add parser and depgraph implementation

foreman.go

@@ -1 +1,116 @@
-package foreman 
+package foreman
+
+import (
+	"errors"
+	"log"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+	"time"
+
+	"github.com/Eslam-Nawara/foreman/internal/depgraph"
+	parser "github.com/Eslam-Nawara/foreman/internal/procparser"
+	"gopkg.in/yaml.v3"
+)
+
+const interval = 50 * time.Millisecond
+
+type Foreman struct {
+	services      map[string]parser.Service
+	verbose       bool
+	logger        *log.Logger
+	servicesMutex sync.Mutex
+}
+
+func New(filePath string, verbose bool) (*Foreman, error) {
+	foreman := &Foreman{
+		services:      map[string]parser.Service{},
+		servicesMutex: sync.Mutex{},
+		logger:        log.New(os.Stdout, "INFO: ", log.Ldate|log.Ltime),
+		verbose:       verbose,
+	}
+
+	yamlMap := make(map[string]map[string]any)
+
+	data, err := os.ReadFile(filePath)
+	if err != nil {
+		return nil, err
+	}
+
+	err = yaml.Unmarshal([]byte(data), yamlMap)
+	if err != nil {
+		return nil, err
+	}
+
+	for serviceName, serviceInfo := range yamlMap {
+		service := parser.ParseService(serviceInfo)
+		service.Name = serviceName
+		foreman.services[serviceName] = service
+	}
+	return foreman, nil
+}
+
+// start all services from yaml file
+func (foreman *Foreman) Start() error {
+	var wg sync.WaitGroup
+	graph := foreman.buildDepGraph()
+
+	if depgraph.IsCyclic(graph) {
+		return errors.New("Cyclic dependencies detected")
+	}
+
+	services := depgraph.TopSort(graph)
+
+	for _, serviceName := range services {
+		wg.Add(1)
+		go func(serviceName string) {
+			defer wg.Done()
+			foreman.runService(serviceName)
+		}(serviceName)
+	}
+
+	go func() {
+		sigChan := make(chan os.Signal)
+		signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
+		<-sigChan
+		foreman.Exit(1)
+	}()
+	wg.Wait()
+	return nil
+}
+
+// start one service and wait for it
+func (foreman *Foreman) runService(serviceName string) error {
+	return nil
+}
+
+func (foreman *Foreman) checker(serviceName string, stopChecker chan bool) {
+}
+
+func (foreman *Foreman) buildDepGraph() map[string][]string {
+	graph := make(map[string][]string)
+	for serviceName, service := range foreman.services {
+		graph[serviceName] = service.Deps
+	}
+	return graph
+}
+
+func (f *Foreman) vLog(msg string) {
+	if f.verbose {
+		f.logger.Print(msg)
+	}
+}
+
+// ُExit kills all the running services and checkers.
+// exits foreman with the given exit status.
+func (f *Foreman) Exit(exitStatus int) {
+	f.servicesMutex.Lock()
+	for _, service := range f.services {
+		if service.Process != nil {
+			syscall.Kill(-service.Process.Pid, syscall.SIGINT)
+		}
+	}
+	f.servicesMutex.Unlock()
+	os.Exit(exitStatus)
+}

go.mod

@@ -0,0 +1,16 @@
+module github.com/Eslam-Nawara/foreman
+
+go 1.19
+
+require (
+	github.com/shirou/gopsutil v3.21.11+incompatible
+	gopkg.in/yaml.v3 v3.0.1
+)
+
+require (
+	github.com/go-ole/go-ole v1.2.6 // indirect
+	github.com/tklauser/go-sysconf v0.3.11 // indirect
+	github.com/tklauser/numcpus v0.6.0 // indirect
+	github.com/yusufpapurcu/wmi v1.2.2 // indirect
+	golang.org/x/sys v0.3.0 // indirect
+)

go.sum

@@ -0,0 +1,18 @@
+github.com/go-ole/go-ole v1.2.6 h1:/Fpf6oFPoeFik9ty7siob0G6Ke8QvQEuVcuChpwXzpY=
+github.com/go-ole/go-ole v1.2.6/go.mod h1:pprOEPIfldk/42T2oK7lQ4v4JSDwmV0As9GaiUsvbm0=
+github.com/shirou/gopsutil v3.21.11+incompatible h1:+1+c1VGhc88SSonWP6foOcLhvnKlUeu/erjjvaPEYiI=
+github.com/shirou/gopsutil v3.21.11+incompatible/go.mod h1:5b4v6he4MtMOwMlS0TUMTu2PcXUg8+E1lC7eC3UO/RA=
+github.com/tklauser/go-sysconf v0.3.11 h1:89WgdJhk5SNwJfu+GKyYveZ4IaJ7xAkecBo+KdJV0CM=
+github.com/tklauser/go-sysconf v0.3.11/go.mod h1:GqXfhXY3kiPa0nAXPDIQIWzJbMCB7AmcWpGR8lSZfqI=
+github.com/tklauser/numcpus v0.6.0 h1:kebhY2Qt+3U6RNK7UqpYNA+tJ23IBEGKkB7JQBfDYms=
+github.com/tklauser/numcpus v0.6.0/go.mod h1:FEZLMke0lhOUG6w2JadTzp0a+Nl8PF/GFkQ5UVIcaL4=
+github.com/yusufpapurcu/wmi v1.2.2 h1:KBNDSne4vP5mbSWnJbO+51IMOXJB67QiYCSBrubbPRg=
+github.com/yusufpapurcu/wmi v1.2.2/go.mod h1:SBZ9tNy3G9/m5Oi98Zks0QjeHVDvuK0qfxQmPyzfmi0=
+golang.org/x/sys v0.0.0-20190916202348-b4ddaad3f8a3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.3.0 h1:w8ZOecv6NaNa/zC8944JTU3vz4u6Lagfk4RPQxv92NQ=
+golang.org/x/sys v0.3.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/depgraph/depgraph.go

@@ -1 +1,57 @@
 package depgraph
+
+const (
+	unvisited         = 0
+	visited           = 1
+	currentlyVisiting = 2
+)
+
+func TopSort(graph map[string][]string) []string {
+	var out []string
+	state := make(map[string]int)
+	var ts func(string)
+
+	ts = func(node string) {
+		if state[node] == visited {
+			return
+		}
+		state[node] = visited
+		for _, child := range graph[node] {
+			ts(child)
+		}
+		out = append(out, node)
+	}
+
+	for node := range graph {
+		ts(node)
+	}
+
+	return out
+}
+
+func IsCyclic(graph map[string][]string) bool {
+	state := make(map[string]int)
+	cyclic := false
+	var dfs func(string)
+
+	dfs = func(node string) {
+		if state[node] == visited {
+			return
+		}
+		if state[node] == currentlyVisiting {
+			cyclic = true
+			return
+		}
+
+		state[node] = currentlyVisiting
+		for _, child := range graph[node] {
+			dfs(child)
+		}
+		state[node] = visited
+	}
+
+	for node := range graph {
+		dfs(node)
+	}
+	return cyclic
+}

internal/procparser/procfile_parser.go

@@ -1 +1,69 @@
-package procparser 
+package procparser
+
+import (
+	"fmt"
+	"os"
+)
+
+type (
+	Service struct {
+		Name    string
+		Status  bool
+		Process *os.Process
+		Cmd     string
+		RunOnce bool
+		Checks  ServiceChecks
+		Deps    []string
+	}
+
+	ServiceChecks struct {
+		Cmd      string
+		TcpPorts []string
+		UdpPorts []string
+	}
+)
+
+func ParseService(serviceMap map[string]any) Service {
+	service := Service{}
+
+	for key, value := range serviceMap {
+		switch key {
+		case "cmd":
+			service.cmd = value.(string)
+		case "run_once":
+			service.RunOnce = value.(bool)
+		case "deps":
+			for _, dep := range value.([]any) {
+				service.Deps = append(service.Deps, dep.(string))
+			}
+		case "checks":
+			service.Checks = parseChecks(value)
+		}
+	}
+	return service
+}
+
+func parseChecks(serviceChecks any) ServiceChecks {
+	checksMap := ServiceChecks{}
+
+	for key, value := range serviceChecks.(map[string]any) {
+		switch key {
+		case "cmd":
+			checksMap.Cmd = value.(string)
+		case "tcp_ports":
+			checksMap.TcpPorts = parsePorts(value)
+		case "udp_ports":
+			checksMap.UdpPorts = parsePorts(value)
+		}
+	}
+	return checksMap
+}
+
+func parsePorts(ports any) []string {
+	var parsedPorts []string
+	for _, port := range ports.([]any) {
+		parsedPorts = append(parsedPorts, fmt.Sprint(port.(int)))
+	}
+
+	return parsedPorts
+}