Agenda

前言
Identity
Role
IAM policy
整體架構
IAM Resource Hierarchy
實際演練

1. 前言

CLOUD IAM 是 GCP 管理資源權限的服務，全名叫Identity and Access Management，中文意思即「身分識別與存取管理」，主要功能是讓GCP知道 誰(Identity) 可以對哪些 資源(Resource) 做 哪些行為(Role)。

2. Identity

Google Account : 可能是開發者或是管理員的電子郵件地址，通常是 gmail.com，也可以是其他域名。
Service Account : 提供給應用程式的帳號，例如應用程式要使用gcp的資源時，就會以被指定的服務帳號來驗證其身分，若有相關權限，即可對GCP資源做權限所允許的行為。
Google Group : 是一個由多個 Google Account 或 Service Account 組成的集合，而每一個Google Group都會有唯一的電子郵件帳號，其用途在管理者可透過這個帳號，直接對集合中的帳號統一授權或是權限調整，提高管理上的便利性 ; 惟須留意，Google Group帳號是無法作為登入GCP時所使用的帳號的。
Google Workspace : 主要是以一個域名來管理，例如某組織註冊域名 xxx.com，並用這個域名為底下員工註冊google帳戶，如 employee_1@xxx.com、employee_2@xxx.com，那麼設定iam的時候，就能一次性的使用xxx.com來管理組織下的權限。
Cloud Identity Domain : 類似於Google Workspace，差別在於如果沒有要使用Workspace的服務，那使用 Cloud Identity Domain 即可。

3. Roles

Roles 與兩項目有相關，即 Resource、Permission，故先簡單描述兩者，接著再介紹Roles。

Resource :

即GCP提供的各種資源，例如 storage、cloudsql、memorystore等等。

Permission :

可以對gcp資源做什麼行為，例如刪除gce的vm，即需要如下圖的權限。

Image Not Showing Possible Reasons

The image was uploaded to a note which you don't have access to
The note which the image was originally uploaded to has been deleted

Learn More →

Roles

Roles 是由一個或多個 Permission 所組成的角色，其類型有以下三種 :

Basic Roles (基本角色) :
有Owner/Editor/Viewer三種role，在啟用gcp project後就會存在了。其中Owner權限最大，擁有project內所有資源的存取權，而Editor是可以修改既已存在的資源並包含Viewer的權限，Viewer則只能對資源進行檢視。這種類型的role在管理權限上是非常不細致的，因此並不建議使用這種方式來管理權限。
Predefined Roles (預定義角色) :
由GCP提供並持續維護與更新的role，這種角色可以針對特定的資源去配置權限，相較於Basic Roles是對整個專案的資源都適用，Predefined Roles在權限控管上的精細度是有所提升的。實例如下圖紅框處，該權限僅限於GCS的建立、讀取、更新和刪除物件及分段上傳:
Image Not Showing Possible Reasons
- The image was uploaded to a note which you don't have access to
- The note which the image was originally uploaded to has been deleted
Learn More →
Custom Roles (自定義角色) :
此種 role 比 Predefined role 又更精細，如下圖紅框處，可以只針對特定權限授予，例如只想授予storage的建立權限，那只加入 storage.bucket.create 即可達到需求。
Image Not Showing Possible Reasons
- The image was uploaded to a note which you don't have access to
- The note which the image was originally uploaded to has been deleted
Learn More →

4. IAM policy

當角色都制定好，再來就是要如何授權給使用者了，此時就會使用到 IAM policy。

Image Not Showing Possible Reasons

The image was uploaded to a note which you don't have access to
The note which the image was originally uploaded to has been deleted

Learn More →

以上圖來說明，IAM policy是由一個或多個Binding的集合，其中Binding就是將某種Roles綁定給使用者的概念。

5. 整體架構

Image Not Showing Possible Reasons

The image was uploaded to a note which you don't have access to
The note which the image was originally uploaded to has been deleted

Learn More →

Cloud IAM 會根據 IAM policy 去查看誰(Identity) 可以對哪些 資源(Resource) 做 哪些行為(Role)，所以當使用者沒有被綁定到Roles，就無法執行該Roles所擁有的權限，此即為IAM的整體概念。

6. IAM Resource Hierarchy

在 GCP 上，所有資源都是以階層的方式進行組織，從上到下依序為:

Organization：根節點，資源的最上層
Folder： Organization 的子項目
Project： Organization 或是 Folder 的子項目
Resource： Project 下面的子項目
Image Not Showing Possible Reasons
- The image was uploaded to a note which you don't have access to
- The note which the image was originally uploaded to has been deleted
Learn More →

7. 實際演練

以下會以GCS作為示範的資源，建置則以terraform方式建立。
簡單描述演練項目及步驟:

terraform前置準備
創建自定義的角色
創建服務帳號
創建iam_policy
驗證iam_policy
condition功能演示

terraform前置準備 (此步驟只限terraform練習才要，用ui練習者可忽略)

ui介面操作:
(1) 先為terraform建置服務帳號
Image Not Showing Possible Reasons
- The image was uploaded to a note which you don't have access to
- The note which the image was originally uploaded to has been deleted
Learn More →
接著產出服務帳戶的金鑰:
Image Not Showing Possible Reasons
- The image was uploaded to a note which you don't have access to
- The note which the image was originally uploaded to has been deleted
Learn More →
(2)創建一個自訂義的角色，角色要擁有以下權限:
```
  iam.roles.get
  iam.roles.create
  iam.roles.delete
  iam.roles.update
  iam.roles.undelete
  iam.serviceAccountKeys.create
  iam.serviceAccountKeys.delete
  iam.serviceAccountKeys.get
  iam.serviceAccounts.create
  iam.serviceAccounts.delete
  iam.serviceAccounts.get
  resourcemanager.projects.setIamPolicy
  resourcemanager.projects.getIamPolicy
```
Image Not Showing Possible Reasons
- The image was uploaded to a note which you don't have access to
- The note which the image was originally uploaded to has been deleted
Learn More →
(3) 建置好角色後，將角色綁訂至terraform的服務帳號
Image Not Showing Possible Reasons
- The image was uploaded to a note which you don't have access to
- The note which the image was originally uploaded to has been deleted
Learn More →

terraform腳本:




























// provider.tf
provider "google" {
  credentials = var.credentials
  project     = var.project
  region      = var.region
}
provider "google-beta" {
  credentials = var.credentials
  project     = var.project
  region      = var.region
}

// variable.tf
variable "credentials" {
  type = string
  default = "terraform-test.json"
}
variable "project" {
  type = string
  default = "iamrich-lab"
}
variable "region" {
  type = string
  default = "asia-east1"
}

//terraform-test.json
-> 將剛剛產出的金鑰內容貼到此份檔案

創建自定義角色

ui的設定位置在:

terraform建置腳本:


























# main.tf
resource "google_project_iam_custom_role" "custom_role"{
  for_each    = var.custom_role_list
  role_id     = each.value.role_id
  title       = each.value.title
  permissions = each.value.permissions
  description = each.value.description
}

# variable.tf
variable "custom_role_list"{
    type = map(object({
      role_id = string
      title   = string
      permissions = list(string)
      description = string
    }))
    default = {
      custom_role_1 = {
        role_id = "CustomRoleFortest1"
        title   = "Custom Role Test 1"
        permissions = ["storage.buckets.create","storage.buckets.get"]
        description = "forIamTest-storage-create"
      }
    }
}

創建服務帳號

ui的設定位置在:

terraform建置腳本:














































#  *main.tf*
#--創建服務帳號
resource "google_service_account" "for-test" {
  for_each     = var.servcieaccount_list
  account_id   = each.value.account_id
  display_name = each.value.display_name
}
#--產出服務帳號的金鑰
resource "google_service_account_key" "mykey" {
  for_each = var.key_list
  service_account_id = google_service_account.for-test[each.key].name
  public_key_type    = each.value.public_key_type
}
#--將上面服務帳號的私鑰 匯出至本機指定的目錄 (等等切換帳號時需用到)
resource "local_file" "download_key_json"{
  for_each  = var.keyjson_list
  content   = base64decode(google_service_account_key.mykey[each.key].private_key)
  filename  = each.value.filename
}

# variable.tf
variable "servcieaccount_list"{
    type = map(map(string))
    default = {
      for_test = {
        account_id = "for-test"
        display_name = "Allow to editor storage."
      }
    }
}
variable "key_list" {
    type = map(map(string))
    default = {
      for_test = {
        public_key_type = "TYPE_X509_PEM_FILE"
      }
    }
}
variable "keyjson_list"{
    type = map(map(string))
    default = {
      for_test ={
        filename = "./serviceaccount_demo/for-test.json"
      }
    }
}

創建iam_policy

ui的設定位置在:

terraform建置腳本:
分別有兩種不同情境:

針對單一帳號設定 policy



































# main.tf
resource "google_project_iam_member" "iam_policy" {
  for_each = var.google_project_iam_member_list
  project = var.project
  role    = each.value.role
  member  = each.value.member
  dynamic "condition" {
    for_each = each.value.condition_config
    content {
        title       = condition.value["title"]
        description = condition.value["description"]
        expression  = condition.value["expression"]
    }
  }
}

# variable.tf
variable "google_project_iam_member_list" {
    type = map(object({
      role    = string
      member   = string
      condition_config = list(object({
        title       = string
        description = string
        expression  = string
      }))
    }))
    default = {
        for_iam_member_1 = {
            role = "projects/iamrich-lab/roles/CustomRoleFortest1"
            member = "serviceAccount:for-test@iamrich-lab.iam.gserviceaccount.com"
            condition_config = []
        }
    }
}

針對多組帳號設定 policy






































# main.tf
resource "google_project_iam_binding" "iam_policy" {
  for_each = var.google_project_iam_binding_list
  project = var.project
  role    = each.value.role
  member  = each.value.muli_member

  dynamic "condition" {
    for_each = each.value.condition_config
    content {
        title       = condition.value["title"]
        description = condition.value["description"]
        expression  = condition.value["expression"]
    }
  }
}

# variable.tf
variable "google_project_iam_binding_list" {
    type = map(object({
      role    = string
      muli_member   = list(string)
      condition_config = list(object({
        title       = string
        description = string
        expression  = string
      }))
    }))
    default = {
        for_iam_muliMember = {
            role = "projects/iamrich-lab/roles/CustomRoleFortest1"
            muli_member = [
             "serviceAccount:for-test@iamrich-lab.iam.gserviceaccount.com",
            ]
            condition_config = []
        }
    }
}

關於Permission有哪些可參考GCP文件

驗證iam_policy (使用剛創建的服務帳號創建+刪除bucket)

ui的設定位置在:

terraform建置腳本:
到這邊我們需要切換資料夾，因為接下來要使用剛剛建好的服務帳號執行，來驗證iam_policy生效。新的資料夾會有以下:







































# main.tf
resource "google_storage_bucket" "bucket"{
  name = "test-20240605"
  location = "ASIA"
  force_destroy = false
  storage_class = "STANDARD"
  cors {
    origin          = ["*"]
    method          = ["GET"]
    response_header = ["Access-Control-Allow-Origin"]
    max_age_seconds = 3600
  }
}

# variable.tf
variable "credentials" {
  type = string
  default = "for-test.json" 
}
variable "project" {
  type = string
  default = "iamrich-lab"
}
variable "region" {
  type = string
  default = "asia-east1"
}

# provider.tf
provider "google" {
  credentials = var.credentials
  project     = var.project
  region      = var.region
}
provider "google-beta" {
  credentials = var.credentials
  project     = var.project
  region      = var.region
}

condition功能演示

ui的設定位置在:

(在創建iam_policy時可以順便設定的)

terraform腳本:
























variable "google_project_iam_member_list" {
    type = map(object({
      role    = string
      member   = string
      condition_config = list(object({
        title       = string
        description = string
        expression  = string
      }))
    }))
    default = {
        for_iam_member_1 = {
            role = "projects/iamrich-lab/roles/CustomRoleFortest1"
            member = "serviceAccount:for-test-1@iamrich-lab.iam.gserviceaccount.com"
            condition_config = [      
                 {
                    title = "condition_test"
                    description = "for-condition-test"
                    expression = "request.time.getHours('Asia/Taipei') >= 9 && request.time.getHours('Asia/Taipei') <= 15 && request.time.getDayOfWeek('Asia/Taipei') >= 1 && request.time.getDayOfWeek('Asia/Taipei') <= 5"
                }
            ]
        }
    }
}

參考文件

https://cloud.google.com/iam/docs/overview?hl=zh-cn
https://cloud.google.com/iam/docs/conditions-overview?hl=zh-cn
https://blog.cloud-ace.tw/identity-security/what-is-cloud-iam/
https://hackmd.io/@kevinhuangtw/SJ2KjoRKc

terraform項目:
google_project_iam_custom_role
google_service_account
google_service_account_key
local_file
google_project_iam
google_storage_bucket

Agenda

1. 前言

2. Identity

3. Roles

Resource :

Permission :

Roles

4. IAM policy

5. 整體架構

6. IAM Resource Hierarchy

7. 實際演練

參考文件

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