使用 ruamel.yaml

如何解决使用 ruamel.yaml

我目前正在使用以下代码加载一个单文档模板 YAML 文件，稍微更改它，并生成（即转储）不同的新部署文件。代码如下所示：

import yaml
import copy
import ruamel.yaml
from ruamel.yaml.scalarstring import (DoubleQuotedScalarstring as dq,SingleQuotedScalarstring as sq)
#As requested,below a summary of the functionality of the function define_exp_parameters
def define_exp_parameters(experiment_template,deployments):
    deployment_list = []
    for duration in range(30,71,1):
        for cpu_cores in range(1,4):
                        
            exp_doc[0]['spec']['annotationCheck'] = 'true'
            deployment_list.append(copy.deepcopy(exp_doc)) 
    return deployment_list   
        
testyaml = ruamel.yaml.YAML()
    
with open(template_dir,'r') as read_file:

    deployments = testyaml.load_all(read_file)
    deployments = list(deployments)
    # define_exp_parameters is used to generate different YAML deployments,each of which are added to a list,which is returned. The list basically consists of x YAML deployment deFinitions which are later dumped in seperate files.
    deployments = define_exp_parameters(experiment_template,deployments)
            
i = 1
for deployment in deployments:
    with open(save_dir) as created_file:
            
        testyaml.default_flow_style = False
            
        testyaml.dump(deployment,created_file)
            
    i += 1

模板如下所示：

apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
Metadata:
  name: teastore-chaos
  namespace: default
spec:
  annotationCheck: 'false'
  enginestate: active
  appinfo:
    appns: default
    applabel: app=teastore
    appkind: deployment
  chaosServiceAccount: litmus-admin
  components:
    runner:
      runnerAnnotations:
        sidecar.istio.io/inject: 'false'
  jobCleanUpPolicy: delete
  experiments:
  - name: pod-cpu-hog

这会生成具有以下结构的文件：

- apiVersion: litmuschaos.io/v1alpha1
  kind: ChaosEngine
  Metadata:
    name: teastore-chaos
    namespace: default
  spec:
    annotationCheck: 'false'
    enginestate: active
    appinfo:
      appns: default
      applabel: app=teastore
      appkind: deployment
    chaosServiceAccount: litmus-admin
    components:
      runner:
        runnerAnnotations:
          sidecar.istio.io/inject: 'false'
    jobCleanUpPolicy: delete
    experiments:
    - name: pod-cpu-hog

但是，我想要的结构如下（即，与模板相同）：

apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
Metadata:
  name: teastore-chaos
  namespace: default
spec:
  annotationCheck: 'false'
  enginestate: active
  appinfo:
    appns: default
    applabel: app=teastore
    appkind: deployment
  chaosServiceAccount: litmus-admin
  components:
    runner:
      runnerAnnotations:
        sidecar.istio.io/inject: 'false'
  jobCleanUpPolicy: delete
  experiments:
  - name: pod-cpu-hog

基本上，第一行不应该有破折号（出于某种原因，它是自动生成/添加的，因为它不在原始模板文件中）并且不应该有额外的第一个缩进整个结构（我认为它与破折号一起出现）。我正在使用 ruamel.yaml 进行转储，因为它保留了字符串中的显式单引号（使用导入的包）。我曾尝试寻找类似案例和 ruamel.yaml 文档，但找不到原因/解决方案。

解决方法

如果没有 define_exp_parameters() 的来源，就不可能准确描述出了什么问题。但是在调用 deployments 之前是一个 list ，它包含一个 dict 元素（带有键 apiVersion、kind 等）。然后调用 deployments 是单个元素列表的列表（哪些元素是上述字典）。您遍历“外部”列表并转储单个元素列表，该列表以块样式为您提供 -，它是块序列元素指示符。

如果您无法修复 define_exp_parameters() 以返回每个元素都是字典的列表，您可以转储 deployment 的第一个元素：

testyaml.dump(deployment[0],created_file)