feat(attributes): add proc status and mem info for linux (#25)

During report creation, we need to generate information about current
process state - for example: memory information

On Linux - we have a really nice way to get those attributes. We should
read /proc/meminfo and /proc/self/status to get information about the
process. Next we need to convert data from the file into attributes

main.go

@@ -32,15 +32,15 @@ var (
 	windowsGUIDCommand = []string{"reg", "query", "\"HKEY_LOCAL_MACHINE\\Software\\Microsoft\\Cryptography\"", "/v", "MachineGuid"}
 	linuxGUIDCommand   = []string{"sh", "-c", "( cat /var/lib/dbus/machine-id /etc/machine-id 2> /dev/null || hostname ) | head -n 1 || :"}
 	freebsdGUIDCommand = []string{"sh", "-c", "kenv -q smbios.system.uuid || sysctl -n kern.hostuuid"}
-	darwinGUIDCommand  = []string{"sh", "-c", "ioreg -rd1 -c IOPlatformExpertDevice | grep IOPlatformUUID | awk -F'= \"' '{print $2}' | tr -d '\"'"}
+	darwinGUIDCommand  = []string{"sh", "-c", "ioreg -rd1 -c IOPlatformExpertDevice | grep IOPlatformUUID | awk -F'= \"' '{print $2}' | tr -d '\"' | tr -d '\n'"}
 
 	windowsCPUCommand = []string{"wmic", "CPU", "get", "NAME"}
 	linuxCPUCommand   = []string{"sh", "-c", "lscpu | grep \"Model name\" | awk -F':' '{print $2}' | sed 's/^[[:space:]]*//'"}
-	darwinCPUCommand  = []string{"sh", "-c", "sysctl -n machdep.cpu.brand_string"}
+	darwinCPUCommand  = []string{"sh", "-c", "sysctl -n machdep.cpu.brand_string | tr -d '\n'"}
 	freebsdCPUCommand = []string{"sh", "-c", "sysctl -n hw.model"}
 
 	linuxOSVersionCommand   = []string{"sh", "-c", "cat /etc/os-release | grep VERSION= | awk -F'=\"' '{print $2}' | tr -d '\"'"}
-	darwinOSVersionCommand  = []string{"sh", "-c", "sw_vers | grep ProductVersion | awk -F':' '{print $2}' | tr -d '\t'"}
+	darwinOSVersionCommand  = []string{"sh", "-c", "sw_vers | grep ProductVersion | awk -F':' '{print $2}' | tr -d '\t' | tr -d '\n'"}
 	freebsdOSVersionCommand = []string{"sh", "-c", "cat /etc/os-release | grep VERSION= | awk -F'=\"' '{print $2}' | tr -d '\"'"}
 )
 
@@ -370,6 +370,10 @@ func processAndSend(payload *reportPayload) {
 	report["sourceCode"] = sourceCode
 	report["classifiers"] = []string{payload.classifier}
 
+	if runtime.GOOS == "linux" {
+		readMemProcInfo()
+	}
+
 	fullUrl := Options.Endpoint
 
 	if len(Options.Token) != 0 { // if token is set that means its old URL.

procmeminfo.go

@@ -0,0 +1,108 @@
+package bt
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+)
+
+const (
+	memPath  = "/proc/meminfo"
+	procPath = "/proc/self/status"
+)
+
+var (
+	paths  = []string{memPath, procPath}
+	mapper = map[string]string{
+		"MemTotal":                   "system.memory.total",
+		"MemFree":                    "system.memory.free",
+		"MemAvailable":               "system.memory.available",
+		"Buffers":                    "system.memory.buffers",
+		"Cached":                     "system.memory.cached",
+		"SwapCached":                 "system.memory.swap.cached",
+		"Active":                     "system.memory.active",
+		"Inactive":                   "system.memory.inactive",
+		"SwapTotal":                  "system.memory.swap.total",
+		"SwapFree":                   "system.memory.swap.free",
+		"Dirty":                      "system.memory.dirty",
+		"Writeback":                  "system.memory.writeback",
+		"Slab":                       "system.memory.slab",
+		"VmallocTotal":               "system.memory.vmalloc.total",
+		"VmallocUsed":                "system.memory.vmalloc.used",
+		"VmallocChunk":               "system.memory.vmalloc.chunk",
+		"nonvoluntary_ctxt_switches": "sched.cs.involuntary",
+		"voluntary_ctxt_switches":    "sched.cs.voluntary",
+		"FDSize":                     "descriptor.count",
+		"VmData":                     "vm.data.size",
+		"VmLck":                      "vm.locked.size",
+		"VmPTE":                      "vm.pte.size",
+		"VmHWM":                      "vm.rss.peak",
+		"VmRSS":                      "vm.rss.size",
+		"VmLib":                      "vm.shared.size",
+		"VmStk":                      "vm.stack.size",
+		"VmSwap":                     "vm.swap.size",
+		"VmPeak":                     "vm.vma.peak",
+		"VmSize":                     "vm.vma.size",
+	}
+)
+
+func readMemProcInfo() {
+	for _, path := range paths {
+		readFile(path)
+	}
+}
+
+func readFile(path string) {
+	file, err := os.Open(path)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer file.Close()
+
+	reader := bufio.NewReader(file)
+	for {
+		l, _, err := reader.ReadLine()
+		if err != nil {
+			if err == io.EOF {
+				break
+			} else {
+				if Options.DebugBacktrace {
+					log.Printf("readFile err: %v", err)
+				}
+				break
+			}
+		}
+
+		values := strings.Split(string(l), ":")
+		if len(values) == 2 {
+			if attr, exists := mapper[values[0]]; exists {
+				value, err := getValue(values[1])
+				if err != nil {
+					continue
+				}
+				Options.Attributes[attr] = value
+			}
+		}
+	}
+}
+
+func getValue(value string) (string, error) {
+	value = strings.TrimSpace(value)
+	if strings.HasSuffix(value, "kB") {
+		value = strings.TrimSuffix(value, " kB")
+
+		atoi, err := strconv.ParseInt(value, 10, 64)
+		if err != nil && Options.DebugBacktrace {
+			log.Printf("readFile err: %v", err)
+			return "", err
+		}
+		atoi *= 1024
+		return fmt.Sprintf("%d", atoi), err
+	}
+
+	return value, nil
+}