Skip to content

fix(infra): secret 読み取り Deny を自アカウントの parameter に絞る #109

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
yook11 merged 1 commit into from
Aug 4, 2026
Merged

fix(infra): secret 読み取り Deny を自アカウントの parameter に絞る #109

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
74 changes: 34 additions & 40 deletions infra/aws/bootstrap/oidc.tf
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -73,13 +73,32 @@ locals {

# secret の実体を CI が読めないようにする。
# 「Terraform から SSM の値を読まない」を運用の約束ではなく IAM の Deny にする。
secret_read_actions = [
"ssm:GetParameter",
"ssm:GetParameters",
"ssm:GetParameterHistory",
"ssm:GetParametersByPath",
"secretsmanager:GetSecretValue",
"kms:Decrypt",
#
# SSM だけ Resource を自アカウント所有の parameter に絞る。AWS が公開する
# /aws/service/* (最新 AMI の ID など) は **account 部が空の ARN** で、`*` で
# 巻き込むと bastion の AMI 参照が Deny で落ちる。秘密は全て自アカウントの
# parameter にあるので、絞っても射程は変わらない。
secret_read_statements = [
{
Sid = "NoOwnParameterValues"
Effect = "Deny"
Action = [
"ssm:GetParameter",
"ssm:GetParameters",
"ssm:GetParameterHistory",
"ssm:GetParametersByPath",
]
Resource = "arn:aws:ssm:*:${local.account_id}:parameter/*"
},
{
Sid = "NoSecretValues"
Effect = "Deny"
Action = [
"secretsmanager:GetSecretValue",
"kms:Decrypt",
]
Resource = "*"
},
]
}

Expand Down Expand Up @@ -168,15 +187,8 @@ resource "aws_iam_role_policy" "plan_deny_secret_read" {
role = aws_iam_role.ci["plan"].id

policy = jsonencode({
Version = "2012-10-17"
Statement = [
{
Sid = "NoSecretValues"
Effect = "Deny"
Action = local.secret_read_actions
Resource = "*"
},
]
Version = "2012-10-17"
Statement = local.secret_read_statements
})
}

Expand All @@ -188,7 +200,7 @@ resource "aws_iam_role_policy" "apply" {

policy = jsonencode({
Version = "2012-10-17"
Statement = [
Statement = concat([
# 本体スタックが触るリージョナルサービス。
#
# ここを action 単位で列挙しないのは意図的。greenfield のスタックで
Expand Down Expand Up @@ -336,13 +348,7 @@ resource "aws_iam_role_policy" "apply" {
# computed なので、ignore_changes を付けても refresh で state に載る)。
# 「値を読まない」を Deny にすることで、data source をうっかり足しても
# apply が失敗して気づく。
{
Sid = "NoSecretValues"
Effect = "Deny"
Action = local.secret_read_actions
Resource = "*"
},
]
], local.secret_read_statements)
})
}

Expand All @@ -357,7 +363,7 @@ resource "aws_iam_role_policy" "push" {

policy = jsonencode({
Version = "2012-10-17"
Statement = [
Statement = concat([
{
Sid = "EcrAuthToken"
Effect = "Allow"
Expand All @@ -378,13 +384,7 @@ resource "aws_iam_role_policy" "push" {
]
Resource = "arn:aws:ecr:${var.region}:${local.account_id}:repository/${var.name_prefix}/*"
},
{
Sid = "NoSecretValues"
Effect = "Deny"
Action = local.secret_read_actions
Resource = "*"
},
]
], local.secret_read_statements)
})
}

Expand All @@ -400,7 +400,7 @@ resource "aws_iam_role_policy" "rollout" {

policy = jsonencode({
Version = "2012-10-17"
Statement = [
Statement = concat([
{
Sid = "EcsRollout"
Effect = "Allow"
Expand Down Expand Up @@ -429,12 +429,6 @@ resource "aws_iam_role_policy" "rollout" {
StringEquals = { "iam:PassedToService" = "ecs-tasks.amazonaws.com" }
}
},
{
Sid = "NoSecretValues"
Effect = "Deny"
Action = local.secret_read_actions
Resource = "*"
},
]
], local.secret_read_statements)
})
}
Loading