WIP

docker.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"docker.io/go-docker/api/types"
+)
+
+type ipsToNamesMap map[string][]string
+
+type dockerClienter interface {
+	ContainerList(context.Context, types.ContainerListOptions) ([]types.Container, error)
+	ContainerInspect(context.Context, string) (types.ContainerJSON, error)
+}
+
+func getAllIPsToNames(client dockerClienter) (ipsToNamesMap, error) {
+	containers, err := client.ContainerList(context.Background(), types.ContainerListOptions{})
+	if err != nil {
+		return nil, err
+	}
+
+	allIPsToNames := make(ipsToNamesMap)
+
+	for _, container := range containers {
+		ipsToNames, err := getIPsToNames(client, container.ID)
+		if err != nil {
+			return nil, err
+		}
+
+		for ip, names := range ipsToNames {
+			if _, ok := allIPsToNames[ip]; !ok {
+				allIPsToNames[ip] = names
+			} else {
+				allIPsToNames[ip] = append(allIPsToNames[ip], names...)
+			}
+		}
+	}
+	return allIPsToNames, nil
+}
+
+func getIPsToNames(client dockerClienter, id string) (ipsToNamesMap, error) {
+	ipsToNames := make(ipsToNamesMap)
+
+	// ContainerList does not return all info, like Aliases
+	// see: curl --unix-socket /var/run/docker.sock http://localhost/containers/json
+	containerFull, err := client.ContainerInspect(context.Background(), id)
+	if err != nil {
+		return nil, err
+	}
+
+	for netName, netInfo := range containerFull.NetworkSettings.Networks {
+		names := make([]string, 4) // 4 is worst-case size if container in a compose project (see below)
+
+		appendNames := func(names []string, name string) []string {
+			names = append(names, fmt.Sprintf("%s", name))
+			names = append(names, fmt.Sprintf("%s.%s", name, netName))
+			if proj, ok := containerFull.Config.Labels["com.docker.compose.project"]; ok {
+				names = append(names, fmt.Sprintf("%s.%s", name, proj))
+				names = append(names, fmt.Sprintf("%s.%s.%s", name, proj, netName))
+			}
+			return names
+		}
+
+		names = appendNames(names, strings.Trim(containerFull.Name, "/"))
+		for _, name := range netInfo.Aliases {
+			names = appendNames(names, name)
+		}
+
+		ipsToNames[netInfo.IPAddress] = names
+	}
+
+	return ipsToNames, nil
+}