Refactor creation of logscript

Instead of using interpolation and here-strings, write function that
renders mustache template. This approach makes code cleaner and more
scalable.

  * data/logscript: add mustach template of 'log/run' script, that is
    installed when "logscript" option in effect.

  * Makefile: set DH_RUNIT_DATADIR variable in "check" target. This way,
    templates from ./data/ directory are used, not from system location.

  * debian/control: add dependency on Text::Hogan library --
    implementation of "mustache" templating standard.

  * dh_runit(template_from_data_directory): new function

  * dh_runit: install 'log/run' with "template_from_data_directory"
    function.

  * t/928935.t: check that "logscript" option correctly creates
    'log/run' script, with correct permissions.

6 files changed, 44 insertions, 14 deletions

diff --git a/Makefile b/Makefile
index 2f77795..0a6c500 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,9 @@
 all:
 check:
-        PATH=$(CURDIR):$(PATH) DH_AUTOSCRIPTDIR=$(CURDIR) prove -I.
+        PATH=$(CURDIR):$(PATH) \
+        DH_AUTOSCRIPTDIR=$(CURDIR) \
+        DH_RUNIT_DATADIR=$(CURDIR)/data \
+        prove -I.
 autopkgtest:
         prove -I.
 .PHONY: check
diff --git a/data/logscript b/data/logscript
new file mode 100644
index 0000000..1ebfb77
--- /dev/null
+++ b/data/logscript
@@ -0,0 +1,5 @@
+#!/bin/sh
+chown -R runit-log:adm '{{ logdir }}'
+chmod 750 '{{ logdir }}'
+chmod u+rw,g+r,o-rwx '{{ logdir }}'/*
+exec chpst -u runit-log svlogd -tt '{{ logdir }}'
diff --git a/debian/control b/debian/control
index 946f548..9b889e1 100644
--- a/debian/control
+++ b/debian/control
@@ -7,6 +7,7 @@ Build-Depends:
  perl,
  perl-doc,
  libfile-copy-recursive-perl,
+ libtext-hogan-perl,
 Standards-Version: 4.3.0
 Vcs-Browser: https://salsa.debian.org/runit-team/dh-runit
 Vcs-Git: https://salsa.debian.org/runit-team/dh-runit.git
@@ -15,6 +16,7 @@ Homepage: https://salsa.debian.org/runit-team/dh-runit
 Package: dh-runit
 Architecture: all
 Depends: debhelper (>= 9),
+         libtext-hogan-perl,
          ${misc:Depends},
          ${shlibs:Depends}
 Description: debhelper add-on to handle runit runscripts
diff --git a/debian/dh-runit.install b/debian/dh-runit.install
index e3f2d9d..a08eda2 100644
--- a/debian/dh-runit.install
+++ b/debian/dh-runit.install
@@ -2,3 +2,4 @@ dh_runit /usr/bin
 postrm-runit   /usr/share/debhelper/autoscripts
 postinst-runit   /usr/share/debhelper/autoscripts
 runit.pm /usr/share/perl5/Debian/Debhelper/Sequence
+data/*   /usr/share/dh-runit/data/
diff --git a/dh_runit b/dh_runit
index 3f45866..9147607 100755
--- a/dh_runit
+++ b/dh_runit
@@ -7,9 +7,33 @@ use Debian::Debhelper::Dh_Lib;
 use File::Find;
 use File::Path qw(make_path);
 use File::stat;
+use Text::Hogan::Compiler;
+use File::Slurp qw(read_file write_file);
 use feature 'signatures';
 no warnings 'experimental';
 
+# Render mustache template {name} from data directory into {dest},
+# substituting {values} hash. If {perm} argument is provided, it is used
+# set permissions of {dest}. Intermediate directories to ${dest} are
+# created as needed.
+#
+# Data directory is specified by {DH_RUNIT_DATADIR} environment
+# variable, and defaults to /usr/share/dh-runit/data.
+sub template_from_data_directory {
+    my ($name, $dest, $values, $perm) = @_;
+    my $datadir = $ENV{DH_RUNIT_DATADIR} || "/usr/share/dh-runit/data";
+    my $template = read_file("${datadir}/${name}");
+    my $compiler = Text::Hogan::Compiler->new;
+    my $output = $compiler->compile($template)->render($values);
+
+    make_path(dirname($dest));
+    write_file($dest, $output);
+
+    if (defined $perm) {
+        chmod $perm, $dest;
+    }
+}
+
 sub parse_options($opts) {
     my $conf = { enable => 1, since => '0.0-0' };
     for my $opt (split(/,/, $opts)) {
@@ -98,17 +122,9 @@ PKG: foreach my $pkg (@{$dh{DOPACKAGES}}) {
             install_dir("$sv_dir/$name/log");
             install_dir($tmp . $logdir);
 
-            my $run_log = "$sv_dir/$name/log/run";
-            open(RUN_LOG, ">$run_log") || die $!;
-            print RUN_LOG << "HERE";
-#!/bin/sh
-chown -R runit-log:adm '$logdir'
-chmod 750 '$logdir'
-chmod u+rw,g+r,o-rwx '$logdir'/*
-exec chpst -u runit-log svlogd -tt '$logdir'
-HERE
-            close(RUN_LOG);
-            chmod(0755, $run_log);
+            template_from_data_directory('logscript', "$sv_dir/$name/log/run",
+                                         { logdir => $logdir }, 0755);
+
             make_symlink("/etc/sv/$name/log/supervise",
                          "/var/lib/runit/log/supervise/$name", $tmp);
             install_dir("$tmp/var/lib/runit/log/supervise/$name");
diff --git a/t/928935.t b/t/928935.t
index 52774ed..5d2fea1 100644
--- a/t/928935.t
+++ b/t/928935.t
@@ -1,10 +1,13 @@
 #!/usr/bin/perl
 use strict;
 use warnings;
-use Test::More tests => 2;
+use Test::More tests => 4;
 use T;
 
-system_ok('dh_runit', 'debian/test.runscript', 'name=test,noreplace');
+system_ok('dh_runit', 'debian/test.runscript', 'name=test,noreplace,logscript');
 
 my $noreplace = 'debian/dh-runit-test/usr/share/runit/meta/test/noreplace';
 ok(-f $noreplace, 'noreplace file correctly created');
+my $logscript = 'debian/dh-runit-test/etc/sv/test/log/run';
+ok(-f $logscript, 'logscript correctly created');
+ok(-x $logscript, 'logscript is executable');