Example 1: Using a Timer Trigger to Periodically Download Files from an OBS Bucket

Scenario

This example guides you through the procedure for creating a Python 2.7 function and associating a timer trigger with it to periodically download files from an OBS bucket.

For details about how to call APIs, see Calling APIs.

Prerequisites

• You have uploaded files to OBS and have recorded the file names, the bucket in which the files are stored, and the address of the bucket.
• You have created an agency in IAM to allow FunctionGraph to access OBS and have recorded the name of the agency.

Overall Procedure

Create a FunctionGraph function and associate a timer trigger with it to periodically download files from an OBS bucket. The procedure is as follows:

1. Create a function. Create a function for downloading files from OBS.
2. Modify the metadata of the function. Modify the OBS address, OBS bucket name, and file name in the function configuration.
3. Execute the function synchronously. Verify whether the function can successfully download files from the OBS bucket.
4. Create a trigger. Create a timer trigger to periodically download files.

Step 1: Create a Function for Downloading Files from OBS

URI: POST /v2/{project_id}/fgs/functions

• Example request

  POST  https://{Endpoint}/v2/{project_id}/fgs/functions
  {
   "code_filename": "index.zip",
   "code_type": "inline",
   "func_code": {
    "file": "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"
   },
   "func_name": "download_file_from_obs",
   "handler": "index.handler",
   "memory_size": 256,
   "package": "default",
   "runtime": "Python2.7",
   "timeout": 30
  }

• Example response

  {
   "func_urn": "urn:fss:{project_name}:{project_id}:function:default:download_file_from_obs:latest",
   "func_name": "download_file_from_obs",
   "domain_id": "89fexxxd636",
   "namespace": "{project_id}",
   "project_name": "xxx",
   "package": "default",
   "runtime": "Python2.7",
   "timeout": 30,
   "handler": "index.handler",
   "memory_size": 256,
   "cpu": 400,
   "code_type": "inline",
   "code_filename": "index.zip",
   "code_size": 1707,
   "digest": "68891a6778848a78bd37a8c0798c91d75a5c87aee6e901303047a52edf05bf2170aac4149d79b3f6a40efe78406a83bf6d8683e7b25da4f0c07e7493aa4ccdcd",
   "version": "latest",
   "image_name": "latest-200603162219@zr2ym",
   "last_modified": "2020-06-03T16:22:19+08:00",
   "strategy_config": {
    "concurrency": -1
   },
   "StrategyConfig": {},
   "enterprise_project_id": "0"
  }

  Record the URN of the function, that is, the value of func_urn in the response.

Step 2: Modify the OBS Address, Bucket Name, and File Name in the Function Configurations

URI: PUT /v2/{project_id}/fgs/functions/{function_urn}/config

• Example request

  PUT  https://{Endpoint}/v2/{project_id}/fgs/functions/{function_urn}/config
  {
   "func_name": "download_file_from_obs",
   "handler": "index.handler",
   "memory_size": 256,
   "runtime": "Python2.7",
   "timeout": 30,
   "user_data": "{\"obs_address\":\"obs.example.example.com\",\"srcBucket\":\" xxx\",\"srcObjName\":\"xxx\"}",
   "xrole": "xxx"
  }

  • function_urn: function URN recorded in Step 1: Create a Function for Downloading Files from OBS
  • obs_address: OBS address
  • srcBucket: name of an OBS bucket
  • srcObjName: file name
  • xrole: agency name
• Example response

  {
   "func_urn": "urn:fss:{project_name}:{project_id}:function:default:download_file_from_obs:latest",
   "func_name": "download_file_from_obs",
   "domain_id": "89fexxxd636",
   "namespace": "{project_id}",
   "project_name": "xxx",
   "package": "default",
   "runtime": "Python2.7",
   "timeout": 30,
   "handler": "index.handler",
   "memory_size": 256,
   "cpu": 400,
   "code_type": "inline",
   "code_filename": "index.zip",
   "code_size": 1707,
   "user_data": "{\"obs_address\":\"obs.example.example.com\",\"srcBucket\":\"xxx\",\"srcObjName\":\"xxx\"}",
   "digest": "68891a6778848a78bd37a8c0798c91d75a5c87aee6e901303047a52edf05bf2170aac4149d79b3f6a40efe78406a83bf6d8683e7b25da4f0c07e7493aa4ccdcd",
   "version": "latest",
   "image_name": "latest-200603165355@varrp",
   "xrole": "xxx",
   "app_xrole": "xxx",
   "last_modified": "2020-06-03T17:25:03+08:00",
   "strategy_config": {
    "concurrency": -1
   },
   "StrategyConfig": {},
   "enterprise_project_id": "0"
  }

Step 3: Test the Function

URI: POST /v2/{project_id}/fgs/functions/{function_urn}/invocations

• Example request

  POST  https://{Endpoint}/v2/{project_id}/fgs/functions/{function_urn}/invocations
  {
   "message": "download file"
  }

  function_urn indicates the function URN recorded in Step 1: Create a Function for Downloading Files from OBS.

• Example response

  "The object downloaded successfully from OBS, and the size is 14 KB"

Step 4: Create a Timer Trigger to Periodically Download Files from OBS

URI: POST /v2/{project_id}/fgs/triggers/{function_urn}

• Example request

  POST  https://{Endpoint}/v2/{project_id}/fgs/triggers/{function_urn}
  {
   "event_data": {
    "name": "Timer-download",
    "schedule_type": "Rate",
    "schedule": "1d"
   },
   "event_type_code": "MessageCreated",
   "trigger_status": "ACTIVE",
   "trigger_type_code": "TIMER"
  }

  function_urn indicates the function URN recorded in Step 1: Create a Function for Downloading Files from OBS.

  The preceding example request is used to download files from the specified OBS bucket every day.

• Example response

  {
   "trigger_id": "461bbe95-c85b-4dc9-a306-9701e77f1d66",
   "trigger_type_code": "TIMER",
   "trigger_status": "ACTIVE",
   "event_data": {
    "name": "Timer-download",
    "schedule": "1d",
    "schedule_type": "Rate"
   },
   "last_updated_time": "2020-06-04T10:33:30+08:00",
   "created_time": "2020-06-04T10:33:30+08:00"
  }