Implement server deletion

server/collection.go

@@ -1,7 +1,18 @@
 package server
 
+import "sync"
+
 type Collection struct {
 	items []*Server
+	mutex *sync.Mutex
+}
+
+// Create a new collection from a slice of servers.
+func NewCollection(servers []*Server) *Collection {
+	return &Collection{
+		items: servers,
+		mutex: &sync.Mutex{},
+	}
 }
 
 // Return all of the items in the collection.
@@ -11,11 +22,17 @@ func (c *Collection) All() []*Server {
 
 // Adds an item to the collection store.
 func (c *Collection) Add(s *Server) {
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+
 	c.items = append(c.items, s)
 }
 
 // Returns only those items matching the filter criteria.
-func (c *Collection) Filter(filter func (*Server) bool) []*Server {
+func (c *Collection) Filter(filter func(*Server) bool) []*Server {
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+
 	r := make([]*Server, 0)
 	for _, v := range c.items {
 		if filter(v) {
@@ -28,7 +45,7 @@ func (c *Collection) Filter(filter func (*Server) bool) []*Server {
 
 // Returns a single element from the collection matching the filter. If nothing is
 // found a nil result is returned.
-func (c *Collection) Find(filter func (*Server) bool) *Server {
+func (c *Collection) Find(filter func(*Server) bool) *Server {
 	for _, v := range c.items {
 		if filter(v) {
 			return v
@@ -36,4 +53,19 @@ func (c *Collection) Find(filter func (*Server) bool) *Server {
 	}
 
 	return nil
-}
+}
+
+// Removes all items from the collection that match the filter function.
+func (c *Collection) Remove(filter func(*Server) bool) {
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+
+	r := make([]*Server, 0)
+	for _, v := range c.items {
+		if !filter(v) {
+			r = append(r, v)
+		}
+	}
+
+	c.items = r
+}

server/environment.go

@@ -40,6 +40,10 @@ type Environment interface {
 	// is not running no error should be returned.
 	Terminate(signal os.Signal) error
 
+	// Destroys the environment removing any containers that were created (in Docker
+	// environments at least).
+	Destroy() error
+
 	// Returns the exit state of the process. The first result is the exit code, the second
 	// determines if the process was killed by the system OOM killer.
 	ExitState() (uint32, bool, error)

server/environment_docker.go

@@ -325,6 +325,18 @@ func (d *DockerEnvironment) Terminate(signal os.Signal) error {
 	)
 }
 
+// Remove the Docker container from the machine. If the container is currently running
+// it will be forcibly stopped by Docker.
+func (d *DockerEnvironment) Destroy() error {
+	ctx := context.Background()
+
+	return d.Client.ContainerRemove(ctx, d.Server.Uuid, types.ContainerRemoveOptions{
+		RemoveVolumes: true,
+		RemoveLinks:   false,
+		Force:         true,
+	})
+}
+
 // Determine the container exit state and return the exit code and wether or not
 // the container was killed by the OOM killer.
 func (d *DockerEnvironment) ExitState() (uint32, bool, error) {

server/server.go

@@ -158,7 +158,7 @@ func LoadDirectory(dir string, cfg *config.SystemConfiguration) error {
 		return err
 	}
 
-	servers = new(Collection)
+	servers = NewCollection(nil)
 
 	for _, file := range f {
 		if !strings.HasSuffix(file.Name(), ".yml") || file.IsDir() {