component/provision: Make components purgable

cmd/purge.go

@@ -75,38 +75,21 @@ func (p purge) Run(context wisski_distillery.Context) error {
 		context.EPrintln(err)
 	}
 
-	// remove the triplestore
-	ts := dis.Triplestore()
-	logging.LogOperation(func() error {
-		logging.LogMessage(context.IOStream, "Removing user %s", instance.GraphDBUsername)
-		if err := ts.PurgeUser(instance.GraphDBUsername); err != nil {
-			context.EPrintln(err)
-		}
-
-		logging.LogMessage(context.IOStream, "Removing repository %s", instance.GraphDBRepository)
-		if err := ts.PurgeRepo(instance.GraphDBRepository); err != nil {
-			context.EPrintln(err)
+	// purge all the instance specific resources
+	if err := logging.LogOperation(func() error {
+		domain := instance.Domain()
+		for _, pc := range dis.Provisionable() {
+			logging.LogMessage(context.IOStream, "Purging %s resources", pc.Name())
+			err := pc.Purge(instance.Instance, domain)
+			if err != nil {
+				return err
+			}
 		}
 
 		return nil
-	}, context.IOStream, "Removing from Triplestore")
-
-	// remove the sql
-	logging.LogOperation(func() error {
-		sql := dis.SQL()
-
-		logging.LogMessage(context.IOStream, "Removing user %s", instance.SqlUsername)
-		if err := sql.PurgeUser(instance.SqlUsername); err != nil {
-			context.EPrintln(err)
-		}
-
-		logging.LogMessage(context.IOStream, "Removing database %s", instance.SqlDatabase)
-		if err := sql.PurgeDatabase(instance.SqlDatabase); err != nil {
-			context.EPrintln(err)
-		}
-
-		return nil
-	}, context.IOStream, "Removing from SQL")
+	}, context.IOStream, "Purging instance-specific resources"); err != nil {
+		return errProvisionGeneric.WithMessageF(slug, err)
+	}
 
 	// remove from bookkeeping
 	logging.LogMessage(context.IOStream, "Removing instance from bookkeeping")

internal/component/provision.go

@@ -4,11 +4,15 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/models"
 )
 
-// Provisionable represents a component with a Provision method.
+// Provisionable represents a component with a Provision and a Purge method.
 type Provisionable interface {
 	Component
 
 	// Provision provisions resources specific to the provided instance.
 	// Domain holds the full (unique) domain name of the given instance.
 	Provision(instance models.Instance, domain string) error
+
+	// Purge purges resources specific to the provided instance.
+	// Domain holds the full (unique) domain name of the given instance.
+	Purge(instance models.Instance, domain string) error
 }

internal/component/sql/provision.go

@@ -4,17 +4,26 @@ import (
 	"errors"
 
 	"github.com/FAU-CDI/wisski-distillery/internal/models"
+	"github.com/FAU-CDI/wisski-distillery/pkg/errorx"
 	"github.com/FAU-CDI/wisski-distillery/pkg/sqle"
 )
 
 var errProvisionInvalidDatabaseParams = errors.New("Provision: Invalid parameters")
 var errProvisionInvalidGrant = errors.New("Provision: Grant failed")
 
-// ProvisionInstance provisions sql-specific resource for the given instance
+// Provision provisions sql-specific resource for the given instance
 func (sql *SQL) Provision(instance models.Instance, domain string) error {
 	return sql.CreateDatabase(instance.SqlDatabase, instance.SqlUsername, instance.SqlPassword)
 }
 
+// Purge purges sql-specific resources for the given instance
+func (sql *SQL) Purge(instance models.Instance, domain string) error {
+	return errorx.First(
+		sql.PurgeDatabase(instance.SqlDatabase),
+		sql.PurgeUser(instance.SqlUsername),
+	)
+}
+
 // CreateDatabase creates a new database with the given name.
 // It then generates a new user, with the name 'user' and the password 'password', that is then granted access to this database.
 //

internal/component/triplestore/provision.go

@@ -7,6 +7,7 @@ import (
 	_ "embed"
 
 	"github.com/FAU-CDI/wisski-distillery/internal/models"
+	"github.com/FAU-CDI/wisski-distillery/pkg/errorx"
 	"github.com/FAU-CDI/wisski-distillery/pkg/unpack"
 	"github.com/tkw1536/goprogram/exit"
 )
@@ -23,6 +24,13 @@ func (ts *Triplestore) Provision(instance models.Instance, domain string) error
 	return ts.CreateRepository(instance.GraphDBRepository, domain, instance.GraphDBUsername, instance.GraphDBPassword)
 }
 
+func (ts *Triplestore) Purge(instance models.Instance, domain string) error {
+	return errorx.First(
+		ts.PurgeRepo(instance.GraphDBRepository),
+		ts.PurgeUser(instance.GraphDBUsername),
+	)
+}
+
 func (ts *Triplestore) CreateRepository(name, domain, user, password string) error {
 	if err := ts.Wait(); err != nil {
 		return err

pkg/errorx/errorx.go

@@ -0,0 +1,11 @@
+package errorx
+
+// First returns the first non-nil error, or nil otherwise.
+func First(errors ...error) error {
+	for _, err := range errors {
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}