docker: make daemon.json editable for additional configs

Signed-off-by: Abiola Ibrahim <[email protected]>

Author: abiosoft

app.go

@@ -83,7 +83,7 @@ func (c colimaApp) Start(conf config.Config) error {
 		return fmt.Errorf("error setting kubernetes version: %w", err)
 	}
 
-	// provision container runtime
+	// provision container runtimes
 	for _, cont := range containers {
 		if err := cont.Provision(); err != nil {
 			return fmt.Errorf("error provisioning %s: %w", cont.Name(), err)

environment/container/docker/docker.go

@@ -89,6 +89,9 @@ func (d dockerRuntime) Provision() error {
 	})
 	a.Add(func() error { return createLaunchdScript(d.launchd) })
 
+	// daemon.json
+	a.Add(d.setupDaemonFile)
+
 	return a.Exec()
 }
 

environment/container/docker/setup.go

@@ -1,7 +1,10 @@
 package docker
 
 import (
+	"encoding/json"
 	"fmt"
+	"github.com/abiosoft/colima/config"
+	"path/filepath"
 )
 
 func (d dockerRuntime) setupSocketSymlink() error {
@@ -27,20 +30,6 @@ func (d dockerRuntime) setupInVM() error {
 		return fmt.Errorf("error installing in VM: %w", err)
 	}
 
-	// enable buildkit by default.
-	// eventually, there should be an easy way to configure docker.
-	// users may want to set other configs like registries e.t.c.
-
-	err = d.guest.Run("sudo", "mkdir", "-p", "/etc/docker")
-	if err != nil {
-		return fmt.Errorf("error setting up default config: %w", err)
-	}
-
-	err = d.guest.Run("sudo", "sh", "-c", `echo '{"features":{"buildkit":true},"exec-opts":["native.cgroupdriver=cgroupfs"]}' > /etc/docker/daemon.json`)
-	if err != nil {
-		return fmt.Errorf("error enabling buildkit: %w", err)
-	}
-
 	return nil
 }
 
@@ -54,3 +43,66 @@ func (d dockerRuntime) fixUserPermission() error {
 	}
 	return nil
 }
+
+var daemonJson struct {
+	Features struct {
+		BuildKit bool `json:"buildkit"`
+	} `json:"features"`
+	ExecOpts []string `json:"exec-opts"`
+}
+
+func init() {
+	// enable buildkit by default.
+	daemonJson.Features.BuildKit = true
+	// k3s needs cgroupfs
+	daemonJson.ExecOpts = append(daemonJson.ExecOpts, "native.cgroupdriver=cgroupfs")
+}
+
+func (d dockerRuntime) createDaemonFile(fileName string) error {
+	b, err := json.MarshalIndent(daemonJson, "", "    ")
+	if err != nil {
+		return fmt.Errorf("error marshaling deamon.json: %w", err)
+	}
+	return d.host.Write(fileName, string(b))
+}
+
+func (d dockerRuntime) setupDaemonFile() error {
+	log := d.Logger()
+	daemonFile := filepath.Join(config.Dir(), "docker", "daemon.json")
+
+	// ensure config directory
+	if err := d.host.RunQuiet("mkdir", "-p", filepath.Dir(daemonFile)); err != nil {
+		return fmt.Errorf("error creating config directory: %w", err)
+	}
+
+	// check daemon.json or create default
+	if _, err := d.host.Stat(daemonFile); err != nil {
+		log.Warnln("daemon.json not found, falling back to default")
+		if err := d.createDaemonFile(daemonFile); err != nil {
+			return fmt.Errorf("error creating daemon.json: %w", err)
+		}
+	}
+
+	daemonFileInVM := filepath.Join(config.CacheDir(), "daemon.json")
+
+	// copy to vm, cache directory is shared by host and vm and guaranteed to be mounted.
+	if err := d.host.RunQuiet("cp", daemonFile, daemonFileInVM); err != nil {
+		return fmt.Errorf("error copying daemon.json to VM: %w", err)
+	}
+
+	// copy to location in VM
+	if err := d.guest.RunQuiet("sudo", "mkdir", "-p", "/etc/docker"); err != nil {
+		return fmt.Errorf("error setting up default config: %w", err)
+	}
+
+	if err := d.guest.RunQuiet("sudo", "cp", daemonFileInVM, "/etc/docker/daemon.json"); err != nil {
+		return fmt.Errorf("error copying deamon.json: %w", err)
+	}
+
+	// config changed, restart is a must
+	if d.Running() {
+		return d.guest.RunQuiet("sudo", "service", "docker", "stop")
+	}
+
+	return nil
+}