errors: rewrite errors to follow go best practices

Errors should not start capitalised and they should not contain the word error
or state that they "failed" as we already know it is an error

Signed-off-by: Kristoffer Dalby <kristoffer@dalby.cc>

hscontrol/db/api_key.go

@@ -78,7 +78,7 @@ func (hsdb *HSDatabase) CreateAPIKey(
 	}
 
 	if err := hsdb.DB.Save(&key).Error; err != nil {
-		return "", nil, fmt.Errorf("failed to save API key to database: %w", err)
+		return "", nil, fmt.Errorf("saving API key to database: %w", err)
 	}
 
 	return keyStr, &key, nil

hscontrol/db/ip.go

@@ -290,7 +290,7 @@ func (db *HSDatabase) BackfillNodeIPs(i *IPAllocator) ([]string, error) {
 			if i.prefix4 != nil && node.IPv4 == nil {
 				ret4, err := i.nextLocked(i.prev4, i.prefix4)
 				if err != nil {
-					return fmt.Errorf("failed to allocate ipv4 for node(%d): %w", node.ID, err)
+					return fmt.Errorf("allocating IPv4 for node(%d): %w", node.ID, err)
 				}
 
 				node.IPv4 = ret4
@@ -302,7 +302,7 @@ func (db *HSDatabase) BackfillNodeIPs(i *IPAllocator) ([]string, error) {
 			if i.prefix6 != nil && node.IPv6 == nil {
 				ret6, err := i.nextLocked(i.prev6, i.prefix6)
 				if err != nil {
-					return fmt.Errorf("failed to allocate ipv6 for node(%d): %w", node.ID, err)
+					return fmt.Errorf("allocating IPv6 for node(%d): %w", node.ID, err)
 				}
 
 				node.IPv6 = ret6

hscontrol/db/node.go

@@ -290,7 +290,7 @@ func RenameNode(tx *gorm.DB,
 
 	err = tx.Model(&types.Node{}).Where("given_name = ? AND id != ?", newName, nodeID).Count(&count).Error
 	if err != nil {
-		return fmt.Errorf("failed to check name uniqueness: %w", err)
+		return fmt.Errorf("checking name uniqueness: %w", err)
 	}
 
 	if count > 0 {
@@ -298,7 +298,7 @@ func RenameNode(tx *gorm.DB,
 	}
 
 	if err := tx.Model(&types.Node{}).Where("id = ?", nodeID).Update("given_name", newName).Error; err != nil {
-		return fmt.Errorf("failed to rename node in the database: %w", err)
+		return fmt.Errorf("renaming node in database: %w", err)
 	}
 
 	return nil
@@ -396,7 +396,7 @@ func RegisterNodeForTest(tx *gorm.DB, node types.Node, ipv4 *netip.Addr, ipv6 *n
 	// adding it to the registrationCache
 	if node.IPv4 != nil || node.IPv6 != nil {
 		if err := tx.Save(&node).Error; err != nil {
-			return nil, fmt.Errorf("failed register existing node in the database: %w", err)
+			return nil, fmt.Errorf("registering existing node in database: %w", err)
 		}
 
 		log.Trace().
@@ -425,14 +425,14 @@ func RegisterNodeForTest(tx *gorm.DB, node types.Node, ipv4 *netip.Addr, ipv6 *n
 	if node.GivenName == "" {
 		givenName, err := EnsureUniqueGivenName(tx, node.Hostname)
 		if err != nil {
-			return nil, fmt.Errorf("failed to ensure unique given name: %w", err)
+			return nil, fmt.Errorf("ensuring unique given name: %w", err)
 		}
 
 		node.GivenName = givenName
 	}
 
 	if err := tx.Save(&node).Error; err != nil {
-		return nil, fmt.Errorf("failed register(save) node in the database: %w", err)
+		return nil, fmt.Errorf("saving node to database: %w", err)
 	}
 
 	log.Trace().

hscontrol/db/preauth_keys.go

@@ -139,7 +139,7 @@ func CreatePreAuthKey(
 	}
 
 	if err := tx.Save(&key).Error; err != nil {
-		return nil, fmt.Errorf("failed to create key in the database: %w", err)
+		return nil, fmt.Errorf("creating key in database: %w", err)
 	}
 
 	return &types.PreAuthKeyNew{
@@ -296,7 +296,7 @@ func DestroyPreAuthKey(tx *gorm.DB, id uint64) error {
 			Where("auth_key_id = ?", id).
 			Update("auth_key_id", nil).Error
 		if err != nil {
-			return fmt.Errorf("failed to clear auth_key_id on nodes: %w", err)
+			return fmt.Errorf("clearing auth_key_id on nodes: %w", err)
 		}
 
 		// Then delete the pre-auth key
@@ -325,7 +325,7 @@ func (hsdb *HSDatabase) DeletePreAuthKey(id uint64) error {
 func UsePreAuthKey(tx *gorm.DB, k *types.PreAuthKey) error {
 	err := tx.Model(k).Update("used", true).Error
 	if err != nil {
-		return fmt.Errorf("failed to update key used status in the database: %w", err)
+		return fmt.Errorf("updating key used status in database: %w", err)
 	}
 
 	k.Used = true

hscontrol/db/text_serialiser.go

@@ -24,7 +24,7 @@ func maybeInstantiatePtr(rv reflect.Value) {
 }
 
 func decodingError(name string, err error) error {
-	return fmt.Errorf("error decoding to %s: %w", name, err)
+	return fmt.Errorf("decoding to %s: %w", name, err)
 }
 
 // TextSerialiser implements the Serialiser interface for fields that
@@ -48,7 +48,7 @@ func (TextSerialiser) Scan(ctx context.Context, field *schema.Field, dst reflect
 		case string:
 			bytes = []byte(v)
 		default:
-			return fmt.Errorf("failed to unmarshal text value: %#v", dbValue)
+			return fmt.Errorf("unmarshalling text value: %#v", dbValue)
 		}
 
 		if isTextUnmarshaler(fieldValue) {