Do a large chunk of the move to go

This commit moves a huge chunk of the code to go. The TODO.md document
indicates what is left to be done.

cmd/system_update.go

@@ -0,0 +1,182 @@
+package cmd
+
+import (
+	"os"
+	"path/filepath"
+
+	wisski_distillery "github.com/FAU-CDI/wisski-distillery"
+	"github.com/FAU-CDI/wisski-distillery/distillery"
+	"github.com/FAU-CDI/wisski-distillery/env"
+	"github.com/FAU-CDI/wisski-distillery/internal/execx"
+	"github.com/FAU-CDI/wisski-distillery/internal/logging"
+	"github.com/FAU-CDI/wisski-distillery/internal/stack"
+	"github.com/tkw1536/goprogram/exit"
+	"github.com/tkw1536/goprogram/parser"
+)
+
+// SystemUpdate is the 'system_update' command
+var SystemUpdate wisski_distillery.Command = systemupdate{}
+
+type systemupdate struct {
+	SkipCoreUpdates bool `short:"s" long:"skip-core-updates" description:"Skip applying operating system and other core system updates"`
+	Positionals     struct {
+		GraphdbZip string `positional-arg-name:"PATH_TO_GRAPHDB_ZIP" required:"1-1" description:"path to the graphdb.zip file"`
+	} `positional-args:"true"`
+}
+
+func (systemupdate) Description() wisski_distillery.Description {
+	return wisski_distillery.Description{
+		Requirements: env.Requirements{
+			NeedsConfig: true,
+		},
+		ParserConfig: parser.Config{
+			IncludeUnknown: true,
+		},
+		Command:     "system_update",
+		Description: "Installs and Update Components of the WissKI Distillery System",
+	}
+}
+
+var errNoGraphDBZip = exit.Error{
+	Message:  "%s does not exist",
+	ExitCode: exit.ExitCommandArguments,
+}
+
+func (s systemupdate) AfterParse() error {
+	_, err := os.Stat(s.Positionals.GraphdbZip)
+	if os.IsNotExist(err) {
+		return errNoGraphDBZip.WithMessageF(s.Positionals.GraphdbZip)
+	}
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+var errFailedToCreateDirectory = exit.Error{
+	Message:  "failed to create directory %s: %s",
+	ExitCode: exit.ExitGeneric,
+}
+
+var errFailedRuntime = exit.Error{
+	Message:  "failed to update runtime: %s",
+	ExitCode: exit.ExitGeneric,
+}
+
+func (si systemupdate) Run(context wisski_distillery.Context) error {
+	dis := context.Environment
+
+	// create all the other directories
+	logging.LogMessage(context.IOStream, "Ensuring distillery installation directories exist")
+	for _, d := range []string{
+		dis.Config.DeployRoot,
+		dis.InstancesDir(),
+		dis.InprogressBackupPath(),
+		dis.FinalBackupPath(),
+	} {
+		context.Println(d)
+		if err := os.MkdirAll(d, os.ModeDir); err != nil {
+			return errFailedToCreateDirectory.WithMessageF(d, err)
+		}
+	}
+
+	if !si.SkipCoreUpdates {
+		// install system updates
+		logging.LogMessage(context.IOStream, "Updating Operating System Packages")
+		if err := si.mustExec(context, "", "apt-get", "update"); err != nil {
+			return err
+		}
+		if err := si.mustExec(context, "", "apt-get", "upgrade", "-y"); err != nil {
+			return err
+		}
+
+		// install docker
+		logging.LogMessage(context.IOStream, "Installing / Updating Docker")
+		if err := si.mustExec(context, "", "apt-get", "install", "curl"); err != nil {
+			return err
+		}
+		if err := si.mustExec(context, "", "/bin/sh", "-c", "curl -fsSL https://get.docker.com -o - | /bin/sh"); err != nil {
+			return err
+		}
+	}
+
+	// create the docker network
+	// TODO: Use docker API for this
+	logging.LogMessage(context.IOStream, "Updating Docker Configuration")
+	si.mustExec(context, "", "docker", "network", "create", "distillery")
+
+	// install and update the various stacks!
+	ctx := stack.InstallationContext{
+		"graphdb.zip": si.Positionals.GraphdbZip,
+	}
+
+	if err := logging.LogOperation(func() error {
+		for _, stack := range dis.Stacks() {
+			if err := logging.LogOperation(func() error {
+				return stack.Install(context.IOStream, ctx)
+			}, context.IOStream, "Installing docker stack %q", stack.Name); err != nil {
+				return err
+			}
+
+			if err := logging.LogOperation(func() error {
+				return stack.Update(context.IOStream, true)
+			}, context.IOStream, "Updating docker stack %q", stack.Name); err != nil {
+				return err
+			}
+		}
+		return nil
+	}, context.IOStream, "Updating Components"); err != nil {
+		return err
+	}
+
+	if err := logging.LogOperation(func() error {
+		if err := distillery.InstallResource(dis.RuntimeDir(), filepath.Join("resources", "runtime"), func(dst, src string) {
+			context.Printf("[copy]  %s\n", dst)
+		}); err != nil {
+			return errFailedRuntime.WithMessageF(err)
+		}
+		return nil
+	}, context.IOStream, "Unpacking Runtime Components"); err != nil {
+		return err
+	}
+
+	if err := logging.LogOperation(func() error {
+		if err := dis.SQLBootstrap(context.IOStream); err != nil {
+			return err
+		}
+		return nil
+	}, context.IOStream, "Bootstraping SQL database"); err != nil {
+		return err
+	}
+
+	if err := logging.LogOperation(func() error {
+		if err := dis.TriplestoreBootstrap(context.IOStream); err != nil {
+			return err
+		}
+		return nil
+	}, context.IOStream, "Bootstraping Triplestore"); err != nil {
+		return err
+	}
+
+	logging.LogMessage(context.IOStream, "System has been updated")
+	return nil
+}
+
+var errMustExecFailed = exit.Error{
+	Message: "process exited with code %d",
+}
+
+// mustExec indicates that the given executable process must complete successfully.
+// If it does not, returns errMustExecFailed
+func (si systemupdate) mustExec(context wisski_distillery.Context, workdir string, exe string, argv ...string) error {
+	if workdir == "" {
+		workdir = context.Environment.Config.DeployRoot
+	}
+	code := execx.Exec(context.IOStream, workdir, exe, argv...)
+	if code != 0 {
+		err := errMustExecFailed.WithMessageF(code)
+		err.ExitCode = exit.ExitCode(code)
+		return err
+	}
+	return nil
+}