Golang List.Newest方法代码示例

// findCompatibleTools finds tools in the list that have the same major, minor
// and patch level as version.Current.
//
// Build number is not important to match; uploaded tools will have
// incremented build number, and we want to match them.
func findCompatibleTools(possibleTools coretools.List, version version.Number) (version.Number, coretools.List) {
	var compatibleTools coretools.List
	for _, tools := range possibleTools {
		if isCompatibleVersion(tools.Version.Number, version) {
			compatibleTools = append(compatibleTools, tools)
		}
	}
	return compatibleTools.Newest()
}

// SetBootstrapTools returns the newest tools from the given tools list,
// and updates the agent-version configuration attribute.
func SetBootstrapTools(environ environs.Environ, possibleTools coretools.List) (coretools.List, error) {
	if len(possibleTools) == 0 {
		return nil, fmt.Errorf("no bootstrap tools available")
	}
	var newVersion version.Number
	newVersion, toolsList := possibleTools.Newest()
	logger.Infof("newest version: %s", newVersion)
	cfg := environ.Config()
	if agentVersion, _ := cfg.AgentVersion(); agentVersion != newVersion {
		cfg, err := cfg.Apply(map[string]interface{}{
			"agent-version": newVersion.String(),
		})
		if err == nil {
			err = environ.SetConfig(cfg)
		}
		if err != nil {
			return nil, fmt.Errorf("failed to update environment configuration: %v", err)
		}
	}
	bootstrapVersion := newVersion
	// We should only ever bootstrap the exact same version as the client,
	// or we risk bootstrap incompatibility. We still set agent-version to
	// the newest version, so the agent will immediately upgrade itself.
	if !isCompatibleVersion(newVersion, version.Current.Number) {
		compatibleVersion, compatibleTools := findCompatibleTools(possibleTools, version.Current.Number)
		if len(compatibleTools) == 0 {
			logger.Warningf(
				"failed to find %s tools, will attempt to use %s",
				version.Current.Number, newVersion,
			)
		} else {
			bootstrapVersion, toolsList = compatibleVersion, compatibleTools
		}
	}
	logger.Infof("picked bootstrap tools version: %s", bootstrapVersion)
	return toolsList, nil
}

// getBootstrapToolsVersion returns the newest tools from the given tools list.
func getBootstrapToolsVersion(possibleTools coretools.List) (coretools.List, error) {
	if len(possibleTools) == 0 {
		return nil, errors.New("no bootstrap tools available")
	}
	var newVersion version.Number
	newVersion, toolsList := possibleTools.Newest()
	logger.Infof("newest version: %s", newVersion)
	bootstrapVersion := newVersion
	// We should only ever bootstrap the exact same version as the client,
	// or we risk bootstrap incompatibility.
	if !isCompatibleVersion(newVersion, jujuversion.Current) {
		compatibleVersion, compatibleTools := findCompatibleTools(possibleTools, jujuversion.Current)
		if len(compatibleTools) == 0 {
			logger.Infof(
				"failed to find %s tools, will attempt to use %s",
				jujuversion.Current, newVersion,
			)
		} else {
			bootstrapVersion, toolsList = compatibleVersion, compatibleTools
		}
	}
	logger.Infof("picked bootstrap tools version: %s", bootstrapVersion)
	return toolsList, nil
}