github.com/openebs/node-disk-manager@v1.9.1-0.20230225014141-4531f06ffa1e/pkg/select/blockdevice/select.go (about)

     1  /*
     2  Copyright 2019 The OpenEBS Authors
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package blockdevice
    18  
    19  import (
    20  	"fmt"
    21  	apis "github.com/openebs/node-disk-manager/api/v1alpha1"
    22  )
    23  
    24  // Filter selects a single block device from a list of block devices
    25  func (c *Config) Filter(bdList *apis.BlockDeviceList) (*apis.BlockDevice, error) {
    26  	if len(bdList.Items) == 0 {
    27  		return nil, fmt.Errorf("no blockdevices found")
    28  	}
    29  
    30  	candidateDevices, err := c.getCandidateDevices(bdList)
    31  	if err != nil {
    32  		return nil, err
    33  	}
    34  	selectedDevice, err := c.getSelectedDevice(candidateDevices)
    35  	if err != nil {
    36  		return nil, err
    37  	}
    38  	return selectedDevice, nil
    39  }
    40  
    41  // getCandidateDevices selects a list of blockdevices from a given block device
    42  // list based on criteria specified in the claim spec
    43  func (c *Config) getCandidateDevices(bdList *apis.BlockDeviceList) (*apis.BlockDeviceList, error) {
    44  
    45  	// filterKeys to be used for filtering, by default active and unclaimed filter is present
    46  	filterKeys := []string{FilterActive,
    47  		FilterUnclaimed,
    48  		// do not consider any devices with legacy annotation for claiming
    49  		FilterOutLegacyAnnotation,
    50  		// remove block devices which do not have the blockdevice tag
    51  		// if selector is present on the BDC, select only those devices
    52  		// this applies to both manual and auto claiming.
    53  		FilterBlockDeviceTag,
    54  	}
    55  
    56  	if c.ManualSelection {
    57  		filterKeys = append(filterKeys,
    58  			FilterBlockDeviceName,
    59  		)
    60  	} else {
    61  		filterKeys = append(filterKeys,
    62  			// Sparse BDs can be claimed only by manual selection. Therefore, all
    63  			// sparse BDs will be filtered out in auto mode
    64  			FilterOutSparseBlockDevices,
    65  			FilterDeviceType,
    66  			FilterVolumeMode,
    67  			FilterNodeName,
    68  		)
    69  	}
    70  
    71  	candidateBD := c.ApplyFilters(bdList, filterKeys...)
    72  
    73  	if len(candidateBD.Items) == 0 {
    74  		return nil, fmt.Errorf("no devices found matching the criteria")
    75  	}
    76  
    77  	return candidateBD, nil
    78  }
    79  
    80  // getSelectedDevice selects a single a block device based on the resource requirements
    81  // requested by the claim
    82  func (c *Config) getSelectedDevice(bdList *apis.BlockDeviceList) (*apis.BlockDevice, error) {
    83  	if c.ManualSelection {
    84  		return &bdList.Items[0], nil
    85  	}
    86  
    87  	// filterKeys for filtering based on resource requirements
    88  	filterKeys := []string{FilterResourceStorage}
    89  
    90  	selectedDevices := c.ApplyFilters(bdList, filterKeys...)
    91  
    92  	if len(selectedDevices.Items) == 0 {
    93  		return nil, fmt.Errorf("could not find a device with matching resource requirements")
    94  	}
    95  
    96  	// will use the first available block device
    97  	return &selectedDevices.Items[0], nil
    98  }