upgrade: version-based migrations

Implement migrations based on the metadata version instead of just
unmarshalling and re-marshalling the config.

pkg/reactor/reactor.go

@@ -31,7 +31,7 @@ type PromoterMetadata struct {
 
 // PromoterConfig is the configuration for drbd-reactors "promoter" plugin.
 type PromoterConfig struct {
-	ID        string                            `toml:"id"`
+	ID        string                            `toml:"id,omitempty"`
 	Resources map[string]PromoterResourceConfig `toml:"resources,omitempty"`
 	Metadata  PromoterMetadata                  `toml:"metadata,omitempty"`
 }

pkg/upgrade/common.go

@@ -0,0 +1,18 @@
+package upgrade
+
+import "github.com/LINBIT/linstor-gateway/pkg/reactor"
+
+// removeID unsets the ID field of the promoter config.
+// Starting with drbd-reactor v1.2.0, configs no longer require an ID. It
+// prints a deprecation warning when it is used, so remove the field.
+func removeID(cfg *reactor.PromoterConfig) error {
+	cfg.ID = ""
+	return nil
+}
+
+func firstResourceId(cfg *reactor.PromoterConfig) string {
+	for k := range cfg.Resources {
+		return k
+	}
+	return ""
+}

pkg/upgrade/iscsi.go

@@ -5,29 +5,40 @@ import (
 	"fmt"
 	"github.com/LINBIT/golinstor/client"
 	"github.com/LINBIT/linstor-gateway/pkg/iscsi"
+	"github.com/LINBIT/linstor-gateway/pkg/reactor"
 )
 
+// iscsiMigrations defines the operations for upgrading a single version.
+// The array index ("n") denotes the starting version; the function at
+// index "n" migrates from version "n" to version "n+1".
+var iscsiMigrations = []func(cfg *reactor.PromoterConfig) error{
+	0: removeID,
+}
+
 func upgradeIscsi(ctx context.Context, linstor *client.Client, name string, forceYes bool, dryRun bool) (bool, error) {
 	const gatewayConfigPath = "/etc/drbd-reactor.d/linstor-gateway-iscsi-%s.toml"
-	cfg, resourceDefinition, volumeDefinitions, resources, err := parseExistingConfig(ctx, linstor, fmt.Sprintf(gatewayConfigPath, name))
+	cfg, _, _, _, err := parseExistingConfig(ctx, linstor, fmt.Sprintf(gatewayConfigPath, name))
 	if err != nil {
 		return false, err
 	}
 	if cfg.Metadata.LinstorGatewaySchemaVersion > iscsi.CurrentVersion {
 		return false, fmt.Errorf("schema version %d is not supported",
 			cfg.Metadata.LinstorGatewaySchemaVersion)
 	}
-
-	parsedCfg, err := iscsi.FromPromoter(cfg, resourceDefinition, volumeDefinitions)
+	newCfg, _, _, _, err := parseExistingConfig(ctx, linstor, fmt.Sprintf(gatewayConfigPath, name))
 	if err != nil {
-		return false, fmt.Errorf("failed to parse config: %w", err)
+		return false, err
 	}
-	newConfig, err := parsedCfg.ToPromoter(resources)
-	if err != nil {
-		return false, fmt.Errorf("failed to generate config: %w", err)
+
+	for i := cfg.Metadata.LinstorGatewaySchemaVersion; i < iscsi.CurrentVersion; i++ {
+		err := iscsiMigrations[i](newCfg)
+		if err != nil {
+			return false, fmt.Errorf("failed to migrate from version %d to %d: %w", i, i+1, err)
+		}
 	}
+	newCfg.Metadata.LinstorGatewaySchemaVersion = iscsi.CurrentVersion
 
-	return maybeWriteNewConfig(ctx, linstor, cfg, newConfig, forceYes, dryRun)
+	return maybeWriteNewConfig(ctx, linstor, cfg, newCfg, forceYes, dryRun)
 }
 
 func Iscsi(ctx context.Context, linstor *client.Client, iqn iscsi.Iqn, forceYes bool, dryRun bool) error {

pkg/upgrade/nfs.go

@@ -4,26 +4,92 @@ import (
 	"context"
 	"fmt"
 	"github.com/LINBIT/golinstor/client"
+	"github.com/LINBIT/linstor-gateway/pkg/iscsi"
 	"github.com/LINBIT/linstor-gateway/pkg/nfs"
+	"github.com/LINBIT/linstor-gateway/pkg/reactor"
 )
 
+// nfsMigrations defines the operations for upgrading a single version.
+// The array index ("n") denotes the starting version; the function at
+// index "n" migrates from version "n" to version "n+1".
+var nfsMigrations = []func(cfg *reactor.PromoterConfig) error{
+	0: initialMigrations,
+}
+
+// initialMigrations combines two migrations that make up version 1.
+func initialMigrations(cfg *reactor.PromoterConfig) error {
+	if err := removeID(cfg); err != nil {
+		return err
+	}
+	return switchIpAndNfsServer(cfg)
+}
+
+// switchIpAndNfsServer changes the order of the resource agents such that
+// the service IP is started before the NFS server. This was previously not
+// the case, leading to an NFS server that is not limited to the service IP.
+func switchIpAndNfsServer(cfg *reactor.PromoterConfig) error {
+	id := firstResourceId(cfg)
+	firstResource := cfg.Resources[id]
+	var serviceIpIndex, nfsServerIndex int
+	for i, entry := range firstResource.Start {
+		switch agent := entry.(type) {
+		case *reactor.ResourceAgent:
+			if agent.Type == "ocf:heartbeat:IPaddr2" {
+				serviceIpIndex = i
+			}
+			if agent.Type == "ocf:heartbeat:nfsserver" {
+				nfsServerIndex = i
+			}
+		}
+	}
+
+	// slice up the "start" list and create a new one with this order:
+	// 1. everything before the nfs server
+	// 2. the service IP
+	// 3. the NFS server
+	// 4. all the exportfs entries
+	// 5. everything after the original service IP index
+	start := firstResource.Start[:nfsServerIndex]
+	serviceIpEntry := firstResource.Start[serviceIpIndex]
+	nfsServerEntry := firstResource.Start[nfsServerIndex]
+	exportFsEntries := firstResource.Start[nfsServerIndex+1 : serviceIpIndex]
+	rest := firstResource.Start[serviceIpIndex+1:]
+
+	var s []reactor.StartEntry
+	s = append(s, start...)
+	s = append(s, serviceIpEntry)
+	s = append(s, nfsServerEntry)
+	s = append(s, exportFsEntries...)
+	s = append(s, rest...)
+	firstResource.Start = s
+	cfg.Resources[id] = firstResource
+	return nil
+}
+
 func upgradeNfs(ctx context.Context, linstor *client.Client, name string, forceYes bool, dryRun bool) (bool, error) {
 	const gatewayConfigPath = "/etc/drbd-reactor.d/linstor-gateway-nfs-%s.toml"
-	cfg, resourceDefinition, volumeDefinitions, resources, err := parseExistingConfig(ctx, linstor, fmt.Sprintf(gatewayConfigPath, name))
+	cfg, _, _, _, err := parseExistingConfig(ctx, linstor, fmt.Sprintf(gatewayConfigPath, name))
 	if err != nil {
 		return false, err
 	}
-
-	parsedCfg, err := nfs.FromPromoter(cfg, resourceDefinition, volumeDefinitions)
-	if err != nil {
-		return false, fmt.Errorf("failed to parse config: %w", err)
+	if cfg.Metadata.LinstorGatewaySchemaVersion > iscsi.CurrentVersion {
+		return false, fmt.Errorf("schema version %d is not supported",
+			cfg.Metadata.LinstorGatewaySchemaVersion)
 	}
-	newConfig, err := parsedCfg.ToPromoter(resources)
+	newCfg, _, _, _, err := parseExistingConfig(ctx, linstor, fmt.Sprintf(gatewayConfigPath, name))
 	if err != nil {
-		return false, fmt.Errorf("failed to generate config: %w", err)
+		return false, err
+	}
+
+	for i := cfg.Metadata.LinstorGatewaySchemaVersion; i < nfs.CurrentVersion; i++ {
+		err := nfsMigrations[i](newCfg)
+		if err != nil {
+			return false, fmt.Errorf("failed to migrate from version %d to %d: %w", i, i+1, err)
+		}
 	}
+	newCfg.Metadata.LinstorGatewaySchemaVersion = nfs.CurrentVersion
 
-	return maybeWriteNewConfig(ctx, linstor, cfg, newConfig, forceYes, dryRun)
+	return maybeWriteNewConfig(ctx, linstor, cfg, newCfg, forceYes, dryRun)
 }
 
 func Nfs(ctx context.Context, linstor *client.Client, name string, forceYes bool, dryRun bool) error {

pkg/upgrade/nvmeof.go

@@ -5,25 +5,40 @@ import (
 	"fmt"
 	"github.com/LINBIT/golinstor/client"
 	"github.com/LINBIT/linstor-gateway/pkg/nvmeof"
+	"github.com/LINBIT/linstor-gateway/pkg/reactor"
 )
 
+// nvmeOfMigrations defines the operations for upgrading a single version.
+// The array index ("n") denotes the starting version; the function at
+// index "n" migrates from version "n" to version "n+1".
+var nvmeOfMigrations = []func(cfg *reactor.PromoterConfig) error{
+	0: removeID,
+}
+
 func upgradeNvmeOf(ctx context.Context, linstor *client.Client, name string, forceYes, dryRun bool) (bool, error) {
 	const gatewayConfigPath = "/etc/drbd-reactor.d/linstor-gateway-nvmeof-%s.toml"
-	cfg, resourceDefinition, volumeDefinitions, resources, err := parseExistingConfig(ctx, linstor, fmt.Sprintf(gatewayConfigPath, name))
+	cfg, _, _, _, err := parseExistingConfig(ctx, linstor, fmt.Sprintf(gatewayConfigPath, name))
 	if err != nil {
 		return false, err
 	}
-
-	parsedCfg, err := nvmeof.FromPromoter(cfg, resourceDefinition, volumeDefinitions)
-	if err != nil {
-		return false, fmt.Errorf("failed to parse config: %w", err)
+	if cfg.Metadata.LinstorGatewaySchemaVersion > nvmeof.CurrentVersion {
+		return false, fmt.Errorf("schema version %d is not supported",
+			cfg.Metadata.LinstorGatewaySchemaVersion)
 	}
-	newConfig, err := parsedCfg.ToPromoter(resources)
+	newCfg, _, _, _, err := parseExistingConfig(ctx, linstor, fmt.Sprintf(gatewayConfigPath, name))
 	if err != nil {
-		return false, fmt.Errorf("failed to generate config: %w", err)
+		return false, err
+	}
+
+	for i := cfg.Metadata.LinstorGatewaySchemaVersion; i < nvmeof.CurrentVersion; i++ {
+		err := nvmeOfMigrations[i](newCfg)
+		if err != nil {
+			return false, fmt.Errorf("failed to migrate from version %d to %d: %w", i, i+1, err)
+		}
 	}
+	newCfg.Metadata.LinstorGatewaySchemaVersion = nvmeof.CurrentVersion
 
-	return maybeWriteNewConfig(ctx, linstor, cfg, newConfig, forceYes, dryRun)
+	return maybeWriteNewConfig(ctx, linstor, cfg, newCfg, forceYes, dryRun)
 }
 
 func NvmeOf(ctx context.Context, linstor *client.Client, nqn nvmeof.Nqn, forceYes, dryRun bool) error {

pkg/upgrade/upgrade.go

@@ -1,34 +1,6 @@
 /*
 Package upgrade migrates existing resources to the latest version.
 We will always try to upgrade to the most modern version of the drbd-reactor configuration.
-
-In practice, this means the following DRBD options:
-
-options {
-   auto-promote no;
-   quorum majority;
-   on-suspended-primary-outdated force-secondary;
-   on-no-quorum io-error;
-}
-
-And the following drbd-reactor settings:
-
-[[promoter]]
-  id = "iscsi-target1"
-  [promoter.resources]
-    [promoter.resources.target1]
-      on-drbd-demote-failure = "reboot-immediate"
-      runner = "systemd"
-      start = [
-        "ocf:heartbeat:Filesystem fs_cluster_private device=/dev/drbd/by-res/target1/0 directory=/srv/ha/internal/target1 fstype=ext4 run_fsck=no",
-        "ocf:heartbeat:portblock pblock0 action=block ip=192.168.122.222 portno=3260 protocol=tcp",
-        "ocf:heartbeat:IPaddr2 service_ip0 cidr_netmask=24 ip=192.168.122.222",
-        "ocf:heartbeat:iSCSITarget target allowed_initiators='' incoming_password='' incoming_username='' iqn=iqn.2020-01.com.linbit:target1 portals=192.168.122.222:3260",
-        "ocf:heartbeat:iSCSILogicalUnit lu1 lun=1 path=/dev/drbd/by-res/target1/1 product_id='LINSTOR iSCSI' scsi_sn=6391f15d target_iqn=iqn.2020-01.com.linbit:target1",
-        "ocf:heartbeat:portblock portunblock0 action=unblock ip=192.168.122.222 portno=3260 protocol=tcp tickle_dir=/srv/ha/internal/target1",
-      ]
-      stop-services-on-exit = true
-      target-as = "Requires"
 */
 package upgrade