refactor: break up cli pkg into nice small chunks

cli/server/init.go

@@ -0,0 +1,64 @@
+package server
+
+import (
+	"context"
+	"fmt"
+	"net"
+
+	"coopcloud.tech/abra/client"
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/swarm"
+	"github.com/urfave/cli/v2"
+)
+
+var serverInitCommand = &cli.Command{
+	Name:      "init",
+	Usage:     "Initialise server for deploying apps",
+	HideHelp:  true,
+	ArgsUsage: "<host>",
+	Description: `
+Initialise swarm mode on the target <host>.
+
+This initialisation explicitly chooses the "single host swarm" mode which uses
+the default IPv4 address as the advertising address. This can be re-configured
+later for more advanced use cases.
+`,
+	Action: func(c *cli.Context) error {
+		host := c.Args().First()
+		if host == "" {
+			cli.ShowSubcommandHelp(c)
+			return nil
+		}
+
+		cl, err := client.NewClientWithContext(host)
+		if err != nil {
+			return err
+		}
+
+		var ipv4 net.IP
+		ips, _ := net.LookupIP(host)
+		for _, ip := range ips {
+			ipv4 = ip.To4()
+		}
+
+		if string(ipv4) == "" {
+			return fmt.Errorf("unable to retrieve ipv4 address for %s", host)
+		}
+
+		ctx := context.Background()
+		initReq := swarm.InitRequest{
+			ListenAddr:    "0.0.0.0:2377",
+			AdvertiseAddr: string(ipv4),
+		}
+		if _, err := cl.SwarmInit(ctx, initReq); err != nil {
+			return err
+		}
+
+		netOpts := types.NetworkCreate{Driver: "overlay", Scope: "swarm"}
+		if _, err := cl.NetworkCreate(ctx, "proxy", netOpts); err != nil {
+			return err
+		}
+
+		return nil
+	},
+}