[v2,5/8] dts: add config parser module

Message ID 20220711145126.295427-6-juraj.linkes@pantheon.tech (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers
Series ssh connection to a node |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Juraj Linkeš July 11, 2022, 2:51 p.m. UTC
  From: Owen Hilyard <ohilyard@iol.unh.edu>

The configuration is split into two parts, one defining the parameters
of the test run and the other defining the topology to be used.

The format of the configuration is YAML. It is validated according to a
json schema which also servers as detailed documentation of the various
configuration fields. This means that the complete set of allowed values
are tied to the schema as a source of truth. This enables making changes
to parts of DTS that interface with config files without a high risk of
breaking someone's configuration.

This configuration system uses immutable objects to represent the
configuration, making IDE/LSP autocomplete work properly.

Signed-off-by: Owen Hilyard <ohilyard@iol.unh.edu>
Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
---
 dts/conf.yaml                              |   7 ++
 dts/framework/config/__init__.py           | 116 +++++++++++++++++++++
 dts/framework/config/conf_yaml_schema.json |  73 +++++++++++++
 dts/framework/exception.py                 |  15 +++
 dts/framework/settings.py                  |  40 +++++++
 5 files changed, 251 insertions(+)
 create mode 100644 dts/conf.yaml
 create mode 100644 dts/framework/config/__init__.py
 create mode 100644 dts/framework/config/conf_yaml_schema.json
 create mode 100644 dts/framework/settings.py
  

Patch

diff --git a/dts/conf.yaml b/dts/conf.yaml
new file mode 100644
index 0000000000..11b5f53a66
--- /dev/null
+++ b/dts/conf.yaml
@@ -0,0 +1,7 @@ 
+executions:
+  - system_under_test: "SUT 1"
+nodes:
+  - name: "SUT 1"
+    hostname: "SUT IP Address or hostname"
+    user: root
+    password: "leave blank to use SSH keys"
diff --git a/dts/framework/config/__init__.py b/dts/framework/config/__init__.py
new file mode 100644
index 0000000000..511e70c9a5
--- /dev/null
+++ b/dts/framework/config/__init__.py
@@ -0,0 +1,116 @@ 
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2010-2021 Intel Corporation
+# Copyright(c) 2022 University of New Hampshire
+#
+
+"""
+Generic port and topology nodes configuration file load function
+"""
+import json
+import os.path
+import pathlib
+from dataclasses import dataclass
+from enum import Enum, auto, unique
+from typing import Any, Optional
+
+import warlock
+import yaml
+
+from framework.settings import get_config_file_path
+
+
+class StrEnum(Enum):
+    @staticmethod
+    def _generate_next_value_(
+        name: str, start: int, count: int, last_values: object
+    ) -> str:
+        return name
+
+
+@unique
+class NodeType(StrEnum):
+    physical = auto()
+    virtual = auto()
+
+
+# Slots enables some optimizations, by pre-allocating space for the defined
+# attributes in the underlying data structure.
+#
+# Frozen makes the object immutable. This enables further optimizations,
+# and makes it thread safe should we every want to move in that direction.
+@dataclass(slots=True, frozen=True)
+class NodeConfiguration:
+    name: str
+    hostname: str
+    user: str
+    password: Optional[str]
+
+    @staticmethod
+    def from_dict(d: dict) -> "NodeConfiguration":
+        return NodeConfiguration(
+            name=d["name"],
+            hostname=d["hostname"],
+            user=d["user"],
+            password=d.get("password"),
+        )
+
+
+@dataclass(slots=True, frozen=True)
+class ExecutionConfiguration:
+    system_under_test: str
+
+    @staticmethod
+    def from_dict(d: dict) -> "ExecutionConfiguration":
+        return ExecutionConfiguration(
+            system_under_test=d["system_under_test"],
+        )
+
+
+@dataclass(slots=True, frozen=True)
+class Configuration:
+    executions: list[ExecutionConfiguration]
+    nodes: list[NodeConfiguration]
+
+    @staticmethod
+    def from_dict(d: dict) -> "Configuration":
+        executions: list[ExecutionConfiguration] = list(
+            map(ExecutionConfiguration.from_dict, d["executions"])
+        )
+        nodes: list[NodeConfiguration] = list(
+            map(NodeConfiguration.from_dict, d["nodes"])
+        )
+        assert len(nodes) > 0, "There must be a node to test"
+
+        for i, n1 in enumerate(nodes):
+            for j, n2 in enumerate(nodes):
+                if i != j:
+                    assert n1.name == n2.name, "Duplicate node names are not allowed"
+
+        node_names = {node.name for node in nodes}
+        for execution in executions:
+            assert (
+                execution.system_under_test in node_names
+            ), f"Unknown SUT {execution.system_under_test} in execution"
+
+        return Configuration(executions=executions, nodes=nodes)
+
+
+def load_config(conf_file_path: str) -> Configuration:
+    """
+    Loads the configuration file and the configuration file schema,
+    validates the configuration file, and creates a configuration object.
+    """
+    conf_file_path: str = get_config_file_path(conf_file_path)
+    with open(conf_file_path, "r") as f:
+        config_data = yaml.safe_load(f)
+    schema_path = os.path.join(
+        pathlib.Path(__file__).parent.resolve(), "conf_yaml_schema.json"
+    )
+
+    with open(schema_path, "r") as f:
+        schema = json.load(f)
+    config: dict[str, Any] = warlock.model_factory(schema, name="_Config")(
+        config_data
+    )
+    config_obj: Configuration = Configuration.from_dict(dict(config))
+    return config_obj
diff --git a/dts/framework/config/conf_yaml_schema.json b/dts/framework/config/conf_yaml_schema.json
new file mode 100644
index 0000000000..8dea50e285
--- /dev/null
+++ b/dts/framework/config/conf_yaml_schema.json
@@ -0,0 +1,73 @@ 
+{
+  "$schema": "https://json-schema.org/draft-07/schema",
+  "title": "DPDK DTS Config Schema",
+  "definitions": {
+    "node_name": {
+      "type": "string",
+      "description": "A unique identifier for a node"
+    },
+    "node_role": {
+      "type": "string",
+      "description": "The role a node plays in DTS",
+      "enum": [
+        "system_under_test",
+        "traffic_generator"
+      ]
+    }
+  },
+  "type": "object",
+  "properties": {
+    "nodes": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "properties": {
+          "name": {
+            "type": "string",
+            "description": "A unique identifier for this node"
+          },
+          "hostname": {
+            "type": "string",
+            "description": "A hostname from which the node running DTS can access this node. This can also be an IP address."
+          },
+          "user": {
+            "type": "string",
+            "description": "The user to access this node with."
+          },
+          "password": {
+            "type": "string",
+            "description": "The password to use on this node. SSH keys are preferred."
+          }
+        },
+        "additionalProperties": false,
+        "required": [
+          "name",
+          "hostname",
+          "user"
+        ]
+      },
+      "minimum": 1
+    },
+    "executions": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "properties": {
+          "system_under_test": {
+            "$ref": "#/definitions/node_name"
+          }
+        },
+        "additionalProperties": false,
+        "required": [
+          "system_under_test"
+        ]
+      },
+      "minimum": 1
+    }
+  },
+  "required": [
+    "executions",
+    "nodes"
+  ],
+  "additionalProperties": false
+}
\ No newline at end of file
diff --git a/dts/framework/exception.py b/dts/framework/exception.py
index 54f9f189a4..252fa47fc4 100644
--- a/dts/framework/exception.py
+++ b/dts/framework/exception.py
@@ -58,3 +58,18 @@  def __init__(self, host: str):
 
     def __str__(self) -> str:
         return f"SSH session with {self.host} has died"
+
+
+class ConfigParseException(Exception):
+
+    """
+    Configuration file parse failure exception.
+    """
+
+    config: str
+
+    def __init__(self, conf_file: str):
+        self.config = conf_file
+
+    def __str__(self) -> str:
+        return f"Failed to parse config file [{self.config}]"
diff --git a/dts/framework/settings.py b/dts/framework/settings.py
new file mode 100644
index 0000000000..ca3cbd71b1
--- /dev/null
+++ b/dts/framework/settings.py
@@ -0,0 +1,40 @@ 
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2010-2021 Intel Corporation
+# Copyright(c) 2022 PANTHEON.tech s.r.o.
+# Copyright(c) 2022 University of New Hampshire
+#
+
+import os
+import re
+
+DEFAULT_CONFIG_FILE_PATH: str = "./conf.yaml"
+
+# DTS global environment variables
+DTS_ENV_PAT: str = r"DTS_*"
+DTS_CFG_FILE: str = "DTS_CFG_FILE"
+
+
+def load_global_setting(key: str) -> str:
+    """
+    Load DTS global setting
+    """
+    if re.match(DTS_ENV_PAT, key):
+        env_key = key
+    else:
+        env_key = "DTS_" + key
+
+    return os.environ.get(env_key, "")
+
+
+def get_config_file_path(conf_file_path: str) -> str:
+    """
+    The root path of framework configs.
+    """
+    if conf_file_path == DEFAULT_CONFIG_FILE_PATH:
+        # if the user didn't specify a path on cmdline, they could've specified
+        # it in the env variable
+        conf_file_path = load_global_setting(DTS_CFG_FILE)
+        if conf_file_path == "":
+            conf_file_path = DEFAULT_CONFIG_FILE_PATH
+
+    return conf_file_path