Fixed overwriting of certs when re-running playbook

Author: Aman

README.md

@@ -1,8 +1,10 @@
 Generate TLS certificates
 =========================
-Generates self-signed CA, client and server certificates. Runs locally on control machine. **Note:** Ansible crypto modules do not support self-signed certs, using `shell` command instead as required.
+Generates self-signed CA, client and server certificates. Runs locally on control machine.
 
-**WARNING: re-running this role in the same output folder will overwrite any existing certs and keys!**
+Notes:
+- Will not overwrite any files in output cert dir
+- Ansible crypto modules do not support signing certs with own CA yet, using `shell` command instead. Should be resolved in Ansible 2.7 using the [ownca provider](https://github.com/ansible/ansible/commit/b61b113fb9e3fcfcb25f4a8aaabad618e3209ce1).
 
 
 Requirements
@@ -37,7 +39,7 @@ Example Playbook
     - include_vars: vars.yaml
 
     - name: Generate certs
-      import_role: 
+      import_role:
         name: generate-tls-certs
 
 ```

tasks/generate-ca-cert.yaml

@@ -8,8 +8,13 @@
 
   - name: Generate self-signed cert for CA
     local_action:
-      module: >
-        shell openssl req -x509 -new -days {{tls_ca_valid_days}} -sha256 -nodes -key {{cert_dir}}/{{tls_ca_key}} -out {{cert_dir}}/{{tls_ca_cert}}
+      module: |
+        shell if [ ! -e {{cert_dir}}/{{tls_ca_cert}} ]
+        then
+        openssl req -x509 -new -days {{tls_ca_valid_days}} -sha256 -nodes -key {{cert_dir}}/{{tls_ca_key}} -out {{cert_dir}}/{{tls_ca_cert}} \
         -subj "{% if tls_ca_country is defined%}/C={{tls_ca_country}}{% endif %}{% if tls_ca_state is defined%}/ST={{tls_ca_state}}{% endif %}{% if tls_ca_locality is defined %}/L={{tls_ca_locality}}{% endif %}{% if tls_ca_organization is defined %}/O={{tls_ca_organization}}{% endif %}{% if tls_ca_organizationalunit is defined %}/OU={{tls_ca_organizationalunit}}{% endif %}/CN={{tls_ca_commonname}}{% if tls_ca_email is defined %}/emailAddress={{tls_ca_email}}{% endif %}"
+        fi
+    args:
+      executable: /bin/bash
     ignore_errors: true
     run_once: true

tasks/generate-client-cert.yaml

@@ -10,9 +10,14 @@
 
   - name: Generate CSR and key for client cert
     local_action:
-      module: >
-        shell openssl req -newkey rsa:{{tls_client_key_size}} -nodes -subj "/CN={{tls_client_commonname}}"
+      module: |
+        shell if [ ! -e {{cert_dir}}/{{tls_client_csr}} ]
+        then
+        openssl req -newkey rsa:{{tls_client_key_size}} -nodes -subj "/CN={{tls_client_commonname}}" \
         -keyout "{{cert_dir}}/{{tls_client_key}}" -out "{{cert_dir}}/{{tls_client_csr}}"
+        fi
+    args:
+      executable: /bin/bash
     ignore_errors: true
     run_once: true
     when: generate_client_cert
@@ -28,9 +33,14 @@
   # @AB TODO: using OpenSSL CA serial file does not always generate unique serial when running playbook against multiple hosts
   - name: Sign client cert request with CA
     local_action:
-      module: >
-        shell openssl x509 -req -sha256 -days {{tls_client_valid_days}} -CA {{cert_dir}}/{{tls_ca_cert}} -CAkey {{cert_dir}}/{{tls_ca_key}}
+      module: |
+        shell if [ ! -e {{cert_dir}}/{{tls_client_cert}} ]
+        then
+        openssl x509 -req -sha256 -days {{tls_client_valid_days}} -CA {{cert_dir}}/{{tls_ca_cert}} -CAkey {{cert_dir}}/{{tls_ca_key}} \
         -set_serial {{ 999999999 | random }} -in {{cert_dir}}/{{tls_client_csr}} -out {{cert_dir}}/{{tls_client_cert}} -extfile {{cert_dir}}/{{tls_client_extfile}}
+        fi
+    args:
+      executable: /bin/bash
     ignore_errors: true
     run_once: true
     when: generate_client_cert

tasks/generate-server-cert.yaml

@@ -2,9 +2,14 @@
   # Generate server cert
   - name: Create CSR for server cert
     local_action:
-      module: >
-        shell openssl req -newkey rsa:{{tls_server_key_size}} -nodes -subj "/CN={{inventory_hostname}}"
+      module: |
+        shell if [ ! -e {{cert_dir}}/{{inventory_hostname_short}}.csr ]
+        then
+        openssl req -newkey rsa:{{tls_server_key_size}} -nodes -subj "/CN={{inventory_hostname}}" \
         -keyout "{{cert_dir}}/{{inventory_hostname_short}}.key" -out "{{cert_dir}}/{{inventory_hostname_short}}.csr"
+        fi
+    args:
+      executable: /bin/bash
     ignore_errors: true
     when: generate_server_cert
 
@@ -19,10 +24,15 @@
 
   - name: Sign server cert request by CA
     local_action:
-      module: >
-        shell openssl x509 -req -sha256 -days {{tls_server_valid_days}}
-        -CA "{{cert_dir}}/{{tls_ca_cert}}" -CAkey "{{cert_dir}}/{{tls_ca_key}}" -set_serial {{ 999999999 | random }}
-        -in "{{cert_dir}}/{{inventory_hostname_short}}.csr" -out "{{cert_dir}}/{{inventory_hostname_short}}.pem"
-        {% if tls_server_enable_san %}-extfile "{{cert_dir}}/{{inventory_hostname_short}}-extfile.cnf"{% endif %}
+      module: |
+        shell if [ ! -e {{cert_dir}}/{{inventory_hostname_short}}.pem ]
+        then
+        openssl x509 -req -sha256 -days {{tls_server_valid_days}} \
+        -CA "{{cert_dir}}/{{tls_ca_cert}}" -CAkey "{{cert_dir}}/{{tls_ca_key}}" -set_serial {{ 999999999 | random }} \
+        -in "{{cert_dir}}/{{inventory_hostname_short}}.csr" -out "{{cert_dir}}/{{inventory_hostname_short}}.pem" {% if tls_server_enable_san %}-extfile "{{cert_dir}}/{{inventory_hostname_short}}-extfile.cnf"{% endif %}
+        
+        fi
+    args:
+      executable: /bin/bash
     ignore_errors: true
     when: generate_server_cert

templates/server-cert-extfile.cnf.j2

@@ -1,3 +1,3 @@
-subjectAltName = DNS:{{inventory_hostname}},DNS:{{inventory_hostname_short}},IP:{{(alt_interface_ip is defined) | ternary(alt_interface_ip, ansible_host)}},IP:0.0.0.0,IP:127.0.0.1
+subjectAltName = DNS:{{inventory_hostname}},DNS:{{inventory_hostname_short}},IP:{{(alt_interface_ip is defined) | ternary(alt_interface_ip, ansible_default_ipv4.address)}},IP:0.0.0.0,IP:127.0.0.1
 
 extendedKeyUsage = serverAuth