github.com/juju/juju@v0.0.0-20240430160146-1752b71fcf00/apiserver/common/life.go (about)

     1  // Copyright 2013 Canonical Ltd.
     2  // Licensed under the AGPLv3, see LICENCE file for details.
     3  
     4  package common
     5  
     6  import (
     7  	"github.com/juju/errors"
     8  	"github.com/juju/names/v5"
     9  
    10  	apiservererrors "github.com/juju/juju/apiserver/errors"
    11  	"github.com/juju/juju/core/life"
    12  	"github.com/juju/juju/rpc/params"
    13  	"github.com/juju/juju/state"
    14  )
    15  
    16  // LifeGetter implements a common Life method for use by various facades.
    17  type LifeGetter struct {
    18  	st         state.EntityFinder
    19  	getCanRead GetAuthFunc
    20  }
    21  
    22  // NewLifeGetter returns a new LifeGetter. The GetAuthFunc will be used on
    23  // each invocation of Life to determine current permissions.
    24  func NewLifeGetter(st state.EntityFinder, getCanRead GetAuthFunc) *LifeGetter {
    25  	return &LifeGetter{
    26  		st:         st,
    27  		getCanRead: getCanRead,
    28  	}
    29  }
    30  
    31  func (lg *LifeGetter) oneLife(tag names.Tag) (life.Value, error) {
    32  	entity0, err := lg.st.FindEntity(tag)
    33  	if err != nil {
    34  		return "", err
    35  	}
    36  	entity, ok := entity0.(state.Lifer)
    37  	if !ok {
    38  		return "", apiservererrors.NotSupportedError(tag, "life cycles")
    39  	}
    40  	return life.Value(entity.Life().String()), nil
    41  }
    42  
    43  // Life returns the life status of every supplied entity, where available.
    44  func (lg *LifeGetter) Life(args params.Entities) (params.LifeResults, error) {
    45  	result := params.LifeResults{
    46  		Results: make([]params.LifeResult, len(args.Entities)),
    47  	}
    48  	if len(args.Entities) == 0 {
    49  		return result, nil
    50  	}
    51  	canRead, err := lg.getCanRead()
    52  	if err != nil {
    53  		return params.LifeResults{}, errors.Trace(err)
    54  	}
    55  	for i, entity := range args.Entities {
    56  		tag, err := names.ParseTag(entity.Tag)
    57  		if err != nil {
    58  			result.Results[i].Error = apiservererrors.ServerError(apiservererrors.ErrPerm)
    59  			continue
    60  		}
    61  		err = apiservererrors.ErrPerm
    62  		if canRead(tag) {
    63  			result.Results[i].Life, err = lg.oneLife(tag)
    64  		}
    65  		result.Results[i].Error = apiservererrors.ServerError(err)
    66  	}
    67  	return result, nil
    68  }