Codepipeline跨账号访问Codecommit

背景

大型企业中代码仓库通常存放在各部门开发账户中，而流水线则位于独立DevOps账户中。

本文我们将介绍如何创建跨账号访问Codecommit代码仓库的Codepipeline流水线，即CodePipeline调用另一个账号中的Codecommit代码仓库。

部署架构图

权限配置

CodePipeline 执行role – CodePipelineServiceRole，关键IAM Policy：允许CodePipeline assume account B中的角色“AssumeAdminRole”。
AssumeAdminRole – CodePipeline-SourceStage实际执行role，添加policy以具有以下权限
- 允许被Account A中CodePipeline Assume
- 允许访问本账户中的CodeCommit
- 允许访问Account A中的S3桶（存放sourceArtifact）
- 允许访问Account A中的KMS
配置KMS Policy，允许CodePipelineServiceRole和AssumeAdminRole访问kms中相应的key
配置S3 Bucket Policy，允许AssumeAdminRole访问S3中相应的bucket
CodeBuild执行role，可配置为自动生成，不是本文重点

流水线执行过程

触发流水线
SourceStage中首先assume AssumeAdminRole，获得访问CodeCommit权限
从AccountB CodeCommit代码仓库拉取代码
将放sourceArtifact存入S3桶
S3服务端加密
执行Build Stage: CodeBuild

账号准备

选择您所在的region，本文以北京Region为例。

准备两个AWS主账号：

代码仓库账号B：提供Codecommit服务，源代码放在这里。
pipeline账号A：提供Codepipeline服务，以及相关联的codebuild、kms密钥和s3桶

代码仓库账号B

一、创建跨账号IAM Role

该Role命名为assume-admin-role，使用权限如下：

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "VisualEditor0",
            "Effect": "Allow",
            "Action": [
                "s3:PutObject",
                "kms:Decrypt",
                "kms:Encrypt",
                "kms:DescribeKey",
                "s3:GetObject*",
                "s3:PutObjectAcl",
                "kms:ReEncrypt*",
                "kms:GenerateDataKey*"
            ],
            "Resource": [
                " arn:aws-cn:kms:cn-north-1:<Account_A_ID>:key/XXX-XXX-XXX-XXX ",
                "arn:aws-cn:s3:::codecommit-sdv-cross-account/*"
            ]
        },
        {
            "Sid": "VisualEditor1",
            "Effect": "Allow",
            "Action": [
                "codecommit:List*"
            ],
            "Resource": "arn:aws-cn:s3:::codecommit-sdv-cross-account/*"
        }
    ]
}

该Role的信任关系如下：

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
                "AWS": [
                    "arn:aws-cn:iam::<Account_A_ID>:root"
                ]
            },
            "Action": "sts:AssumeRole"
        }
    ]
}

二、创建CodeCommit Repository

该Repo命名为：cros-account-b-repo，并在该Repo中创建文件demo.txt。

流水线账号A

三、创建Codepipeline IAM Role

创建IAM Role，名为：AWSCodePipelineServiceRole-cn-north-1-sdv-pipeline-cros，为Codepipeline的创建做准备。

该role关联Codepipeline默认Role的权限策略，具体如下：

{
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "iam:PassRole"
            ],
            "Resource": "*",
            "Condition": {
                "StringEqualsIfExists": {
                    "iam:PassedToService": [
                        "cloudformation.amazonaws.com",
                        "elasticbeanstalk.amazonaws.com",
                        "ec2.amazonaws.com",
                        "ecs-tasks.amazonaws.com"
                    ]
                }
            }
        },
        {
            "Effect": "Allow",
            "Action": [
                "codecommit:CancelUploadArchive",
                "codecommit:GetBranch",
                "codecommit:GetCommit",
                "codecommit:GetRepository",
                "codecommit:GetUploadArchiveStatus",
                "codecommit:UploadArchive"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "codedeploy:CreateDeployment",
                "codedeploy:GetApplication",
                "codedeploy:GetApplicationRevision",
                "codedeploy:GetDeployment",
                "codedeploy:GetDeploymentConfig",
                "codedeploy:RegisterApplicationRevision"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "elasticbeanstalk:*",
                "ec2:*",
                "elasticloadbalancing:*",
                "autoscaling:*",
                "cloudwatch:*",
                "s3:*",
                "sns:*",
                "cloudformation:*",
                "rds:*",
                "sqs:*",
                "ecs:*"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "lambda:InvokeFunction",
                "lambda:ListFunctions"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "cloudformation:CreateStack",
                "cloudformation:DeleteStack",
                "cloudformation:DescribeStacks",
                "cloudformation:UpdateStack",
                "cloudformation:CreateChangeSet",
                "cloudformation:DeleteChangeSet",
                "cloudformation:DescribeChangeSet",
                "cloudformation:ExecuteChangeSet",
                "cloudformation:SetStackPolicy",
                "cloudformation:ValidateTemplate"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "codebuild:BatchGetBuilds",
                "codebuild:StartBuild",
                "codebuild:BatchGetBuildBatches",
                "codebuild:StartBuildBatch"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "servicecatalog:ListProvisioningArtifacts",
                "servicecatalog:CreateProvisioningArtifact",
                "servicecatalog:DescribeProvisioningArtifact",
                "servicecatalog:DeleteProvisioningArtifact",
                "servicecatalog:UpdateProduct"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "cloudformation:ValidateTemplate"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "ecr:DescribeImages"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "states:DescribeExecution",
                "states:DescribeStateMachine",
                "states:StartExecution"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "appconfig:StartDeployment",
                "appconfig:StopDeployment",
                "appconfig:GetDeployment"
            ],
            "Resource": "*"
        }
    ],
    "Version": "2012-10-17"
}

除了默认权限策略，为了提供跨账号调用，该Role还需要加入如下权限策略：

{
    "Version": "2012-10-17",
    "Statement": {
        "Effect": "Allow",
        "Action": "sts:AssumeRole",
        "Resource": [
            "arn:aws-cn:iam::<Account_B_ID>:role/*"
        ]
    }
}

四、创建KMS秘钥

创建名为：account_a_cros_kms的KMS秘钥。

在定义秘钥使用权限时，需要加入Codepipeline所关联的Role（上一步创建名为：AWSCodePipelineServiceRole-cn-north-1-sdv-pipeline-cros的IAM Role）和Account B的账号ID。记录KMS ARN为：arn:aws-cn:kms:cn-north-1:<Account_A_ID>:key/XXX-XXX-XXX-XXX

五、创建S3桶

这里创建名为：codecommit-sdv-cross-account的S3桶。

这里S3桶命名为 codecommit-sdv-cross-account。然后编辑存储桶权限，即权限->存储通权限，点击编辑按钮，添加如下policy json:

{
"Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "Statement1",
            "Effect": "Allow",
            "Principal": {
                "AWS": "arn:aws-cn:iam::<Account_B_ID>:root"
            },
            "Action": [
                "s3:Get*",
                "s3:Put*"
            ],
            "Resource": "arn:aws-cn:s3:::codecommit-sdv-cross-account/*"
        },
        {
            "Sid": "Statement2",
            "Effect": "Allow",
            "Principal": {
                "AWS": "arn:aws-cn:iam:: <Account_B_ID>:root"
            },
            "Action": "s3:ListBucket",
            "Resource": "arn:aws-cn:s3:::codecommit-sdv-cross-account"
        }
    ]
}

六、创建CodeBuild

创建名为：sdv-build的codebuild项目，供codepipeline调用。

在Buildspec中添加命令如下：

七、创建Codepipeline

对于跨账号调用Codecommit的Codepipeline只能通过AWS CLI创建，准备如下pipeline.json文件，

{
    "pipeline": {
        "roleArn": "arn:aws-cn:iam::<Account_A_ID>:role/service-role/AWSCodePipelineServiceRole-cn-north-1-sdv-pipeline-cros", 
        "stages": [
            {
                "name": "Source", 
                "actions": [
                    {
                        "inputArtifacts": [], 
                        "name": "Source", 
                        "region": "cn-north-1", 
                        "namespace": "SourceVariables", 
                        "actionTypeId": {
                            "category": "Source", 
                            "owner": "AWS", 
                            "version": "1", 
                            "provider": "CodeCommit"
                        }, 
                        "outputArtifacts": [
                            {
                                "name": "SourceArtifact"
                            }
                        ], 
                        "roleArn":"arn:aws-cn:iam::<Account_B_ID>:role/assume-admin-role",
                        "configuration": {
                            "BranchName": "master", 
                            "PollForSourceChanges": "false", 
                            "RepositoryName": "cros-account-b-repo"
                        }, 
                        "runOrder": 1
                    }
                ]
            }, 
            {
                "name": "Build", 
                "actions": [
                    {
                        "inputArtifacts": [
                            {
                                "name": "SourceArtifact"
                            }
                        ], 
                        "name": "Build", 
                        "region": "cn-north-1", 
                        "namespace": "BuildVariables", 
                        "actionTypeId": {
                            "category": "Build", 
                            "owner": "AWS", 
                            "version": "1", 
                            "provider": "CodeBuild"
                        }, 
                        "outputArtifacts": [
                            {
                                "name": "BuildArtifact"
                            }
                        ], 
                        "configuration": {
                            "ProjectName": "sdv-build"
                        }, 
                        "runOrder": 1
                    }
                ]
            }
        ], 
        "artifactStore": {
            "type": "S3", 
            "location": "codecommit-sdv-cross-account",
            "encryptionKey": {
               "id": " arn:aws-cn:kms:cn-north-1:<Account_A_ID>:key/XXX-XXX-XXX-XXX ",
               "type": "KMS"
            }
       },
        "name": "pipeline-cros", 
        "version": 1
    }
}

这里计划在Account A创建名为pipeline-cros的codepipeline，该pipeline以Account B的codecommit repo: cros-account-b-repo (master branch)作为源，并利用预先准备好的位于Account A的codebuild进行流水线的执行。

使用如上Json，并利用AWS cli执行命令如下：

aws codepipeline create-pipeline –cli-input-json file://pipeline.json # 创建pipeline

同时codebuild会打印日志如下：

……
[Container] 2022/07/18 03:23:11 Entering phase BUILD
[Container] 2022/07/18 03:23:11 Running command ls
demo.txt
[Container] 2022/07/18 03:23:11 Phase complete: BUILD State: SUCCEEDED
……

亚马逊AWS官方博客