xref: /freebsd/usr.sbin/etcupdate/etcupdate.8 (revision e5b786625f7f82a1fa91e41823332459ea5550f9)
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2.\" Written by: John H. Baldwin <jhb@FreeBSD.org>
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26.Dd August 9, 2022
27.Dt ETCUPDATE 8
28.Os
29.Sh NAME
30.Nm etcupdate
31.Nd "manage updates to system files not updated by installworld"
32.Sh SYNOPSIS
33.Nm
34.Op Fl npBFN
35.Op Fl d Ar workdir
36.Op Fl r | Fl s Ar source | Fl t Ar tarball
37.Op Fl A Ar patterns
38.Op Fl D Ar destdir
39.Op Fl I Ar patterns
40.Op Fl L Ar logfile
41.Op Fl M Ar options
42.Op Fl m Ar make
43.Nm
44.Cm build
45.Op Fl BN
46.Op Fl d Ar workdir
47.Op Fl s Ar source
48.Op Fl L Ar logfile
49.Op Fl M Ar options
50.Op Fl m Ar make
51.Ar tarball
52.Nm
53.Cm diff
54.Op Fl d Ar workdir
55.Op Fl D Ar destdir
56.Op Fl I Ar patterns
57.Op Fl L Ar logfile
58.Nm
59.Cm extract
60.Op Fl BN
61.Op Fl d Ar workdir
62.Op Fl s Ar source | Fl t Ar tarball
63.Op Fl D Ar destdir
64.Op Fl L Ar logfile
65.Op Fl M Ar options
66.Op Fl m Ar make
67.Nm
68.Cm resolve
69.Op Fl p
70.Op Fl d Ar workdir
71.Op Fl D Ar destdir
72.Op Fl L Ar logfile
73.Nm
74.Cm revert
75.Op Fl d Ar workdir
76.Op Fl D Ar destdir
77.Op Fl L Ar logfile
78.Ar
79.Nm
80.Cm status
81.Op Fl d Ar workdir
82.Op Fl D Ar destdir
83.Sh DESCRIPTION
84The
85.Nm
86utility is a tool for managing updates to files that are not updated as
87part of
88.Sq make installworld
89such as files in
90.Pa /etc .
91It manages updates by doing a three-way merge of changes made to these
92files against the local versions.
93It is also designed to minimize the amount of user intervention with
94the goal of simplifying upgrades for clusters of machines.
95.Pp
96To perform a three-way merge,
97.Nm
98keeps copies of the current and previous versions of files that it manages.
99These copies are stored in two trees known as the
100.Dq current
101and
102.Dq previous
103trees.
104During a merge,
105.Nm
106compares the
107.Dq current
108and
109.Dq previous
110copies of each file to determine which changes need to be merged into the
111local version of each file.
112If a file can be updated without generating a conflict,
113.Nm
114will update the file automatically.
115If the local changes to a file conflict with the changes made to a file in
116the source tree,
117then a merge conflict is generated.
118The conflict must be resolved after the merge has finished.
119The
120.Nm
121utility will not perform a new merge until all conflicts from an earlier
122merge are resolved.
123.Sh MODES
124The
125.Nm
126utility supports several modes of operation.
127The mode is specified via an optional command argument.
128If present, the command must be the first argument on the command line.
129If a command is not specified, the default mode is used.
130.Ss Default Mode
131The default mode merges changes from the source tree to the destination
132directory.
133First,
134it updates the
135.Dq current
136and
137.Dq previous
138trees.
139Next,
140it compares the two trees merging changes into the destination directory.
141Finally,
142it displays warnings for any conditions it could not handle automatically.
143.Pp
144If the
145.Fl r
146option is not specified,
147then the first step taken is to update the
148.Dq current
149and
150.Dq previous
151trees.
152If a
153.Dq current
154tree already exists,
155then that tree is saved as the
156.Dq previous
157tree.
158An older
159.Dq previous
160tree is removed if it exists.
161By default the new
162.Dq current
163tree is built from a source tree.
164However,
165if a tarball is specified via the
166.Fl t
167option,
168then the tree is extracted from that tarball instead.
169.Pp
170Next,
171.Nm
172compares the files in the
173.Dq current
174and
175.Dq previous
176trees.
177If a file was removed from the
178.Dq current
179tree,
180then it will be removed from the destination directory only if it
181does not have any local modifications.
182If a file was added to the
183.Dq current
184tree,
185then it will be copied to the destination directory only if it
186would not clobber an existing file.
187If a file is changed in the
188.Dq current
189tree,
190then
191.Nm
192will attempt to merge the changes into the version of the file in the
193destination directory.
194If the merge encounters conflicts,
195then a version of the file with conflict markers will be saved for
196future resolution.
197If the merge does not encounter conflicts,
198then the merged version of the file will be saved in the destination
199directory.
200If
201.Nm
202is not able to safely merge in changes to a file other than a merge conflict,
203it will generate a warning.
204.Pp
205For each file that is updated a line will be output with a leading character
206to indicate the action taken.
207The possible actions follow:
208.Pp
209.Bl -tag -width "A" -compact -offset indent
210.It A
211Added
212.It C
213Conflict
214.It D
215Deleted
216.It M
217Merged
218.It U
219Updated
220.El
221.Pp
222Finally,
223if any warnings were encountered they are displayed after the merge has
224completed.
225.Pp
226Note that for certain files
227.Nm
228will perform post-install actions any time that the file is updated.
229Specifically,
230.Xr pwd_mkdb 8
231is invoked if
232.Pa /etc/master.passwd
233is changed,
234.Xr cap_mkdb 1
235is invoked to update
236.Pa /etc/login.conf.db
237if
238.Pa /etc/login.conf
239is changed,
240.Xr newaliases 1
241is invoked if
242.Pa /etc/mail/aliases
243is changed,
244.Xr services_mkdb 8
245is invoked if
246.Pa /etc/services
247is changed,
248.Xr tzsetup 8
249is invoked if
250.Pa /etc/localtime
251is changed and if
252.Fa /var/db/zoneinfo
253exists,
254and
255.Pa /etc/rc.d/motd
256is invoked if
257.Pa /etc/motd
258is changed.
259One exception is that if
260.Pa /etc/mail/aliases
261is changed and the destination directory is not the default,
262then a warning will be issued instead.
263This is due to a limitation of the
264.Xr newaliases 1
265command.
266Similarly,
267if
268.Pa /etc/motd
269is changed and the destination directory is not the default,
270then
271.Pa /etc/rc.d/motd
272will not be executed due to a limitation of that script.
273In this case no warning is issued as the result of
274.Pa /etc/rc.d/motd
275is merely cosmetic and will be corrected on the next reboot.
276.Ss Build Mode
277The
278.Cm build
279mode is used to build a tarball that contains a snapshot of a
280.Dq current
281tree.
282This tarball can be used by the default and extract modes.
283Using a tarball can allow
284.Nm
285to perform a merge without requiring a source tree that matches the
286currently installed world.
287The
288.Fa tarball
289argument specifies the name of the file to create.
290The file will be a
291.Xr tar 5
292file compressed with
293.Xr bzip2 1 .
294.Ss Diff Mode
295The
296.Cm diff
297mode compares the versions of files in the destination directory to the
298.Dq current
299tree and generates a unified format diff of the changes.
300This can be used to determine which files have been locally modified and how.
301Note that
302.Nm
303does not manage files that are not maintained in the source tree such as
304.Pa /etc/fstab
305and
306.Pa /etc/rc.conf .
307.Ss Extract Mode
308The
309.Cm extract
310mode generates a new
311.Dq current
312tree.
313Unlike the default mode,
314it does not save any existing
315.Dq current
316tree and does not modify any existing
317.Dq previous
318tree.
319The new
320.Dq current
321tree can either be built from a source tree or extracted from a tarball.
322.Ss Resolve Mode
323The
324.Cm resolve
325mode is used to resolve any conflicts encountered during a merge.
326In this mode,
327.Nm
328iterates over any existing conflicts prompting the user for actions to take
329on each conflicted file.
330For each file, the following actions are available:
331.Pp
332.Bl -tag -width "(tf) theirs-full" -compact
333.It (p)  postpone
334Ignore this conflict for now.
335.It (df) diff-full
336Show all changes made to the merged file as a unified diff.
337.It (e)  edit
338Change the merged file in an editor.
339.It (r)  resolved
340Install the merged version of the file into the destination directory.
341.It (mf) mine-full
342Use the version of the file in the destination directory and ignore any
343changes made to the file in the
344.Dq current
345tree.
346.It (tf) theirs-full
347Use the version of the file from the
348.Dq current
349tree and discard any local changes made to the file.
350.It (h)  help
351Display the list of commands.
352.El
353.Ss Revert Mode
354The
355.Cm revert
356mode is used to restore the stock versions of files.
357In this mode,
358.Nm
359installs the stock version of requested files.
360This mode cannot be used to restore directories, only individual files.
361.Ss Status Mode
362The
363.Cm status
364mode shows a summary of the results of the most recent merge.
365First it lists any files for which there are unresolved conflicts.
366Next it lists any warnings generated during the last merge.
367If the last merge did not generate any conflicts or warnings,
368then nothing will be output.
369.Sh OPTIONS
370The following options are available.
371Note that most options do not apply to all modes.
372.Bl -tag -width ".Fl A Ar patterns"
373.It Fl A Ar patterns
374Always install the new version of any files that match any of the patterns
375listed in
376.Ar patterns .
377Each pattern is evaluated as an
378.Xr sh 1
379shell pattern.
380This option may be specified multiple times to specify multiple patterns.
381Multiple space-separated patterns may also be specified in a single
382option.
383Note that ignored files specified via the
384.Ev IGNORE_FILES
385variable or the
386.Fl I
387option will not be installed.
388.It Fl B
389Do not build generated files in a private object tree.
390Instead,
391reuse the generated files from a previously built object tree that matches
392the source tree.
393This can be useful to avoid gratuitous conflicts in
394.Xr sendmail 8
395configuration
396files when bootstrapping.
397It can also be useful for building a tarball that matches a specific
398world build.
399.It Fl D Ar destdir
400Specify an alternate destination directory as the target of a merge.
401This is analogous to the
402.Dv DESTDIR
403variable used with
404.Sq make installworld .
405The default destination directory is an empty string which results in
406merges updating
407.Pa /etc
408on the local machine.
409.It Fl d Ar workdir
410Specify an alternate directory to use as the work directory.
411The work directory is used to store the
412.Dq current
413and
414.Dq previous
415trees as well as unresolved conflicts.
416The default work directory is
417.Pa <destdir>/var/db/etcupdate .
418.It Fl F
419Ignore changes in the FreeBSD ID string when comparing files in the
420destination directory to files in either of the
421.Dq current
422or
423.Dq previous
424trees.
425In
426.Cm diff
427mode,
428this reduces noise due to FreeBSD ID string changes in the output.
429During an update this can simplify handling for harmless conflicts caused
430by FreeBSD ID string changes.
431.Pp
432Specifically,
433if a file in the destination directory is identical to the same file in the
434.Dq previous
435tree modulo the FreeBSD ID string,
436then the file is treated as if it was unmodified and the
437.Dq current
438version of the file will be installed.
439Similarly,
440if a file in the destination directory is identical to the same file in the
441.Dq current
442tree modulo the FreeBSD ID string,
443then the
444.Dq current
445version of the file will be installed to update the ID string.
446If the
447.Dq previous
448and
449.Dq current
450versions of the file are identical,
451then
452.Nm
453will not change the file in the destination directory.
454.Pp
455Due to limitations in the
456.Xr diff 1
457command,
458this option may not have an effect if there are other changes in a file that
459are close to the FreeBSD ID string.
460.It Fl I Ar patterns
461Ignore any files that match any of the patterns listed in
462.Ar patterns .
463No warnings or other messages will be generated for those files during a
464merge.
465Each pattern is evaluated as an
466.Xr sh 1
467shell pattern.
468This option may be specified multiple times to specify multiple patterns.
469Multiple space-separated patterns may also be specified in a single
470option.
471.It Fl L Ar logfile
472Specify an alternate path for the log file.
473The
474.Nm
475utility logs each command that it invokes along with the standard output
476and standard error to this file.
477By default the log file is stored in a file named
478.Pa log
479in the work directory.
480.It Fl M Ar options
481Pass
482.Ar options
483as additional parameters to
484.Xr make 1
485when building a
486.Dq current
487tree.
488This can be used for to set the
489.Dv TARGET
490or
491.Dv TARGET_ARCH
492variables for a cross-build.
493.It Fl m Ar make
494Use
495.Ar make
496as the
497.Xr make 1
498binary when building a
499.Dq current
500tree.
501.It Fl n
502Enable
503.Dq dry-run
504mode.
505Do not merge any changes to the destination directory.
506Instead,
507report what actions would be taken during a merge.
508Note that the existing
509.Dq current
510and
511.Dq previous
512trees will not be changed.
513If the
514.Fl r
515option is not specified,
516then a temporary
517.Dq current
518tree will be extracted to perform the comparison.
519.It Fl N
520Perform a
521.Dv NO_ROOT
522build when building a
523.Dq current
524tree.
525The resulting tree will include a corresponding
526.Pa METALOG
527file at its root.
528.It Fl p
529Enable
530.Dq pre-world
531mode.
532Only merge changes to files that are necessary to successfully run
533.Sq make installworld
534or
535.Sq make installkernel .
536When this flag is enabled,
537the existing
538.Dq current
539and
540.Dq previous
541trees are left alone.
542Instead,
543a temporary tree is populated with the necessary files.
544This temporary tree is compared against the
545.Dq current
546tree.
547This allows a normal update to be run after
548.Sq make installworld
549has completed.
550Any conflicts generated during a
551.Dq pre-world
552update should be resolved by a
553.Dq pre-world
554.Cm resolve .
555.It Fl r
556Do not update the
557.Dq current
558and
559.Dq previous
560trees during a merge.
561This can be used to
562.Dq re-run
563a previous merge operation.
564.It Fl s Ar source
565Specify an alternate source tree to use when building or extracting a
566.Dq current
567tree.
568The default source tree is
569.Pa /usr/src .
570.It Fl t Ar tarball
571Extract a new
572.Dq current
573tree from a tarball previously generated by the
574.Cm build
575command rather than building the tree from a source tree.
576.El
577.Sh CONFIG FILE
578The
579.Nm
580utility can also be configured by setting variables in an optional
581configuration file named
582.Pa /etc/etcupdate.conf .
583Note that command line options override settings in the configuration file.
584The configuration file is executed by
585.Xr sh 1 ,
586so it uses that syntax to set configuration variables.
587The following variables can be set:
588.Bl -tag -width ".Ev ALWAYS_INSTALL"
589.It Ev ALWAYS_INSTALL
590Always install files that match any of the patterns listed in this variable
591similar to the
592.Fl A
593option.
594.It Ev DESTDIR
595Specify an alternate destination directory similar to the
596.Fl D
597option.
598.It Ev EDITOR
599Specify a program to edit merge conflicts.
600.It Ev FREEBSD_ID
601Ignore changes in the FreeBSD ID string similar to the
602.Fl F
603option.
604This is enabled by setting the variable to a non-empty value.
605.It Ev IGNORE_FILES
606Ignore files that match any of the patterns listed in this variable
607similar to the
608.Fl I
609option.
610.It Ev LOGFILE
611Specify an alternate path for the log file similar to the
612.Fl L
613option.
614.It Ev MAKE_CMD
615Specify the
616.Xr make 1
617binary when building a
618.Dq current
619tree similar to the
620.Fl m
621option.
622.It Ev MAKE_OPTIONS
623Pass additional options to
624.Xr make 1
625when building a
626.Dq current
627tree similar to the
628.Fl M
629option.
630.It Ev SRCDIR
631Specify an alternate source tree similar to the
632.Fl s
633option.
634.It Ev WORKDIR
635Specify an alternate work directory similar to the
636.Fl d
637option.
638.El
639.Sh ENVIRONMENT
640The
641.Nm
642utility uses the program identified in the
643.Ev EDITOR
644environment variable to edit merge conflicts.
645If
646.Ev EDITOR
647is not set,
648.Xr vi 1
649is used as the default editor.
650.Sh FILES
651.Bl -tag -width ".Pa /var/db/etcupdate/log" -compact
652.It Pa /etc/etcupdate.conf
653Optional config file.
654.It Pa /var/db/etcupdate
655Default work directory used to store trees and other data.
656.It Pa /var/db/etcupdate/log
657Default log file.
658.El
659.Sh EXIT STATUS
660.Ex -std
661.Sh EXAMPLES
662To compare the files in
663.Pa /etc
664with the stock versions:
665.Pp
666.Dl "etcupdate diff"
667.Pp
668To merge changes after an upgrade via the buildworld and installworld process:
669.Pp
670.Dl "etcupdate"
671.Pp
672To resolve any conflicts generated during a merge:
673.Pp
674.Dl "etcupdate resolve"
675.Ss Bootstrapping
676The
677.Nm
678utility may need to be bootstrapped before it can be used.
679The
680.Cm diff
681command will fail with an error about a missing reference tree if
682bootstrapping is needed.
683.Pp
684Bootstrapping
685.Nm
686requires a source tree that matches the currently installed world.
687The easiest way to ensure this is to bootstrap
688.Nm
689before updating the source tree to start the next world upgrade cycle.
690First,
691generate a reference tree:
692.Pp
693.Dl "etcupdate extract"
694.Pp
695Second,
696use the
697.Cm diff
698command to compare the reference tree to your current files in
699.Pa /etc .
700Undesired differences should be removed using an editor,
701.Xr patch 1 ,
702or by copying files from the reference tree
703.Po
704located at
705.Pa /var/db/etcupdate/current
706by default
707.Pc
708.
709.Pp
710If the tree at
711.Pa /usr/src
712is already newer than the currently installed world,
713a new tree matching the currently installed world can be checked out to
714a temporary location.
715The reference tree for
716.Nm
717can then be generated via:
718.Pp
719.Dl "etcupdate extract -s /path/to/tree"
720.Pp
721The
722.Cm diff
723command can be used as above to remove undesired differences.
724Afterwards,
725the changes in the tree at
726.Pa /usr/src
727can be merged via a regular merge.
728.Sh DIAGNOSTICS
729The following warning messages may be generated during a merge.
730Note that several of these warnings cover obscure cases that should occur
731rarely if at all in practice.
732For example,
733if a file changes from a file to a directory in the
734.Dq current
735tree
736and the file was modified in the destination directory,
737then a warning will be triggered.
738In general,
739when a warning references a pathname,
740the corresponding file in the destination directory is not changed by a
741merge operation.
742.Bl -diag
743.It "Directory mismatch: <path> (<type>)"
744An attempt was made to create a directory at
745.Pa path
746but an existing file of type
747.Dq type
748already exists for that path name.
749.It "Modified link changed: <file> (<old> became <new>)"
750The target of a symbolic link named
751.Pa file
752was changed from
753.Dq old
754to
755.Dq new
756in the
757.Dq current
758tree.
759The symbolic link has been modified to point to a target that is neither
760.Dq old
761nor
762.Dq new
763in the destination directory.
764.It "Modified mismatch: <file> (<new> vs <dest>)"
765A file named
766.Pa file
767of type
768.Dq new
769was modified in the
770.Dq current
771tree,
772but the file exists as a different type
773.Dq dest
774in the destination directory.
775.It "Modified <type> changed: <file> (<old> became <new>)"
776A file named
777.Pa file
778changed type from
779.Dq old
780in the
781.Dq previous
782tree to type
783.Dq new
784in the
785.Dq current
786tree.
787The file in the destination directory of type
788.Dq type
789has been modified,
790so it could not be merged automatically.
791.It "Modified <type> remains: <file>"
792The file of type
793.Dq type
794named
795.Pa file
796has been removed from the
797.Dq current
798tree,
799but it has been locally modified.
800The modified version of the file remains in the destination directory.
801.It "Needs update: /etc/localtime (required manual update via tzsetup(8))"
802The
803.Fa /var/db/zoneinfo
804file does not exist,
805so
806.Nm
807was not able to refresh
808.Fa /etc/localtime
809from its source file in
810.Fa /usr/share/zoneinfo .
811Running
812.Xr tzsetup 8
813will both refresh
814.Fa /etc/localtime
815and generate
816.Fa /var/db/zoneinfo
817permitting future updates to refresh
818.Fa /etc/localtime
819automatically.
820.It "Needs update: /etc/mail/aliases.db (required manual update via newaliases(1))"
821The file
822.Pa /etc/mail/aliases
823was updated during a merge with a non-empty destination directory.
824Due to a limitation of the
825.Xr newaliases 1
826command,
827.Nm
828was not able to automatically update the corresponding aliases database.
829.It "New file mismatch: <file> (<new> vs <dest>)"
830A new file named
831.Pa file
832of type
833.Dq new
834has been added to the
835.Dq current
836tree.
837A file of that name already exists in the destination directory,
838but it is of a different type
839.Dq dest .
840.It "New link conflict: <file> (<new> vs <dest>)"
841A symbolic link named
842.Pa file
843has been added to the
844.Dq current
845tree that links to
846.Dq new .
847A symbolic link of the same name already exists in the destination
848directory,
849but it links to a different target
850.Dq dest .
851.It "Non-empty directory remains: <file>"
852The directory
853.Pa file
854was removed from the
855.Dq current
856tree,
857but it contains additional files in the destination directory.
858These additional files as well as the directory remain.
859.It "Remove mismatch: <file> (<old> became <new>)"
860A file named
861.Pa file
862changed from type
863.Dq old
864in the
865.Dq previous
866tree to type
867.Dq new
868in the
869.Dq current
870tree,
871but it has been removed in the destination directory.
872.It "Removed file changed: <file>"
873A file named
874.Pa file
875was modified in the
876.Dq current
877tree,
878but it has been removed in the destination directory.
879.It "Removed link changed: <file> (<old> became <new>)"
880The target of a symbolic link named
881.Pa file
882was changed from
883.Dq old
884to
885.Dq new
886in the
887.Dq current
888tree,
889but it has been removed in the destination directory.
890.El
891.Sh SEE ALSO
892.Xr cap_mkdb 1 ,
893.Xr diff 1 ,
894.Xr make 1 ,
895.Xr newaliases 1 ,
896.Xr sh 1 ,
897.Xr mergemaster 8 ,
898.Xr pwd_mkdb 8 ,
899.Xr services_mkdb 8 ,
900.Xr tzsetup 8
901.Sh HISTORY
902The
903.Nm
904utility first appeared in
905.Fx 10.0 .
906.Sh AUTHORS
907The
908.Nm
909utility was written by
910.An John Baldwin Aq Mt jhb@FreeBSD.org .
911.Sh BUGS
912Rerunning a merge does not automatically delete conflicts left over from a
913previous merge.
914Any conflicts must be resolved before the merge can be rerun.
915It is not clear if this is a feature or a bug.
916.Pp
917There is no way to easily automate conflict resolution for specific files.
918For example, one can imagine a syntax along the lines of
919.Pp
920.Dl "etcupdate resolve tf /some/file"
921.Pp
922to resolve a specific conflict in an automated fashion.
923.Pp
924Bootstrapping
925.Nm
926often results in gratuitous diffs in
927.Pa /etc/mail/*.cf
928that cause conflicts in the first merge.
929If an object tree that matches the source tree is present when bootstrapping,
930then passing the
931.Fl B
932flag to the
933.Cm extract
934command can work around this.
935