clair/ext/vulnmdsrc/driver.go
2019-01-10 13:50:46 -05:00

97 lines
2.7 KiB
Go

// Copyright 2017 clair authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package vulnmdsrc exposes functions to dynamically register vulnerability
// metadata sources used to update a Clair database.
package vulnmdsrc
import (
"sync"
"github.com/coreos/clair/database"
)
var (
appendersM sync.RWMutex
appenders = make(map[string]Appender)
)
// AppendFunc is the type of a callback provided to an Appender.
type AppendFunc func(metadataKey string, metadata interface{}, severity database.Severity)
// Appender represents anything that can fetch vulnerability metadata and
// append it to a Vulnerability.
type Appender interface {
// BuildCache loads metadata into memory such that it can be quickly accessed
// for future calls to Append.
BuildCache(database.Datastore) error
// AddMetadata adds metadata to the given database.Vulnerability.
// It is expected that the fetcher uses .Lock.Lock() when manipulating the Metadata map.
// Append
Append(vulnName string, callback AppendFunc) error
// PurgeCache deallocates metadata from memory after all calls to Append are
// finished.
PurgeCache()
// Clean deletes any allocated resources.
// It is invoked when Clair stops.
Clean()
}
// RegisterAppender makes an Appender available by the provided name.
//
// If called twice with the same name, the name is blank, or if the provided
// Appender is nil, this function panics.
func RegisterAppender(name string, a Appender) {
if name == "" {
panic("vulnmdsrc: could not register an Appender with an empty name")
}
if a == nil {
panic("vulnmdsrc: could not register a nil Appender")
}
appendersM.Lock()
defer appendersM.Unlock()
if _, dup := appenders[name]; dup {
panic("vulnmdsrc: RegisterAppender called twice for " + name)
}
appenders[name] = a
}
// Appenders returns the list of the registered Appenders.
func Appenders() map[string]Appender {
appendersM.RLock()
defer appendersM.RUnlock()
ret := make(map[string]Appender)
for k, v := range appenders {
ret[k] = v
}
return ret
}
// CleanAll is a utility function that calls Clean() on every registered
// Appender.
func CleanAll() {
for _, appender := range Appenders() {
appender.Clean()
}
}