docs: mismatch cli utility (#4348)

Signed-off-by: Meet Soni <[email protected]>

Author: inosmeet

.github/actions/spelling/allow.txt

@@ -16,6 +16,7 @@ api
 apk
 apparmor
 ares
+argparse
 Args
 asn
 asottile
@@ -702,6 +703,7 @@ URI
 uri
 URIs
 url
+URLs
 urlopen
 usecase
 username

doc/mismatch_cli.md

@@ -0,0 +1,138 @@
+# Mismatch Database Management Tool Documentation
+
+## Overview
+
+The Mismatch Database Management Tool is a command-line utility designed to facilitate the management and querying of a mismatch database. This tool provides two main functionalities:
+
+1. **Lookup**: Retrieve vendor information for a given Package URL (PURL) from the mismatch database.
+2. **Loader**: Set up or refresh the mismatch database using data from a specified directory.
+
+## Prerequisites
+
+Ensure the following Python modules are installed:
+
+- `sqlite3`: For SQLite database operations.
+- `argparse`: For command-line argument parsing.
+- `cve_bin_tool.mismatch_loader`: To execute the mismatch loader functionality.
+
+## Directory Structure
+
+The script operates within a specific directory structure as shown below:
+
+```
+project_root/
+│
+├── data/               # Directory containing the mismatch relations
+│
+└── mismatch/           # Directory containing the script
+    └── cli.py          # The main script file
+```
+
+## Data Directory
+
+The `data/` directory is a key component of the Mismatch Database Management Tool. It houses the structured data files that are used to populate or refresh the mismatch database.
+
+### Directory Structure
+
+The structure of the `data/` directory is organized as follows:
+
+```
+data/
+└── namespace/
+    └── product/
+        └── mismatch_relations.yml
+```
+
+### Explanation of Contents
+
+- **namespace/**: This directory represents a logical grouping, such as a software ecosystem, project, or domain.
+
+- **product/**: Each `namespace/` contains one or more `product/` directories. Each directory corresponds to a specific product within that namespace.
+
+- **mismatch_relations.yml**: This YAML file inside each `product/` directory contains the data related to mismatches. It typically includes:
+
+  - **purls**: A list of package URLs (PURLs) associated with the product. For example:
+    ```yaml
+    purls:
+      - pkg:pypi/zstandard
+    ```
+  
+  - **invalid_vendors**: A list of vendors that are considered invalid or mismatched for the given PURLs. For example:
+    ```yaml
+    invalid_vendors:
+      - facebook
+    ```
+
+## Usage
+
+The script can be executed using different subcommands, each serving a distinct purpose.
+
+### 1. Lookup Command
+
+The `lookup` command allows you to search for vendor information based on a PURL in the mismatch database.
+
+**Syntax:**
+```bash
+python -m mismatch.cli lookup <purl> [--database <db_file>]
+```
+
+**Parameters:**
+- `<purl>`: (Required) The Package URL to search within the mismatch database.
+- `--database`: (Optional) Path to the SQLite database file. Defaults to the pre-configured location if not provided.
+
+**Example:**
+```bash
+python -m mismatch.cli lookup pkg:namespace/product --database /path/to/mismatch.db
+```
+
+### 2. Loader Command
+
+The `loader` command initializes or updates the mismatch database using data from a specified directory.
+
+**Syntax:**
+```bash
+python -m mismatch.cli loader [--dir <data_dir>] [--database <db_file>]
+```
+
+**Parameters:**
+- `--dir`: (Optional) Directory containing the data files to be loaded. Defaults to the \`data/\` directory in the project root.
+- `--database`: (Optional) Path to the SQLite database file. Defaults to the pre-configured location if not provided.
+
+**Example:**
+```bash
+python -m mismatch.cli loader --dir /path/to/data --database /path/to/mismatch.db
+```
+
+### 3. Default Behavior
+
+If the script is executed without any subcommands, it defaults to running the `loader` command using the default directory and database file:
+
+**Syntax:**
+```bash
+python -m mismatch.cli
+```
+
+This command will trigger the `loader` functionality with default parameters.
+
+## Example Commands
+
+Here are some sample commands that demonstrate how to use the script:
+
+1. **Look Up Vendor Information for a PURL**:
+   ```bash
+   python -m mismatch.cli lookup pkg:namespace/product
+   ```
+
+2. **Refresh the Database Using Default Settings**:
+   ```bash
+   python -m mismatch.cli
+   ```
+
+3. **Specify Custom Data Directory and Database File for Loader**:
+   ```bash
+   python -m mismatch.cli loader --dir /custom/data/dir --database /custom/db/file.db
+   ```
+
+## Conclusion
+
+The Mismatch Database Management Tool is a robust utility designed to streamline the management and querying of a mismatch database.

mismatch/cli.py

@@ -1,10 +1,12 @@
 import argparse
 import os
 import sqlite3
+from pathlib import Path
 
-from cve_bin_tool.cvedb import DBNAME, DISK_LOCATION_DEFAULT
 from cve_bin_tool.mismatch_loader import run_mismatch_loader
 
+DBNAME = "cve.db"
+DISK_LOCATION_DEFAULT = Path("~").expanduser() / ".cache" / "cve-bin-tool"
 parent_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 data_dir = os.path.join(parent_dir, "data")
 dbpath = DISK_LOCATION_DEFAULT / DBNAME