Add formatting filter for BESU_ENV_OPTS

It allows for the `besu_env_opts` variable to be either a whitespace
separated string or a list

Signed-off-by: Edward Evans <edward.evans@consensys.net>

README.md

@@ -82,7 +82,7 @@ All variables which can be overridden are stored in [defaults/main.yml](defaults
 | `besu_permissions_accounts_contract_address` | ___unset___ | The contract address for onchain accounts permissioning |
 | `besu_permissions_nodes_contract_address` | ___unset___ | The contract address for onchain nodes permissioning |
 | `besu_cmdline_args` | "" | Command line args that are passed in as overrides |
-| `besu_env_opts` | "" | Environmental variable BESU_OPTS that gets passed to the JVM. eg: -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005 |
+| `besu_env_opts` | [] | Settings passed to the JVM through `BESU_OPTS` environment variable. eg: `-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005` |
 | `orion_version` | ___unset___ | Version of Orion installed. When supplied, adds required privacy config items and requires `orion_config_dir` and `orion_key_name` to be set |
 | `orion_config_dir` | ___unset___ | Path to Orion configuration directory |
 | `orion_key_name` | ___unset___ | Name of the Node Key |

filter_plugins/besu_filters.py

@@ -0,0 +1,18 @@
+#! /usr/bin/env python
+
+from typing import Union, List
+
+
+class FilterModule(object):
+    def filters(self):
+        return {
+            'besu_opts_format': self.besuOptsFormat,
+        }
+
+    def besuOptsFormat(self, besu_env_opts: Union[str, List[str]]):
+        if isinstance(besu_env_opts, str):
+            besu_env_opts = besu_env_opts.split()
+
+        escaped_besu_env_opts = [item.replace('"', '\\"') for item in besu_env_opts]
+
+        return f'''"{'" "'.join(escaped_besu_env_opts)}"'''

templates/besu.service.j2

@@ -9,7 +9,7 @@ Environment=HOME=/home/{{ besu_user }}
 {% if besu_log4j_config_file %}
 Environment=LOG4J_CONFIGURATION_FILE={{ besu_log4j_config_file }}
 {% endif %}
-Environment=BESU_OPTS={{ besu_env_opts }}
+Environment='BESU_OPTS={{ besu_env_opts|besu_opts_format }}'
 Type=simple
 {% if besu_cmdline_args %}
 ExecStart=/bin/sh -c "{{ besu_current_dir }}/bin/besu --config-file={{ besu_config_dir }}/config.toml {{ besu_cmdline_args|quote }} >> {{besu_log_dir}}/besu.log 2>&1"