多行 yaml 输入到 mustache 模板输出为 JSON

Question

我有以下shell sn-p

inputs="ingress_test_inputs.yaml"
auth_annotations="    # type of authentication
    nginx.ingress.kubernetes.io/auth-type: basic
    # name of the secret that contains the user/password definitions
    nginx.ingress.kubernetes.io/auth-secret: basic-auth
    # message to display with an appropriate context why the authentication is required
    nginx.ingress.kubernetes.io/auth-realm: 'Authentication Required - foo'"
echo "---" >$inputs
echo "namespace: qa" >> $inputs
echo "auth_annotations: ${auth_annotations}" >> $inputs

echo "----- Ingress inputs (${inputs}) -----"
cat $inputs

echo 'apiversion: extenstions/v1beta
kind: Ingress
metadata:
  name: aname
  annotations:
    kubernetes.io/ingress.class: "nginx-internal"
    nginx.ingress.kubernetes.io/server-snippet: |
      add_header Content-Security-Policy      "frame-ancestors 'self'";
      {{{auth_annotations}}}
spec:
  rules:
    - host: bla-bla-bla.{{namespace}}.example.com' >ingress.mustache
echo "----- Raw Ingress (ingress.mustache): -----"
cat ingress.mustache

mustache $inputs ingress.mustache > ingress-1.0.yaml

echo "----- Will apply the following ingress: -----"
cat ingress-1.0.yaml

但是，当我运行此命令时，auth_annotations 的输出似乎被转换为 JSON 格式（元素之间有 =>，末尾有逗号）（参见规范之前的行：）...

----- Ingress inputs (ingress_test_inputs.yaml) -----
---
namespace: qa
auth_annotations:     # type of authentication
    nginx.ingress.kubernetes.io/auth-type: basic
    # name of the secret that contains the user/password definitions
    nginx.ingress.kubernetes.io/auth-secret: basic-auth
    # message to display with an appropriate context why the authentication is required
    nginx.ingress.kubernetes.io/auth-realm: 'Authentication Required - foo'
----- Raw Ingress (ingress.mustache): -----
apiversion: extenstions/v1beta
kind: Ingress
metadata:
  name: aname
  annotations:
    kubernetes.io/ingress.class: "nginx-internal"
    nginx.ingress.kubernetes.io/server-snippet: |
      add_header Content-Security-Policy      "frame-ancestors self";
      {{{auth_annotations}}}
----- Will apply the following ingress: -----
apiversion: extenstions/v1beta
kind: Ingress
metadata:
  name: aname
  annotations:
    kubernetes.io/ingress.class: "nginx-internal"
    nginx.ingress.kubernetes.io/server-snippet: |
      add_header Content-Security-Policy      "frame-ancestors self";
      {"nginx.ingress.kubernetes.io/auth-type"=>"basic", "nginx.ingress.kubernetes.io/auth-secret"=>"basic-auth", "nginx.ingress.kubernetes.io/auth-realm"=>"Authentication Required - foo"}

我原以为我的原始 YAML 会完整地粘贴到这些行中。它甚至剥离了 cmets（我并不真正关心）但是，这不是我所期望的行为。为什么 mustache 对待多行输入与单行输入不同？

我曾尝试搜索类似的问题，但未能找到答案。

编辑：添加了单行变量，用于比较输入。

Answer 1

这里有几个问题：

• Mustache 不知道 ingress.mustache 是一个 YAML 文件。它不会将其解析为 YAML，实际上假定它是 HTML（因为它会使用 HTML 实体转义 HTML 特殊字符）。

  由此产生的问题是，当提示插入您的值时，mustache 不知道当前的缩进等，因此它无法粘贴您的 YAML，同时通过添加到您的原始缩进中来保持相对结构完整。 $inputs.

• Mustache 使用 YAML 进行输入，但不用于输出。您看到的是 mustache 对 auth_annotations 值的表示。 Mustache 已将 YAML 解析为内部结构，但不知道您希望将其呈现为 YAML。

• 问题不在于单行与多行，而是简单内容（标量）与复杂内容（映射）。

为了能够正确缩进你的变量，你必须带着小胡子走过结构并通过一个部分将它们插入。然而，mustache 不能遍历映射值，只能遍历序列。所以你需要做的是让你的输入成为一个可以通过 mustache 迭代的序列：

auth_annotations="    # type of authentication
    - {key: nginx.ingress.kubernetes.io/auth-type, value: basic}
      # name of the secret that contains the user/password definitions
    - {key: nginx.ingress.kubernetes.io/auth-secret, value: basic-auth}
      # message to display with an appropriate context why the authentication is required
    - {key: nginx.ingress.kubernetes.io/auth-realm, value: 'Authentication Required - foo'}"

然后，您可以通过修改模板插入它，使用小胡子部分迭代您的列表：

echo 'apiversion: extenstions/v1beta
kind: Ingress
metadata:
  name: aname
  annotations:
    kubernetes.io/ingress.class: "nginx-internal"
    nginx.ingress.kubernetes.io/server-snippet: |
      add_header Content-Security-Policy      "frame-ancestors 'self'";
    {{#auth_annotations}}
    {{key}}: {{value}}
    {{/auth_annotations}}
spec:
  rules:
    - host: bla-bla-bla.{{namespace}}.example.com' >ingress.mustache

Answer 2

这是脚本的精简版本，它演示了问题。

inputs="ingress_test_inputs.yaml"
auth_annotations="
    foo: bar baz
    sam: jam man"
echo "namespace: qa" > $inputs
echo "auth_annotations: ${auth_annotations}" >> $inputs

echo "----- Ingress inputs (${inputs}) -----"
cat $inputs

echo '---
metadata:
  annotations:
    nginx/thing:
      another_thing:
      {{{auth_annotations}}}
spec:
  rules:
    - host: bla-bla-bla.{{{ namespace }}}.example.com' >ingress.mustache

echo "----- Raw Ingress (ingress.mustache): -----"
cat ingress.mustache

mustache $inputs ingress.mustache > ingress-1.0.yaml

echo "----- Will apply the following ingress: -----"
cat ingress-1.0.yaml

这给出了与我发布的原始问题相同的问题。

----- Ingress inputs (ingress_test_inputs.yaml) -----
namespace: qa
auth_annotations:
    foo: bar baz
    sam: jam man
----- Raw Ingress (ingress.mustache): -----
---
metadata:
  annotations:
    nginx/thing:
      another_thing:
      {{{auth_annotations}}}
spec:
  rules:
    - host: bla-bla-bla.{{{ namespace }}}.example.com
----- Will apply the following ingress: -----
---
metadata:
  annotations:
    nginx/thing:
      another_thing:
      {"foo"=>"bar baz", "sam"=>"jam man"}
spec:
  rules:
    - host: bla-bla-bla.qa.example.com

但是，如果我将“mustache”替换为 bash 实现的“mo”，它可以工作：-

----- Ingress inputs (ingress_test_inputs.yaml) -----
namespace: qa
auth_annotations:
    foo: bar baz
    sam: jam man
----- Raw Ingress (ingress.mustache): -----
---
metadata:
  annotations:
    nginx/thing:
      another_thing:
      {{{auth_annotations}}}
spec:
  rules:
    - host: bla-bla-bla.{{{ namespace }}}.example.com
----- Will apply the following ingress: -----
namespace: qa
auth_annotations:
    foo: bar baz
    sam: jam man
---
metadata:
  annotations:
    nginx/thing:
      another_thing:

spec:
  rules:
    - host: bla-bla-bla..example.com

在我看来，这表明 Ruby gem 中存在错误，因为当它作为输出的一部分时，它不能正确处理 YAML。