service.go

package graph

import (
	"strings"

	floatschema "git.autistici.org/ai3/tools/float-dashboard/schema/float"
)

// ServiceGraph extracts a service dependency graph from a float schema.
func ServiceGraph(services map[string]*floatschema.Service) *Graph {
	g := NewGraph()

	// Create all nodes first.
	for svcname, s := range services {
		pelists := [][]floatschema.PublicEndpoint{s.PublicEndpoints, s.PublicTCPEndpoints}
		for _, pelist := range pelists {
			for _, pe := range pelist {
				name := pe.Name
				if name == "" {
					name = pe.Domains[0]
				}
				g.addNode(newWebNode(name, svcname))
			}
		}
		for _, c := range s.Containers {
			g.addNode(NewNode(mkTag(c.Name, svcname), svcname))
		}
		for _, sv := range s.SystemdServices {
			if strings.HasPrefix(sv, "docker-") {
				continue
			}
			name := strings.TrimSuffix(sv, ".service")
			g.addNode(NewNode(mkTag(name, svcname), svcname))
		}
	}

	// Now add all edges.
	for svcname, s := range services {
		pelists := [][]floatschema.PublicEndpoint{s.PublicEndpoints, s.PublicTCPEndpoints}
		for _, pelist := range pelists {
			for _, pe := range pelist {
				name := pe.Name
				if name == "" {
					name = pe.Domains[0]
				}
				g.addEdge(INTERNET, name)

				// Match the port with a container, if possible, or
				// fall back to the first systemd unit defined for the
				// service.
				if c := findContainerByPort(s, pe.Port); c != nil {
					g.addEdge(name, mkTag(c.Name, svcname))
				} else if unitName, ok := findFirstRealSystemdService(s); ok {
					g.addEdge(name, mkTag(unitName, svcname))
				}
			}
		}
		for _, d := range s.Annotations.Dependencies {
			g.addEdge(nodeNameFromDep(d.Client, svcname),
				nodeNameFromDep(d.Server, svcname))
		}
	}

	return g
}

func nodeNameFromDep(name, svcname string) string {
	if strings.Contains(name, "/") {
		return name
	}
	return mkTag(name, svcname)
}

func findContainerByPort(service *floatschema.Service, port int) *floatschema.Container {
	for i := 0; i < len(service.Containers); i++ {
		c := &service.Containers[i]
		if c.Port > 0 && c.Port == port {
			return c
		}
		for _, p := range c.Ports {
			if p == port {
				return c
			}
		}
	}
	return nil
}

func findFirstRealSystemdService(service *floatschema.Service) (string, bool) {
	for _, s := range service.SystemdServices {
		if !strings.HasPrefix(s, "docker-") {
			return strings.TrimSuffix(s, ".service"), true
		}
	}
	return "", false
}