install from a hand-written oci-compose; Log2RAM journal fix

OCI manager Apps
- "Install an image that is not in the catalog" reads an oci-compose from a file of the host or from an address.
- A file written by hand states the image, its ports, variables and volumes, and what the installation asks; the rest is completed when it is read. A complete file, or the record of an installation, is installed as it is, and of a record only the template is used.
- Errors name the field they are in, also on a host without python3-jsonschema.
- oci/README.md describes the engine and the oci-compose block by block, with two examples in oci/examples/.
- The documentation page of the option covers it, in English and Spanish.

Log2RAM (reported by @f3rs3n)
- The sync removes the old active journal file from the disk copy, so a boot no longer restores it and journald deletes its oldest archives first. Log2RAM optimization 1.7; it takes effect from the next reboot.

Translations
- The bot keeps "oci-compose" as written.
- Spanish texts for the new option and for the Log2RAM notice.

.github/scripts/tests/test_log2ram_journal_sync.py

@@ -0,0 +1,93 @@
+"""Log2RAM syncs only the archived journal files, so the active file it found
+on disk when it was installed stays there and is restored at every boot.
+journald then continues an old sequence and deletes its newest archives first.
+The post-install makes the sync remove that file from the disk copy."""
+
+from pathlib import Path
+import shutil
+import stat
+import subprocess
+import tempfile
+import unittest
+
+ROOT = Path(__file__).resolve().parents[3]
+SHARED = ROOT / "scripts/global/utils-install-functions.sh"
+FLOWS = {"auto_post_install.sh": "install_log2ram_auto", "customizable_post_install.sh": "configure_log2ram"}
+
+# The sync of Log2RAM in its journald-aware mode, as its project ships it.
+JOURNALD_AWARE = '''#!/usr/bin/env bash
+sync_to_disk() {
+    is_safe
+
+    local optional_params=()
+
+    if journald_logrotate; then
+        optional_params+=("--include=journal/*/*@*.journal")
+        optional_params+=("--exclude=journal/*/*")
+    fi
+
+    rsync -aXv --no-acls --delete-after "${optional_params[@]}" "${RAM_LOG}"/ "${HDD_LOG}"/
+}
+'''
+NOT_AWARE = '''#!/usr/bin/env bash
+sync_to_disk() {
+    rsync -aXv --delete-after "${RAM_LOG}"/ "${HDD_LOG}"/
+}
+'''
+
+
+def gnu_sed():
+    return shutil.which("bash") and subprocess.run(["sed", "--version"], capture_output=True).returncode == 0
+
+
+@unittest.skipUnless(gnu_sed(), "bash and GNU sed are needed")
+class Log2ramJournalSyncTests(unittest.TestCase):
+    def correct(self, folder, content, times=1):
+        script = Path(folder) / "log2ram"
+        script.write_text(content)
+        script.chmod(0o755)
+        calls = "; ".join(['pmx_log2ram_drop_stale_journal "$1"; echo "rc=$?"'] * times)
+        # As the change journal does, the new content is read whole before it is written.
+        write = 'pmx_write_file() { local content; content="$(cat)"; printf "%s\\n" "$content" > "$1"; }'
+        run = subprocess.run(["bash", "-c", f'source "{SHARED}"; {write}; {calls}',
+                              "bash", str(script)], capture_output=True, text=True, check=False)
+        return script, run.stdout.split()
+
+    def test_the_sync_removes_what_it_does_not_copy(self):
+        with tempfile.TemporaryDirectory() as folder:
+            script, results = self.correct(folder, JOURNALD_AWARE)
+            lines = script.read_text().splitlines()
+            position = lines.index('        optional_params+=("--exclude=journal/*/*")')
+            self.assertEqual(lines[position + 1], '        optional_params+=("--delete-excluded")')
+            self.assertEqual(lines[position + 2], "    fi")
+            self.assertEqual(results, ["rc=0"])
+            self.assertEqual(subprocess.run(["bash", "-n", str(script)]).returncode, 0)
+            self.assertTrue(script.stat().st_mode & stat.S_IXUSR)
+            self.assertEqual(Path(str(script) + ".proxmenux.bak").read_text(), JOURNALD_AWARE)
+
+    def test_it_is_applied_once(self):
+        with tempfile.TemporaryDirectory() as folder:
+            script, results = self.correct(folder, JOURNALD_AWARE, times=2)
+            self.assertEqual(results, ["rc=0", "rc=1"])
+            self.assertEqual(script.read_text().count("--delete-excluded"), 1)
+
+    def test_a_sync_that_copies_every_file_is_left_as_it_is(self):
+        with tempfile.TemporaryDirectory() as folder:
+            script, results = self.correct(folder, NOT_AWARE)
+            self.assertEqual(results, ["rc=1"])
+            self.assertEqual(script.read_text(), NOT_AWARE)
+            self.assertFalse(Path(str(script) + ".proxmenux.bak").exists())
+
+    def test_both_flows_apply_it_to_new_and_existing_installations(self):
+        for name, function in FLOWS.items():
+            with self.subTest(flow=name):
+                text = (ROOT / "scripts/post_install" / name).read_text()
+                self.assertEqual(text.count("pmx_log2ram_drop_stale_journal"), 2)
+                # An existing installation is told that it needs a reboot.
+                self.assertIn('if pmx_log2ram_drop_stale_journal "$log2ram_bin"; then\n        NECESSARY_REBOOT=1', text)
+                # The version is what offers the update to existing installations.
+                self.assertIn(f'{function}() {{\n    local FUNC_VERSION="1.7"', text)
+
+
+if __name__ == "__main__":
+    unittest.main()