pmbootstrap init: ask for release channel (MR 1912)

Ask for release channel and switch pmaports branch to the related branch
defined in channels.cfg.

Store in pmbootstrap.cfg whether the user chose a channel (boolean). If
the user did not choose a channel yet, suggest the recommended channel
from channels.cfg (currently "edge").

pmb/config/__init__.py

@@ -42,6 +42,7 @@ config_keys = ["aports",
                "device",
                "extra_packages",
                "hostname",
+               "is_default_channel",
                "jobs",
                "kernel",
                "keymap",
@@ -61,6 +62,7 @@ defaults = {
     "alpine_version": "edge",  # alternatively: latest-stable
     "aports": "$WORK/cache_git/pmaports",
     "ccache_size": "5G",
+    "is_default_channel": True,
     # aes-xts-plain64 would be better, but this is not supported on LineageOS
     # kernel configs
     "cipher": "aes-cbc-plain64",

pmb/config/init.py

@@ -72,6 +72,39 @@ def ask_for_work_path(args):
                           " inside it! Please try again.")
 
 
+def ask_for_channel(args):
+    """ Ask for the postmarketOS release channel. The channel dictates, which
+        pmaports branch pmbootstrap will check out, and which repository URLs
+        will be used when initializing chroots.
+        :returns: channel name (e.g. "edge", "stable") """
+    channels_cfg = pmb.helpers.git.parse_channels_cfg(args)
+    count = len(channels_cfg["channels"])
+
+    # List channels
+    logging.info("Choose the postmarketOS release channel.")
+    logging.info(f"Available ({count}):")
+    for channel, channel_data in channels_cfg["channels"].items():
+        logging.info(f"* {channel}: {channel_data['description']}")
+
+    # Default for first run: "recommended" from channels.cfg
+    # Otherwise, if valid: channel from pmaports.cfg of current branch
+    # The actual channel name is not saved in pmbootstrap.cfg, because then we
+    # would need to sync it with what is checked out in pmaports.git.
+    default = pmb.config.pmaports.read_config(args)["channel"]
+    choices = channels_cfg["channels"].keys()
+    if args.is_default_channel or default not in choices:
+        default = channels_cfg["meta"]["recommended"]
+
+    # Ask until user gives valid channel
+    while True:
+        ret = pmb.helpers.cli.ask(args, "Channel", None, default,
+                                  complete=choices)
+        if ret in choices:
+            return ret
+        logging.fatal("ERROR: Invalid channel specified, please type in one"
+                      " from the list above.")
+
+
 def ask_for_ui(args):
     ui_list = pmb.helpers.ui.list(args)
     logging.info("Available user interfaces (" +
@@ -365,6 +398,11 @@ def frontend(args):
     # Clone pmaports
     pmb.config.pmaports.init(args)
 
+    # Choose release channel, possibly switch pmaports branch
+    channel = ask_for_channel(args)
+    pmb.config.pmaports.switch_to_channel_branch(args, channel)
+    cfg["pmbootstrap"]["is_default_channel"] = "False"
+
     # Device
     device, device_exists, kernel, nonfree = ask_for_device(args)
     cfg["pmbootstrap"]["device"] = device

pmb/config/pmaports.py

@@ -124,3 +124,38 @@ def init(args):
         clone(args)
     symlink(args)
     read_config(args)
+
+
+def switch_to_channel_branch(args, channel_new):
+    """ Checkout the channel's branch in pmaports.git.
+        :channel_new: channel name (e.g. "edge", "stable")
+        :returns: True if another branch was checked out, False otherwise """
+    # Check current pmaports branch channel
+    channel_current = read_config(args)["channel"]
+    if channel_current == channel_new:
+        return False
+
+    # List current and new branches/channels
+    channels_cfg = pmb.helpers.git.parse_channels_cfg(args)
+    branch_new = channels_cfg["channels"][channel_new]["branch_pmaports"]
+    branch_current = pmb.helpers.git.rev_parse(args, args.aports,
+                                               extra_args=["--abbrev-ref"])
+    logging.info(f"Currently checked out branch '{branch_current}' of"
+                 f" pmaports.git is on channel '{channel_current}'.")
+    logging.info(f"Switching to branch '{branch_new}' on channel"
+                 f" '{channel_new}'...")
+
+    # Attempt to switch branch (git gives a nice error message, mentioning
+    # which files need to be committed/stashed, so just pass it through)
+    if pmb.helpers.run.user(args, ["git", "checkout", branch_new],
+                            args.aports, "interactive", check=False):
+        raise RuntimeError("Failed to switch branch. Go to your pmaports and"
+                           " fix what git complained about, then try again: "
+                           f"{args.aports}")
+
+    # Invalidate all caches
+    pmb.helpers.args.add_cache(args)
+
+    # Verify pmaports.cfg on new branch
+    read_config(args)
+    return True

test/test_config_pmaports.py

@@ -0,0 +1,50 @@
+# Copyright 2020 Oliver Smith
+# SPDX-License-Identifier: GPL-3.0-or-later
+""" Test pmb/config/pmaports.py """
+import pytest
+import sys
+
+import pmb_test
+import pmb_test.const
+import pmb_test.git
+import pmb.config
+import pmb.config.workdir
+import pmb.config.pmaports
+
+
+@pytest.fixture
+def args(request):
+    import pmb.parse
+    cfg = f"{pmb_test.const.testdata}/channels.cfg"
+    sys.argv = ["pmbootstrap.py", "--config-channels", cfg, "init"]
+    args = pmb.parse.arguments()
+    args.log = args.work + "/log_testsuite.txt"
+    pmb.helpers.logging.init(args)
+    request.addfinalizer(args.logfd.close)
+    return args
+
+
+def test_switch_to_channel_branch(args, monkeypatch, tmpdir):
+    path, run_git = pmb_test.git.prepare_tmpdir(args, monkeypatch, tmpdir)
+    args.aports = path
+
+    # Pretend to have channel=edge in pmaports.cfg
+    def read_config(args):
+        return {"channel": "edge"}
+    monkeypatch.setattr(pmb.config.pmaports, "read_config", read_config)
+
+    # Success: Channel does not change
+    func = pmb.config.pmaports.switch_to_channel_branch
+    assert func(args, "edge") is False
+
+    # Fail: git error (could be any error, but here: branch does not exist)
+    with pytest.raises(RuntimeError) as e:
+        func(args, "stable")
+    assert str(e.value).startswith("Failed to switch branch")
+
+    # Success: switch channel and change branch
+    run_git(["checkout", "-b", "v20.05"])
+    run_git(["checkout", "master"])
+    assert func(args, "stable") is True
+    branch = pmb.helpers.git.rev_parse(args, path, extra_args=["--abbrev-ref"])
+    assert branch == "v20.05"

test/test_questions.py

@@ -16,7 +16,8 @@ import pmb.helpers.logging
 @pytest.fixture
 def args(tmpdir, request):
     import pmb.parse
-    sys.argv = ["pmbootstrap.py", "init"]
+    cfg = f"{pmb_test.const.testdata}/channels.cfg"
+    sys.argv = ["pmbootstrap.py", "--config-channels", cfg, "init"]
     args = pmb.parse.arguments()
     args.log = args.work + "/log_testsuite.txt"
     pmb.helpers.logging.init(args)
@@ -287,3 +288,8 @@ def test_questions_hostname(args, monkeypatch):
     # Device name: empty string
     fake_answers(monkeypatch, [device])
     assert func(args, device) == ""
+
+
+def test_questions_channel(args, monkeypatch):
+    fake_answers(monkeypatch, ["invalid-channel", "stable"])
+    assert pmb.config.init.ask_for_channel(args) == "stable"