Use str_replace for known_hosts

There is a limit to how long input data can be for the heat script hook.
It turns out that data longer than 131072, will return an Argument list
to long error. To get around this, we need to pass this data in a
different way so that the heat script hook will work.

Change-Id: Ie3bd17ca9863e7687721e8c2628e485ea1849321
Closes-Bug: #1772071

extraconfig/tasks/ssh/known_hosts_config.yaml

@@ -11,26 +11,32 @@ resources:
     type: OS::Heat::SoftwareConfig
     properties:
       group: script
-      inputs:
-        - name: known_hosts
-          default: {get_param: known_hosts}
       config: |
-        #!/bin/bash
-        set -eux
-        set -o pipefail
+        str_replace:
+          params:
+            KNOWN_HOSTS: {get_param: known_hosts}
+          template: |
+            #!/bin/bash
+            set -eux
+            set -o pipefail
 
-        echo "Creating ssh known hosts file"
+            echo "Creating ssh known hosts file"
 
-        if [ ! -z "${known_hosts}" ]; then
-          echo "${known_hosts}"
-          echo -ne "${known_hosts}" > /etc/ssh/ssh_known_hosts
-          chmod 0644 /etc/ssh/ssh_known_hosts
-        else
-          rm -f /etc/ssh/ssh_known_hosts
-          echo "No ssh known hosts"
-        fi
+            if [ -d /etc/ssh/ssh_known_hosts ]; then
+                rm -rf /etc/ssh/ssh_known_hosts
+            fi
+            cat <<EOF | grep -v '^$' >/etc/ssh/ssh_known_hosts
+            KNOWN_HOSTS
+            EOF
+            if [ ! -s /etc/ssh/ssh_known_hosts ]; then
+              echo "No known hosts"
+              rm -f /etc/ssh/ssh_known_hosts
+            else
+              echo "$(cat /etc/ssh/ssh_known_hosts | wc -l) known hosts"
+              chmod 0644 /etc/ssh/ssh_known_hosts
+            fi
 
 outputs:
   OS::stack_id:
     description: The SSHKnownHostsConfig resource.
-    value: {get_resource: SSHKnownHostsConfig}
+    value: {get_resource: SSHKnownHostsConfig}

overcloud.j2.yaml

@@ -488,6 +488,7 @@ resources:
     depends_on:
 {% for role_inner in roles %}
       - {{role_inner.name}}HostsDeployment
+      - {{role_inner.name}}SshKnownHostsDeployment
 {% endfor %}
     properties:
       name: {{role.name}}AllNodesDeployment