无法通过另一个workflowTemplate将输出参数从一个workflow Template传递到工作流

Question

我有两个工作流模板generate-output、lib-read-outputs和一个工作流output-paramter，如下所示

1. generate-output.yaml

apiVersion: argoproj.io/v1alpha1
kind: WorkflowTemplate
metadata:
name: generate-output
spec:
entrypoint: main
templates:
- name: main
dag:
tasks:
# Generate Json for Outputs
- name: read-outputs
arguments:
parameters:
- name: outdata
value: |
{
"version": 4,
"terraform_version": "0.14.11",
"serial": 0,
"lineage": "732322df-5bd43-6e92-8f46-56c0dddwe83cb4",
"outputs": {
"key_alias_arn": {
"value": "arn:aws:kms:us-west-2:123456789:alias/tetsing-key",
"type": "string",
"sensitive": true
},
"key_arn": {
"value": "arn:aws:kms:us-west-2:123456789:alias/tetsing-key",
"type": "string",
"sensitive": true
}
}
}
template: retrieve-outputs
# Create Json
- name: retrieve-outputs
inputs:
parameters:
- name: outdata
script:
image: python
command: [python]
env:
- name: OUTDATA
value: "{{inputs.parameters.outdata}}"
source: |
import json
import os
OUTDATA = json.loads(os.environ["OUTDATA"])
with open('/tmp/templates_lst.json', 'w') as outfile:
outfile.write(str(json.dumps(OUTDATA['outputs'])))
volumeMounts:
- name: out
mountPath: /tmp
volumes:
- name: out
emptyDir: { }
outputs:
parameters:
- name: message
valueFrom:
path: /tmp/templates_lst.json

2. lib-read-outputs.yaml

apiVersion: argoproj.io/v1alpha1
kind: WorkflowTemplate
metadata:
name: lib-read-outputs
spec:
entrypoint: main
templates:
- name: main
dag:
tasks:
# Read Outputs
- name: lib-wft
templateRef:
name: generate-output
template: main

3. output-paramter.yaml

apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
generateName: output-paramter-
spec:
entrypoint: main
templates:
- name: main
dag:
tasks:
# Json Output data task1
- name: wf
templateRef:
name: lib-read-outputs
template: main
- name: lib-wf2
dependencies: [wf]
arguments:
parameters:
- name: outputResult
value: "{{tasks.wf.outputs.parameters.message}}"
template: whalesay
- name: whalesay
inputs:
parameters:
- name: outputResult
container:
image: docker/whalesay:latest
command: [cowsay]
args: ["{{inputs.parameters.outputResult}}"]

我正在尝试通过lib-read-outputs将工作流模板generate-output中生成的输出参数传递给工作流output-paramter

当我执行它们时，它会给出以下错误-Failed: invalid spec: templates.main.tasks.lib-wf2 failed to resolve {{tasks.wf.outputs.parameters.message}}

Answer 1

DAG和步骤模板默认不生成输出

DAG和步骤模板不会自动生成其子模板的输出，即使只有一个子模板也是如此。

例如，这里的no-parameters模板不会产生输出，即使它调用了一个有输出的模板。

apiVersion: argoproj.io/v1alpha1
kind: WorkflowTemplate
spec:
templates:
- name: no-parameters
dag:
tasks:
- name: get-a-parameter
template: get-a-parameter

如果你考虑一个有多个任务的DAG模板，这种输出的缺乏是有意义的：

apiVersion: argoproj.io/v1alpha1
kind: WorkflowTemplate
spec:
templates:
- name: no-parameters
dag:
tasks:
- name: get-a-parameter
template: get-a-parameter
- name: get-another-parameter
depends: get-a-parameter
template: get-another-parameter

no-parameters应该产生哪些任务的输出？由于不清楚，DAG和步骤模板在默认情况下根本不生成输出。

您可以将模板视为类似函数。您不会期望函数隐式地返回它调用的函数的输出。

def get_a_string():
return "Hello, world!"
def call_get_a_string():
get_a_string()
print(call_get_a_string())  # This prints nothing.

但是DAG或步骤模板可以转发输出

通过设置其outputs字段，可以使DAG或步骤模板向前输出。

apiVersion: argoproj.io/v1alpha1
kind: WorkflowTemplate
metadata:
name: get-parameters-wftmpl
spec:
templates:
- name: get-parameters
dag:
tasks:
- name: get-a-parameter
template: get-a-parameter
- name: get-another-parameter
depends: get-a-parameter
template: get-another-parameter
# This is the critical part!
outputs:
parameters:
- name: parameter-1
valueFrom: 
expression: "tasks['get-a-parameter'].outputs.parameters['parameter-name']"
- name: parameter-2
valueFrom: 
expression: "tasks['get-another-parameter'].outputs.parameters['parameter-name']"
---
apiVersion: argoproj.io/v1alpha1
kind: Workflow
spec:
templates:
- name: print-parameter
dag:
tasks:
- name: get-parameters
templateRef:
name: get-parameters-wftmpl
template: get-parameters 
- name: print-parameter
depends: get-parameters
template: print-parameter
arguments:
parameters:
- name: parameter
value: "{{tasks.get-parameters.outputs.parameters.parameter-1}}"

继续Python的类比：

def get_a_string():
return "Hello, world!"
def call_get_a_string():
return get_a_string()  # Add 'return'.
print(call_get_a_string())  # This prints "Hello, world!".

所以，在你的具体情况下

1. 将outputs节添加到generate-parameter工作流模板中的main模板，以转发retrieve-parameters模板的输出参数。

   apiVersion: argoproj.io/v1alpha1
   kind: WorkflowTemplate
   metadata:
   name: generate-parameter
   spec:
   entrypoint: main
   templates:
   - name: main
   outputs:
   parameters:
   - name: message
   valueFrom: 
   expression: "tasks['read-parameters'].outputs.parameters.message"
   dag:
   tasks:
   # ... the rest of the file ...
   

2. 在lib-read-parameters工作流模板中的main模板中添加一个outputs节，以转发generate-parameter的参数。

   apiVersion: argoproj.io/v1alpha1
   kind: WorkflowTemplate
   metadata:
   name: lib-read-parameters
   spec:
   entrypoint: main
   templates:
   - name: main
   outputs:
   parameters:
   - name: message
   valueFrom:
   expression: "tasks['lib-wft'].outputs.parameters.message"
   dag:
   tasks:
   # ... the rest of the file ...