huawei-cloud-functiongraph-trigger-create

Create FunctionGraph triggers on Huawei Cloud. Supports scheduled TIMER triggers (Quartz Cron expressions or fixed Rate values) and event-driven OBS triggers that run a function when objects are created or deleted in an OBS bucket. Use this skill when users ask to create a trigger, schedule function execution, set up periodic tasks, configure a timer, or run a function as soon as a file is uploaded to OBS. Triggered by keywords like "create trigger", "set up trigger", "schedule function", "periodic task", "timer", "cron", "OBS trigger", "object storage trigger", "event trigger", "event-driven", "trigger on upload", "bucket notification", "FunctionGraph trigger", "创建云函数触发器", "配置云函数触发器", "云函数定时触发", "定时执行", "定时任务", "创建定时器", "OBS触发器", "对象存储触发器", "事件触发器", "上传触发".

Overview

This skill enables the creation of triggers for Huawei Cloud FunctionGraph functions. Two trigger types are supported:

• TIMER (scheduled trigger): invokes the function on a schedule described by a Quartz Cron expression or by a fixed Rate value.
• OBS (event-driven trigger, new): invokes the function when objects are created or deleted in an OBS bucket, which covers real-time processing scenarios such as masking or sanitizing sensitive data as soon as a file is uploaded.

Typical scenarios:

• Periodic data processing, scheduled backup operations, regular monitoring and health checks, time-based notifications (TIMER).
• Upload-triggered processing: real-time data masking, thumbnail generation, format conversion, search indexing or malware scanning of newly uploaded objects (OBS).

Supported Trigger Types and Capability Boundaries

Supported trigger types

--trigger-type	Trigger	Configuration parameters	Typical use
TIMER (default)	Scheduled trigger	--schedule with --schedule-type (Cron or Rate), optional --user-event	Periodic function execution
OBS	Object storage event trigger	--bucket and --events, optional --prefix and --suffix	Run the function when an object is created or deleted

Trigger types that are NOT supported

This skill implements only TIMER and OBS. The FunctionGraph service also offers other trigger types, but this skill does not support them and does not document them:

• APIG, CTS, DDS, DMS, DIS, LTS, SMN, KAFKA, RABBITMQ, DEDICATEDGATEWAY, OPENSOURCEKAFKA, APIC, GAUSSMONGO, EVENTGRID

For those types, use the FunctionGraph console or the KooCLI hcloud FunctionGraph trigger commands.

Capability boundary: create only

This skill only creates triggers. It does not:

• delete a trigger
• update or modify an existing trigger
• disable or enable an existing trigger
• list or query existing triggers

Triggers that need to be removed, changed or inspected must be handled by the user in the FunctionGraph console (Function details → Triggers) or with the KooCLI hcloud FunctionGraph commands. Every run of this skill creates a new trigger; running it again with the same trigger name for the same function fails with TriggerAlreadyExists instead of updating the existing trigger.

Prerequisites

Before using this skill, ensure the following requirements are met:

1. Python Environment: Python 3.9+ installed
2. SDK Installation: Install FunctionGraph SDK: pip install huaweicloudsdkfunctiongraph
3. Environment Variables: Configure the following environment variables:
   • HUAWEI_AK: Huawei Cloud Access Key
   • HUAWEI_SK: Huawei Cloud Secret Key
   • HUAWEI_REGION: Target region (e.g., cn-north-4)
   • HUAWEI_PROJECT_ID: Project ID
4. FunctionGraph Function: Target function must already exist in the specified region
5. OBS Bucket (OBS triggers only): The bucket must already exist in the same region as the function, and the function must be authorized to read from it
6. Network Access: Stable network connection to Huawei Cloud API endpoints

Workflow

The complete workflow consists of the following steps.

Step 1: Load environment variables and authenticate（加载环境变量/鉴权）

The script reads the following environment variables at startup:

• HUAWEI_AK: Huawei Cloud Access Key (required)
• HUAWEI_SK: Huawei Cloud Secret Key (required)
• HUAWEI_REGION: Target region, defaults to cn-north-4
• HUAWEI_PROJECT_ID: Project ID

If HUAWEI_AK or HUAWEI_SK is missing, the script prints Config error: Please set environment variables HUAWEI_AK and HUAWEI_SK and exits before any API call.

Step 2: Confirm the target function URN（确认 function_urn）

Pass the target function URN via --function-urn, e.g. urn:fss:cn-north-4:project_id:function:default:my-function:latest. Before creating the trigger, the script verifies that the function exists by calling ShowFunctionConfig. If the function is not found, it returns FunctionNotFound and stops without creating anything.

Step 3: Choose the trigger type（选择触发器类型）

Pass --trigger-type TIMER (the default) or --trigger-type OBS. The type determines which parameters are required in the next step:

• TIMER requires --schedule; --bucket, --events, --prefix and --suffix are ignored.
• OBS requires --bucket and --events; --schedule, --schedule-type and --user-event are ignored.

Step 4: Confirm the trigger configuration（确认触发配置）

Verify the trigger parameters (see Parameter Confirmation):

For a TIMER trigger:

• --name: Trigger name, 1-64 characters
• --schedule: Quartz Cron expression (6-7 fields) for Cron, or a rate value such as 5m for Rate
• --schedule-type: Cron (default) or Rate
• --user-event: Optional additional user event data

For an OBS trigger:

• --name: Event notification name, 1-64 characters
• --bucket: Name of the existing OBS bucket that acts as the event source; it cannot be changed after the trigger is created
• --events: Comma-separated object events, e.g. ObjectCreated:* or Put,Post (see OBS Event Types)
• --prefix / --suffix: Optional filters that limit the notification to object keys starting with / ending with the given string
• --status: use ACTIVE; OBS triggers cannot be disabled after creation

The script validates all parameters (required fields per trigger type, Cron syntax, name length, status value) before calling the API.

Step 5: Execute the creation script（执行 create_trigger.py）

Run from the skill directory. TIMER example:

bash

python3 scripts/create_trigger.py \
    --function-urn "urn:fss:cn-north-4:project_id:function:default:my-function:latest" \
    --trigger-type "TIMER" \
    --name "daily-trigger" \
    --schedule "0 0 2 * * ?" \
    --schedule-type "Cron" \
    --status "ACTIVE"

OBS example:

bash

python3 scripts/create_trigger.py \
    --function-urn "urn:fss:cn-north-4:project_id:function:default:my-function:latest" \
    --trigger-type "OBS" \
    --name "mask-on-upload" \
    --bucket "my-input-bucket" \
    --events "ObjectCreated:*" \
    --prefix "uploads/" \
    --status "ACTIVE"

Step 6: Verify the result（验证结果）

• On success, the script prints a JSON response with status: "success", the created trigger_id, trigger_name, trigger_type (TIMER or OBS) and enable_status. A TIMER response also contains schedule; an OBS response also contains bucket and events.
• On failure, it prints status: "failed" with an error_code (InvalidParameter, FunctionNotFound, NetworkError, TriggerAlreadyExists, TriggerLimitExceeded, InternalError) and exits with a non-zero code. Fix the corresponding parameter and re-run the script.
• You can also confirm the result in the FunctionGraph console: Function details → Triggers tab, where the new trigger should be listed with its status.

Core Commands

Basic Command Structure

bash

python3 scripts/create_trigger.py \
    --function-urn "<function-urn>" \
    --trigger-type "<TIMER|OBS>" \
    --name "<trigger-name>" \
    --status "<ACTIVE|DISABLED>" \
    <type-specific parameters>

TIMER Trigger Examples

Cron Expression Trigger

bash

python3 scripts/create_trigger.py \
    --function-urn "urn:fss:cn-north-4:project_id:function:default:my-function:latest" \
    --name "hourly-report" \
    --schedule "0 0 8 * * ?" \
    --schedule-type "Cron"

Fixed Rate Trigger

bash

python3 scripts/create_trigger.py \
    --function-urn "urn:fss:cn-north-4:project_id:function:default:my-function:latest" \
    --name "every-5min" \
    --schedule "5m" \
    --schedule-type "Rate"

Timer with Additional User Event

bash

python3 scripts/create_trigger.py \
    --function-urn "urn:fss:cn-north-4:project_id:function:default:my-function:latest" \
    --trigger-type "TIMER" \
    --name "nightly-job" \
    --schedule "0 30 1 * * ?" \
    --schedule-type "Cron" \
    --user-event "{\"mode\": \"full\"}" \
    --status "ACTIVE"

OBS Trigger Examples

Run on Every Object Creation

bash

python3 scripts/create_trigger.py \
    --function-urn "urn:fss:cn-north-4:project_id:function:default:my-function:latest" \
    --trigger-type "OBS" \
    --name "on-object-created" \
    --bucket "my-input-bucket" \
    --events "ObjectCreated:*" \
    --status "ACTIVE"

Real-Time Data Masking for Uploads under a Prefix

bash

python3 scripts/create_trigger.py \
    --function-urn "urn:fss:cn-north-4:project_id:function:default:my-function:latest" \
    --trigger-type "OBS" \
    --name "mask-uploads" \
    --bucket "my-input-bucket" \
    --events "Put,Post" \
    --prefix "uploads/" \
    --suffix ".csv" \
    --status "ACTIVE"

Run on Object Deletion

bash

python3 scripts/create_trigger.py \
    --function-urn "urn:fss:cn-north-4:project_id:function:default:my-function:latest" \
    --trigger-type "OBS" \
    --name "on-object-removed" \
    --bucket "my-input-bucket" \
    --events "ObjectRemoved:*" \
    --status "ACTIVE"

OBS Event Types

Pass one or more events as a comma-separated list, e.g. --events "Put,Post" or --events "ObjectCreated:*".

Event	Meaning
ObjectCreated	All object creation operations: Put, Post, Copy and multipart upload completion. ObjectCreated:* also matches them
Put	Object uploaded with the Put method
Post	Object uploaded with the Post method
Copy	Object created by copying another object
CompleteMultipartUpload	Multipart upload (segments) merged into a complete object
ObjectRemoved	Object deleted. ObjectRemoved:* also matches Delete and DeleteMarkerCreated
Delete	Object version deleted with an explicit version ID
DeleteMarkerCreated	Delete marker created when no version ID is specified

OBS Prefix and Suffix Filters

• --prefix limits notifications to object keys that start with the given string, e.g. uploads/.
• --suffix limits notifications to object keys that end with the given string, e.g. .csv.
• Both are optional and can be combined. Leave them out to be notified for every matching event in the bucket.
• Prefix/suffix filtering is performed by OBS and reduces function invocations, which also reduces cost.

Cron Expression Format

FunctionGraph uses Quartz Cron format with 6 or 7 fields (the 7th field year is optional):

text

┌───────────── second (0-59)
│ ┌───────────── minute (0-59)
│ │ ┌───────────── hour (0-23)
│ │ │ ┌───────────── day of month (1-31)
│ │ │ │ ┌───────────── month (1-12)
│ │ │ │ │ ┌───────────── day of week (1-7, 1=Sunday)
│ │ │ │ │ │ ┌───────────── year (optional, e.g. 2026)
│ │ │ │ │ │ │
* * * * * ? *

Only this subset is supported: numbers, *, ? (day or day-of-week only), ranges (a-b), steps (*/n) and lists (a,b,c). Quartz modifiers such as L, W and # are not supported and are rejected with an explicit error message instead of a generic numeric error.

For detailed Cron expression reference including special characters and common examples, see Cron Expression Reference.

Parameter Confirmation

Before creating the trigger, confirm the following parameters:

Parameter	CLI Argument	Required	Description	Example
function_urn	--function-urn	Yes (always)	Target function URN	urn:fss:cn-north-4:xxx:function:default:my-func:latest
trigger_type	--trigger-type	No (default TIMER)	TIMER or OBS	OBS
trigger_name	--name	Yes (always)	TIMER: trigger name; OBS: event notification name (1-64 chars)	daily-trigger
enable_status	--status	No (default ACTIVE)	ACTIVE or DISABLED; OBS triggers cannot be disabled after creation (only TIMER, DDS, DMS, KAFKA and LTS trigger types support disabling), so use ACTIVE with --trigger-type OBS	ACTIVE
schedule	--schedule	Yes for TIMER, ignored for OBS	Cron expression or Rate value	0 0 2 * * ? or 5m
schedule_type	--schedule-type	No (default Cron)	Cron or Rate; TIMER only	Cron
user_event	--user-event	No (default empty)	Additional user event data; TIMER only	optional info
bucket	--bucket	Yes for OBS, ignored for TIMER	OBS bucket name that acts as the event source	my-input-bucket
events	--events	Yes for OBS, ignored for TIMER	Comma-separated object events	ObjectCreated:* or Put,Post
prefix	--prefix	No; OBS only	Object key prefix filter	uploads/
suffix	--suffix	No; OBS only	Object key suffix filter	.csv

Confirmation Checklist

• Function URN is correct and the function exists
• Trigger type selected (TIMER or OBS)
• For TIMER: Cron expression or Rate value has been validated
• For OBS: bucket exists in the same region and the events are valid
• Trigger name follows naming conventions
• IAM permissions are sufficient (including OBS read access for OBS triggers)
• Region matches the function location

Output Format

Success Response (TIMER)

json

{
    "status": "success",
    "trigger_id": "timer-xxx-xxx-xxx",
    "trigger_name": "daily-trigger",
    "trigger_type": "TIMER",
    "schedule": "0 0 2 * * ?",
    "enable_status": "ACTIVE",
    "message": "Trigger created successfully"
}

Success Response (OBS)

json

{
    "status": "success",
    "trigger_id": "obs-xxx-xxx-xxx",
    "trigger_name": "mask-uploads",
    "trigger_type": "OBS",
    "bucket": "my-input-bucket",
    "events": ["Put", "Post"],
    "enable_status": "ACTIVE",
    "message": "Trigger created successfully"
}

Error Response

json

{
    "status": "failed",
    "error_code": "TriggerAlreadyExists",
    "message": "Trigger with the same name already exists"
}

Error codes: InvalidParameter, FunctionNotFound, NetworkError, TriggerAlreadyExists, TriggerLimitExceeded, InternalError.

For complete error codes and troubleshooting information, see Cron Expression Reference.

Verification Method

After creating the trigger, verify the configuration:

1. List Function Triggers

Navigate to FunctionGraph console → Function details → Triggers tab to view all triggers

2. Check Trigger Details

Navigate to FunctionGraph console → Function details → Triggers → View trigger details

3. Check the OBS Event Source (OBS triggers)

Navigate to the OBS console → the target bucket → Events/Notification rules, and confirm the rule that matches the trigger name, bucket, events, prefix and suffix.

4. Monitor Trigger Execution

Navigate to FunctionGraph console → Function details → Triggers → View execution history

Expected indicators:

• Trigger status: Active
• TIMER only: next execution time is correctly calculated
• OBS only: uploading a matching object (respecting the prefix/suffix filter) produces a function invocation

Best Practices

TIMER Best Practices

1. Avoid frequent executions: Use intervals ≥ 5 minutes unless necessary
2. Consider timezone: FunctionGraph uses UTC by default
3. Use ? for unused day field: Either day-of-month or day-of-week should use ?
4. Validate before creation: Test expressions using online Cron validators

OBS Best Practices

1. Filter aggressively: Use --prefix and --suffix so the function runs only for the objects it is meant to process
2. Keep the function idempotent: OBS notifications are at-least-once; the same object event can be delivered more than once, so mask/replace operations must produce the same result when repeated
3. Write results to a different bucket or prefix: Avoid writing the function output back into the same prefix that triggers it, which would create an infinite invocation loop
4. Pick precise events: Use Put/Post for uploads and ObjectRemoved for deletions instead of ObjectCreated/ObjectRemoved when the function only handles one operation
5. Watch the runtime: Large objects may need more memory and a longer timeout than the default configuration

Naming Conventions

• Use descriptive names: daily-data-sync, mask-on-upload
• Follow pattern: [frequency|event]-[purpose]
• Maximum 64 characters
• Use lowercase with hyphens

Security Considerations

1. Least privilege: Grant minimal IAM permissions, including read access to the OBS bucket for OBS triggers
2. Enable encryption: Use KMS for sensitive function inputs
3. Monitor executions: Set up Cloud Eye alarms for failures
4. Protect notification payloads: OBS events may contain object keys; make sure log and trace settings do not leak sensitive names

Operational Recommendations

1. Start with disabled status for testing
2. Document trigger purpose in the trigger name
3. Set appropriate retries for transient failures
4. Monitor first executions after enabling

Reference Documents

For detailed information, refer to:

• SDK Installation Guide
• IAM Policies
• Verification Method
• Acceptance Criteria
• Cron Expression Reference
• OBS Trigger Guide

Important Notes

Compatibility Notes

This skill is designed to work with Huawei Cloud FunctionGraph API. The tags field helps with skill discovery and categorization.

Limitations

1. Create only: triggers cannot be deleted, updated, disabled or listed by this skill
2. TIMER and OBS only: other trigger types (APIG, CTS, DDS, DMS, DIS, LTS, SMN, KAFKA, RABBITMQ and so on) are not supported
3. Maximum triggers: Each function supports up to 10 triggers by default
4. OBS event delivery: notifications may be delivered more than once, so functions must tolerate duplicate events
5. OBS bucket: the bucket cannot be renamed or replaced after the trigger is created, and the function must be able to read the bucket
6. Cron precision: Second-level scheduling may have minor delays
7. Timeout handling: Function timeout should be less than trigger interval
8. Cold start: First executions may have additional latency

Cost Implications

• No additional cost for trigger configuration
• Function execution billed per invocation
• For OBS triggers, cost grows with the number of matching object events; prefix/suffix filters reduce invocations
• Consider execution frequency for cost optimization

Common Pitfalls

1. Wrong timezone: Remember FunctionGraph uses UTC
2. Overlapping schedules: Multiple triggers may cause concurrent executions
3. Long-running functions: Ensure function completes before the next trigger
4. Cron syntax errors: Validate expression format before deployment
5. Recursive OBS triggers: writing output into the watched prefix triggers the function again
6. Mismatched region: the OBS bucket and the function must be in the same region

For troubleshooting and error codes, refer to Cron Expression Reference.