使用Go语言向YAML文件追加内容。

huangapple
go评论113阅读模式
英文:

appending to YAML file using go lang

问题

我正在编写一个使用Golang编写的程序，将规则追加到文件中，如下所示：

所需格式：

customRules:
custom-rules.yaml: |-
- rule: Pod Created in Kube Namespace
append: true
condition: and (k8s_audit_never_true)
source: k8s_audit
- rule: Create files below dev
append: true
condition: and (never_true)
source: syscall

我编写了一个Go程序，但无法按照上述格式进行追加，我不知道我漏掉了什么。

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"io/ioutil"
  6. 	"log"
  8. 	"gopkg.in/yaml.v2"
  9. )
  11. type AutoGenerated struct {
  12. 	CustomRules CustomRules `yaml:"customRules"`
  13. }
  15. type CustomRulesYaml struct {
  16. 	Rule      string `yaml:"rule"`
  17. 	Append    bool   `yaml:"append"`
  18. 	Condition string `yaml:"condition"`
  19. 	Source    string `yaml:"source"`
  20. }
  22. type CustomRules struct {
  23. 	CustomRulesYaml []CustomRulesYaml `yaml:"custom-rules.yaml"`
  24. }
  26. func main() {
  27. 	// yfile, err := ioutil.ReadFile("/home/revaa/falco/custom_rules.yaml")
  28. 	// if err != nil {
  29. 	// 	log.Fatal(err)
  30. 	// }
  32. 	c1 := CustomRulesYaml{"K8s serviceaccount created", false, "(never_true)", "k8s-audit"}
  33. 	c2 := CustomRulesYaml{"k8s service created", false, "never_true", "k8s-audit"}
  34. 	c := []CustomRulesYaml{c1, c2}
  35. 	c3 := CustomRules{c}
  36. 	data := AutoGenerated{c3}
  37. 	check, err := yaml.Marshal(&data)
  39. 	if err != nil {
  40. 		log.Fatal(err)
  41. 	}
  43. 	err2 := ioutil.WriteFile("/home/revaa/falco/custom_rules.yaml", check, 0)
  45. 	if err2 != nil {
  46. 		log.Fatal(err2)
  47. 	}
  49. 	fmt.Println("data written")
  50. }

这是我的Go代码，运行程序后，YAML文件没有按照所需格式进行追加。而是以以下方式追加了值：

customRules:
custom-rules.yaml:

  • rule: K8s serviceaccount created
    append: false
    condition: (never_true)
    source: k8s-audit
  • rule: k8s service created
    append: false
    condition: never_true
    source: k8s-audit

为什么我没有得到所需格式的YAML文件？

英文:

I writing a golang program which append rule to the file as mentioned below
Required format:

  1. customRules:
  2.   custom-rules.yaml: |-
  3.     - rule: Pod Created in Kube Namespace
  4.       append: true
  5.       condition: and (k8s_audit_never_true)
  6.       source: k8s_audit
  7.     - rule: Create files below dev
  8.       append: true
  9.       condition: and (never_true)
  10.       source: syscall

I wrote a go program which failing to be in the above format I can't get what Iam missing.

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"io/ioutil"
  6. 	"log"
  8. 	"gopkg.in/yaml.v2"
  9. )
  11. type AutoGenerated struct {
  12. 	CustomRules CustomRules `yaml:"customRules"`
  13. }
  14. type CustomRulesYaml struct {
  15. 	Rule      string `yaml:"rule"`
  16. 	Append    bool   `yaml:"append"`
  17. 	Condition string `yaml:"condition"`
  18. 	Source    string `yaml:"source"`
  19. }
  20. type CustomRules struct {
  21. 	CustomRulesYaml []CustomRulesYaml `yaml:"custom-rules.yaml"`
  22. }
  24. func main() {
  25. 	// yfile, err := ioutil.ReadFile("/home/revaa/falco/custom_rules.yaml")
  26. 	// if err != nil {
  27. 	// 	log.Fatal(err)
  28. 	// }
  29. 	c1 := CustomRulesYaml{"K8s serviceaccount created", false, "(never_true)", "k8s-audit"}
  30. 	c2 := CustomRulesYaml{"k8s service created", false, "never_true", "k8s-audit"}
  31. 	c := []CustomRulesYaml{c1, c2}
  32. 	c3 := CustomRules{c}
  33. 	data := AutoGenerated{c3}
  34. 	check, err := yaml.Marshal(&data)
  36. 	if err != nil {
  38. 		log.Fatal(err)
  39. 	}
  41. 	err2 := ioutil.WriteFile("/home/revaa/falco/custom_rules.yaml", check, 0)
  43. 	if err2 != nil {
  45. 		log.Fatal(err2)
  46. 	}
  48. 	fmt.Println("data written")
  50. }

Here is my go code, on running the program the YAML is not getting appended in the above format. The values are appended as below instead.

  1. customRules:
  2.   custom-rules.yaml:
  3.   - rule: K8s serviceaccount created
  4.     append: false
  5.     condition: (never_true)
  6.     source: k8s-audit
  7.   - rule: k8s service created
  8.     append: false
  9.     condition: never_true
  10.     source: k8s-audit

Why Iam not getting the YAML file in the required format?

答案1

得分: 1

您提供的输入格式表示以下YAML结构：

  • 有一个包含一个键值对的字典。
    • 键是customRules。
    • 值是一个字典。

上述值中存储的字典有一个条目：

  • 键是custom-rules.yaml。
  • 值是一个字符串。

上述值中存储的字符串是：

  1. "- rule: Pod Created in Kube Namespace\n  append: true\n  condition: and (k8s_audit_never_true)\n  source: k8s_audit\n- rule: Create files below dev\n  append: true\n  condition: and (never_true)\n  source: syscall"

也就是说，这不是一个列表类型。它是一个单独的字符串。

事实上，这个单独的字符串是有效的（尽管有点可疑）YAML，如果读取，它将生成一个列表（在Go中是一个切片），其中包含2个元素，每个元素都是一个字典（通常对应于Go中的映射或结构类型）。

如果你确实需要这个，那么你的代码就接近正确了。你不需要将[]CustomRulesYaml包装在一个类型中，而是需要进行两次编组。这是你的代码在Go Playground上的一个变体，它的输出是：

  1. custom-rules.yaml: |
  2.   - rule: K8s serviceaccount created
  3.     append: false
  4.     condition: (never_true)
  5.     source: k8s-audit
  6.   - rule: k8s service created
  7.     append: false
  8.     condition: never_true
  9.     source: k8s-audit

现在，请注意，此输出中有一个带有管道符号|但没有后缀连字符-。这是因为编组的字符串string(asBytes)以换行符结尾。它可能应该以换行符结尾，这就是为什么yaml.Marshal会生成一个换行符。但是您的示例输入没有以换行符结尾，这就是为什么您的示例输入中有|-而不仅仅是|的原因：-表示“不包括该换行符”。

要从您现有的代码中获得那个，您需要去掉换行符，例如，在构建c3中的字符串之前添加：

  1. asBytes = asBytes[0:len(asBytes)-1] // 删除尾随换行符

然后进行编组。

英文:

Your required input format represents the following YAML structure:

  • There is a dictionary with one key-value pair.
    • The key is customRules.
    • The value is a dictionary.

The dictionary stored in the value above has one entry:

  • The key is custom-rules.yaml.
  • The value is a string.

The string stored in the value above is:

  1. "- rule: Pod Created in Kube Namespace\n  append: true\n  condition: and (k8s_audit_never_true)\n  source: k8s_audit\n- rule: Create files below dev\n  append: true\n  condition: and (never_true)\n  source: syscall"

That is, this is not a list type. It's a single string.

Now, the fact is that this single string is valid—albeit slightly dodgy—YAML, and if read, it will produce a list (a slice, in Go) of 2 elements, each of which is a dictionary (generally corresponding to a map or struct type in Go).

Your code is close to right, then, if you really do need this. Instead of wrapping the []CustomRulesYaml in a type, you need to marshal twice. Here's a variant of your code on the Go Playground whose output is:

  1. custom-rules.yaml: |
  2.   - rule: K8s serviceaccount created
  3.     append: false
  4.     condition: (never_true)
  5.     source: k8s-audit
  6.   - rule: k8s service created
  7.     append: false
  8.     condition: never_true
  9.     source: k8s-audit

Now, note that this output has a pipe symbol | without a suffix hyphen -. That's because the marshaled string, string(asBytes), ends with a newline. It probably should end with a newline, which is why yaml.Marshal produced one. But your sample input doesn't end with a newline, which is why your sample input has |- instead of just |: the - means "don't include that newline".

To get that from your existing code, you will have to strip off the newline, e.g., add:

  1. asBytes = asBytes[0:len(asBytes)-1] // delete trailing newline

before building the string in c3 and marshaling it.

huangapple
  • 本文由 发表于 2021年11月11日 12:50:47
  • 转载请务必保留本文链接：https://go.coder-hub.com/69923341.html
  • glide-golang
  • go
  • go-structtag
  • yaml
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