Generate individual certificates for k8s hosts

roles/kubernetes/master/templates/manifests/kube-apiserver.manifest.j2

@@ -35,10 +35,10 @@ spec:
     - --service-node-port-range={{ kube_apiserver_node_port_range }}
     - --client-ca-file={{ kube_cert_dir }}/ca.pem
     - --basic-auth-file={{ kube_users_dir }}/known_users.csv
-    - --tls-cert-file={{ kube_cert_dir }}/apiserver.pem
-    - --tls-private-key-file={{ kube_cert_dir }}/apiserver-key.pem
+    - --tls-cert-file={{ kube_cert_dir }}/apiserver-{{ inventory_hostname }}.pem
+    - --tls-private-key-file={{ kube_cert_dir }}/apiserver-{{ inventory_hostname }}-key.pem
     - --token-auth-file={{ kube_token_dir }}/known_tokens.csv
-    - --service-account-key-file={{ kube_cert_dir }}/apiserver-key.pem
+    - --service-account-key-file={{ kube_cert_dir }}/apiserver-{{ inventory_hostname }}-key.pem
     - --secure-port={{ kube_apiserver_port }}
     - --insecure-port={{ kube_apiserver_insecure_port }}
 {% if kube_api_runtime_config is defined %}

roles/kubernetes/master/templates/manifests/kube-controller-manager.manifest.j2

@@ -23,7 +23,7 @@ spec:
     - controller-manager
     - --master={{ kube_apiserver_endpoint }}
     - --leader-elect=true
-    - --service-account-private-key-file={{ kube_cert_dir }}/apiserver-key.pem
+    - --service-account-private-key-file={{ kube_cert_dir }}/apiserver-{{ inventory_hostname }}-key.pem
     - --root-ca-file={{ kube_cert_dir }}/ca.pem
     - --cluster-signing-cert-file={{ kube_cert_dir }}/ca.pem
     - --cluster-signing-key-file={{ kube_cert_dir }}/ca-key.pem

roles/kubernetes/node/templates/node-kubeconfig.yaml.j2

@@ -8,8 +8,8 @@ clusters:
 users:
 - name: kubelet
   user:
-    client-certificate: {{ kube_cert_dir }}/node.pem
-    client-key: {{ kube_cert_dir }}/node-key.pem
+    client-certificate: {{ kube_cert_dir }}/node-{{ inventory_hostname }}.pem
+    client-key: {{ kube_cert_dir }}/node-{{ inventory_hostname }}-key.pem
 contexts:
 - context:
     cluster: local

roles/kubernetes/secrets/files/make-ssl.sh

@@ -27,8 +27,11 @@ Usage : $(basename $0) -f <config> [-d <ssldir>]
       -f | --config       : Openssl configuration file
       -d | --ssldir       : Directory where the certificates will be installed
 
-               ex :
-               $(basename $0) -f openssl.conf -d /srv/ssl
+      Environmental variables MASTERS and HOSTS should be set to generate keys
+      for each host.
+
+           ex :
+           MASTERS=node1 HOSTS="node1 node2" $(basename $0) -f openssl.conf -d /srv/ssl
 EOF
 }
 
@@ -61,21 +64,37 @@ cd "${tmpdir}"
 mkdir -p "${SSLDIR}"
 
 # Root CA
-openssl genrsa -out ca-key.pem 2048 > /dev/null 2>&1
-openssl req -x509 -new -nodes -key ca-key.pem -days 10000 -out ca.pem -subj "/CN=kube-ca" > /dev/null 2>&1
+if [ -e "$SSLDIR/ca-key.pem" ]; then
+    # Reuse existing CA
+    cp $SSLDIR/{ca.pem,ca-key.pem} .
+else
+    openssl genrsa -out ca-key.pem 2048 > /dev/null 2>&1
+    openssl req -x509 -new -nodes -key ca-key.pem -days 10000 -out ca.pem -subj "/CN=kube-ca" > /dev/null 2>&1
+fi
 
-# Apiserver
-openssl genrsa -out apiserver-key.pem 2048 > /dev/null 2>&1
-openssl req -new -key apiserver-key.pem -out apiserver.csr -subj "/CN=kube-apiserver" -config ${CONFIG} > /dev/null 2>&1
-openssl x509 -req -in apiserver.csr -CA ca.pem -CAkey ca-key.pem -CAcreateserial -out apiserver.pem -days 365 -extensions v3_req -extfile ${CONFIG} > /dev/null 2>&1
-cat ca.pem >> apiserver.pem
+if [ -n "$MASTERS" ]; then
+    for host in $MASTERS; do
+        # kube-apiserver key
+        openssl genrsa -out apiserver-${host}-key.pem 2048 > /dev/null 2>&1
+        openssl req -new -key apiserver-${host}-key.pem -out apiserver-${host}.csr -subj "/CN=kube-apiserver-${host}" -config ${CONFIG} > /dev/null 2>&1
+        openssl x509 -req -in apiserver-${host}.csr -CA ca.pem -CAkey ca-key.pem -CAcreateserial -out apiserver-${host}.pem -days 365 -extensions v3_req -extfile ${CONFIG} > /dev/null 2>&1
+        cat ca.pem >> apiserver-${host}.pem
+
+        # admin key
+        openssl genrsa -out admin-${host}-key.pem 2048 > /dev/null 2>&1
+        openssl req -new -key admin-${host}-key.pem -out admin-${host}.csr -subj "/CN=kube-admin-${host}" > /dev/null 2>&1
+        openssl x509 -req -in admin-${host}.csr -CA ca.pem -CAkey ca-key.pem -CAcreateserial -out admin-${host}.pem -days 365 > /dev/null 2>&1
+    done
+fi
 
 # Nodes and Admin
-for i in node admin; do
-    openssl genrsa -out ${i}-key.pem 2048 > /dev/null 2>&1
-    openssl req -new -key ${i}-key.pem -out ${i}.csr -subj "/CN=kube-${i}" > /dev/null 2>&1
-    openssl x509 -req -in ${i}.csr -CA ca.pem -CAkey ca-key.pem -CAcreateserial -out ${i}.pem -days 365 > /dev/null 2>&1
-done
+if [ -n "$HOSTS" ]; then
+    for host in $HOSTS; do
+        openssl genrsa -out node-${host}-key.pem 2048 > /dev/null 2>&1
+        openssl req -new -key node-${host}-key.pem -out node-${host}.csr -subj "/CN=kube-node-${host}" > /dev/null 2>&1
+        openssl x509 -req -in node-${host}.csr -CA ca.pem -CAkey ca-key.pem -CAcreateserial -out node-${host}.pem -days 365 > /dev/null 2>&1
+    done
+fi
 
 # Install certs
 mv *.pem ${SSLDIR}/

roles/kubernetes/secrets/tasks/check-certs.yml

@@ -1,36 +1,49 @@
 ---
 - name: "Check_certs | check if the certs have already been generated on first master"
   stat:
-    path: "{{ kube_cert_dir }}/ca.pem"
+    path: "{{ kube_cert_dir }}/{{ item }}"
   delegate_to: "{{groups['kube-master'][0]}}"
   register: kubecert_master
   run_once: true
+  with_items: >-
+       ['ca.pem',
+       {% for host in groups['k8s-cluster'] %}
+       'node-{{ host }}-key.pem'
+       {% if not loop.last %}{{','}}{% endif %}
+       {% endfor %}]
 
-- name: "Check_certs | Set default value for 'sync_certs' and 'gen_certs' to false"
+- name: "Check_certs | Set default value for 'sync_certs', 'gen_certs', and 'secret_changed'  to false"
   set_fact:
     sync_certs: false
     gen_certs: false
+    secret_changed: false
 
-- name: "Check_certs | Set 'sync_certs' and 'gen_certs' to true"
+- name: "Check_certs | Set 'gen_certs' to true"
   set_fact:
     gen_certs: true
-  when: not kubecert_master.stat.exists
+  when: "not {{ item.stat.exists }}"
   run_once: true
+  with_items: "{{ kubecert_master.results }}"
 
 - name: "Check certs | check if a cert already exists"
   stat:
-    path: "{{ kube_cert_dir }}/ca.pem"
+    path: "{{ kube_cert_dir }}/{{ item }}"
   register: kubecert
+  with_items:
+    - ca.pem
+    - node-{{ inventory_hostname }}-key.pem
 
 - name: "Check_certs | Set 'sync_certs' to true"
   set_fact:
     sync_certs: true
   when: >-
       {%- set certs = {'sync': False} -%}
-      {%- for server in play_hosts
-         if (not hostvars[server].kubecert.stat.exists|default(False)) or
-         (hostvars[server].kubecert.stat.checksum|default('') != kubecert_master.stat.checksum|default('')) -%}
-         {%- set _ = certs.update({'sync': True}) -%}
+      {%- for host in groups['k8s-cluster'] %}
+        {% if host == inventory_hostname %}
+          {% if (not kubecert.results[0].stat.exists|default(False)) or
+              (kubecert.results[1].stat.checksum|default('') != kubecert_master.results[loop.index].stat.checksum|default('')) -%}
+            {%- set _ = certs.update({'sync': True}) -%}
+          {% endif %}
+        {% endif %}
       {%- endfor -%}
       {{ certs.sync }}
-  run_once: true

roles/kubernetes/secrets/tasks/gen_certs.yml

@@ -18,35 +18,65 @@
 
 - name: Gen_certs | run cert generation script
   command: "{{ kube_script_dir }}/make-ssl.sh -f {{ kube_config_dir }}/openssl.conf -d {{ kube_cert_dir }}"
+  environment:
+    - MASTERS: "{% for m in groups['kube-master'] %}
+                  {% if hostvars[m].sync_certs|default(true) %}
+                    {{ m }}
+                  {% endif %}
+                {% endfor %}"
+    - HOSTS: "{% for h in groups['k8s-cluster'] %}
+                {% if hostvars[h].sync_certs|default(true) %}
+                    {{ h }}
+                {% endif %}
+              {% endfor %}"
   run_once: yes
   delegate_to: "{{groups['kube-master'][0]}}"
   when: gen_certs|default(false)
   notify: set secret_changed
 
 - set_fact:
-    master_certs: ['ca-key.pem', 'admin.pem', 'admin-key.pem', 'apiserver-key.pem', 'apiserver.pem']
-    node_certs: ['ca.pem', 'node.pem', 'node-key.pem']
+    all_master_certs: "['ca-key.pem',
+                      {% for node in groups['kube-master'] %}
+                      'admin-{{ node }}.pem',
+                      'admin-{{ node }}-key.pem',
+                      'apiserver-{{ node }}.pem',
+                      'apiserver-{{ node }}-key.pem',
+                      {% endfor %}]"
+    my_master_certs: ['ca-key.pem',
+                     'admin-{{ inventory_hostname }}.pem',
+                     'admin-{{ inventory_hostname }}-key.pem',
+                     'apiserver-{{ inventory_hostname }}.pem',
+                     'apiserver-{{ inventory_hostname }}-key.pem'
+                     ]
+    all_node_certs: "['ca.pem',
+                    {% for node in groups['k8s-cluster'] %}
+                    'node-{{ node }}.pem',
+                    'node-{{ node }}-key.pem',
+                    {% endfor %}]"
+    my_node_certs: ['ca.pem', 'node-{{ inventory_hostname }}.pem', 'node-{{ inventory_hostname }}-key.pem']
   tags: facts
 
 - name: Gen_certs | Gather master certs
-  shell: "tar cfz - -C {{ kube_cert_dir }} {{ master_certs|join(' ') }} {{ node_certs|join(' ') }} | base64 --wrap=0"
+  shell: "tar cfz - -C {{ kube_cert_dir }} {{ my_master_certs|join(' ') }} {{ all_node_certs|join(' ') }} | base64 --wrap=0"
   register: master_cert_data
   delegate_to: "{{groups['kube-master'][0]}}"
-  run_once: true
-  when: sync_certs|default(false)
+  when: inventory_hostname in groups['kube-master'] and sync_certs|default(false) and
+        inventory_hostname != groups['kube-master'][0]
 
 - name: Gen_certs | Gather node certs
-  shell: "tar cfz - -C {{ kube_cert_dir }} {{ node_certs|join(' ') }} | base64 --wrap=0"
+  shell: "tar cfz - -C {{ kube_cert_dir }} {{ my_node_certs|join(' ') }} | base64 --wrap=0"
   register: node_cert_data
   delegate_to: "{{groups['kube-master'][0]}}"
-  run_once: true
-  when: sync_certs|default(false)
+  when: inventory_hostname in groups['kube-node'] and
+        sync_certs|default(false) and
+        inventory_hostname != groups['kube-master'][0]
 
 - name: Gen_certs | Copy certs on masters
   shell: "echo '{{master_cert_data.stdout|quote}}' | base64 -d | tar xz -C {{ kube_cert_dir }}"
   changed_when: false
   when: inventory_hostname in groups['kube-master'] and sync_certs|default(false) and
         inventory_hostname != groups['kube-master'][0]
+  notify: set secret_changed
 
 - name: Gen_certs | Copy certs on nodes
   shell: "echo '{{node_cert_data.stdout|quote}}' | base64 -d | tar xz -C {{ kube_cert_dir }}"
@@ -54,6 +84,7 @@
   when: inventory_hostname in groups['kube-node'] and
         sync_certs|default(false) and
         inventory_hostname != groups['kube-master'][0]
+  notify: set secret_changed
 
 - name: Gen_certs | check certificate permissions
   file:
@@ -93,4 +124,3 @@
 - name: Gen_certs | update ca-certificates (RedHat)
   command: update-ca-trust extract
   when: kube_ca_cert.changed and ansible_os_family == "RedHat"
-