github.com/rogpeppe/juju@v0.0.0-20140613142852-6337964b789e/environs/tools/validation.go (about)

     1  // Copyright 2013 Canonical Ltd.
     2  // Licensed under the AGPLv3, see LICENCE file for details.
     3  
     4  package tools
     5  
     6  import (
     7  	"fmt"
     8  
     9  	"github.com/juju/juju/environs/simplestreams"
    10  	"github.com/juju/juju/version"
    11  )
    12  
    13  // ToolsMetadataLookupParams is used to query metadata for matching tools.
    14  type ToolsMetadataLookupParams struct {
    15  	simplestreams.MetadataLookupParams
    16  	Version string
    17  	Major   int
    18  	Minor   int
    19  }
    20  
    21  // ValidateToolsMetadata attempts to load tools metadata for the specified cloud attributes and returns
    22  // any tools versions found, or an error if the metadata could not be loaded.
    23  func ValidateToolsMetadata(params *ToolsMetadataLookupParams) ([]string, *simplestreams.ResolveInfo, error) {
    24  	if len(params.Architectures) == 0 {
    25  		return nil, nil, fmt.Errorf("required parameter arches not specified")
    26  	}
    27  	if len(params.Sources) == 0 {
    28  		return nil, nil, fmt.Errorf("required parameter sources not specified")
    29  	}
    30  	if params.Version == "" && params.Major == 0 {
    31  		params.Version = version.Current.Number.String()
    32  	}
    33  	var toolsConstraint *ToolsConstraint
    34  	if params.Version == "" {
    35  		toolsConstraint = NewGeneralToolsConstraint(params.Major, params.Minor, false, simplestreams.LookupParams{
    36  			CloudSpec: simplestreams.CloudSpec{
    37  				Region:   params.Region,
    38  				Endpoint: params.Endpoint,
    39  			},
    40  			Series: []string{params.Series},
    41  			Arches: params.Architectures,
    42  		})
    43  	} else {
    44  		versNum, err := version.Parse(params.Version)
    45  		if err != nil {
    46  			return nil, nil, err
    47  		}
    48  		toolsConstraint = NewVersionedToolsConstraint(versNum, simplestreams.LookupParams{
    49  			CloudSpec: simplestreams.CloudSpec{
    50  				Region:   params.Region,
    51  				Endpoint: params.Endpoint,
    52  			},
    53  			Series: []string{params.Series},
    54  			Arches: params.Architectures,
    55  		})
    56  	}
    57  	matchingTools, resolveInfo, err := Fetch(params.Sources, simplestreams.DefaultIndexPath, toolsConstraint, false)
    58  	if err != nil {
    59  		return nil, resolveInfo, err
    60  	}
    61  	if len(matchingTools) == 0 {
    62  		return nil, resolveInfo, fmt.Errorf("no matching tools found for constraint %+v", toolsConstraint)
    63  	}
    64  	versions := make([]string, len(matchingTools))
    65  	for i, tm := range matchingTools {
    66  		vers := version.Binary{
    67  			Number: version.MustParse(tm.Version),
    68  			Series: tm.Release,
    69  			Arch:   tm.Arch,
    70  		}
    71  		versions[i] = vers.String()
    72  	}
    73  	return versions, resolveInfo, nil
    74  }