github.com/wallyworld/juju@v0.0.0-20161013125918-6cf1bc9d917a/apiserver/application/charmstore.go

// Copyright 2015 Canonical Ltd.
// Licensed under the AGPLv3, see LICENCE file for details.

package application

import (
	"fmt"
	"io"
	"net/url"
	"os"

	"github.com/juju/errors"
	"github.com/juju/utils"
	"github.com/juju/version"
	"gopkg.in/juju/charm.v6-unstable"
	"gopkg.in/juju/charmrepo.v2-unstable"
	"gopkg.in/juju/charmrepo.v2-unstable/csclient"
	csparams "gopkg.in/juju/charmrepo.v2-unstable/csclient/params"
	"gopkg.in/macaroon-bakery.v1/httpbakery"
	"gopkg.in/macaroon.v1"

	"github.com/juju/juju/apiserver/params"
	"github.com/juju/juju/environs/config"
	"github.com/juju/juju/state"
	jujuversion "github.com/juju/juju/version"
)

// TODO - we really want to avoid this, which we can do by refactoring code requiring this
// to use interfaces.
// NewCharmStoreRepo instantiates a new charm store repository.
// It is exported for testing purposes.
var NewCharmStoreRepo = newCharmStoreFromClient

func newCharmStoreFromClient(csClient *csclient.Client) charmrepo.Interface {
	return charmrepo.NewCharmStoreFromClient(csClient)
}

// AddCharmWithAuthorization adds the given charm URL (which must include revision) to
// the environment, if it does not exist yet. Local charms are not
// supported, only charm store URLs. See also AddLocalCharm().
//
// The authorization macaroon, args.CharmStoreMacaroon, may be
// omitted, in which case this call is equivalent to AddCharm.
func AddCharmWithAuthorization(st *state.State, args params.AddCharmWithAuthorization) error {
	charmURL, err := charm.ParseURL(args.URL)
	if err != nil {
		return err
	}
	if charmURL.Schema != "cs" {
		return fmt.Errorf("only charm store charm URLs are supported, with cs: schema")
	}
	if charmURL.Revision < 0 {
		return fmt.Errorf("charm URL must include revision")
	}

	// First, check if a pending or a real charm exists in state.
	stateCharm, err := st.PrepareStoreCharmUpload(charmURL)
	if err != nil {
		return err
	}
	if stateCharm.IsUploaded() {
		// Charm already in state (it was uploaded already).
		return nil
	}

	// Open a charm store client.
	repo, err := openCSRepo(args)
	if err != nil {
		return err
	}
	modelConfig, err := st.ModelConfig()
	if err != nil {
		return err
	}
	repo = config.SpecializeCharmRepo(repo, modelConfig).(*charmrepo.CharmStore)

	// Get the charm and its information from the store.
	downloadedCharm, err := repo.Get(charmURL)
	if err != nil {
		cause := errors.Cause(err)
		if httpbakery.IsDischargeError(cause) || httpbakery.IsInteractionError(cause) {
			return errors.NewUnauthorized(err, "")
		}
		return errors.Trace(err)
	}

	if err := checkMinVersion(downloadedCharm); err != nil {
		return errors.Trace(err)
	}

	// Open it and calculate the SHA256 hash.
	downloadedBundle, ok := downloadedCharm.(*charm.CharmArchive)
	if !ok {
		return errors.Errorf("expected a charm archive, got %T", downloadedCharm)
	}
	archive, err := os.Open(downloadedBundle.Path)
	if err != nil {
		return errors.Annotate(err, "cannot read downloaded charm")
	}
	defer archive.Close()
	bundleSHA256, size, err := utils.ReadSHA256(archive)
	if err != nil {
		return errors.Annotate(err, "cannot calculate SHA256 hash of charm")
	}
	if _, err := archive.Seek(0, 0); err != nil {
		return errors.Annotate(err, "cannot rewind charm archive")
	}

	ca := CharmArchive{
		ID:     charmURL,
		Charm:  downloadedCharm,
		Data:   archive,
		Size:   size,
		SHA256: bundleSHA256,
	}
	if args.CharmStoreMacaroon != nil {
		ca.Macaroon = macaroon.Slice{args.CharmStoreMacaroon}
	}

	// Store the charm archive in environment storage.
	return StoreCharmArchive(st, ca)
}

func openCSRepo(args params.AddCharmWithAuthorization) (charmrepo.Interface, error) {
	csClient, err := openCSClient(args)
	if err != nil {
		return nil, err
	}
	repo := NewCharmStoreRepo(csClient)
	return repo, nil
}

func openCSClient(args params.AddCharmWithAuthorization) (*csclient.Client, error) {
	csURL, err := url.Parse(csclient.ServerURL)
	if err != nil {
		return nil, err
	}
	csParams := csclient.Params{
		URL:        csURL.String(),
		HTTPClient: httpbakery.NewHTTPClient(),
	}

	if args.CharmStoreMacaroon != nil {
		// Set the provided charmstore authorizing macaroon
		// as a cookie in the HTTP client.
		// TODO(cmars) discharge any third party caveats in the macaroon.
		ms := []*macaroon.Macaroon{args.CharmStoreMacaroon}
		httpbakery.SetCookie(csParams.HTTPClient.Jar, csURL, ms)
	}
	csClient := csclient.New(csParams)
	channel := csparams.Channel(args.Channel)
	if channel != csparams.NoChannel {
		csClient = csClient.WithChannel(channel)
	}
	return csClient, nil
}

func checkMinVersion(ch charm.Charm) error {
	minver := ch.Meta().MinJujuVersion
	if minver != version.Zero && minver.Compare(jujuversion.Current) > 0 {
		return minVersionError(minver, jujuversion.Current)
	}
	return nil
}

type minJujuVersionErr struct {
	*errors.Err
}

func minVersionError(minver, jujuver version.Number) error {
	err := errors.NewErr("charm's min version (%s) is higher than this juju environment's version (%s)",
		minver, jujuver)
	err.SetLocation(1)
	return minJujuVersionErr{&err}
}

// CharmArchive is the data that needs to be stored for a charm archive in
// state.
type CharmArchive struct {
	// ID is the charm URL for which we're storing the archive.
	ID *charm.URL

	// Charm is the metadata about the charm for the archive.
	Charm charm.Charm

	// Data contains the bytes of the archive.
	Data io.Reader

	// Size is the number of bytes in Data.
	Size int64

	// SHA256 is the hash of the bytes in Data.
	SHA256 string

	// Macaroon is the authorization macaroon for accessing the charmstore.
	Macaroon macaroon.Slice
}

// StoreCharmArchive stores a charm archive in environment storage.
func StoreCharmArchive(st *state.State, archive CharmArchive) error {
	storage := newStateStorage(st.ModelUUID(), st.MongoSession())
	storagePath, err := charmArchiveStoragePath(archive.ID)
	if err != nil {
		return errors.Annotate(err, "cannot generate charm archive name")
	}
	if err := storage.Put(storagePath, archive.Data, archive.Size); err != nil {
		return errors.Annotate(err, "cannot add charm to storage")
	}

	info := state.CharmInfo{
		Charm:       archive.Charm,
		ID:          archive.ID,
		StoragePath: storagePath,
		SHA256:      archive.SHA256,
		Macaroon:    archive.Macaroon,
	}

	// Now update the charm data in state and mark it as no longer pending.
	_, err = st.UpdateUploadedCharm(info)
	if err != nil {
		alreadyUploaded := err == state.ErrCharmRevisionAlreadyModified ||
			errors.Cause(err) == state.ErrCharmRevisionAlreadyModified ||
			state.IsCharmAlreadyUploadedError(err)
		if err := storage.Remove(storagePath); err != nil {
			if alreadyUploaded {
				logger.Errorf("cannot remove duplicated charm archive from storage: %v", err)
			} else {
				logger.Errorf("cannot remove unsuccessfully recorded charm archive from storage: %v", err)
			}
		}
		if alreadyUploaded {
			// Somebody else managed to upload and update the charm in
			// state before us. This is not an error.
			return nil
		}
	}
	return nil
}

// charmArchiveStoragePath returns a string that is suitable as a
// storage path, using a random UUID to avoid colliding with concurrent
// uploads.
func charmArchiveStoragePath(curl *charm.URL) (string, error) {
	uuid, err := utils.NewUUID()
	if err != nil {
		return "", err
	}
	return fmt.Sprintf("charms/%s-%s", curl.String(), uuid), nil
}

// ResolveCharm resolves the best available charm URLs with series, for charm
// locations without a series specified.
func ResolveCharms(st *state.State, args params.ResolveCharms) (params.ResolveCharmResults, error) {
	var results params.ResolveCharmResults

	envConfig, err := st.ModelConfig()
	if err != nil {
		return params.ResolveCharmResults{}, err
	}
	repo := config.SpecializeCharmRepo(
		NewCharmStoreRepo(csclient.New(csclient.Params{})),
		envConfig)

	for _, ref := range args.References {
		result := params.ResolveCharmResult{}
		curl, err := charm.ParseURL(ref)
		if err != nil {
			result.Error = err.Error()
		} else {
			curl, err := resolveCharm(curl, repo)
			if err != nil {
				result.Error = err.Error()
			} else {
				result.URL = curl.String()
			}
		}
		results.URLs = append(results.URLs, result)
	}
	return results, nil
}

func resolveCharm(ref *charm.URL, repo charmrepo.Interface) (*charm.URL, error) {
	if ref.Schema != "cs" {
		return nil, fmt.Errorf("only charm store charm references are supported, with cs: schema")
	}

	// Resolve the charm location with the repository.
	resolved, _, err := repo.Resolve(ref)
	if err != nil {
		return nil, err
	}
	if resolved.Series == "" {
		return nil, errors.Errorf("no series found in charm URL %q", resolved)
	}
	return resolved.WithRevision(ref.Revision), nil
}