pmb.config.workdir: save/check chroot init date (!1878)

Whenever initializing new chroots, save the date in $WORK/workdir.cfg.
Add pmb.config.workdir.chroots_outdated() to check if it's time to zap
the chroots or not (since we don't update them automatically). Mark them
as outdated after two days.

This will be the first check in "pmbootstrap status" (future patches).
Related: #1829

pmb/chroot/init.py

@@ -8,6 +8,7 @@ import filecmp
 import pmb.chroot
 import pmb.chroot.apk_static
 import pmb.config
+import pmb.config.workdir
 import pmb.helpers.repo
 import pmb.helpers.run
 import pmb.parse.arch
@@ -73,6 +74,8 @@ def init(args, suffix="native"):
     copy_resolv_conf(args, suffix)
     pmb.chroot.apk.update_repository_list(args, suffix)
 
+    pmb.config.workdir.chroot_save_date(args, suffix)
+
     # Install alpine-base
     pmb.helpers.repo.update(args, arch)
     pmb.chroot.apk_static.run(args, ["--no-progress", "--root", chroot,

pmb/chroot/zap.py

@@ -6,6 +6,7 @@ import math
 import os
 
 import pmb.chroot
+import pmb.config.workdir
 import pmb.helpers.pmaports
 import pmb.helpers.run
 import pmb.parse.apkindex
@@ -72,6 +73,9 @@ def zap(args, confirm=True, dry=False, pkgs_local=False, http=False,
                 if not dry:
                     pmb.helpers.run.root(args, ["rm", "-rf", match])
 
+    # Remove config init dates for deleted chroots
+    pmb.config.workdir.clean(args)
+
     # Chroots were zapped, so no repo lists exist anymore
     args.cache["apk_repository_list_updated"].clear()
 

pmb/config/__init__.py

@@ -148,6 +148,10 @@ chroot_device_nodes = [
 # You can force-update them with 'pmbootstrap update'.
 apkindex_retention_time = 4
 
+
+# When chroot is considered outdated (in seconds)
+chroot_outdated = 3600 * 24 * 2
+
 #
 # BUILD
 #

pmb/config/workdir.py

@@ -0,0 +1,87 @@
+# Copyright 2020 Oliver Smith
+# SPDX-License-Identifier: GPL-3.0-or-later
+""" Save, read, verify workdir state related information in $WORK/workdir.cfg,
+    for example the init dates of the chroots. This is not saved in
+    pmbootstrap.cfg, because pmbootstrap.cfg is not tied to a specific work
+    dir. """
+import configparser
+import os
+import time
+
+import pmb.config
+
+
+def chroot_save_date(args, suffix):
+    """ Save the chroot initialization date in $WORK/workdir.cfg. """
+    # Read existing cfg
+    cfg = configparser.ConfigParser()
+    path = args.work + "/workdir.cfg"
+    if os.path.isfile(path):
+        cfg.read(path)
+
+    # Set current date for chroot suffix
+    key = "chroot-init-dates"
+    if key not in cfg:
+        cfg[key] = {}
+    cfg[key][suffix] = str(int(time.time()))
+
+    # Write back
+    with open(path, "w") as handle:
+        cfg.write(handle)
+
+
+def chroots_outdated(args):
+    """ Check if init dates from workdir.cfg indicate that any chroot is
+        outdated.
+        :returns: True if any of the chroots are outdated and should be zapped,
+                  False otherwise """
+    # Skip if workdir.cfg doesn't exist
+    path = args.work + "/workdir.cfg"
+    if not os.path.exists(path):
+        return False
+
+    cfg = configparser.ConfigParser()
+    cfg.read(path)
+    key = "chroot-init-dates"
+    if key not in cfg:
+        return False
+
+    date_outdated = time.time() - pmb.config.chroot_outdated
+    for suffix in cfg[key]:
+        date_init = int(cfg[key][suffix])
+        if date_init <= date_outdated:
+            return True
+    return False
+
+
+def clean(args):
+    """ Remove obsolete data data from workdir.cfg.
+        :returns: None if workdir does not exist,
+                  True if config was rewritten,
+                  False if config did not change """
+    # Skip if workdir.cfg doesn't exist
+    path = args.work + "/workdir.cfg"
+    if not os.path.exists(path):
+        return None
+
+    # Read
+    cfg = configparser.ConfigParser()
+    cfg.read(path)
+
+    # Remove entries for deleted chroots
+    key = "chroot-init-dates"
+    changed = False
+    if key in cfg:
+        for suffix in cfg[key]:
+            path_suffix = args.work + "/chroot_" + suffix
+            if os.path.exists(path_suffix):
+                continue
+            changed = True
+            del cfg[key][suffix]
+
+    # Write back
+    if changed:
+        with open(path, "w") as handle:
+            cfg.write(handle)
+
+    return changed

test/test_config_workdir.py

@@ -0,0 +1,103 @@
+# Copyright 2020 Oliver Smith
+# SPDX-License-Identifier: GPL-3.0-or-later
+""" Test pmb/config/workdir.py """
+import os
+import pytest
+import sys
+import time
+
+import pmb_test  # noqa
+import pmb.config
+import pmb.config.workdir
+
+
+@pytest.fixture
+def args(request):
+    import pmb.parse
+    sys.argv = ["pmbootstrap", "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_chroot_save_date(args, tmpdir, monkeypatch):
+    # Override time.time()
+    def fake_time():
+        return 1234567890.1234
+    monkeypatch.setattr(time, "time", fake_time)
+
+    args.work = str(tmpdir)
+    func = pmb.config.workdir.chroot_save_date
+    func(args, "native")
+
+    expected = "[chroot-init-dates]\nnative = 1234567890\n\n"
+    with open(args.work + "/workdir.cfg", "r") as handle:
+        assert handle.read() == expected
+
+    # Write again (different code path)
+    func(args, "buildroot_armhf")
+    expected = ("[chroot-init-dates]\nnative = 1234567890\n"
+                "buildroot_armhf = 1234567890\n\n")
+    with open(args.work + "/workdir.cfg", "r") as handle:
+        assert handle.read() == expected
+
+
+def test_chroots_outdated(args, tmpdir, monkeypatch):
+    args.work = str(tmpdir)
+
+    # Override time.time(): now is "100"
+    def fake_time():
+        return 100.0
+    monkeypatch.setattr(time, "time", fake_time)
+
+    # workdir.cfg does not exist
+    func = pmb.config.workdir.chroots_outdated
+    assert func(args) is False
+
+    # workdir.cfg is empty file
+    with open(args.work + "/workdir.cfg", "w") as handle:
+        handle.write("")
+    assert func(args) is False
+
+    # Write fake workdir.cfg: native was created at "90"
+    with open(args.work + "/workdir.cfg", "w") as handle:
+        handle.write("[chroot-init-dates]\nnative = 90\n\n")
+
+    # Outdated (date_outdated: 90)
+    monkeypatch.setattr(pmb.config, "chroot_outdated", 10)
+    assert func(args) is True
+
+    # Not outdated (date_outdated: 89)
+    monkeypatch.setattr(pmb.config, "chroot_outdated", 11)
+    assert func(args) is False
+
+
+def test_clean(args, tmpdir):
+    args.work = str(tmpdir)
+
+    # 0. workdir.cfg does not exist
+    func = pmb.config.workdir.clean
+    assert func(args) is None
+
+    # Write fake workdir.cfg
+    cfg_fake = "[chroot-init-dates]\nnative = 1337\n\n"
+    with open(args.work + "/workdir.cfg", "w") as handle:
+        handle.write(cfg_fake)
+
+    # 1. chroot_native dir exists
+    os.makedirs(args.work + "/chroot_native")
+    assert func(args) is False
+
+    # workdir.cfg: unchanged
+    with open(args.work + "/workdir.cfg", "r") as handle:
+        assert handle.read() == cfg_fake
+
+    # 2. chroot_native dir does not exist
+    os.rmdir(args.work + "/chroot_native")
+    assert func(args) is True
+
+    # workdir.cfg: "native" entry removed
+    with open(args.work + "/workdir.cfg", "r") as handle:
+        assert handle.read() == "[chroot-init-dates]\n\n"