day2: edgex-go version:geneva

元数据微服务

1. 元数据微服务并不是自己有一个数据库，而是定义了一系列对数据库容器edgex-redis的操作方法。
2. 元数据负责的信息有DeviceReports, Devices, DeviceProfiles, Addressables, DeviceServices, ProvisionWatchers, Commands 。并提供了这些数据与数据库 edgex-redis的操作方法，如添加、删除、修改等。
3. 这些方法以api的方式提供给其他微服务，当收到其他服务的请求，就执行对应的动作。

源码分析

配置文件

配置文件的大部分结构都相同，所以请看此文章，配置文件说明

下面介绍元数据服务自定义的内容：

type WritableInfo struct {LogLevel   string// 设定输出日志等级，有"TRACE, DEBUG, INFO, WARN, ERROR"EnableValueDescriptorManagement bool// 使能值描述管理}

todo!!

// Notification Info provides properties related to the assembly of notification contenttype NotificationInfo struct {Content    stringDescriptionstringLabel      stringPostDeviceChanges boolSender     stringSlugstring}

代码结构

. # /internal/core/metadata├── config# 配置文件的相关处理，可以看到，配置文件中的Writeable、Notification结构中的参数是各个微服务自定义的。其他参数结构相同├── container# 容器注入（DIC）需要用到的函数，返回实例├── errors# error相关函数├── interfaces# 定义数据库的接口，具体实现在 operators 中│   └── mocks# 好像是测试所用└── operators# 面向数据库的操作，实现与数据库通信、将数据存入数据库，以及向数据库查询信息等等。此部分操作是外部不可见的。    ├── addressable# 对数据库的操作按数据类型进行了分类，不同数据的操作分别位于不同的文件夹下。    │   └── mocks# 测试所用吧    ├── command    │   └── mocks    ├── device    │   └── mocks    ├── device_profile    │   └── mocks    └── device_service# 面向外部的操作，即为 httpserver 特定路由(​.../v1​/config, etc)设计对应的处理函数。也就是为外界提供的API的实现。rest_addressable.gorest_addressable_test.gorest_command.gorest_command_test.gorest_device.gorest_deviceprofile.gorest_deviceprofile_test.gorest_devicereport.gorest_deviceservice.gorest_deviceservice_test.gorest_device_test.gorest_provisionwatcher.go

Dockerfile

过程都类似，先编译得到可执行文件，再放到一个新的环境中运行。此处用的scratch，官方说明：该镜像是一个空的镜像，可以用于构建busybox等超小镜像，可以说是真正的从零开始构建属于自己的镜像。要知道，一个官方的ubuntu镜像有60MB+，CentOS镜像有70MB+。可以把一个可执行文件扔进来直接执行。

edgex-go源码中所有服务运行所需的配置文件都位于/cmd/各个服务/res/configuration.toml下，运行环境中配置文件位于/res/configuration.toml。

启动流程

数据库接口

Edgex-go下面是edgex-go中所有微服务具有的操作数据库的方法，存储的信息包括Events, Readings, ValueDescriptors, DeviceReports, Devices, DeviceProfiles, Addressables, DeviceServices, ProvisionWatchers, Commands, Notifications, Subscriptions, Transmissions, Intervals, IntervalActions共15类。不同的微服务负责不同的信息并实现对应的函数，其中（通过源码中internel/*/*/interfaces/db.go知悉），

• coredata负责Events, Readings, ValueDescriptors3类；
• metadata 负责DeviceReports, Devices, DeviceProfiles, Addressables, DeviceServices, ProvisionWatchers, Commands 7类；
• support-scheduler负责intervals, intervalActions2类；
• support-notifications负责Notifications, Subscriptions, Transmissions,三类。

type DBClient interface {CloseSession()/*EventsNOTE: Readings that contain binary data will not be persisted.*/Events() ([]contract.Event, error)EventsWithLimit(limit int) ([]contract.Event, error)AddEvent(e correlation.Event) (string, error)UpdateEvent(e correlation.Event) errorEventById(id string) (contract.Event, error)EventsByChecksum(checksum string) ([]contract.Event, error)EventCount() (int, error)EventCountByDeviceId(id string) (int, error)DeleteEventById(id string) errorDeleteEventsByDevice(deviceId string) (int, error)EventsForDeviceLimit(id string, limit int) ([]contract.Event, error)EventsForDevice(id string) ([]contract.Event, error)EventsByCreationTime(startTime, endTime int64, limit int) ([]contract.Event, error)EventsOlderThanAge(age int64) ([]contract.Event, error)EventsPushed() ([]contract.Event, error)ScrubAllEvents() error/*ReadingsNOTE: Readings that contain binary data will not be persisted.*/Readings() ([]contract.Reading, error)AddReading(r contract.Reading) (string, error)UpdateReading(r contract.Reading) errorReadingById(id string) (contract.Reading, error)ReadingCount() (int, error)DeleteReadingById(id string) errorDeleteReadingsByDevice(deviceId string) errorReadingsByDevice(id string, limit int) ([]contract.Reading, error)ReadingsByValueDescriptor(name string, limit int) ([]contract.Reading, error)ReadingsByValueDescriptorNames(names []string, limit int) ([]contract.Reading, error)ReadingsByCreationTime(start, end int64, limit int) ([]contract.Reading, error)ReadingsByDeviceAndValueDescriptor(deviceId, valueDescriptor string, limit int) ([]contract.Reading, error)/*ValueDescriptors*/ValueDescriptors() ([]contract.ValueDescriptor, error)AddValueDescriptor(v contract.ValueDescriptor) (string, error)UpdateValueDescriptor(cvd contract.ValueDescriptor) errorDeleteValueDescriptorById(id string) errorValueDescriptorByName(name string) (contract.ValueDescriptor, error)ValueDescriptorsByName(names []string) ([]contract.ValueDescriptor, error)ValueDescriptorById(id string) (contract.ValueDescriptor, error)ValueDescriptorsByUomLabel(uomLabel string) ([]contract.ValueDescriptor, error)ValueDescriptorsByLabel(label string) ([]contract.ValueDescriptor, error)ValueDescriptorsByType(t string) ([]contract.ValueDescriptor, error)ScrubAllValueDescriptors() error/*Device Reports*/GetAllDeviceReports() ([]contract.DeviceReport, error)GetDeviceReportByName(n string) (contract.DeviceReport, error)GetDeviceReportByDeviceName(n string) ([]contract.DeviceReport, error)GetDeviceReportById(id string) (contract.DeviceReport, error)GetDeviceReportsByAction(n string) ([]contract.DeviceReport, error)AddDeviceReport(d contract.DeviceReport) (string, error)UpdateDeviceReport(dr contract.DeviceReport) errorDeleteDeviceReportById(id string) error/*Devices*/GetAllDevices() ([]contract.Device, error)AddDevice(d contract.Device, commands []contract.Command) (string, error)UpdateDevice(d contract.Device) errorDeleteDeviceById(id string) errorGetDevicesByProfileId(id string) ([]contract.Device, error)GetDeviceById(id string) (contract.Device, error)GetDeviceByName(n string) (contract.Device, error)GetDevicesByServiceId(id string) ([]contract.Device, error)GetDevicesWithLabel(l string) ([]contract.Device, error)/*Device Profiles*/GetAllDeviceProfiles() ([]contract.DeviceProfile, error)GetDeviceProfileById(id string) (contract.DeviceProfile, error)GetDeviceProfilesByModel(model string) ([]contract.DeviceProfile, error)GetDeviceProfilesWithLabel(l string) ([]contract.DeviceProfile, error)GetDeviceProfilesByManufacturerModel(man string, mod string) ([]contract.DeviceProfile, error)GetDeviceProfilesByManufacturer(man string) ([]contract.DeviceProfile, error)GetDeviceProfileByName(n string) (contract.DeviceProfile, error)AddDeviceProfile(dp contract.DeviceProfile) (string, error)UpdateDeviceProfile(dp contract.DeviceProfile) errorDeleteDeviceProfileById(id string) error/*Addressables*/GetAddressables() ([]contract.Addressable, error)UpdateAddressable(a contract.Addressable) errorGetAddressableById(id string) (contract.Addressable, error)AddAddressable(a contract.Addressable) (string, error)GetAddressableByName(n string) (contract.Addressable, error)GetAddressablesByTopic(t string) ([]contract.Addressable, error)GetAddressablesByPort(p int) ([]contract.Addressable, error)GetAddressablesByPublisher(p string) ([]contract.Addressable, error)GetAddressablesByAddress(add string) ([]contract.Addressable, error)DeleteAddressableById(id string) error/*Device Services*/GetDeviceServiceByName(n string) (contract.DeviceService, error)GetDeviceServiceById(id string) (contract.DeviceService, error)GetAllDeviceServices() ([]contract.DeviceService, error)GetDeviceServicesByAddressableId(id string) ([]contract.DeviceService, error)GetDeviceServicesWithLabel(l string) ([]contract.DeviceService, error)AddDeviceService(ds contract.DeviceService) (string, error)UpdateDeviceService(ds contract.DeviceService) errorDeleteDeviceServiceById(id string) error/*Provision Watchers*/GetAllProvisionWatchers() (pw []contract.ProvisionWatcher, err error)GetProvisionWatcherByName(n string) (pw contract.ProvisionWatcher, err error)GetProvisionWatchersByIdentifier(k string, v string) (pw []contract.ProvisionWatcher, err error)GetProvisionWatchersByServiceId(id string) (pw []contract.ProvisionWatcher, err error)GetProvisionWatchersByProfileId(id string) (pw []contract.ProvisionWatcher, err error)GetProvisionWatcherById(id string) (pw contract.ProvisionWatcher, err error)AddProvisionWatcher(pw contract.ProvisionWatcher) (string, error)UpdateProvisionWatcher(pw contract.ProvisionWatcher) errorDeleteProvisionWatcherById(id string) error/*Commands*/GetAllCommands() ([]contract.Command, error)GetCommandById(id string) (contract.Command, error)GetCommandsByName(n string) ([]contract.Command, error)GetCommandsByDeviceId(did string) ([]contract.Command, error)GetCommandByNameAndDeviceId(cname string, did string) (contract.Command, error)ScrubMetadata() error/*Notifications*/GetNotifications() ([]contract.Notification, error)GetNotificationById(id string) (contract.Notification, error)GetNotificationBySlug(slug string) (contract.Notification, error)GetNotificationBySender(sender string, limit int) ([]contract.Notification, error)GetNotificationsByLabels(labels []string, limit int) ([]contract.Notification, error)GetNotificationsByStartEnd(start int64, end int64, limit int) ([]contract.Notification, error)GetNotificationsByStart(start int64, limit int) ([]contract.Notification, error)GetNotificationsByEnd(end int64, limit int) ([]contract.Notification, error)GetNewNotifications(limit int) ([]contract.Notification, error)GetNewNormalNotifications(limit int) ([]contract.Notification, error)AddNotification(n contract.Notification) (string, error)UpdateNotification(n contract.Notification) errorMarkNotificationProcessed(n contract.Notification) errorDeleteNotificationById(id string) errorDeleteNotificationBySlug(slug string) errorDeleteNotificationsOld(age int) error/*Subscriptions*/GetSubscriptionBySlug(slug string) (contract.Subscription, error)GetSubscriptionByCategories(categories []string) ([]contract.Subscription, error)GetSubscriptionByLabels(labels []string) ([]contract.Subscription, error)GetSubscriptionByCategoriesLabels(categories []string, labels []string) ([]contract.Subscription, error)GetSubscriptionByReceiver(receiver string) ([]contract.Subscription, error)GetSubscriptionById(id string) (contract.Subscription, error)DeleteSubscriptionById(id string) errorAddSubscription(sub contract.Subscription) (string, error)UpdateSubscription(sub contract.Subscription) errorDeleteSubscriptionBySlug(slug string) errorGetSubscriptions() ([]contract.Subscription, error)/*Transmissions*/AddTransmission(t contract.Transmission) (string, error)UpdateTransmission(t contract.Transmission) errorDeleteTransmission(age int64, status contract.TransmissionStatus) errorGetTransmissionById(id string) (contract.Transmission, error)GetTransmissionsByNotificationSlug(slug string, limit int) ([]contract.Transmission, error)GetTransmissionsByNotificationSlugAndStartEnd(slug string, start int64, end int64, limit int) ([]contract.Transmission, error)GetTransmissionsByStartEnd(start int64, end int64, limit int) ([]contract.Transmission, error)GetTransmissionsByStart(start int64, limit int) ([]contract.Transmission, error)GetTransmissionsByEnd(end int64, limit int) ([]contract.Transmission, error)GetTransmissionsByStatus(limit int, status contract.TransmissionStatus) ([]contract.Transmission, error)Cleanup() errorCleanupOld(age int) error/*Intervals*/Intervals() ([]contract.Interval, error)IntervalsWithLimit(limit int) ([]contract.Interval, error)IntervalByName(name string) (contract.Interval, error)IntervalById(id string) (contract.Interval, error)AddInterval(interval contract.Interval) (string, error)UpdateInterval(interval contract.Interval) errorDeleteIntervalById(id string) error/*Interval Actions*/IntervalActions() ([]contract.IntervalAction, error)IntervalActionsWithLimit(limit int) ([]contract.IntervalAction, error)IntervalActionsByIntervalName(name string) ([]contract.IntervalAction, error)IntervalActionsByTarget(name string) ([]contract.IntervalAction, error)IntervalActionById(id string) (contract.IntervalAction, error)IntervalActionByName(name string) (contract.IntervalAction, error)AddIntervalAction(action contract.IntervalAction) (string, error)UpdateIntervalAction(action contract.IntervalAction) errorDeleteIntervalActionById(id string) errorScrubAllIntervalActions() (int, error)ScrubAllIntervals() (int, error)}

数据库存储的数据样例可以看这，应该是对应源码go-mod-core-contracts/models目录下各个文件中定义的结构，但并不是此结构中的所有参数都会保存到数据库。

core-metadata api 列表

API看此网页：网页API说明

api除了查看文档，在源码edgex-go/api目录下也有说明。此处也可看出metadata负责对DeviceReports, Devices, DeviceProfiles, Addressables, DeviceServices, ProvisionWatchers, Commands 7类信息的管理。

redis

Redis 教程
Redis 命令参考

使用docker-compose启动EdgeX后连接redis数据库，查看值。docker exec -it edgex-redis redis-cli

redis 默认有16个database，但edgex-go中并没有说一类数据用一个database来存储，而是所有数据都存储在一个database中，所以上面连接redis数据库，查看键值会很乱。微服务的配置文件中：

[Databases]  [Databases.Primary]  Host = 'localhost'  Name = 'coredata'  Password = 'password'  Username = 'core'  Port = 6379  Timeout = 5000  Type = 'redisdb'

Username, Name 可能会产生误导，让人怀疑是不是使用了不同的database，但其实那些参数是使用Mongo数据库时才需要的，Redis并未用到！

// keykeys * // 查看所有keyexists key// 检查key是否存在，存在返回1type key// key 值类型scan 0 match ** count 10// 迭代数据库中的数据库键// string key:"string"get key// 返回key对应string// hash key: field1 value1 field2 value2 ...HGETALL key// 返回key中的所有值// set// sort set

所有ID类键都是string类型，保存了完整的信息，如设备配置文件会分配一个ID作为键，将文件内容合成一个字符串作为值保存。

使用命令行中连接redis查看数据比较麻烦，这里推荐redis可视工具 treeNMS。

总结

metadata 管理了多中类型的数据，设备服务启动时，也会将信息注册到metadata。需要注意和consul区分开来，consul保存的是微服务的配置信息，即/cmd/res/configuration.toml文件，而metadata 保存的是设备配置文件，设备id等具体信息。