From 3b4555344cef5784cf6ec4546bd8a604d83e53c3 Mon Sep 17 00:00:00 2001
From: Dane Everitt <dane@daneeveritt.com>
Date: Fri, 5 Apr 2019 21:59:27 -0700
Subject: [PATCH] Build out the docker environment a bit more

---
 server/environment_docker.go | 61 +++++++++++++++++++++++++++++++++---
 server/server.go             |  8 +++--
 2 files changed, 62 insertions(+), 7 deletions(-)

diff --git a/server/environment_docker.go b/server/environment_docker.go
index 5054742..22595f8 100644
--- a/server/environment_docker.go
+++ b/server/environment_docker.go
@@ -2,6 +2,7 @@ package server
 
 import (
 	"fmt"
+	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/mount"
 	"github.com/docker/docker/client"
@@ -11,6 +12,7 @@ import (
 	"os"
 	"strconv"
 	"strings"
+	"time"
 )
 
 // Defines the docker configuration used by the daemon when interacting with
@@ -46,32 +48,83 @@ type DockerConfiguration struct {
 	TimezonePath string `yaml:"timezone_path"`
 }
 
+// Defines the base environment for Docker instances running through Wings.
 type DockerEnvironment struct {
 	Server *Server
 
 	// Defines the configuration for the Docker instance that will allow us to connect
 	// and create and modify containers.
 	Configuration DockerConfiguration
+
+	// The Docker client being used for this instance.
+	Client *client.Client
+}
+
+// Creates a new base Docker environment. A server must still be attached to it.
+func NewDockerEnvironment(cfg DockerConfiguration) (*DockerEnvironment, error) {
+	cli, err := client.NewClientWithOpts(client.FromEnv)
+	if err != nil {
+		return nil, err
+	}
+
+	return &DockerEnvironment{
+		Configuration: cfg,
+		Client:        cli,
+	}, nil
 }
 
 // Ensure that the Docker environment is always implementing all of the methods
 // from the base environment interface.
 var _ Environment = (*DockerEnvironment)(nil)
 
+// Determines if the container exists in this environment.
 func (d *DockerEnvironment) Exists() bool {
-	return true
+	_, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid)
+
+	return err == nil
 }
 
+// Checks if there is a container that already exists for the server. If so that
+// container is started. If there is no container, one is created and then started.
 func (d *DockerEnvironment) Start() error {
-	return nil
+	c, err := d.Client.ContainerInspect(context.Background(), d.Server.Uuid)
+	if err != nil {
+		// @todo what?
+		return err
+	}
+
+	// No reason to try starting a container that is already running.
+	if c.State.Running {
+		return nil
+	}
+
+	opts := types.ContainerStartOptions{}
+
+	return d.Client.ContainerStart(context.Background(), d.Server.Uuid, opts)
 }
 
+// Stops the container that the server is running in. This will allow up to 10
+// seconds to pass before a failure occurs.
 func (d *DockerEnvironment) Stop() error {
-	return nil
+	t := time.Second * 10
+
+	return d.Client.ContainerStop(context.Background(), d.Server.Uuid, &t)
 }
 
+// Forcefully terminates the container using the signal passed through.
 func (d *DockerEnvironment) Terminate(signal os.Signal) error {
-	return nil
+	ctx := context.Background()
+
+	c, err := d.Client.ContainerInspect(ctx, d.Server.Uuid)
+	if err != nil {
+		return err
+	}
+
+	if !c.State.Running {
+		return nil
+	}
+
+	return d.Client.ContainerKill(ctx, d.Server.Uuid, signal.String())
 }
 
 // Creates a new container for the server using all of the data that is currently
diff --git a/server/server.go b/server/server.go
index 33cbbdd..8b5ed8b 100644
--- a/server/server.go
+++ b/server/server.go
@@ -173,9 +173,11 @@ func FromConfiguration(data []byte, cfg DockerConfiguration) (*Server, error) {
 	// this logic in. When we're ready to support other environment we'll need to make
 	// some modifications here obviously.
 	var env Environment
-	env = &DockerEnvironment{
-		Server:        s,
-		Configuration: cfg,
+	if t, err := NewDockerEnvironment(cfg); err != nil {
+		t.Server = s
+		env = t
+	} else {
+		return nil, err
 	}
 
 	s.environment = env