github.com/containerd/nerdctl/v2@v2.0.0-beta.5.0.20240520001846-b5758f54fa28/pkg/idutil/containerwalker/containerwalker.go (about)

     1  /*
     2     Copyright The containerd 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 containerwalker
    18  
    19  import (
    20  	"context"
    21  	"fmt"
    22  	"regexp"
    23  	"strings"
    24  
    25  	"github.com/containerd/containerd"
    26  	"github.com/containerd/nerdctl/v2/pkg/labels"
    27  )
    28  
    29  type Found struct {
    30  	Container  containerd.Container
    31  	Req        string // The raw request string. name, short ID, or long ID.
    32  	MatchIndex int    // Begins with 0, up to MatchCount - 1.
    33  	MatchCount int    // 1 on exact match. > 1 on ambiguous match. Never be <= 0.
    34  }
    35  
    36  type OnFound func(ctx context.Context, found Found) error
    37  
    38  type ContainerWalker struct {
    39  	Client  *containerd.Client
    40  	OnFound OnFound
    41  }
    42  
    43  // Walk walks containers and calls w.OnFound .
    44  // Req is name, short ID, or long ID.
    45  // Returns the number of the found entries.
    46  func (w *ContainerWalker) Walk(ctx context.Context, req string) (int, error) {
    47  	if strings.HasPrefix(req, "k8s://") {
    48  		return -1, fmt.Errorf("specifying \"k8s://...\" form is not supported (Hint: specify ID instead): %q", req)
    49  	}
    50  	filters := []string{
    51  		fmt.Sprintf("labels.%q==%s", labels.Name, req),
    52  		fmt.Sprintf("id~=^%s.*$", regexp.QuoteMeta(req)),
    53  	}
    54  
    55  	containers, err := w.Client.Containers(ctx, filters...)
    56  	if err != nil {
    57  		return -1, err
    58  	}
    59  
    60  	matchCount := len(containers)
    61  	for i, c := range containers {
    62  		f := Found{
    63  			Container:  c,
    64  			Req:        req,
    65  			MatchIndex: i,
    66  			MatchCount: matchCount,
    67  		}
    68  		if e := w.OnFound(ctx, f); e != nil {
    69  			return -1, e
    70  		}
    71  	}
    72  	return matchCount, nil
    73  }
    74  
    75  // WalkAll calls `Walk` for each req in `reqs`.
    76  //
    77  // It can be used when the matchCount is not important (e.g., only care if there
    78  // is any error or if matchCount == 0 (not found error) when walking all reqs).
    79  // If `forceAll`, it calls `Walk` on every req
    80  // and return all errors joined by `\n`. If not `forceAll`, it returns the first error
    81  // encountered while calling `Walk`.
    82  func (w *ContainerWalker) WalkAll(ctx context.Context, reqs []string, forceAll bool) error {
    83  	var errs []string
    84  	for _, req := range reqs {
    85  		n, err := w.Walk(ctx, req)
    86  		if err == nil && n == 0 {
    87  			err = fmt.Errorf("no such container: %s", req)
    88  		}
    89  		if err != nil {
    90  			if !forceAll {
    91  				return err
    92  			}
    93  			errs = append(errs, err.Error())
    94  		}
    95  	}
    96  	if len(errs) > 0 {
    97  		return fmt.Errorf("%d errors:\n%s", len(errs), strings.Join(errs, "\n"))
    98  	}
    99  	return nil
   100  }