StackStorm介紹
StackStorm是一個強大的自動化平臺，結合DevOps和ChatOps，提供可擴展、靈活和健壯的工具鏈用於應用、服務和工作流的自動化能力。
Inquiry
在自動化任務執行的過程中，往往會需要等待確認的步驟，比如需要人工審覈，需要外部系統的確認。爲此StackStorm提供一種Action的交互機制Inquiry，通過執行core.ask發起Inquiry，進入pending掛起狀態，直到Inquiry收到回覆才繼續執行。
下面是一個Mistral Workflow的規格文件examples.mistral-ask-basic.yaml：
version: '2.0'
examples.mistral-ask-basic: description: A basic Mistral workflow illustrating the use of Inquiries type: direct output: result: <% task(task1).result.response %> tasks: task1: action: core.ask input: route: developers schema: type: object properties: secondfactor: type: string description: Please enter second factor for authenticating to "foo" service required: True on-success: - task2
task2: action: core.local input: cmd: echo "We can now authenticate to 'foo' service with <% task(task1).result.response.secondfactor %>" |
task1的action就是core.ask,core.ask需要提供的入參就是Inquiry的規格：
Parameter | Description |
schema | A JSON schema that will be used to validate the response data. A basic schema will be provided by default, or you can provide one here. Only valid responses will cause the action to succeed, and the workflow to continue. |
ttl | Time (in minutes) until an unacknowledged Inquiry is garbage-collected. Set to 0 to disable garbage collection for this Inquiry. NOTE - Inquiry garbage collection is not enabled by default, so this field does nothing unless it is turned on. |
roles | A list of RBAC roles that are permitted to respond to the action. Defaults to empty list, which permits all roles. This requires enterprise features |
users | A list of users that are permitted to respond to the action. Defaults to empty list, which permits all users. |
route | An arbitrary string that can be used to filter different Inquiries inside rules. This can be helpful for deciding who to notify of an incoming Inquiry. |
執行Workflow，task1就會掛起：
$ st2 run examples.mistral-ask-basic . id: 5afbd3802b2556015687ce09 action.ref: examples.mistral-ask-basic parameters: None status: paused start_timestamp: Wed, 16 May 2018 06:45:20 UTC end_timestamp: +--------------------------+---------+-------+----------+-------------------------------+ | id | status | task | action | start_timestamp | +--------------------------+---------+-------+----------+-------------------------------+ | 5afbd3802b2556015687ce0c | pending | task1 | core.ask | Wed, 16 May 2018 06:45:20 UTC | +--------------------------+---------+-------+----------+-------------------------------+ |
這時候就會產生一個Inquiry:
$ st2 inquiry list +--------------------------+-------+-------+------------+------+ | id | roles | users | route | ttl | +--------------------------+-------+-------+------------+------+ | 5afbd3802b2556015687ce0c | | | developers | 1440 | +--------------------------+-------+-------+------------+------+ |
然後進行回覆：
$ st2 inquiry respond -r '{"secondfactor": "bar"}' 5afbd3802b2556015687ce0c |
那麼Workflow就會繼續執行：
$ st2 execution get 5afbd3802b2556015687ce09 id: 5afbd3802b2556015687ce09 action.ref: examples.mistral-ask-basic parameters: None status: succeeded (450s elapsed) result_task: task2 result: failed: false return_code: 0 stderr: '' stdout: We can now authenticate to 'foo' service with bar succeeded: true start_timestamp: Wed, 16 May 2018 06:45:20 UTC end_timestamp: Wed, 16 May 2018 06:52:50 UTC +--------------------------+------------------------+-------+------------+-------------------------------+ | id | status | task | action | start_timestamp | +--------------------------+------------------------+-------+------------+-------------------------------+ | 5afbd3802b2556015687ce0c | succeeded (1s elapsed) | task1 | core.ask | Wed, 16 May 2018 06:45:20 UTC | | 5afbd5402b2556015687ce0e | succeeded (0s elapsed) | task2 | core.local | Wed, 16 May 2018 06:52:48 UTC | +--------------------------+------------------------+-------+------------+-------------------------------+ |
參考
- https://github.com/StackStorm/st2docs/blob/master/docs/source/inquiries.rst
作者簡介
吳龍輝，現任網宿科技雲計算架構師，致力於雲計算PaaS的研究和實踐，《Kubernetes實戰》作者，活躍於CloudFoundry，Docker，Kubernetes等開源社區，貢獻代碼和撰寫技術文檔。郵箱：[email protected]