mkosi: add --pager option and page summary

This makes 'summary' behave similarly to various systemd and git commands that
start a pager whenever lengthy output is expected. The interesting part of the
summary is often near the top, paging makes it easier to immediately see the
interesting lines.

The pager is enabled by default (when on tty, etc.), but can be disabled with
--pager=no.

This copies the implementation I wrote for rpmautospec [1].
Same as in rpmautospec, we don't want to page normal output, but only stuff
like 'summary' and '--help', where we can generate the whole string upfront and
pass it to the built-in pager. The only tweak that is made is that $LESS is set
in the environment so that the output looks nice. $MKOSI_LESS can be used to
override the options if desired.

[1] https://pagure.io/fedora-infra/rpmautospec/c/8833528b70829a56a8c4a7094f6b9c5433d5face

When 'timedatectl' was ran with stdin=tty, stdout=PIPE, mkosi would get stopped
by SIGTTY. I don't understand why this happens — 'timedatectl' shouldn't touch
its stdin at all. Redirecting it from /dev/null solves the issue, and seems the
right thing to do anyway.

diff --git a/man/mkosi.1 b/man/mkosi.1
index dcb23874f07ef1edebf7e8ffba4af74e3e5e21d3..8b8c4c00cb0e2e6e42e242df58550ff8bdb44bbe 100644 (file)
--- a/man/mkosi.1
+++ b/man/mkosi.1
@@ -1472,6 +1472,9 @@ whether a build without or with networking is being executed
 (\f[C]WithNetwork=no\f[R]).
 The build script should avoid any network communication in case
 \f[C]$WITH_NETWORK\f[R] is \f[C]0\f[R].
+.IP \[bu] 2
+\f[V]$MKOSI_LESS\f[R] overrides options for \f[V]less\f[R] when it is
+invoked by \f[V]mkosi\f[R] to page output.
 .SH EXAMPLES
 .PP
 Create and run a raw \f[I]GPT\f[R] image with \f[I]ext4\f[R], as

diff --git a/mkosi.md b/mkosi.md
index a21621096eec9bb3185f37bd6463a17928d786ff..c09415f308d7f93ec697e55f89ca801d5889bce3 100644 (file)
--- a/mkosi.md
+++ b/mkosi.md
@@ -1256,6 +1256,9 @@ variables:
   The build script should avoid any network communication in case
   `$WITH_NETWORK` is `0`.
 
+* `$MKOSI_LESS` overrides options for `less` when it is invoked by
+  `mkosi` to page output.
+
 # EXAMPLES
 
 Create and run a raw *GPT* image with *ext4*, as `image.raw`:

diff --git a/mkosi/__init__.py b/mkosi/__init__.py
index 7d1dd4f3a95fad5022cf535abeef7a472bb4f9bf..8de2020ddf98b041b6fa0c32e56672633aa5462f 100644 (file)
--- a/mkosi/__init__.py
+++ b/mkosi/__init__.py
@@ -9,6 +9,7 @@ import datetime
 import errno
 import hashlib
 import http.server
+import io
 import itertools
 import json
 import os
@@ -57,6 +58,7 @@ from mkosi.log import (
 )
 from mkosi.manifest import GenericVersion, Manifest
 from mkosi.mounts import dissect_and_mount, mount_overlay, scandir_recursive
+from mkosi.pager import page
 from mkosi.remove import unlink_try_hard
 from mkosi.run import (
     become_root,
@@ -1031,7 +1033,12 @@ def load_credentials(args: argparse.Namespace) -> dict[str, str]:
         creds[key] = value
 
     if "firstboot.timezone" not in creds:
-        tz = run(["timedatectl", "show", "-p", "Timezone", "--value"], text=True, stdout=subprocess.PIPE).stdout.strip()
+        tz = run(
+            ["timedatectl", "show", "-p", "Timezone", "--value"],
+            text=True,
+            stdin=subprocess.DEVNULL,
+            stdout=subprocess.PIPE,
+        ).stdout.strip()
         creds["firstboot.timezone"] = tz
 
     if "firstboot.locale" not in creds:
@@ -1041,7 +1048,13 @@ def load_credentials(args: argparse.Namespace) -> dict[str, str]:
         creds["firstboot.hostname"] = machine_name(args)
 
     if args.ssh and "ssh.authorized_keys.root" not in creds and "SSH_AUTH_SOCK" in os.environ:
-        key = run(["ssh-add", "-L"], text=True, stdout=subprocess.PIPE, env=os.environ).stdout.strip()
+        key = run(
+            ["ssh-add", "-L"],
+            text=True,
+            stdin=subprocess.DEVNULL,
+            stdout=subprocess.PIPE,
+            env=os.environ,
+        ).stdout.strip()
         creds["ssh.authorized_keys.root"] = key
 
     return creds
@@ -1334,69 +1347,72 @@ def line_join_source_target_list(array: Sequence[tuple[Path, Optional[Path]]]) -
 
 
 def print_summary(config: MkosiConfig) -> None:
-    print("COMMANDS:")
+    f = io.StringIO()
+    say: Callable[..., None] = lambda *args, **kwargs: print(*args, **kwargs, file=f)
 
-    print("                      verb:", config.verb)
-    print("                   cmdline:", " ".join(config.cmdline))
+    say("COMMANDS:")
 
-    print("\nDISTRIBUTION:")
+    say("                      verb:", config.verb)
+    say("                   cmdline:", " ".join(config.cmdline))
 
-    print("              Distribution:", config.distribution.name)
-    print("                   Release:", none_to_na(config.release))
-    print("              Architecture:", config.architecture)
+    say("\nDISTRIBUTION:")
+
+    say("              Distribution:", config.distribution.name)
+    say("                   Release:", none_to_na(config.release))
+    say("              Architecture:", config.architecture)
 
     if config.mirror is not None:
-        print("                    Mirror:", config.mirror)
+        say("                    Mirror:", config.mirror)
 
     if config.local_mirror is not None:
-        print("      Local Mirror (build):", config.local_mirror)
+        say("      Local Mirror (build):", config.local_mirror)
 
-    print("  Repo Signature/Key check:", yes_no(config.repository_key_check))
+    say("  Repo Signature/Key check:", yes_no(config.repository_key_check))
 
     if config.repositories is not None and len(config.repositories) > 0:
-        print("              Repositories:", ",".join(config.repositories))
+        say("              Repositories:", ",".join(config.repositories))
 
     if config.initrds:
-        print("                   Initrds:", ",".join(os.fspath(p) for p in config.initrds))
+        say("                   Initrds:", ",".join(os.fspath(p) for p in config.initrds))
 
-    print("\nOUTPUT:")
+    say("\nOUTPUT:")
 
     if config.image_id is not None:
-        print("                  Image ID:", config.image_id)
+        say("                  Image ID:", config.image_id)
 
     if config.image_version is not None:
-        print("             Image Version:", config.image_version)
+        say("             Image Version:", config.image_version)
 
-    print("             Output Format:", config.output_format.name)
+    say("             Output Format:", config.output_format.name)
 
     maniformats = (" ".join(i.name for i in config.manifest_format)) or "(none)"
-    print("          Manifest Formats:", maniformats)
+    say("          Manifest Formats:", maniformats)
 
     if config.output_dir:
-        print("          Output Directory:", config.output_dir)
+        say("          Output Directory:", config.output_dir)
 
     if config.workspace_dir:
-        print("       Workspace Directory:", config.workspace_dir)
+        say("       Workspace Directory:", config.workspace_dir)
 
-    print("                    Output:", config.output)
-    print("           Output Checksum:", none_to_na(config.output_checksum if config.checksum else None))
-    print("          Output Signature:", none_to_na(config.output_signature if config.sign else None))
-    print("    Output nspawn Settings:", none_to_na(config.output_nspawn_settings if config.nspawn_settings is not None else None))
+    say("                    Output:", config.output)
+    say("           Output Checksum:", none_to_na(config.output_checksum if config.checksum else None))
+    say("          Output Signature:", none_to_na(config.output_signature if config.sign else None))
+    say("    Output nspawn Settings:", none_to_na(config.output_nspawn_settings if config.nspawn_settings is not None else None))
 
-    print("               Incremental:", yes_no(config.incremental))
-    print("               Compression:", should_compress_output(config) or "no")
+    say("               Incremental:", yes_no(config.incremental))
+    say("               Compression:", should_compress_output(config) or "no")
 
-    print("       Kernel Command Line:", " ".join(config.kernel_command_line))
-    print("           UEFI SecureBoot:", yes_no(config.secure_boot))
+    say("       Kernel Command Line:", " ".join(config.kernel_command_line))
+    say("           UEFI SecureBoot:", yes_no(config.secure_boot))
 
     if config.secure_boot_key:
-        print("       SecureBoot Sign Key:", config.secure_boot_key)
+        say("       SecureBoot Sign Key:", config.secure_boot_key)
     if config.secure_boot_certificate:
-        print("    SecureBoot Certificate:", config.secure_boot_certificate)
+        say("    SecureBoot Certificate:", config.secure_boot_certificate)
 
-    print("\nCONTENT:")
+    say("\nCONTENT:")
 
-    print("                  Packages:", line_join_list(config.packages))
+    say("                  Packages:", line_join_list(config.packages))
 
     if config.distribution in (
         Distribution.fedora,
@@ -1405,50 +1421,51 @@ def print_summary(config: MkosiConfig) -> None:
         Distribution.rocky,
         Distribution.alma,
     ):
-        print("        With Documentation:", yes_no(config.with_docs))
+        say("        With Documentation:", yes_no(config.with_docs))
 
-    print("             Package Cache:", none_to_none(config.cache_dir))
-    print("               Extra Trees:", line_join_source_target_list(config.extra_trees))
-    print("      CleanPackageMetadata:", yes_no_auto(config.clean_package_metadata))
+    say("             Package Cache:", none_to_none(config.cache_dir))
+    say("               Extra Trees:", line_join_source_target_list(config.extra_trees))
+    say("      CleanPackageMetadata:", yes_no_auto(config.clean_package_metadata))
 
     if config.remove_files:
-        print("              Remove Files:", line_join_list(config.remove_files))
+        say("              Remove Files:", line_join_list(config.remove_files))
     if config.remove_packages:
-        print("           Remove Packages:", line_join_list(config.remove_packages))
+        say("           Remove Packages:", line_join_list(config.remove_packages))
 
-    print("             Build Sources:", config.build_sources)
-    print("           Build Directory:", none_to_none(config.build_dir))
-    print("         Install Directory:", none_to_none(config.install_dir))
-    print("            Build Packages:", line_join_list(config.build_packages))
+    say("             Build Sources:", config.build_sources)
+    say("           Build Directory:", none_to_none(config.build_dir))
+    say("         Install Directory:", none_to_none(config.install_dir))
+    say("            Build Packages:", line_join_list(config.build_packages))
 
-    print("              Build Script:", path_or_none(config.build_script, check_script_input))
+    say("              Build Script:", path_or_none(config.build_script, check_script_input))
 
     env = [f"{k}={v}" for k, v in config.environment.items()]
     if config.build_script:
-        print("                 Run tests:", yes_no(config.with_tests))
+        say("                 Run tests:", yes_no(config.with_tests))
 
-    print("        Postinstall Script:", path_or_none(config.postinst_script, check_script_input))
-    print("            Prepare Script:", path_or_none(config.prepare_script, check_script_input))
-    print("           Finalize Script:", path_or_none(config.finalize_script, check_script_input))
+    say("        Postinstall Script:", path_or_none(config.postinst_script, check_script_input))
+    say("            Prepare Script:", path_or_none(config.prepare_script, check_script_input))
+    say("           Finalize Script:", path_or_none(config.finalize_script, check_script_input))
 
-    print("        Script Environment:", line_join_list(env))
-    print("      Scripts with network:", yes_no(config.with_network))
-    print("           nspawn Settings:", none_to_none(config.nspawn_settings))
+    say("        Script Environment:", line_join_list(env))
+    say("      Scripts with network:", yes_no(config.with_network))
+    say("           nspawn Settings:", none_to_none(config.nspawn_settings))
 
-    print("                  Password:", ("(default)" if config.password is None else "(set)"))
-    print("                 Autologin:", yes_no(config.autologin))
+    say("                  Password:", ("(default)" if config.password is None else "(set)"))
+    say("                 Autologin:", yes_no(config.autologin))
 
     if config.output_format == OutputFormat.disk:
-        print("\nVALIDATION:")
+        say("\nVALIDATION:")
 
-        print("                  Checksum:", yes_no(config.checksum))
-        print("                      Sign:", yes_no(config.sign))
-        print("                   GPG Key:", ("default" if config.key is None else config.key))
+        say("                  Checksum:", yes_no(config.checksum))
+        say("                      Sign:", yes_no(config.sign))
+        say("                   GPG Key:", ("default" if config.key is None else config.key))
 
-    print("\nHOST CONFIGURATION:")
+    say("\nHOST CONFIGURATION:")
 
-    print("        Extra search paths:", line_join_list(config.extra_search_paths))
-    print("      QEMU Extra Arguments:", line_join_list(config.qemu_args))
+    say("        Extra search paths:", line_join_list(config.extra_search_paths))
+    say("      QEMU Extra Arguments:", line_join_list(config.qemu_args))
+    page(f.getvalue(), config.pager)
 
 
 def make_output_dir(state: MkosiState) -> None:

diff --git a/mkosi/backend.py b/mkosi/backend.py
index bec6eea93d4e9e91af4a5e57b98641cb89789e3c..fd90b7b4c8f51298762c89297410dc021ab7b0db 100644 (file)
--- a/mkosi/backend.py
+++ b/mkosi/backend.py
@@ -269,6 +269,7 @@ class MkosiConfig:
     initrds: list[Path]
     kernel_command_line_extra: list[str]
     acl: bool
+    pager: bool
 
     # QEMU-specific options
     qemu_gui: bool

diff --git a/mkosi/config.py b/mkosi/config.py
index ecf6032f437a2e7d8b194956b5b7d48c979dfef4..df150954fa72337f127be91f8e7c8bb996ec26b7 100644 (file)
--- a/mkosi/config.py
+++ b/mkosi/config.py
@@ -821,6 +821,13 @@ class MkosiConfigParser:
             action="append",
             default=[],
         )
+        parser.add_argument(
+            "--no-pager",
+            action="store_false",
+            dest="pager",
+            default=True,
+            help="Enable paging for long output",
+        )
 
 
         group = parser.add_argument_group("Distribution options")
@@ -1329,4 +1336,3 @@ class MkosiConfigParser:
             setattr(namespace, s.dest, default)
 
         return namespace
-

diff --git a/mkosi/pager.py b/mkosi/pager.py
new file mode 100644 (file)
index 0000000..6131671
--- /dev/null
+++ b/mkosi/pager.py
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: LGPL-2.1+
+
+import os
+import pydoc
+from typing import Optional
+
+
+def page(text: str, enabled: Optional[bool]) -> None:
+    if enabled:
+        # Initialize less options from $MKOSI_LESS or provide a suitable fallback.
+        # F: don't page if one screen
+        # X: do not clear screen
+        # M: verbose prompt
+        # K: quit on ^C
+        os.environ["LESS"] = os.getenv("MKOSI_LESS", "FXMK")
+        pydoc.pager(text)
+    else:
+        print(text)