autogenerate_pipeline: use dictionary instead of self

In the script for autogenerating the rust-vmm-ci tests, we were using
self directly for setting the configuration of the tests, and then
we were returning vars(self). This was a pretty obfuscated way of
returning a JSON, so instead we're now just explicitly declaring
a dictionary as part of self, and returning that instead. This
is needed for future extensions as well as we want to be able to
extend the tool such that it supports any keys from the input
to be passed as they are so that we don't need to keep changing it
whenever we need to add support for another Buildkite configuration
parameter.

Signed-off-by: Andreea Florescu <fandree@amazon.com>

.buildkite/autogenerate_pipeline.py

@@ -85,25 +85,26 @@ class BuildkiteStep:
         """
         Initialize a Buildkite step with default values.
         """
-
         # Default values.
         # The order in which the attributes are initialized is the same as the
         # order in which the keys will appear in the YAML file, because Python
         # dictionaries are ordered. For readability reasons, this order should
         # not be changed.
-        self.label = None
-        self.command = None
-        self.retry = {'automatic': False}
-        self.agents = {'os': 'linux'}
-        self.plugins = [
-            {
-                f"docker#{DOCKER_PLUGIN_VERSION}": {
-                    'image': f"rustvmm/dev:{CONTAINER_VERSION}",
-                    'always-pull': True
+        self.step_config = {
+            'label': None,
+            'command': None,
+            'retry': {'automatic': False},
+            'agents': {'os': 'linux'},
+            'plugins': [
+                {
+                    f"docker#{DOCKER_PLUGIN_VERSION}": {
+                        'image': f"rustvmm/dev:{CONTAINER_VERSION}",
+                        'always-pull': True
+                    }
                 }
-            }
-        ]
-        self.timeout_in_minutes = 5
+            ],
+            'timeout_in_minutes': 5
+        }
 
     def _set_platform(self, platform):
         """ Set platform if given in the json input. """
@@ -113,24 +114,24 @@ class BuildkiteStep:
             # setting the tags on the host.
             if platform == 'aarch64':
                 platform = 'arm'
-            self.agents['platform'] = f"{platform}.metal"
+            self.step_config['agents']['platform'] = f"{platform}.metal"
 
     def _set_conditional(self, conditional):
         """ Set conditional if given in the json input. """
 
         if conditional:
-            setattr(self, 'if', conditional)
+            self.step_config['if'] = conditional
 
     def _set_timeout_in_minutes(self, timeout):
         """ Set the timeout if given in the json input. """
         if timeout:
-            self.timeout_in_minutes = timeout
+            self.step_config['timeout_in_minutes'] = timeout
 
     def _add_docker_config(self, cfg):
         """ Add configuration for docker if given in the json input. """
 
         if cfg:
-            target = self.plugins[0][f"docker#{DOCKER_PLUGIN_VERSION}"]
+            target = self.step_config['plugins'][0][f"docker#{DOCKER_PLUGIN_VERSION}"]
             for key, val in cfg.items():
                 target[key] = val
 
@@ -165,7 +166,7 @@ class BuildkiteStep:
         """
 
         env_var = None
-        platform = self.agents.get('platform')
+        platform = self.step_config['agents'].get('platform')
 
         # Since the platform is optional, only override the config if the
         # platform was provided.
@@ -175,7 +176,7 @@ class BuildkiteStep:
             if platform == 'arm.metal' and AARCH64_AGENT_TAGS:
                 env_var = AARCH64_AGENT_TAGS
 
-        target = self.agents
+        target = self.step_config['agents']
         self._env_change_config(test_name, env_var, target, override=True)
 
     def _env_add_docker_config(self, test_name):
@@ -184,7 +185,7 @@ class BuildkiteStep:
         `DOCKER_PLUGIN_CONFIG` environment variable.
         """
 
-        target = self.plugins[0][f"docker#{DOCKER_PLUGIN_VERSION}"]
+        target = self.step_config['plugins'][0][f"docker#{DOCKER_PLUGIN_VERSION}"]
         self._env_change_config(test_name, DOCKER_PLUGIN_CONFIG, target)
 
     def _env_override_timeout(self, test_name):
@@ -210,7 +211,7 @@ class BuildkiteStep:
         # Mandatory keys.
         assert test_name, "Step is missing test name."
         platform_string = f"-{platform}" if platform else ""
-        self.label = f"{test_name}{platform_string}"
+        self.step_config['label'] = f"{test_name}{platform_string}"
 
         assert command, "Step is missing command."
         if "{target_platform}" in command:
@@ -219,7 +220,7 @@ class BuildkiteStep:
             command = command.replace(
                 "{target_platform}", platform
             )
-        self.command = command
+        self.step_config['command'] = command
 
         # Optional keys.
         self._set_platform(platform)
@@ -233,7 +234,7 @@ class BuildkiteStep:
         self._env_override_timeout(test_name)
 
         # Return the object's attributes and their values as a dictionary.
-        return vars(self)
+        return self.step_config
 
 
 class BuildkiteConfig:
@@ -243,10 +244,13 @@ class BuildkiteConfig:
     be put into yaml format by the pyyaml package.
     """
 
+    def __init__(self):
+        self.bk_config = None
+
     def build(self, input):
         """ Build the final Buildkite configuration fron the json input. """
 
-        self.steps = []
+        self.bk_config = {'steps': []}
         tests = input.get('tests')
         assert tests, "Input is missing list of tests."
 
@@ -270,10 +274,10 @@ class BuildkiteConfig:
 
                 step = BuildkiteStep()
                 step_output = step.build(step_input)
-                self.steps.append(step_output)
+                self.bk_config['steps'].append(step_output)
 
         # Return the object's attributes and their values as a dictionary.
-        return vars(self)
+        return self.bk_config
 
 
 def generate_pipeline(config_file):