From b84b0a6eedfcf4ea2b1fae160783b04b5fc86e1f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9gis=20Behmo?= <regis@behmo.com>
Date: Mon, 18 Mar 2019 22:38:13 +0100
Subject: [PATCH] Add convenient "config printvalue" command

---
 CHANGELOG.md    |  1 +
 tutor/config.py | 13 +++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d009c52..5012fd8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## Latest
 
+- [Feature] Add convenient `config printvalue` command
 - [Feature] Customize docker registry
 - [Feature] Load configuration parameters from the system environment
 - [Improvement] Automatic environment re-generation after re-configuration
diff --git a/tutor/config.py b/tutor/config.py
index 5fa60f4..77aadfe 100644
--- a/tutor/config.py
+++ b/tutor/config.py
@@ -42,6 +42,18 @@ def save(root, silent, set_):
 def printroot(root):
     click.echo(root)
 
+@click.command(help="Print a configuration value")
+@opts.root
+@click.argument("key")
+def printvalue(root, key):
+    config = {}
+    load_current(config, root)
+    load_defaults(config)
+    try:
+        print(config[key])
+    except KeyError:
+        raise exceptions.TutorError("Missing configuration value: {}".format(key))
+
 def load(root):
     """
     Load configuration, and generate it interactively if the file does not
@@ -200,3 +212,4 @@ def config_path(root):
 
 config.add_command(save)
 config.add_command(printroot)
+config.add_command(printvalue)