures the required network for the docker environment.
 func ConfigureDocker(c *config.DockerConfiguration) error {
 	// Ensure the required docker network exists on the system.
-	cli, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
+	cli, err := DockerClient()
 	if err != nil {
 		return err
 	}
diff --git a/environment/docker/environment.go b/environment/docker/environment.go
index 4893032..2a0d7aa 100644
--- a/environment/docker/environment.go
+++ b/environment/docker/environment.go
@@ -55,7 +55,7 @@ type Environment struct {
 // reference the container from here on out. This should be unique per-server (we use the UUID
 // by default). The container does not need to exist at this point.
 func New(id string, m *Metadata, c *environment.Configuration) (*Environment, error) {
-	cli, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
+	cli, err := environment.DockerClient()
 	if err != nil {
 		return nil, err
 	}
diff --git a/server/install.go b/server/install.go
index f6bdaa1..2666fb7 100644
--- a/server/install.go
+++ b/server/install.go
@@ -129,7 +129,7 @@ func NewInstallationProcess(s *Server, script *api.InstallationScript) (*Install
 	ctx, cancel := context.WithCancel(context.Background())
 	s.installer.cancel = &cancel
 
-	if c, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation()); err != nil {
+	if c, err := environment.DockerClient(); err != nil {
 		return nil, errors.WithStack(err)
 	} else {
 		proc.client = c