doc/todo/Auto-setup_and_maintain_Mercurial_wrapper_hooks.mdwn

   1 Attempt to fix a `TODO` in `Automator.pm` in combination with the Mercurial backend.
   2
   3 1. To define hooks, Mercurial uses paths given in the config file `.hg/hgrc`. To enable Mercurial to call `ikiwiki-wrapper` automatically after blog/wiki setup, ikiwiki thus needs to create `hgrc`.
   4 2. To reflect changes in `$config{srcdir}` and/or `$config{mercurial_wrapper}`, relevant lines in `hgrc` need to be updated on wrapper creation.
   5
   6 ikiwiki can keep track of lines in `hgrc` for which it is responsible by adding a `.ikiwiki` suffix to its hooks. This is correct and recommended markup, Mercurial-wise.
   7
   8 Two ways follow below. I prefer the long one. --[[Daniel Andersson]]
   9
  10 Compact way (addresses only point 1)
  11 ------------------------------------
  12 [This patch at pastebin](http://pastebin.com/by9f4dwX) ([raw version](http://pastebin.com/raw.php?i=by9f4dwX)).
  13
  14 Set default `ikiwiki-wrapper` path.
  15
  16         diff -r 8faf136ca94f Setup/Automator.pm
  17         --- a/Setup/Automator.pm        Tue Jul 19 21:04:13 2011 +0200
  18         +++ b/Setup/Automator.pm        Wed Jul 20 15:33:21 2011 +0200
  19         @@ -75,8 +75,7 @@
  20                                 print STDERR "warning: do not know how to set up the bzr_wrapper hook!\n";
  21                         }
  22                         elsif ($config{rcs} eq 'mercurial') {
  23         -                       # TODO
  24         -                       print STDERR "warning: do not know how to set up the mercurial_wrapper hook!\n";
  25         +                       $config{mercurial_wrapper}=$config{srcdir}."/.hg/ikiwiki-wrapper";
  26                         }
  27                         elsif ($config{rcs} eq 'tla') {
  28                                 # TODO
  29
  30 Create `$config{srcdir}/.hg/hgrc` with hook info during auto-installation script. Use relative paths to not require manual `hgrc` intervention if `$config{srcdir}` is changed. If `$config{mercurial_wrapper}` is changed, manual edit of `hgrc` is needed to catch the new wrapper path.
  31
  32 (Is there a security risk with relative paths?)
  33
  34         @@ -187,6 +186,22 @@
  35                         die "ikiwiki --wrappers --setup $config{dumpsetup} failed";
  36                 }
  37
  38         +       # Setup initial config file for Mercurial to hook up the wrapper.
  39         +       if ($config{rcs} eq 'mercurial' && exists $config{mercurial_wrapper}
  40         +               && length $config{mercurial_wrapper}) {
  41         +               # Use a relative path to avoid having to manually change the
  42         +               # autogenerated hgrc if the user changes $config{srcdir}.
  43         +               use File::Spec;
  44         +               my $mercurial_wrapper_relpath=File::Spec->abs2rel($config{mercurial_wrapper}, $config{srcdir});
  45         +               open (HGRC, '>', $config{srcdir}.'/.hg/hgrc');
  46         +               print HGRC <<EOF;
  47         +[hooks]
  48         +post-commit.ikiwiki = $mercurial_wrapper_relpath
  49         +incoming.ikiwiki = $mercurial_wrapper_relpath
  50         +EOF
  51         +               close (HGRC);
  52         +       }
  53         +
  54                 # Add it to the wikilist.
  55                 mkpath("$ENV{HOME}/.ikiwiki");
  56                 open (WIKILIST, ">>$ENV{HOME}/.ikiwiki/wikilist") || die "$ENV{HOME}/.ikiwiki/wikilist: $!";
  57
  58
  59 Less compact but more robust way (addresses point 1 and 2)
  60 ----------------------------------------------------------
  61 [This complete patch at pastebin](http://pastebin.com/AcDHjbK6) ([raw version](http://pastebin.com/raw.php?i=AcDHjbK6)).
  62
  63 This way leaks onto additional files and adds general functionality that may or may not be wanted. The main part of the extra code is contained within `mercurial.pm`, though.
  64
  65 Set default `ikiwiki-wrapper` path.
  66
  67         diff -r b08179653c00 IkiWiki/Setup/Automator.pm
  68         --- a/IkiWiki/Setup/Automator.pm        Wed Jul 20 16:56:09 2011 +0200
  69         +++ b/IkiWiki/Setup/Automator.pm        Wed Jul 20 19:28:21 2011 +0200
  70         @@ -75,8 +75,7 @@
  71                                 print STDERR "warning: do not know how to set up the bzr_wrapper hook!\n";
  72                         }
  73                         elsif ($config{rcs} eq 'mercurial') {
  74         -                       # TODO
  75         -                       print STDERR "warning: do not know how to set up the mercurial_wrapper hook!\n";
  76         +                       $config{mercurial_wrapper}=$config{srcdir}."/.hg/ikiwiki-wrapper";
  77                         }
  78                         elsif ($config{rcs} eq 'tla') {
  79                                 # TODO
  80
  81 Create `$config{srcdir}/.hg/hgrc` during auto-installation with hook info.
  82
  83         @@ -182,6 +181,19 @@
  84                         }
  85                 }
  86
  87         +       # Setup initial config file for Mercurial to hook up the wrapper. The
  88         +       # path to the wrapper will be automatically added when it is generated.
  89         +       if ($config{rcs} eq 'mercurial' && exists $config{mercurial_wrapper}
  90         +               && length $config{mercurial_wrapper}) {
  91         +               open (HGRC, '>', $config{srcdir}.'/.hg/hgrc');
  92         +               print HGRC <<EOF;
  93         +[hooks]
  94         +post-commit.ikiwiki =
  95         +incoming.ikiwiki =
  96         +EOF
  97         +               close (HGRC);
  98         +       }
  99         +
 100                 # Add wrappers, make live.
 101                 if (system("ikiwiki", "--wrappers", "--setup", $config{dumpsetup}) != 0) {
 102                         die "ikiwiki --wrappers --setup $config{dumpsetup} failed";
 103
 104 `hgrc` is setup initially. Below follows code to keep `hgrc` updated.
 105
 106 Add backend specific function `rcs_wrapper_postcall()` for later call in `Wrappers.pm`.
 107
 108         diff -r b08179653c00 IkiWiki/Plugin/mercurial.pm
 109         --- a/IkiWiki/Plugin/mercurial.pm       Wed Jul 20 16:56:09 2011 +0200
 110         +++ b/IkiWiki/Plugin/mercurial.pm       Wed Jul 20 19:28:21 2011 +0200
 111         @@ -21,6 +21,7 @@
 112                 hook(type => "rcs", id => "rcs_diff", call => \&rcs_diff);
 113                 hook(type => "rcs", id => "rcs_getctime", call => \&rcs_getctime);
 114                 hook(type => "rcs", id => "rcs_getmtime", call => \&rcs_getmtime);
 115         +       hook(type => "rcs", id => "rcs_wrapper_postcall", call => \&rcs_wrapper_postcall);
 116          }
 117
 118          sub checkconfig () {
 119
 120 Pass variable to `gen_wrapper()` to decide if `rcs_wrapper_postcall()` should run. Default is `1` to update `hgrc`, since it is done non-intrusive (won't create `hgrc` if it doesn't exist, won't overwrite anything unless it is set by ikiwiki itself).
 121
 122         @@ -28,6 +29,7 @@
 123                         push @{$config{wrappers}}, {
 124                                 wrapper => $config{mercurial_wrapper},
 125                                 wrappermode => (defined $config{mercurial_wrappermode} ? $config{mercurial_wrappermode} : "06755"),
 126         +                       wrapper_postcall => (defined $config{mercurial_wrapper_hgrc_update} ? $config{mercurial_wrapper_hgrc_update} : "1"),
 127                         };
 128                 }
 129          }
 130
 131 Include default configuration value and comment.
 132
 133         @@ -53,6 +55,13 @@
 134                                 safe => 0,
 135                                 rebuild => 0,
 136                         },
 137         +               mercurial_wrapper_hgrc_update => {
 138         +                       type => "string",
 139         +                       example => "1",
 140         +                       description => "updates existing hgrc to reflect path changes for mercurial_wrapper",
 141         +                       safe => 0,
 142         +                       rebuild => 0,
 143         +               },
 144                         historyurl => {
 145                                 type => "string",
 146                                 example => "http://example.com:8000/log/tip/\[[file]]",
 147
 148 `hgrc` should be updated to point to the new wrapper path. The regexp transforms lines as e.g.
 149
 150         post-commit.ikiwiki = /home/daniel/blog/.hg/ikiwiki-wrapper-oldpath
 151         incoming.ikiwiki = /home/daniel/blog/.hg/ikiwiki-wrapper-oldpath
 152
 153 to
 154
 155         post-commit.ikiwiki = $config{mercurial_wrapper}
 156         incoming.ikiwiki = $config{mercurial_wrapper}
 157
 158 with absolute paths.
 159
 160         @@ -402,4 +411,23 @@
 161                 return findtimes($file, 0);
 162          }
 163
 164         +sub rcs_wrapper_postcall($) {
 165         +       # Update hgrc if it exists. Change post-commit/incoming hooks with the
 166         +       # .ikiwiki suffix to point to the wrapper path given in the setup file.
 167         +       # Work with a tempfile to not delete hgrc if the loop is interrupted
 168         +       # midway.
 169         +       my $hgrc=$config{srcdir}.'/.hg/hgrc';
 170         +       my $backup_suffix='.ikiwiki.bak';
 171         +       if (-e $hgrc) {
 172         +               use File::Spec;
 173         +               my $mercurial_wrapper_abspath=File::Spec->rel2abs($config{mercurial_wrapper}, $config{srcdir});
 174         +               local ($^I, @ARGV)=($backup_suffix, $hgrc);
 175         +               while (<>) {
 176         +                       s/^(post-commit|incoming)(\.ikiwiki[ \t]*=[ \t]*).*$/$1$2$mercurial_wrapper_abspath/;
 177         +                       print;
 178         +               }
 179         +               unlink($hgrc.$backup_suffix);
 180         +       }
 181         +}
 182         +
 183          1
 184
 185 `rcs_wrapper_postcall` is made available.
 186
 187         diff -r b08179653c00 IkiWiki.pm
 188         --- a/IkiWiki.pm        Wed Jul 20 16:56:09 2011 +0200
 189         +++ b/IkiWiki.pm        Wed Jul 20 19:28:21 2011 +0200
 190         @@ -2059,6 +2059,10 @@
 191                 $hooks{rcs}{rcs_getmtime}{call}->(@_);
 192          }
 193
 194         +sub rcs_wrapper_postcall (@) {
 195         +       $hooks{rcs}{rcs_wrapper_postcall}{call}->(@_);
 196         +}
 197         +
 198          sub rcs_receive () {
 199                 $hooks{rcs}{rcs_receive}{call}->();
 200          }
 201
 202
 203 `rcs_wrapper_postcall` is called if $config{wrapper_postcall} is true, which it should only be for Mercurial at the moment.
 204
 205         diff -r b08179653c00 IkiWiki/Wrapper.pm
 206         --- a/IkiWiki/Wrapper.pm        Wed Jul 20 16:56:09 2011 +0200
 207         +++ b/IkiWiki/Wrapper.pm        Wed Jul 20 19:28:21 2011 +0200
 208         @@ -238,6 +238,10 @@
 209                 }
 210                 #translators: The parameter is a filename.
 211                 debug(sprintf(gettext("successfully generated %s"), $wrapper));
 212         +
 213         +       if (defined $config{wrapper_postcall} && $config{wrapper_postcall} ) {
 214         +               IkiWiki::rcs_wrapper_postcall();
 215         +       }
 216          }
 217
 218          1