Split the jinja rendering and json reading into two different functions

cookbooks/aws-parallelcluster-environment/files/cloudwatch/cloudwatch_agent_common_utils.py

@@ -18,19 +18,3 @@ def render_jinja_template(template_file_path):
         f.write(rendered_template)
     return template_file_path
 
-
-def read_jinja_template_at(path):
-    """Read the JSON file at path as a Jinja template."""
-    try:
-        with open(render_jinja_template(path), encoding="utf-8") as input_file:
-            return json.load(input_file)
-    except FileNotFoundError:
-        fail(f"No file exists at {path}")
-    except ValueError:
-        fail(f"File at {path} contains invalid JSON")
-    return None
-
-
-def fail(message):
-    """Exit nonzero with the given error message."""
-    sys.exit(message)

cookbooks/aws-parallelcluster-environment/files/cloudwatch/cloudwatch_agent_config_util.py

@@ -17,9 +17,10 @@
 import json
 import os
 import shutil
+import sys
 
 import jsonschema
-from cloudwatch_agent_common_utils import fail, read_jinja_template_at
+from cloudwatch_agent_common_utils import render_jinja_template
 
 DEFAULT_SCHEMA_PATH = os.path.realpath(os.path.join(os.path.curdir, "cloudwatch_agent_config_schema.json"))
 SCHEMA_PATH = os.environ.get("CW_LOGS_CONFIGS_SCHEMA_PATH", DEFAULT_SCHEMA_PATH)
@@ -28,6 +29,11 @@
 LOG_CONFIGS_BAK_PATH = f"{LOG_CONFIGS_PATH}.bak"
 
 
+def _fail(message):
+    """Exit nonzero with the given error message."""
+    sys.exit(message)
+
+
 def parse_args():
     """Parse command line args."""
     parser = argparse.ArgumentParser(
@@ -57,9 +63,9 @@ def _read_json_at(path):
         with open(path, encoding="utf-8") as input_file:
             return json.load(input_file)
     except FileNotFoundError:
-        fail(f"No file exists at {path}")
+        _fail(f"No file exists at {path}")
     except ValueError:
-        fail(f"File at {path} contains invalid JSON")
+        _fail(f"File at {path} contains invalid JSON")
     return None
 
 
@@ -70,7 +76,7 @@ def _read_schema():
 
 def _read_log_configs():
     """Read the current version of the CloudWatch log configs file, cloudwatch_agent_config.json."""
-    return read_jinja_template_at(LOG_CONFIGS_PATH)
+    return _read_json_at(LOG_CONFIGS_PATH)
 
 
 def _validate_json_schema(input_json):
@@ -79,7 +85,7 @@ def _validate_json_schema(input_json):
     try:
         jsonschema.validate(input_json, schema)
     except jsonschema.exceptions.ValidationError as validation_err:
-        fail(str(validation_err))
+        _fail(str(validation_err))
 
 
 def _validate_timestamp_keys(input_json):
@@ -89,7 +95,7 @@ def _validate_timestamp_keys(input_json):
         valid_keys |= set(config.get("timestamp_formats").keys())
     for log_config in input_json.get("log_configs"):
         if log_config.get("timestamp_format_key") not in valid_keys:
-            fail(
+            _fail(
                 f"Log config with log_stream_name {log_config.get('log_stream_name')} and "
                 f"file_path {log_config.get('file_path'),} contains an invalid timestamp_format_key: "
                 f"{log_config.get('timestamp_format_key')}. Valid values are {', '.join(valid_keys),}"
@@ -108,12 +114,13 @@ def _validate_log_config_fields_uniqueness(input_json):
     for field in unique_fields:
         duplicates = _get_duplicate_values([config.get(field) for config in input_json.get("log_configs")])
         if duplicates:
-            fail(f"The following {field} values are used multiple times: {', '.join(duplicates)}")
+            _fail(f"The following {field} values are used multiple times: {', '.join(duplicates)}")
 
 
 def validate_json(input_json=None):
     """Ensure the structure of input_json matches that of the file it will be added to."""
     if input_json is None:
+        render_jinja_template(LOG_CONFIGS_PATH)
         input_json = _read_log_configs()
     _validate_json_schema(input_json)
     _validate_timestamp_keys(input_json)

cookbooks/aws-parallelcluster-environment/files/cloudwatch/write_cloudwatch_agent_json.py

@@ -11,7 +11,7 @@
 import os
 import socket
 
-from cloudwatch_agent_common_utils import read_jinja_template_at
+from cloudwatch_agent_common_utils import render_jinja_template
 
 AWS_CLOUDWATCH_CFG_PATH = "/opt/aws/amazon-cloudwatch-agent/etc/amazon-cloudwatch-agent.json"
 DEFAULT_METRICS_COLLECTION_INTERVAL = 60
@@ -63,6 +63,12 @@ def add_instance_log_stream_prefixes(configs):
     return configs
 
 
+def read_data(config_path):
+    """Read in log configuration data from config_path."""
+    with open(config_path, encoding="utf-8") as infile:
+        return json.load(infile)
+
+
 def select_configs_for_scheduler(configs, scheduler):
     """Filter out from configs those entries whose 'schedulers' list does not contain scheduler."""
     return [config for config in configs if scheduler in config["schedulers"]]
@@ -217,7 +223,7 @@ def get_dict_value(value, attributes, default=None):
 def main():
     """Create cloudwatch agent config file."""
     args = parse_args()
-    config_data = read_jinja_template_at(args.config)
+    config_data = read_data(render_jinja_template(args.config))
     log_configs = select_logs(config_data["log_configs"], args)
     log_configs = add_timestamps(log_configs, config_data["timestamp_formats"])
     log_configs = add_log_group_name_params(args.log_group, log_configs)

cookbooks/aws-parallelcluster-environment/test/controls/cloudwatch_spec.rb

@@ -40,7 +40,7 @@
 
   describe file('/usr/local/bin/write_cloudwatch_agent_json.py') do
     it { should exist }
-    its('sha256sum') { should eq '5a2ec92e78c49b2064fea88564b0ffe8ccfda92798de1d8bf8a94158e8c1f366' }
+    its('sha256sum') { should eq 'f24283f824072456394ab01cd014d37a977fc63fe951c9dd4a7df982bf6e5a82' }
     its('owner') { should eq 'root' }
     its('group') { should eq 'root' }
     its('mode') { should cmp '0755' }
@@ -64,15 +64,15 @@
 
   describe file('/usr/local/bin/cloudwatch_agent_config_util.py') do
     it { should exist }
-    its('sha256sum') { should eq '68b2a5e96a87eeb4da90cbbb1a4d3796f410b2c2e2c69f084e6515149b6bd29b' }
+    its('sha256sum') { should eq '9062b9bd5066871e5a4ac5b6e7eaf75e3f97221618861002a7a0dd952c5dbc74' }
     its('owner') { should eq 'root' }
     its('group') { should eq 'root' }
     its('mode') { should cmp '0644' }
   end
 
   describe file('/usr/local/bin/cloudwatch_agent_common_utils.py') do
     it { should exist }
-    its('sha256sum') { should eq '2cedb9bf8d430717afe638d989b3f1b97632dfeb89a730c812c4382bc94920ee' }
+    its('sha256sum') { should eq 'bb6287646444e41990097138980efa026eb105b2ba930772ba8b22a00fd19825' }
     its('owner') { should eq 'root' }
     its('group') { should eq 'root' }
     its('mode') { should cmp '0755' }