kt: Add list-kernels command

It will show all the kernels we support.

The implementation is under kt/commands/list-kernels folder.
To keep things cleaner, the actual logic is done in impl.py,
while command.py is used for the click interface, like argument and helper logic.

Signed-off-by: Roxana Nicolescu <rnicolescu@ciq.com>

Author: roxanan1996

bin/kt

@@ -4,6 +4,8 @@ import logging
 
 import click
 
+from kt.commands.list_kernels.command import list_kernels
+
 epilog = """
 Base of all tooling used for kernel development.
 
@@ -19,6 +21,7 @@ def cli():
 def main():
     logging.basicConfig(format="%(levelname)s:%(message)s", level=logging.INFO)
 
+    cli.add_command(list_kernels)
     cli()
 
 

kt/KT.md

@@ -100,3 +100,48 @@ if the base_path is ~/ciq.
 
 The KernelInfo dataclass will be used later when we set up each kernel working
 environment.
+
+## Commands
+
+Make sure kt is reachable from anywhere by adding it's location to PATH.
+Example
+```
+export PATH=$HOME/ciq/kernel-src-tree-tools/bin:$PATH
+```
+If you are unsure how to use kt, just run it with --help.
+Example:
+```
+$ kt --help
+```
+
+Run --help for subcommands as well.
+
+Autocompletion works relatively well. Make sure it's enabled for your shell.
+Check the official doc for [click](https://click.palletsprojects.com/en/stable/shell-completion/#enabling-completion)
+Example for zsh:
+```
+eval "$(_KT_COMPLETE=zsh_source kt)"
+```
+
+A command implementation is under ```kt/commands/<command>``` folder.
+To keep things cleaner, the actual logic is done in impl.py,
+while command.py is used for the click interface, like argument and helper logic.
+
+### kt list-kernels
+It shows the kernels we currently maintain. The data is taken from
+KernelsInfo object which represents the kernels.yaml file in kt/data.
+
+Example:
+
+```
+$ kt list-kernels
+cbr-7.9
+fips-8.10
+fips-8.6
+fips-9.2
+fipslegacy-8.6
+lts-8.6
+lts-8.8
+lts-9.2
+lts-9.4
+```

kt/commands/list_kernels/command.py

@@ -0,0 +1,18 @@
+import click
+
+from kt.commands.list_kernels.impl import main
+
+epilog = """
+It list all the kernels we currently maintain.
+
+Example:
+
+\b
+$ kt list-kernels
+
+"""
+
+
+@click.command(epilog=epilog)
+def list_kernels():
+    main()

kt/commands/list_kernels/impl.py

@@ -0,0 +1,9 @@
+from kt.ktlib.config import Config
+from kt.ktlib.kernels import KernelsInfo
+
+
+def main():
+    config = Config.load()
+    kernels = KernelsInfo.from_yaml(config=config).kernels
+    for k in sorted(kernels):
+        print(k)