Completely re-work the server configuration to be separated out better

server/resources.go

@@ -4,29 +4,37 @@ import (
 	"github.com/docker/docker/api/types"
 	"math"
 	"sync"
+	"sync/atomic"
 )
 
 // Defines the current resource usage for a given server instance. If a server is offline you
 // should obviously expect memory and CPU usage to be 0. However, disk will always be returned
 // since that is not dependent on the server being running to collect that data.
 type ResourceUsage struct {
-	sync.RWMutex
+	mu sync.RWMutex
+
+	// The current server status.
+	State string `json:"state" default:"offline"`
 
 	// The total amount of memory, in bytes, that this server instance is consuming. This is
 	// calculated slightly differently than just using the raw Memory field that the stats
 	// return from the container, so please check the code setting this value for how that
 	// is calculated.
 	Memory uint64 `json:"memory_bytes"`
+
 	// The total amount of memory this container or resource can use. Inside Docker this is
 	// going to be higher than you'd expect because we're automatically allocating overhead
 	// abilities for the container, so its not going to be a perfect match.
 	MemoryLimit uint64 `json:"memory_limit_bytes"`
+
 	// The absolute CPU usage is the amount of CPU used in relation to the entire system and
 	// does not take into account any limits on the server process itself.
 	CpuAbsolute float64 `json:"cpu_absolute"`
+
 	// The current disk space being used by the server. This is cached to prevent slow lookup
 	// issues on frequent refreshes.
 	Disk int64 `json:"disk_bytes"`
+
 	// Current network transmit in & out for a container.
 	Network struct {
 		RxBytes uint64 `json:"rx_bytes"`
@@ -34,11 +42,29 @@ type ResourceUsage struct {
 	} `json:"network"`
 }
 
+// Returns the resource usage stats for the server instance. If the server is not running, only the
+// disk space currently used will be returned. When the server is running all of the other stats will
+// be returned.
+//
+// When a process is stopped all of the stats are zeroed out except for the disk.
+func (s *Server) Proc() *ResourceUsage {
+	s.resources.mu.RLock()
+	defer s.resources.mu.RUnlock()
+
+	return &s.resources
+}
+
+func (ru *ResourceUsage) setInternalState(state string) {
+	ru.mu.Lock()
+	ru.State = state
+	ru.mu.Unlock()
+}
+
 // Resets the usages values to zero, used when a server is stopped to ensure we don't hold
 // onto any values incorrectly.
 func (ru *ResourceUsage) Empty() {
-	ru.Lock()
-	defer ru.Unlock()
+	ru.mu.Lock()
+	defer ru.mu.Unlock()
 
 	ru.Memory = 0
 	ru.CpuAbsolute = 0
@@ -46,6 +72,27 @@ func (ru *ResourceUsage) Empty() {
 	ru.Network.RxBytes = 0
 }
 
+func (ru *ResourceUsage) SetDisk(i int64) {
+	ru.mu.Lock()
+	defer ru.mu.Unlock()
+
+	ru.Disk = i
+}
+
+func (ru *ResourceUsage) UpdateFromDocker(v *types.StatsJSON) {
+	ru.mu.Lock()
+	defer ru.mu.Unlock()
+
+	ru.CpuAbsolute = ru.calculateDockerAbsoluteCpu(&v.PreCPUStats, &v.CPUStats)
+	ru.Memory = ru.calculateDockerMemory(v.MemoryStats)
+	ru.MemoryLimit = v.MemoryStats.Limit
+}
+
+func (ru *ResourceUsage) UpdateNetworkBytes(nw *types.NetworkStats) {
+	atomic.AddUint64(&ru.Network.RxBytes, nw.RxBytes)
+	atomic.AddUint64(&ru.Network.TxBytes, nw.TxBytes)
+}
+
 // The "docker stats" CLI call does not return the same value as the types.MemoryStats.Usage
 // value which can be rather confusing to people trying to compare panel usage to
 // their stats output.
@@ -55,7 +102,7 @@ func (ru *ResourceUsage) Empty() {
 // correct memory value anyways.
 //
 // @see https://github.com/docker/cli/blob/96e1d1d6/cli/command/container/stats_helpers.go#L227-L249
-func (ru *ResourceUsage) CalculateDockerMemory(stats types.MemoryStats) uint64 {
+func (ru *ResourceUsage) calculateDockerMemory(stats types.MemoryStats) uint64 {
 	if v, ok := stats.Stats["total_inactive_file"]; ok && v < stats.Usage {
 		return stats.Usage - v
 	}
@@ -71,7 +118,7 @@ func (ru *ResourceUsage) CalculateDockerMemory(stats types.MemoryStats) uint64 {
 // by the defined CPU limits on the container.
 //
 // @see https://github.com/docker/cli/blob/aa097cf1aa19099da70930460250797c8920b709/cli/command/container/stats_helpers.go#L166
-func (ru *ResourceUsage) CalculateAbsoluteCpu(pStats *types.CPUStats, stats *types.CPUStats) float64 {
+func (ru *ResourceUsage) calculateDockerAbsoluteCpu(pStats *types.CPUStats, stats *types.CPUStats) float64 {
 	// Calculate the change in CPU usage between the current and previous reading.
 	cpuDelta := float64(stats.CPUUsage.TotalUsage) - float64(pStats.CPUUsage.TotalUsage)