github.com/felipejfc/helm@v2.1.2+incompatible/cmd/helm/resolver/resolver.go (about)

     1  /*
     2  Copyright 2016 The Kubernetes Authors All rights reserved.
     3  Licensed under the Apache License, Version 2.0 (the "License");
     4  you may not use this file except in compliance with the License.
     5  You may obtain a copy of the License at
     6  
     7  http://www.apache.org/licenses/LICENSE-2.0
     8  
     9  Unless required by applicable law or agreed to in writing, software
    10  distributed under the License is distributed on an "AS IS" BASIS,
    11  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  See the License for the specific language governing permissions and
    13  limitations under the License.
    14  */
    15  
    16  package resolver
    17  
    18  import (
    19  	"bytes"
    20  	"encoding/json"
    21  	"fmt"
    22  	"strings"
    23  	"time"
    24  
    25  	"github.com/Masterminds/semver"
    26  
    27  	"k8s.io/helm/cmd/helm/helmpath"
    28  	"k8s.io/helm/pkg/chartutil"
    29  	"k8s.io/helm/pkg/provenance"
    30  	"k8s.io/helm/pkg/repo"
    31  )
    32  
    33  // Resolver resolves dependencies from semantic version ranges to a particular version.
    34  type Resolver struct {
    35  	chartpath string
    36  	helmhome  helmpath.Home
    37  }
    38  
    39  // New creates a new resolver for a given chart and a given helm home.
    40  func New(chartpath string, helmhome helmpath.Home) *Resolver {
    41  	return &Resolver{
    42  		chartpath: chartpath,
    43  		helmhome:  helmhome,
    44  	}
    45  }
    46  
    47  // Resolve resolves dependencies and returns a lock file with the resolution.
    48  func (r *Resolver) Resolve(reqs *chartutil.Requirements, repoNames map[string]string) (*chartutil.RequirementsLock, error) {
    49  	d, err := HashReq(reqs)
    50  	if err != nil {
    51  		return nil, err
    52  	}
    53  
    54  	// Now we clone the dependencies, locking as we go.
    55  	locked := make([]*chartutil.Dependency, len(reqs.Dependencies))
    56  	missing := []string{}
    57  	for i, d := range reqs.Dependencies {
    58  		constraint, err := semver.NewConstraint(d.Version)
    59  		if err != nil {
    60  			return nil, fmt.Errorf("dependency %q has an invalid version/constraint format: %s", d.Name, err)
    61  		}
    62  
    63  		repoIndex, err := repo.LoadIndexFile(r.helmhome.CacheIndex(repoNames[d.Name]))
    64  		if err != nil {
    65  			return nil, fmt.Errorf("no cached repo found. (try 'helm repo update'). %s", err)
    66  		}
    67  
    68  		vs, ok := repoIndex.Entries[d.Name]
    69  		if !ok {
    70  			return nil, fmt.Errorf("%s chart not found in repo %s", d.Name, d.Repository)
    71  		}
    72  
    73  		locked[i] = &chartutil.Dependency{
    74  			Name:       d.Name,
    75  			Repository: d.Repository,
    76  		}
    77  		found := false
    78  		// The version are already sorted and hence the first one to satisfy the constraint is used
    79  		for _, ver := range vs {
    80  			v, err := semver.NewVersion(ver.Version)
    81  			if err != nil || len(ver.URLs) == 0 {
    82  				// Not a legit entry.
    83  				continue
    84  			}
    85  			if constraint.Check(v) {
    86  				found = true
    87  				locked[i].Version = v.Original()
    88  				break
    89  			}
    90  		}
    91  
    92  		if !found {
    93  			missing = append(missing, d.Name)
    94  		}
    95  	}
    96  	if len(missing) > 0 {
    97  		return nil, fmt.Errorf("Can't get a valid version for repositories %s. Try changing the version constraint in requirements.yaml", strings.Join(missing, ", "))
    98  	}
    99  	return &chartutil.RequirementsLock{
   100  		Generated:    time.Now(),
   101  		Digest:       d,
   102  		Dependencies: locked,
   103  	}, nil
   104  }
   105  
   106  // HashReq generates a hash of the requirements.
   107  //
   108  // This should be used only to compare against another hash generated by this
   109  // function.
   110  func HashReq(req *chartutil.Requirements) (string, error) {
   111  	data, err := json.Marshal(req)
   112  	if err != nil {
   113  		return "", err
   114  	}
   115  	s, err := provenance.Digest(bytes.NewBuffer(data))
   116  	return "sha256:" + s, err
   117  }