feat: added basic scaffolding for host executor

backend/executor/exec.go

@@ -1,16 +1,15 @@
 package executor
 
-import "time"
-
 // Service is a service that handles executing commands on the main host and does a first processing of the raw data it gets from the system
 type Service interface {
-	SlurmQueue() []string
-	SlurmJobs() []string
+	SlurmQueue() ([]string, error)
+	SlurmJobs() ([]string, error)
 
-	NodeUptime(hostname string) time.Time
+	NodeUptime(hostname string) (string, error)
 
-	Temperature(hostname string) float64
-	MemoryUsage(hostname string) int64
-	StorageUsage(hostname string) int64
-	NetworkUploadDownload(hostname string) (int64, int64)
+	Temperature(hostname string) (string, error)
+	MemoryUsage(hostname string) (string, error)
+	StorageUsage(hostname string) (string, error)
+	NetworkUpload(hostname string) (string, error)
+	NetworkDownload(hostname string) (string, error)
 }

backend/executor/hostrunner.go

@@ -0,0 +1,72 @@
+package executor
+
+import (
+	"bytes"
+	"fmt"
+	"os/exec"
+	"strings"
+)
+
+type HostRunner struct{}
+
+func (HostRunner) SlurmQueue() ([]string, error) {
+	panic("todo")
+}
+
+func (HostRunner) SlurmJobs() ([]string, error) {
+	panic("todo")
+}
+
+func (HostRunner) NodeUptime(hostname string) (string, error) {
+	panic("todo")
+}
+
+func (HostRunner) Temperature(hostname string) (string, error) {
+	panic("todo")
+}
+
+func (HostRunner) MemoryUsage(hostname string) (string, error) {
+	panic("todo")
+}
+
+func (HostRunner) StorageUsage(hostname string) (string, error) {
+	panic("todo")
+}
+
+func (HostRunner) NetworkUpload(hostname string) (string, error) {
+	panic("todo")
+}
+
+func (HostRunner) NetworkDownload(hostname string) (string, error) {
+	panic("todo")
+}
+
+//
+// Internals
+//
+
+// run a shell command and returns its output as string
+func run(command string) (string, error) {
+	buf := &bytes.Buffer{}
+
+	// ctx := context.Background()
+	// ctx, cancel := context.WithTimeout(ctx, 1*time.Second)
+	// defer cancel()
+	// cmd := exec.CommandContext(ctx, "sh", "-c", command)
+
+	cmd := exec.Command("sh", "-c", command)
+	cmd.Stdout = buf
+
+	// BUG: Al momento se questo comando ci mette troppo tutto si blocca, quindi sarebbe meglio
+	// usare un context per dare un timeout al comando
+	if err := cmd.Run(); err != nil {
+		return "", err
+	}
+
+	return buf.String(), nil
+}
+
+// run a shell command on a given remote via ssh and returns its output as string, does a bit of escaping
+func runOnRemote(destination, command string) (string, error) {
+	return run(fmt.Sprintf(`ssh %s '%s'`, destination, strings.ReplaceAll(command, `'`, `\'`)))
+}

backend/executor/mock.go

@@ -1,43 +1,46 @@
 package executor
 
-import "time"
-
 var _ Service = &Mock{}
 
 type Mock struct {
-	SlurmQueueFunc            func() []string
-	SlurmJobsFunc             func() []string
-	NodeUptimeFunc            func(hostname string) time.Time
-	TemperatureFunc           func(hostname string) float64
-	MemoryUsageFunc           func(hostname string) int64
-	StorageUsageFunc          func(hostname string) int64
-	NetworkUploadDownloadFunc func(hostname string) (int64, int64)
+	SlurmQueueFunc      func() ([]string, error)
+	SlurmJobsFunc       func() ([]string, error)
+	NodeUptimeFunc      func(hostname string) (string, error)
+	TemperatureFunc     func(hostname string) (string, error)
+	MemoryUsageFunc     func(hostname string) (string, error)
+	StorageUsageFunc    func(hostname string) (string, error)
+	NetworkUploadFunc   func(hostname string) (string, error)
+	NetworkDownloadFunc func(hostname string) (string, error)
 }
 
-func (ex *Mock) SlurmQueue() []string {
-	return ex.SlurmQueueFunc()
+func (m Mock) SlurmQueue() ([]string, error) {
+	return m.SlurmQueueFunc()
 }
 
-func (ex *Mock) SlurmJobs() []string {
-	return ex.SlurmJobsFunc()
+func (m Mock) SlurmJobs() ([]string, error) {
+	return m.SlurmJobsFunc()
 }
 
-func (ex *Mock) NodeUptime(hostname string) time.Time {
-	return ex.NodeUptimeFunc(hostname)
+func (m Mock) NodeUptime(hostname string) (string, error) {
+	return m.NodeUptimeFunc(hostname)
 }
 
-func (ex *Mock) Temperature(hostname string) float64 {
-	return ex.TemperatureFunc(hostname)
+func (m Mock) Temperature(hostname string) (string, error) {
+	return m.TemperatureFunc(hostname)
 }
 
-func (ex *Mock) MemoryUsage(hostname string) int64 {
-	return ex.MemoryUsageFunc(hostname)
+func (m Mock) MemoryUsage(hostname string) (string, error) {
+	return m.MemoryUsageFunc(hostname)
 }
 
-func (ex *Mock) StorageUsage(hostname string) int64 {
-	return ex.StorageUsageFunc(hostname)
+func (m Mock) StorageUsage(hostname string) (string, error) {
+	return m.StorageUsageFunc(hostname)
 }
 
-func (ex *Mock) NetworkUploadDownload(hostname string) (int64, int64) {
-	return ex.NetworkUploadDownloadFunc(hostname)
+func (m Mock) NetworkUpload(hostname string) (string, error) {
+	return m.NetworkUploadFunc(hostname)
+}
+
+func (m Mock) NetworkDownload(hostname string) (string, error) {
+	return m.NetworkDownloadFunc(hostname)
 }