Support Linux

internal/commands/config/config.go

@@ -53,12 +53,15 @@ func runConfig(cmd *cobra.Command, args []string) error {
 		// to be absolute[1].
 		//
 		// 2. GitLab Runner uses relative paths internally which results in improper directory traversal[2],
-		// this is why we use "/private/tmp" instead of just "/tmp" here as a workaround.
+		// so instead of "/tmp" we need to use "/private/tmp" here as a workaround.
+		//
+		// 3. However, there's no "/private/tmp" on Linux. So we use the lowest common denominator
+		// in the form of "/var/tmp". It's both (1) not a symbolic link and (2) is present on both platforms.
 		//
 		// [1]: https://docs.gitlab.com/runner/configuration/advanced-configuration.html#the-runners-section
 		// [2]: https://gitlab.com/gitlab-org/gitlab-runner/-/issues/31003
-		BuildsDir: "/private/tmp/builds",
-		CacheDir:  "/private/tmp/cache",
+		BuildsDir: "/var/tmp/builds",
+		CacheDir:  "/var/tmp/cache",
 		JobEnv:    map[string]string{},
 	}
 
@@ -95,15 +98,14 @@ func runConfig(cmd *cobra.Command, args []string) error {
 	// Figure out the builds directory override to use
 	switch {
 	case tartConfig.HostDir:
-		gitlabRunnerConfig.BuildsDir = fmt.Sprintf("/Users/%s/hostdir", tartConfig.SSHUsername)
+		gitlabRunnerConfig.JobEnv[tart.EnvTartExecutorInternalBuildsDirOnHost] = gitLabEnv.HostDirPath()
 
 		if err := os.MkdirAll(gitLabEnv.HostDirPath(), 0700); err != nil {
 			return err
 		}
 	case buildsDir != "":
-		gitlabRunnerConfig.BuildsDir = fmt.Sprintf("/Users/%s/buildsdir", tartConfig.SSHUsername)
 		buildsDir = os.ExpandEnv(buildsDir)
-		gitlabRunnerConfig.JobEnv[tart.EnvTartExecutorInternalBuildsDir] = buildsDir
+		gitlabRunnerConfig.JobEnv[tart.EnvTartExecutorInternalBuildsDirOnHost] = buildsDir
 
 		if err := os.MkdirAll(buildsDir, 0700); err != nil {
 			return err
@@ -115,9 +117,8 @@ func runConfig(cmd *cobra.Command, args []string) error {
 	// Figure out the cache directory override to use
 	switch {
 	case cacheDir != "":
-		gitlabRunnerConfig.CacheDir = fmt.Sprintf("/Users/%s/cachedir", tartConfig.SSHUsername)
 		cacheDir = os.ExpandEnv(cacheDir)
-		gitlabRunnerConfig.JobEnv[tart.EnvTartExecutorInternalCacheDir] = cacheDir
+		gitlabRunnerConfig.JobEnv[tart.EnvTartExecutorInternalCacheDirOnHost] = cacheDir
 
 		if err := os.MkdirAll(cacheDir, 0700); err != nil {
 			return err
@@ -126,6 +127,11 @@ func runConfig(cmd *cobra.Command, args []string) error {
 		gitlabRunnerConfig.CacheDir = guestCacheDir
 	}
 
+	// Propagate builds and cache directory locations in the guest
+	// because GitLab Runner won't do this for us
+	gitlabRunnerConfig.JobEnv[tart.EnvTartExecutorInternalBuildsDir] = gitlabRunnerConfig.BuildsDir
+	gitlabRunnerConfig.JobEnv[tart.EnvTartExecutorInternalCacheDir] = gitlabRunnerConfig.CacheDir
+
 	jsonBytes, err := json.MarshalIndent(&gitlabRunnerConfig, "", "  ")
 	if err != nil {
 		return err

internal/commands/prepare/install-gitlab-runner-auto.sh

@@ -10,7 +10,18 @@
 #
 set -euo pipefail
 
-GITLAB_RUNNER_URL="https://gitlab-runner-downloads.s3.amazonaws.com/latest/binaries/gitlab-runner-darwin-arm64"
+OS=$(uname -s | tr '[:upper:]' '[:lower:]')
+ARCH=$(uname -m)
+case $ARCH in
+  aarch64)
+      ARCH="arm64"
+      ;;
+  x86_64)
+      ARCH="amd64"
+      ;;
+esac
+
+GITLAB_RUNNER_URL="https://gitlab-runner-downloads.s3.amazonaws.com/latest/binaries/gitlab-runner-${OS}-${ARCH}"
 GITLAB_RUNNER_PATH="/usr/local/bin/gitlab-runner"
 
 # Is GitLab Runner already installed?

internal/commands/prepare/install-gitlab-runner-curl.sh

@@ -10,8 +10,19 @@
 #
 set -euo pipefail
 
+OS=$(uname -s | tr '[:upper:]' '[:lower:]')
+ARCH=$(uname -m)
+case $ARCH in
+  aarch64)
+      ARCH="arm64"
+      ;;
+  x86_64)
+      ARCH="amd64"
+      ;;
+esac
+
 GITLAB_RUNNER_VERSION="latest"
-GITLAB_RUNNER_URL="https://gitlab-runner-downloads.s3.amazonaws.com/${GITLAB_RUNNER_VERSION}/binaries/gitlab-runner-darwin-arm64"
+GITLAB_RUNNER_URL="https://gitlab-runner-downloads.s3.amazonaws.com/${GITLAB_RUNNER_VERSION}/binaries/gitlab-runner-${OS}-${ARCH}"
 GITLAB_RUNNER_PATH="/usr/local/bin/gitlab-runner"
 
 # Is GitLab Runner already installed?

internal/commands/prepare/prepare.go

@@ -191,29 +191,51 @@ func runPrepareVM(cmd *cobra.Command, args []string) error {
 		log.Printf("Timezone was set to %s!\n", tz)
 	}
 
-	dirsToMount := []string{}
-	if config.HostDir {
-		dirsToMount = append(dirsToMount, "hostdir")
+	type MountPoint struct {
+		Name string
+		Path string
 	}
-	if _, ok := os.LookupEnv(tart.EnvTartExecutorInternalBuildsDir); ok {
-		dirsToMount = append(dirsToMount, "buildsdir")
+
+	vmInfo, err := vm.Info(cmd.Context())
+	if err != nil {
+		return err
 	}
-	if _, ok := os.LookupEnv(tart.EnvTartExecutorInternalCacheDir); ok {
-		dirsToMount = append(dirsToMount, "cachedir")
+
+	var mountPoints []MountPoint
+
+	if _, ok := os.LookupEnv(tart.EnvTartExecutorInternalBuildsDirOnHost); ok {
+		mountPoints = append(mountPoints, MountPoint{
+			Name: "buildsdir",
+			Path: os.Getenv(tart.EnvTartExecutorInternalBuildsDir),
+		})
+	}
+	if _, ok := os.LookupEnv(tart.EnvTartExecutorInternalCacheDirOnHost); ok {
+		mountPoints = append(mountPoints, MountPoint{
+			Name: "cachedir",
+			Path: os.Getenv(tart.EnvTartExecutorInternalCacheDir),
+		})
 	}
 
-	for _, dirToMount := range dirsToMount {
-		log.Printf("Mounting %s...\n", dirToMount)
+	for _, mountPoint := range mountPoints {
+		log.Printf("Mounting %s on %s...\n", mountPoint.Name, mountPoint.Path)
 
 		session, err := ssh.NewSession()
 		if err != nil {
 			return err
 		}
 		defer session.Close()
 
-		mountPoint := fmt.Sprintf("/Users/%s/%s", config.SSHUsername, dirToMount)
-		mkdirScript := fmt.Sprintf("mkdir -p %s", mountPoint)
-		mountScript := fmt.Sprintf("mount_virtiofs tart.virtiofs.%s.%s %s", dirToMount, gitLabEnv.JobID, mountPoint)
+		var command string
+
+		if vmInfo.OS == "darwin" {
+			command = "mount_virtiofs"
+		} else {
+			command = "sudo mount -t virtiofs"
+		}
+
+		mkdirScript := fmt.Sprintf("mkdir -p %s", mountPoint.Path)
+		mountScript := fmt.Sprintf("%s tart.virtiofs.%s.%s %s", command, mountPoint.Name,
+			gitLabEnv.JobID, mountPoint.Path)
 		session.Stdin = bytes.NewBufferString(strings.Join([]string{mkdirScript, mountScript, ""}, "\n"))
 		session.Stdout = os.Stdout
 		session.Stderr = os.Stderr

internal/tart/config.go

@@ -24,10 +24,20 @@ const (
 	// by the user.
 	EnvTartExecutorInternalBuildsDir = "TART_EXECUTOR_INTERNAL_BUILDS_DIR"
 
+	// EnvTartExecutorInternalBuildsDirOnHost is an internal environment variable
+	// that does not use the "CUSTOM_ENV_" prefix, thus preventing the override
+	// by the user.
+	EnvTartExecutorInternalBuildsDirOnHost = "TART_EXECUTOR_INTERNAL_BUILDS_DIR_ON_HOST"
+
 	// EnvTartExecutorInternalCacheDir is an internal environment variable
 	// that does not use the "CUSTOM_ENV_" prefix, thus preventing the override
 	// by the user.
 	EnvTartExecutorInternalCacheDir = "TART_EXECUTOR_INTERNAL_CACHE_DIR"
+
+	// EnvTartExecutorInternalCacheDirOnHost is an internal environment variable
+	// that does not use the "CUSTOM_ENV_" prefix, thus preventing the override
+	// by the user.
+	EnvTartExecutorInternalCacheDirOnHost = "TART_EXECUTOR_INTERNAL_CACHE_DIR_ON_HOST"
 )
 
 type Config struct {

internal/tart/vm.go

@@ -3,6 +3,7 @@ package tart
 import (
 	"bytes"
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -35,6 +36,10 @@ type VM struct {
 	id string
 }
 
+type VMInfo struct {
+	OS string `json:"os"`
+}
+
 func ExistingVM(gitLabEnv gitlab.Env) *VM {
 	return &VM{
 		id: gitLabEnv.VirtualMachineID(),
@@ -143,15 +148,14 @@ func (vm *VM) Start(
 		runArgs = append(runArgs, "--disk", customDiskMount)
 	}
 
-	if config.HostDir {
-		hostDir := gitLabEnv.HostDirPath()
-		runArgs = append(runArgs, "--dir", fmt.Sprintf("%s:tag=tart.virtiofs.hostdir.%s", hostDir, gitLabEnv.JobID))
-	} else if buildsDir, ok := os.LookupEnv(EnvTartExecutorInternalBuildsDir); ok {
-		runArgs = append(runArgs, "--dir", fmt.Sprintf("%s:tag=tart.virtiofs.buildsdir.%s", buildsDir, gitLabEnv.JobID))
+	if buildsDir, ok := os.LookupEnv(EnvTartExecutorInternalBuildsDirOnHost); ok {
+		runArgs = append(runArgs, "--dir", fmt.Sprintf("%s:tag=tart.virtiofs.buildsdir.%s",
+			buildsDir, gitLabEnv.JobID))
 	}
 
-	if cacheDir, ok := os.LookupEnv(EnvTartExecutorInternalCacheDir); ok {
-		runArgs = append(runArgs, "--dir", fmt.Sprintf("%s:tag=tart.virtiofs.cachedir.%s", cacheDir, gitLabEnv.JobID))
+	if cacheDir, ok := os.LookupEnv(EnvTartExecutorInternalCacheDirOnHost); ok {
+		runArgs = append(runArgs, "--dir", fmt.Sprintf("%s:tag=tart.virtiofs.cachedir.%s",
+			cacheDir, gitLabEnv.JobID))
 	}
 
 	runArgs = append(runArgs, vm.id)
@@ -278,6 +282,21 @@ func (vm *VM) IP(ctx context.Context, config Config) (string, error) {
 	return strings.TrimSpace(stdout), nil
 }
 
+func (vm *VM) Info(ctx context.Context) (*VMInfo, error) {
+	stdout, _, err := TartExec(ctx, "get", "--format", "json", vm.id)
+	if err != nil {
+		return nil, err
+	}
+
+	var vmInfo VMInfo
+
+	if err := json.Unmarshal([]byte(stdout), &vmInfo); err != nil {
+		return nil, err
+	}
+
+	return &vmInfo, nil
+}
+
 func (vm *VM) Stop() error {
 	_, _, err := TartExec(context.Background(), "stop", vm.id)