Close #326: Implement command to retrieve and set configuration values (#359)

* Implement command to retrieve and set configuration values
* qemu: show advice to use "pmbootstrap config"
* Allow "pmbootstrap config" without positional arguments (prints the full config)
* Check valid variable names

pmb/helpers/frontend.py

@@ -21,6 +21,8 @@ along with pmbootstrap.  If not, see <http://www.gnu.org/licenses/>.
 
 import logging
 import json
+import sys
+
 import pmb.aportgen
 import pmb.build
 import pmb.config
@@ -80,6 +82,25 @@ def chroot(args):
     pmb.chroot.root(args, args.command, suffix, log=False)
 
 
+def config(args):
+    pmb.helpers.logging.disable()
+    if args.name and args.name not in pmb.config.defaults:
+        valid_keys = ", ".join(sorted(pmb.config.defaults.keys()))
+        print("The variable name you have specified is invalid.")
+        print("The following are supported: " + valid_keys)
+        sys.exit(1)
+
+    cfg = pmb.config.load(args)
+    if args.value:
+        cfg["pmbootstrap"][args.name] = args.value
+        pmb.config.save(args, cfg)
+    elif args.name:
+        value = cfg["pmbootstrap"].get(args.name, "")
+        print(value)
+    else:
+        cfg.write(sys.stdout)
+
+
 def index(args):
     pmb.build.index_repo(args)
 

pmb/helpers/logging.py

@@ -101,3 +101,8 @@ def init(args):
     log_handler._args = args
     handler.setFormatter(formatter)
     root_logger.addHandler(handler)
+
+
+def disable():
+    logger = logging.getLogger()
+    logger.disabled = True

pmb/parse/arguments.py

@@ -218,6 +218,12 @@ def arguments():
     parse_apkindex.add_argument("apkindex_path")
     parse_apkindex.add_argument("package", default=None, nargs="?")
 
+    # Action: config
+    config = sub.add_parser("config",
+                            help="get and set pmbootstrap options")
+    config.add_argument("name", nargs="?", help="variable name")
+    config.add_argument("value", nargs="?", help="set variable to value")
+
     # Action: qemu
     qemu = sub.add_parser("qemu")
     qemu.add_argument("--arch", choices=["aarch64", "arm", "x86_64"],

pmb/qemu/run.py

@@ -40,7 +40,8 @@ def system_image(args, device):
         logging.debug("Could not find system image: " + path)
         img_command = "pmbootstrap install"
         if device != args.device:
-            img_command = "pmbootstrap init' and '" + img_command
+            img_command = ("pmbootstrap config device " + device +
+                           "' and '" + img_command)
         message = "The system image '{0}' has not been generated yet, please" \
                   " run '{1}' first.".format(device, img_command)
         raise RuntimeError(message)