如何在Go模板（Helm）中应用递归格式化？

huangapple
go评论112阅读模式
英文:

How do you apply a recursive formatting with Go Templates (Helm)?

问题

我正在使用helm，并给定一个yaml对象，我想要将其展开并应用一些递归格式化。

给定以下内容：

  1. some_map:
  2.   with: different
  3.   indentation:
  4.     levels: and
  5.   nested:
  6.     sub: 
  7.       maps: "42"
  8.     and_more:
  9.       maps: 42

我想要（例如）得到以下结果：

  1. some_map.with="different"
  2. some_map.indentation.levels="and"
  3. some_map.nested.sub.maps="42"
  4. some_map.nested.and_more.maps=42

我还没有在helm文档中找到关于递归循环的内容，请记住，示例中递归的格式（如果不是根节点，则为"%v.%v"，否则为"%v=%v"）可能会有所不同。

英文:

I'm using helm and given a yaml object I want to flatten it while applying some recursive formatting.

Given this:

  1. some_map:
  2.   with: different
  3.   indentation:
  4.     levels: and
  5.   nested:
  6.     sub: 
  7.       maps: "42"
  8.     and_more:
  9.       maps: 42

I want to (for example) get this:

  1. some_map.with="different"
  2. some_map.indentation.levels="and"
  3. some_map.nested.sub.maps="42"
  4. some_map.nested.and_more.maps=42

I haven't read anything about recursive looping in the helm docs, keep in mind that the format of the recursion in the example ( "%v.%v" if !root else "%v=%v" ) may vary.

答案1

得分: 3

是的，似乎{{ define支持对{{ include的递归使用，尽管不清楚递归的深度。

我编写了一个验证它是否可行的 PoC 示例：

  1. {{- define "bob" -}}
  2. {{- $it := . -}}
  3. {{- $knd := kindOf . -}}
  4. {{- if eq $knd "map" }}
  5. {{- range (keys .) }}
  6. {{- $k := . }}
  7. {{- $v := get $it . }}
  8. {{- $vk := kindOf $v }}
  9. {{- if eq $vk "map" }}
  10. {{-   printf "%s." $k }}
  11. {{-   include "bob" $v }}
  12. {{- else }}
  13. {{-   printf "%s=%s\n" $k (toJson $v) }}
  14. {{- end }}
  15. {{- end }}
  16. {{- else }}
  17. {{ toJson . }}#k({{ $knd }})
  18. {{- end }}
  19. {{- end -}}

调用方式如下：

  1. {{ $fred := dict 
  2.     "alpha" (dict "a0" "a0ch0")
  3.     "beta" (dict "beta0" (dict "beta00" 1234))
  4.     "charlie" (list "ch0" "ch1" "ch2") }}
  5. data:
  6.   theData: |
  7. {{ toJson $fred | indent 4 }}
  8.   toml: |
  9. {{ include "bob" $fred | indent 4 }}

生成的结果如下：

  1. data:
  2.   theData: |
  3.         {"alpha":{"a0":"a0ch0"},"beta":{"beta0":{"beta00":1234}},"charlie":["ch0","ch1","ch2"]}
  4.   toml: |
  5.     alpha.a0="a0ch0"
  6.     beta.beta0.beta00=1234
  7.     charlie=["ch0","ch1","ch2"]

另外，你引用的示例似乎涉及到最外层的变量名，我认为 Helm 不知道这个变量名，所以你需要使用一个人工包装器 dict 来实现这种行为：{{ include "toToml" (dict "some_map" .Values.some_map) }}。

英文:

Yes, it seems that {{ define supports recursive use of {{ include, although unknown to what depth

The PoC I whipped up to see if it could work

  1. {{- define "bob" -}}
  2. {{- $it := . -}}
  3. {{- $knd := kindOf . -}}
  4. {{- if eq $knd "map" }}
  5. {{- range (keys .) }}
  6. {{- $k := . }}
  7. {{- $v := get $it . }}
  8. {{- $vk := kindOf $v }}
  9. {{- if eq $vk "map" }}
  10. {{-   printf "%s." $k }}
  11. {{-   include "bob" $v }}
  12. {{- else }}
  13. {{-   printf "%s=%s\n" $k (toJson $v) }}
  14. {{- end }}
  15. {{- end }}
  16. {{- else }}
  17. {{ toJson . }}#k({{ $knd }})
  18. {{- end }}
  19. {{- end -}}

invoked as

  1. {{ $fred := dict 
  2.     "alpha" (dict "a0" "a0ch0")
  3.     "beta" (dict "beta0" (dict "beta00" 1234))
  4.     "charlie" (list "ch0" "ch1" "ch2") }}
  5. data:
  6.   theData: |
  7. {{ toJson $fred | indent 4 }}
  8.   toml: |
  9. {{ include "bob" $fred | indent 4 }}

produced

  1. data:
  2.   theData: |
  3.         {"alpha":{"a0":"a0ch0"},"beta":{"beta0":{"beta00":1234}},"charlie":["ch0","ch1","ch2"]}
  4.   toml: |
  5.     alpha.a0="a0ch0"
  6.     beta.beta0.beta00=1234
  7.     charlie=["ch0","ch1","ch2"]

Also, your cited example seems to make reference to the outermost variable name, which I don't think helm knows about, so you'd need an artificial wrapper dict in order to get that behavior: {{ include "toToml" (dict "some_map" .Values.some_map) }}

答案2

得分: 1

另一种方法

_helpers.tpl:

  1. {{- define "template.flattenFn" -}}
  2.   {{- $ctx := . -}}
  3.   {{- if or (eq (kindOf .data) "map") (eq (kindOf .data) "slice") }}
  4.     {{- range $key, $value := .data }}
  5.       {{- include "template.flattenFn" (dict "prefixes" (append $ctx.prefixes $key) "data" $value ) }}
  6.     {{- end }}
  7.   {{- else }}
  8.     {{-   printf "\"%s\":%s, "  (join "__" .prefixes) (toJson .data) }}
  9.   {{- end }}
  10. {{- end -}}
  12. {{- define "template.flatten" -}}
  13.  {{- include "template.flattenFn" (dict "prefixes" list "data" . ) }} 
  14. {{- end -}}

values.yaml

  1. environment_map:
  2.   Log:
  3.     Level:
  4.       Default: Debug
  5.     Target:
  6.     - Name: Console
  7.       Args:
  8.         formatter: "JsonFormatter"

usage

  1. {{- range $env, $value := include "template.flatten" .Values.environment_map | fromYaml }}
  2.   - name: {{ $env }}
  3.     value: {{ $value | quote }}

result

  1. - name: Log__Level__Default
  2.   value: "Debug"
  3. - name: Log__Target__0__Args__formatter
  4.   value: "JsonFormatter"
  5. - name: Log__Target__0__Name
  6.   value: "Console"
英文:

another approach

_helpers.tpl:

  1.  {{- define "template.flattenFn" -}}
  2.   {{- $ctx := . -}}
  3.   {{- if or (eq (kindOf .data) "map") (eq (kindOf .data) "slice") }}
  4.     {{- range $key, $value := .data }}
  5.       {{- include "template.flattenFn" (dict "prefixes" (append $ctx.prefixes $key) "data" $value ) }}
  6.     {{- end }}
  7.   {{- else }}
  8.     {{-   printf "\"%s\":%s, "  (join "__" .prefixes) (toJson .data) }}
  9.   {{- end }}
  10. {{- end -}}
  12. {{- define "template.flatten" -}}
  13.  {{- include "template.flattenFn" (dict "prefixes" list "data" . ) }} 
  14. {{- end -}}

values.yaml

  1.   environment_map:
  2.     Log:
  3.       Level:
  4.         Default: Debug
  5.       Target:
  6.       - Name: Console
  7.         Args:
  8.           formatter: "JsonFormatter"

usage

  1. {{- range $env, $value := include "template.flatten" .Values.environment_map | fromYaml }}
  2.   - name: {{ $env }}
  3.     value: {{ $value | quote }}

result

  1.     - name: Log__Level__Default
  2.       value: "Debug"
  3.     - name: Log__Target__0__Args__formatter
  4.       value: "JsonFormatter"
  5.     - name: Log__Target__0__Name
  6.       value: "Console"

答案3

得分: 0

感谢@mdaniel的答案，它帮助/允许我解决了我的问题！然而，他的（快速，我明白了）解决方案存在问题，如果您具有相同前缀的多个值。继续使用他的示例：

  1. {{ $fred := dict
  2.     "alpha" (dict "a0" "a0ch0")
  3.     "beta" (dict "beta0" (dict "beta00" 1234))
  4.     "charlie" (list "ch0" "ch1" "ch2")
  5.     "problem" (dict "beta0" (dict "1" "1" "2" "2" )) }}
  6. data:
  7.   theData: |
  8. {{ toJson $fred | indent 4 }}
  9.   toml: |
  10. {{ include "bob" $fred | indent 4 }}

将产生以下结果：

  1. data:
  2.   theData: |
  3.         {"alpha":{"a0":"a0ch0"},"beta":{"beta0":{"beta00":1234}},"charlie":["ch0","ch1","ch2"],"problem":{"beta0":{"1":"1","2":"2"}}}
  4.   toml: |
  5.     problem.beta0.1="1"
  6.     2="2"
  7.     alpha.a0="a0ch0"
  8.     beta.beta0.beta00=1234
  9.     charlie=["ch0","ch1","ch2"]

这是不正确的。还有另一个问题是顺序丢失的问题，不知道为什么或如何修复它，但这不是很大的问题。

我的额外要求是，我需要在所有行中添加公共前缀。如果没有它，您可以定义另一个模板来简化使用，但这很容易做到。

免责声明：我对helm/go-templating完全不熟悉，所以以下内容可能不是最佳解决方案，但它应该解决这些问题。

继续使用上面的示例：

  1. {{ $fred := dict
  2.     "alpha" (dict "a0" "a0ch0")
  3.     "beta" (dict "beta0" (dict "beta00" 1234))
  4.     "charlie" (list "ch0" "ch1" "ch2")
  5.     "problem" (dict "beta0" (dict "1" "1" "2" "2" )) }}
  6. data:
  7.   theData: |
  8. {{ toJson $fred | indent 4 }}
  9.   toml: |
  10. {{ include "flattenYaml" (dict "prefix" "added_prefix" "data" $fred) | indent 4 }}

将产生以下结果：

  1. data:
  2.   theData: |
  3.         {"alpha":{"a0":"a0ch0"},"beta":{"beta0":{"beta00":1234}},"charlie":["ch0","ch1","ch2"],"problem":{"beta0":{"1":"1","2":"2"}}}
  4.   toml: |
  5.     added_prefix.alpha.a0="a0ch0"
  6.     added_prefix.beta.beta0.beta00=1234
  7.     added_prefix.charlie=["ch0","ch1","ch2"]
  8.     added_prefix.problem.beta0.1="1"
  9.     added_prefix.problem.beta0.2="2"

而flattenYaml模板的源代码如下：

  1. {{- define "flattenYaml" -}}
  2. {{- $dict := . -}}
  3. {{- $prefix := $dict.prefix -}}
  4. {{- $data := $dict.data -}}
  5. {{- $knd := kindOf $data -}}
  6.     {{- if eq $knd "map" }}
  7.         {{- range (keys $data) }}
  8.             {{- $key := . }}
  9.             {{- $prefixedKey := (printf "%s.%s" $prefix $key) }}
  10.             {{- $value := get $data $key }}
  11.             {{- $valueKind := kindOf $value }}
  12.             {{- if eq $valueKind "map" }}
  13.                 {{-   include "flattenYaml" (dict "prefix" ($prefixedKey) "data" $value) }}
  14.             {{- else }}
  15.                 {{-   printf "%s=%s\n" $prefixedKey (toJson $value) }}
  16.             {{- end }}
  17.         {{- end }}
  18.     {{- else }}
  19.         {{ toJson . }}#k({{ $knd }})
  20.     {{- end }}
  21. {{- end -}}

免责声明2：我不知道原始解决方案中的#k ...在{{ toJson . }}#k({{ $knd }})中是什么意思，如果它在您的面前爆炸了，请不要感到惊讶；）

编辑：
原来的

  1. {{ toJson . }}#k({{ $knd }})

实际上在我的面前爆炸了，我仍然不知道#k应该起什么作用，但以下替换修复了我的问题：

  1. {{- if ne $data nil }}
  2.     {{- toJson $data }}
  3. {{- end }}
英文:

Thanks to @mdaniel for his answer, which helped/allowed me to fix my problem! His (quick, I get it) solution has problem though if you have move values with same prefix. To carry on with his example:

  1. {{ $fred := dict
  2.     "alpha" (dict "a0" "a0ch0")
  3.     "beta" (dict "beta0" (dict "beta00" 1234))
  4.     "charlie" (list "ch0" "ch1" "ch2")
  5.     "problem" (dict "beta0" (dict "1" "1" "2" "2" )) }}
  6. data:
  7.   theData: |
  8. {{ toJson $fred | indent 4 }}
  9.   toml: |
  10. {{ include "bob" $fred | indent 4 }}

will produce:

  1. data:
  2.   theData: |
  3.     {"alpha":{"a0":"a0ch0"},"beta":{"beta0":{"beta00":1234}},"charlie":["ch0","ch1","ch2"],"problem":{"beta0":{"1":"1","2":"2"}}}
  4.   toml: |
  5.     problem.beta0.1="1"
  6.     2="2"
  7.     alpha.a0="a0ch0"
  8.     beta.beta0.beta00=1234
  9.     charlie=["ch0","ch1","ch2"]

which is not correct. Also there is another eye-candy problem of lost order, no idea why or how to fix it, but that's not such biggie.

My extra requirement was, that I needed to add common prefix to all lines. Without it you can define another template simplifying usage, but that's trivial to do.

disclaimer: I'm totally new to helm/go-templating, so following isn't probably optimal, but it should fix these issues.

To carry on with example again:

  1. {{ $fred := dict
  2.     "alpha" (dict "a0" "a0ch0")
  3.     "beta" (dict "beta0" (dict "beta00" 1234))
  4.     "charlie" (list "ch0" "ch1" "ch2")
  5.     "problem" (dict "beta0" (dict "1" "1" "2" "2" )) }}
  6. data:
  7.   theData: |
  8. {{ toJson $fred | indent 4 }}
  9.   toml: |
  10. {{ include "flattenYaml" (dict "prefix" "added_prefix" "data" $fred) | indent 4 }}

will produce:

  1. data:
  2.   theData: |
  3.     {"alpha":{"a0":"a0ch0"},"beta":{"beta0":{"beta00":1234}},"charlie":["ch0","ch1","ch2"],"problem":{"beta0":{"1":"1","2":"2"}}}
  4.   toml: |
  5.     added_prefix.alpha.a0="a0ch0"
  6.     added_prefix.beta.beta0.beta00=1234
  7.     added_prefix.charlie=["ch0","ch1","ch2"]
  8.     added_prefix.problem.beta0.1="1"
  9.     added_prefix.problem.beta0.2="2"

and template source for flattenYaml looks like this:

  1. {{- define "flattenYaml" -}}
  2. {{- $dict := . -}}
  3. {{- $prefix := $dict.prefix -}}
  4. {{- $data := $dict.data -}}
  5. {{- $knd := kindOf $data -}}
  6.     {{- if eq $knd "map" }}
  7.         {{- range (keys $data) }}
  8.             {{- $key := . }}
  9.             {{- $prefixedKey := (printf "%s.%s" $prefix $key) }}
  10.             {{- $value := get $data $key }}
  11.             {{- $valueKind := kindOf $value }}
  12.             {{- if eq $valueKind "map" }}
  13.                 {{-   include "flattenYaml" (dict "prefix" ($prefixedKey) "data" $value) }}
  14.             {{- else }}
  15.                 {{-   printf "%s=%s\n" $prefixedKey (toJson $value) }}
  16.             {{- end }}
  17.         {{- end }}
  18.     {{- else }}
  19.         {{ toJson . }}#k({{ $knd }})
  20.     {{- end }}
  21. {{- end -}}

disclaimer 2: I have no idea what #k ... in {{ toJson . }}#k({{ $knd }}) from original solution does, do not be surprised if it explodes into your face 如何在Go模板（Helm）中应用递归格式化？

edit:
the

  1.     {{ toJson . }}#k({{ $knd }})

actually blew into my face, still don't know what #k should serve, but following replacement fixed my issue:

  1.     {{- if ne $data nil }}
  2.         {{- toJson $data }}
  3.     {{- end }}

huangapple
  • 本文由 发表于 2022年7月14日 19:36:53
  • 转载请务必保留本文链接：https://go.coder-hub.com/72979870.html
  • go
  • go-templates
  • kubernetes
  • kubernetes-helm
匿名

发表评论

匿名网友

:?: :razz: :sad: :evil: :!: :smile: :oops: :grin: :eek: :shock: :???: :cool: :lol: :mad: :twisted: :roll: :wink: :idea: :arrow: :neutral: :cry: :mrgreen:

确定