From 41fef29badd7809daffb89ae58c97f0f7c1218dc Mon Sep 17 00:00:00 2001 From: Ben Vincent Date: Sun, 2 Aug 2026 21:29:18 +1000 Subject: [PATCH 1/2] Add Vault-scoped agent kubernetes roles + agents AppRole Give agentic workloads domain-scoped kubernetes credentials so they stop needing cluster-admin/root. Adds four least-privilege kubernetes secret engine roles, an `agents` AppRole (role_id-only, CIDR-bound to the agent workstation) that can mint them, and a write-capable KV grant for the kubernetes secrets subtree. - Add kubernetes_secret_backend_role configs agent-dhcp/dns/certs/storage with generated_role_rules scoping each to its operator CRDs + pod/log reads. - Add creds policies for each role, bound to Ben's cluster-operator ldap group (human kubectl use) and the agents AppRole (programmatic use). - Add the `agents` AppRole: bind_secret_id false, token_bound_cidrs 10.10.12.200/32, deterministic role_id, 1h/4h TTLs. - Add kv/kubernetes/agents policy granting the AppRole create/read/update/list on the kubernetes KV subtree (no delete). Claude-Session: https://claude.ai/code/session_01JUoARVdmhxKQHyyyp1pxeT --- config/auth_approle_role/approle/agents.yaml | 6 ++++ .../kubernetes/au/syd1/agent-certs.yaml | 4 +++ .../kubernetes/au/syd1/agent-dhcp.yaml | 4 +++ .../kubernetes/au/syd1/agent-dns.yaml | 4 +++ .../kubernetes/au/syd1/agent-storage.yaml | 4 +++ .../kubernetes/au/syd1/creds/agent-certs.yaml | 12 +++++++ .../kubernetes/au/syd1/creds/agent-dhcp.yaml | 12 +++++++ .../kubernetes/au/syd1/creds/agent-dns.yaml | 12 +++++++ .../au/syd1/creds/agent-storage.yaml | 12 +++++++ policies/kv/kubernetes/agents.yaml | 17 ++++++++++ .../kubernetes/au/syd1/roles/agent-certs.yaml | 33 +++++++++++++++++++ .../kubernetes/au/syd1/roles/agent-dhcp.yaml | 26 +++++++++++++++ .../kubernetes/au/syd1/roles/agent-dns.yaml | 26 +++++++++++++++ .../au/syd1/roles/agent-storage.yaml | 23 +++++++++++++ 14 files changed, 195 insertions(+) create mode 100644 config/auth_approle_role/approle/agents.yaml create mode 100644 config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-certs.yaml create mode 100644 config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-dhcp.yaml create mode 100644 config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-dns.yaml create mode 100644 config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-storage.yaml create mode 100644 policies/kubernetes/au/syd1/creds/agent-certs.yaml create mode 100644 policies/kubernetes/au/syd1/creds/agent-dhcp.yaml create mode 100644 policies/kubernetes/au/syd1/creds/agent-dns.yaml create mode 100644 policies/kubernetes/au/syd1/creds/agent-storage.yaml create mode 100644 policies/kv/kubernetes/agents.yaml create mode 100644 resources/secret_backend/kubernetes/au/syd1/roles/agent-certs.yaml create mode 100644 resources/secret_backend/kubernetes/au/syd1/roles/agent-dhcp.yaml create mode 100644 resources/secret_backend/kubernetes/au/syd1/roles/agent-dns.yaml create mode 100644 resources/secret_backend/kubernetes/au/syd1/roles/agent-storage.yaml diff --git a/config/auth_approle_role/approle/agents.yaml b/config/auth_approle_role/approle/agents.yaml new file mode 100644 index 0000000..8a23894 --- /dev/null +++ b/config/auth_approle_role/approle/agents.yaml @@ -0,0 +1,6 @@ +token_ttl: 3600 +token_max_ttl: 14400 +bind_secret_id: false +token_bound_cidrs: + - "10.10.12.200/32" +use_deterministic_role_id: true diff --git a/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-certs.yaml b/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-certs.yaml new file mode 100644 index 0000000..10fd4ed --- /dev/null +++ b/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-certs.yaml @@ -0,0 +1,4 @@ +allowed_kubernetes_namespaces: + - "cert-manager" +kubernetes_role_type: "Role" +extra_labels: {} diff --git a/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-dhcp.yaml b/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-dhcp.yaml new file mode 100644 index 0000000..c5ed8f5 --- /dev/null +++ b/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-dhcp.yaml @@ -0,0 +1,4 @@ +allowed_kubernetes_namespaces: + - "dhcp-system" +kubernetes_role_type: "Role" +extra_labels: {} diff --git a/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-dns.yaml b/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-dns.yaml new file mode 100644 index 0000000..b758647 --- /dev/null +++ b/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-dns.yaml @@ -0,0 +1,4 @@ +allowed_kubernetes_namespaces: + - "*" +kubernetes_role_type: "ClusterRole" +extra_labels: {} diff --git a/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-storage.yaml b/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-storage.yaml new file mode 100644 index 0000000..b1f1301 --- /dev/null +++ b/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-storage.yaml @@ -0,0 +1,4 @@ +allowed_kubernetes_namespaces: + - "cephrgw-system" +kubernetes_role_type: "Role" +extra_labels: {} diff --git a/policies/kubernetes/au/syd1/creds/agent-certs.yaml b/policies/kubernetes/au/syd1/creds/agent-certs.yaml new file mode 100644 index 0000000..fcc78b7 --- /dev/null +++ b/policies/kubernetes/au/syd1/creds/agent-certs.yaml @@ -0,0 +1,12 @@ +# Allow access to agent-certs Kubernetes credentials +--- +rules: + - path: "kubernetes/au/syd1/creds/agent-certs" + capabilities: + - update + +auth: + ldap: + - kubernetes_au_syd1_cluster_operator + approle: + - agents diff --git a/policies/kubernetes/au/syd1/creds/agent-dhcp.yaml b/policies/kubernetes/au/syd1/creds/agent-dhcp.yaml new file mode 100644 index 0000000..76e007d --- /dev/null +++ b/policies/kubernetes/au/syd1/creds/agent-dhcp.yaml @@ -0,0 +1,12 @@ +# Allow access to agent-dhcp Kubernetes credentials +--- +rules: + - path: "kubernetes/au/syd1/creds/agent-dhcp" + capabilities: + - update + +auth: + ldap: + - kubernetes_au_syd1_cluster_operator + approle: + - agents diff --git a/policies/kubernetes/au/syd1/creds/agent-dns.yaml b/policies/kubernetes/au/syd1/creds/agent-dns.yaml new file mode 100644 index 0000000..e61a423 --- /dev/null +++ b/policies/kubernetes/au/syd1/creds/agent-dns.yaml @@ -0,0 +1,12 @@ +# Allow access to agent-dns Kubernetes credentials +--- +rules: + - path: "kubernetes/au/syd1/creds/agent-dns" + capabilities: + - update + +auth: + ldap: + - kubernetes_au_syd1_cluster_operator + approle: + - agents diff --git a/policies/kubernetes/au/syd1/creds/agent-storage.yaml b/policies/kubernetes/au/syd1/creds/agent-storage.yaml new file mode 100644 index 0000000..0463013 --- /dev/null +++ b/policies/kubernetes/au/syd1/creds/agent-storage.yaml @@ -0,0 +1,12 @@ +# Allow access to agent-storage Kubernetes credentials +--- +rules: + - path: "kubernetes/au/syd1/creds/agent-storage" + capabilities: + - update + +auth: + ldap: + - kubernetes_au_syd1_cluster_operator + approle: + - agents diff --git a/policies/kv/kubernetes/agents.yaml b/policies/kv/kubernetes/agents.yaml new file mode 100644 index 0000000..ea89078 --- /dev/null +++ b/policies/kv/kubernetes/agents.yaml @@ -0,0 +1,17 @@ +# Allow the agents AppRole to manage the kubernetes KV subtree (no delete) +--- +rules: + - path: "kv/data/kubernetes/*" + capabilities: + - create + - read + - update + - list + - path: "kv/metadata/kubernetes/*" + capabilities: + - read + - list + +auth: + approle: + - agents diff --git a/resources/secret_backend/kubernetes/au/syd1/roles/agent-certs.yaml b/resources/secret_backend/kubernetes/au/syd1/roles/agent-certs.yaml new file mode 100644 index 0000000..995710d --- /dev/null +++ b/resources/secret_backend/kubernetes/au/syd1/roles/agent-certs.yaml @@ -0,0 +1,33 @@ +--- +rules: + - apiGroups: + - "cert-manager.io" + - "acme.cert-manager.io" + resources: + - "*" + verbs: + - "*" + - apiGroups: + - "" + resources: + - "secrets" + verbs: + - "get" + - "list" + - "watch" + - "delete" + - apiGroups: + - "" + resources: + - "pods" + verbs: + - "get" + - "list" + - "watch" + - apiGroups: + - "" + resources: + - "pods/log" + verbs: + - "get" + - "list" diff --git a/resources/secret_backend/kubernetes/au/syd1/roles/agent-dhcp.yaml b/resources/secret_backend/kubernetes/au/syd1/roles/agent-dhcp.yaml new file mode 100644 index 0000000..a425a34 --- /dev/null +++ b/resources/secret_backend/kubernetes/au/syd1/roles/agent-dhcp.yaml @@ -0,0 +1,26 @@ +--- +rules: + - apiGroups: + - "kea.unkin.net" + resources: + - "*" + verbs: + - "*" + - apiGroups: + - "" + resources: + - "pods" + - "services" + - "configmaps" + - "events" + verbs: + - "get" + - "list" + - "watch" + - apiGroups: + - "" + resources: + - "pods/log" + verbs: + - "get" + - "list" diff --git a/resources/secret_backend/kubernetes/au/syd1/roles/agent-dns.yaml b/resources/secret_backend/kubernetes/au/syd1/roles/agent-dns.yaml new file mode 100644 index 0000000..ba92724 --- /dev/null +++ b/resources/secret_backend/kubernetes/au/syd1/roles/agent-dns.yaml @@ -0,0 +1,26 @@ +--- +rules: + - apiGroups: + - "bind.unkin.net" + resources: + - "*" + verbs: + - "*" + - apiGroups: + - "" + resources: + - "pods" + - "services" + - "configmaps" + - "events" + verbs: + - "get" + - "list" + - "watch" + - apiGroups: + - "" + resources: + - "pods/log" + verbs: + - "get" + - "list" diff --git a/resources/secret_backend/kubernetes/au/syd1/roles/agent-storage.yaml b/resources/secret_backend/kubernetes/au/syd1/roles/agent-storage.yaml new file mode 100644 index 0000000..6c5b6d3 --- /dev/null +++ b/resources/secret_backend/kubernetes/au/syd1/roles/agent-storage.yaml @@ -0,0 +1,23 @@ +--- +rules: + - apiGroups: + - "ceph.unkin.net" + resources: + - "*" + verbs: + - "*" + - apiGroups: + - "" + resources: + - "pods" + verbs: + - "get" + - "list" + - "watch" + - apiGroups: + - "" + resources: + - "pods/log" + verbs: + - "get" + - "list" -- 2.47.3 From 680a0455e55c5cdfaae8f3fb4be0d3e81d7aab36 Mon Sep 17 00:00:00 2001 From: Ben Vincent Date: Sun, 2 Aug 2026 21:45:26 +1000 Subject: [PATCH 2/2] Rework agent-dns to service_account_name mode against a static SA Instead of generating cluster-wide RBAC, the agent-dns role now mints tokens for a static GitOps-managed service account (argocd-apps#332) whose per-namespace RoleBindings confine access to exactly the four bind namespaces. Ordering: the argocd-apps RBAC must sync before these creds are usable, since Vault mints tokens for an SA that must already exist. - extend the kubernetes_secret_backend_role module with an optional service_account_name; when set, generated_role_rules and kubernetes_role_type are omitted (the SA's own bindings supply RBAC). - switch the agent-dns role to service_account_name agent-dns with allowed_kubernetes_namespaces bind-system; drop its generated rules. Claude-Session: https://claude.ai/code/session_01JUoARVdmhxKQHyyyp1pxeT --- .../kubernetes/au/syd1/agent-dns.yaml | 4 +-- modules/vault_cluster/main.tf | 1 + .../kubernetes_secret_backend_role/main.tf | 9 +++++-- .../variables.tf | 6 +++++ modules/vault_cluster/variables.tf | 1 + .../kubernetes/au/syd1/roles/agent-dns.yaml | 26 ------------------- 6 files changed, 17 insertions(+), 30 deletions(-) delete mode 100644 resources/secret_backend/kubernetes/au/syd1/roles/agent-dns.yaml diff --git a/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-dns.yaml b/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-dns.yaml index b758647..634dd96 100644 --- a/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-dns.yaml +++ b/config/kubernetes_secret_backend_role/kubernetes/au/syd1/agent-dns.yaml @@ -1,4 +1,4 @@ allowed_kubernetes_namespaces: - - "*" -kubernetes_role_type: "ClusterRole" + - "bind-system" +service_account_name: "agent-dns" extra_labels: {} diff --git a/modules/vault_cluster/main.tf b/modules/vault_cluster/main.tf index 3940844..e7851bb 100644 --- a/modules/vault_cluster/main.tf +++ b/modules/vault_cluster/main.tf @@ -299,6 +299,7 @@ module "kubernetes_secret_backend_role" { allowed_kubernetes_namespaces = each.value.allowed_kubernetes_namespaces kubernetes_role_type = each.value.kubernetes_role_type extra_labels = each.value.extra_labels + service_account_name = each.value.service_account_name depends_on = [module.kubernetes_secret_backend] } diff --git a/modules/vault_cluster/modules/kubernetes_secret_backend_role/main.tf b/modules/vault_cluster/modules/kubernetes_secret_backend_role/main.tf index 6833a9a..8e56de5 100644 --- a/modules/vault_cluster/modules/kubernetes_secret_backend_role/main.tf +++ b/modules/vault_cluster/modules/kubernetes_secret_backend_role/main.tf @@ -2,6 +2,10 @@ locals { # Auto-generate role rules path: resources/secret_backend/{backend_path}/roles/{role_name}.yaml role_rules_file = "resources/secret_backend/${var.backend}/roles/${var.name}.yaml" + # service_account_name mode mints tokens for a pre-existing SA, so the + # generated_role_rules / kubernetes_role_type binding fields must be unset. + use_service_account = var.service_account_name != null + # Auto-generate extra labels based on country/region and role name auto_labels = merge(var.extra_labels, { vault-region = "${var.country}-${var.region}" @@ -13,7 +17,8 @@ resource "vault_kubernetes_secret_backend_role" "role" { backend = var.backend name = var.name allowed_kubernetes_namespaces = var.allowed_kubernetes_namespaces - kubernetes_role_type = var.kubernetes_role_type - generated_role_rules = file("${path.module}/../../../../../../../../${local.role_rules_file}") + kubernetes_role_type = local.use_service_account ? null : var.kubernetes_role_type + generated_role_rules = local.use_service_account ? null : file("${path.module}/../../../../../../../../${local.role_rules_file}") + service_account_name = var.service_account_name extra_labels = local.auto_labels } diff --git a/modules/vault_cluster/modules/kubernetes_secret_backend_role/variables.tf b/modules/vault_cluster/modules/kubernetes_secret_backend_role/variables.tf index 43d1fbf..af2a6a3 100644 --- a/modules/vault_cluster/modules/kubernetes_secret_backend_role/variables.tf +++ b/modules/vault_cluster/modules/kubernetes_secret_backend_role/variables.tf @@ -34,4 +34,10 @@ variable "extra_labels" { description = "Additional labels to apply to generated Kubernetes objects" type = map(string) default = {} +} + +variable "service_account_name" { + description = "Pre-existing service account to mint tokens for. When set, RBAC comes from that SA's own bindings instead of generated_role_rules." + type = string + default = null } \ No newline at end of file diff --git a/modules/vault_cluster/variables.tf b/modules/vault_cluster/variables.tf index 2c59ddc..87787f5 100644 --- a/modules/vault_cluster/variables.tf +++ b/modules/vault_cluster/variables.tf @@ -285,6 +285,7 @@ variable "kubernetes_secret_backend_role" { allowed_kubernetes_namespaces = optional(list(string), ["*"]) kubernetes_role_type = optional(string, "Role") extra_labels = optional(map(string), {}) + service_account_name = optional(string) })) default = {} } diff --git a/resources/secret_backend/kubernetes/au/syd1/roles/agent-dns.yaml b/resources/secret_backend/kubernetes/au/syd1/roles/agent-dns.yaml deleted file mode 100644 index ba92724..0000000 --- a/resources/secret_backend/kubernetes/au/syd1/roles/agent-dns.yaml +++ /dev/null @@ -1,26 +0,0 @@ ---- -rules: - - apiGroups: - - "bind.unkin.net" - resources: - - "*" - verbs: - - "*" - - apiGroups: - - "" - resources: - - "pods" - - "services" - - "configmaps" - - "events" - verbs: - - "get" - - "list" - - "watch" - - apiGroups: - - "" - resources: - - "pods/log" - verbs: - - "get" - - "list" -- 2.47.3