Golang使用Terraform管理云资源实践

os/exec

terraform init

terraform plan

terraform apply

exec.Command

package main

import (
    "bytes"
    "fmt"
    "log"
    "os"
    "os/exec"
    "path/filepath"
)

func runTerraform(dir string, args ...string) (string, string, error) {
    cmdArgs := append([]string{"-no-color"}, args...) // 禁用颜色输出，方便解析
    cmd := exec.Command("terraform", cmdArgs...)
    cmd.Dir = dir // 设置Terraform的工作目录

    var stdoutBuf, stderrBuf bytes.Buffer
    cmd.Stdout = &stdoutBuf
    cmd.Stderr = &stderrBuf

    log.Printf("Executing in %s: terraform %s", dir, cmdArgs)
    err := cmd.Run()

    return stdoutBuf.String(), stderrBuf.String(), err
}

func main() {
    // 假设你的Terraform配置在 ./terraform_configs/dev 目录下
    tfConfigDir := filepath.Join(".", "terraform_configs", "dev")
    if _, err := os.Stat(tfConfigDir); os.IsNotExist(err) {
        log.Fatalf("Terraform config directory does not exist: %s", tfConfigDir)
    }

    // 1. 初始化Terraform
    stdout, stderr, err := runTerraform(tfConfigDir, "init")
    if err != nil {
        log.Printf("Terraform init failed: %v", err)
        log.Println("Stderr:\n", stderr)
        log.Println("Stdout:\n", stdout)
        return
    }
    fmt.Println("Terraform init successful.")
    fmt.Println("Stdout:\n", stdout)

    // 2. 规划变更
    // 对于 plan，你可能需要捕获JSON输出以便后续解析
    // stdout, stderr, err = runTerraform(tfConfigDir, "plan", "-out=tfplan.out")
    // if err != nil { /* ... */ }

    // 3. 应用变更
    stdout, stderr, err = runTerraform(tfConfigDir, "apply", "-auto-approve")
    if err != nil {
        log.Printf("Terraform apply failed: %v", err)
        log.Println("Stderr:\n", stderr)
        log.Println("Stdout:\n", stdout)
        return
    }
    fmt.Println("Terraform apply successful.")
    fmt.Println("Stdout:\n", stdout)

    // 你也可以在这里解析 stdout 获取输出变量等
}

cmd.Env

// ... 在 runTerraform 函数内部或外部
cmd.Env = os.Environ() // 继承当前进程的环境变量
cmd.Env = append(cmd.Env, "AWS_ACCESS_KEY_ID=YOUR_ACCESS_KEY", "AWS_SECRET_ACCESS_KEY=YOUR_SECRET_KEY")
// 或者更推荐的方式是从安全存储（如Vault）获取凭证

-json

terraform plan -json

// 运行 terraform plan -json
// ...
// 假设 planJSONOutput 是 plan -json 的 stdout
// var planData map[string]interface{}
// err = json.Unmarshal([]byte(planJSONOutput), &planData)
// if err != nil { /* ... */ }
// 然后可以检查 planData["resource_changes"] 等信息

exec.Command

error

stderr

stderr

text/template

.tf

package main

import (
    "bytes"
    "fmt"
    "log"
    "os"
    "text/template"
)

// 定义一个Go结构体来承载模板数据
type S3BucketConfig struct {
    BucketName string
    Region     string
    Tags       map[string]string
}

// Terraform配置模板
const s3Template = `
resource "aws_s3_bucket" "{{.BucketName}}" {
  bucket = "{{.BucketName}}"
  acl    = "private"
  region = "{{.Region}}"

  {{- if .Tags }}
  tags = {
    {{- range $key, $value := .Tags }}
    "{{$key}}" = "{{$value}}"
    {{- end }}
  }
  {{- end }}
}

output "s3_bucket_id" {
  value = aws_s3_bucket.{{.BucketName}}.id
}
`

func main() {
    config := S3BucketConfig{
        BucketName: "my-app-data-bucket-dynamic-123",
        Region:     "us-east-1",
        Tags: map[string]string{
            "Project":     "DynamicInfra",
            "Environment": "Production",
            "ManagedBy":   "GolangApp",
        },
    }

    tmpl, err := template.New("s3_bucket").Parse(s3Template)
    if err != nil {
        log.Fatalf("Failed to parse template: %v", err)
    }

    var buf bytes.Buffer
    err = tmpl.Execute(&buf, config)
    if err != nil {
        log.Fatalf("Failed to execute template: %v", err)
    }

    // 将生成的HCL写入文件
    outputFileName := fmt.Sprintf("./generated_configs/%s.tf", config.BucketName)
    err = os.MkdirAll(filepath.Dir(outputFileName), 0755) // 确保目录存在
    if err != nil {
        log.Fatalf("Failed to create directory: %v", err)
    }

    err = os.WriteFile(outputFileName, buf.Bytes(), 0644)
    if err != nil {
        log.Fatalf("Failed to write generated .tf file: %v", err)
    }

    fmt.Printf("Successfully generated Terraform config to %s\n", outputFileName)
    fmt.Println(buf.String())

    // 接下来可以调用 runTerraform(filepath.Dir(outputFileName), "apply", "-auto-approve") 来应用这个配置
}