1Rex::Commands::File(3)User Contributed Perl DocumentationRex::Commands::File(3)
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3
4

NAME

6       Rex::Commands::File - Transparent File Manipulation
7

DESCRIPTION

9       With this module you can manipulate files.
10

SYNOPSIS

12        task "read_passwd", "server01", sub {
13          my $fh = file_read "/etc/passwd";
14          for my $line ($fh->read_all) {
15            print $line;
16          }
17          $fh->close;
18        };
19
20        task "read_passwd2", "server01", sub {
21          say cat "/etc/passwd";
22        };
23
24
25        task "write_passwd", "server01", sub {
26          my $fh = file_write "/etc/passwd";
27          $fh->write("root:*:0:0:root user:/root:/bin/sh\n");
28          $fh->close;
29        };
30
31        delete_lines_matching "/var/log/auth.log", matching => "root";
32        delete_lines_matching "/var/log/auth.log", matching => qr{Failed};
33        delete_lines_matching "/var/log/auth.log",
34                       matching => "root", qr{Failed}, "nobody";
35
36        file "/path/on/the/remote/machine",
37          source => "/path/on/local/machine";
38
39        file "/path/on/the/remote/machine",
40          content => "foo bar";
41
42        file "/path/on/the/remote/machine",
43          source => "/path/on/local/machine",
44          owner  => "root",
45          group  => "root",
46          mode  => 400,
47          on_change => sub { say shift, " was changed."; },
48          on_no_change => sub { say shift, " wasn't changed."; };
49

EXPORTED FUNCTIONS

51   template($file, @params)
52       Parse a template and return the content.
53
54       By default, it uses Rex::Template. If any of the template_ng or 1.3 (or
55       newer) feature flag is enabled, then Rex::Template::NG is used instead
56       of this module (recommended).
57
58       For more advanced functionality, you may use your favorite template
59       engine via the set_template_function configuration option.
60
61       Embedded templates
62
63       Use "__DATA__" to embed templates at the end of the file. Prefix
64       embedded template names with "@". If embedding multiple templates, mark
65       their end with @end.
66
67       Single template
68
69        my $content = template( '@hello', name => 'world' ); # Hello, world!
70        __DATA__
71        @hello
72        Hello, <%= $name -%>!
73
74       Multiple templates
75
76       Use @end to separate multiple templates inside "__DATA__".
77
78        my $content     = template( '@hello', name => 'world' ); # Hello, world!
79        my $alternative = template( '@hi',    name => 'world' ); # Hi, world!
80
81        __DATA__
82        @hello
83        Hello, <%= $name -%>!
84        @end
85
86        @hi
87        Hi, <%= $name -%>!
88        @end
89
90       File templates
91
92        my $content = template("/files/templates/vhosts.tpl",
93                      name      => "test.lan",
94                      webmaster => 'webmaster@test.lan');
95
96       The file name specified is subject to "path_map" processing as
97       documented under the file() function to resolve to a physical file
98       name.
99
100       In addition to the "path_map" processing, if the -E command line switch
101       is used to specify an environment name, existence of a file ending with
102       '.<env>' is checked and has precedence over the file without one, if it
103       exists. E.g. if rex is started as:
104
105        $ rex -E prod task1
106
107       then in task1 defined as:
108
109        task "task1", sub {
110           say template("files/etc/ntpd.conf");
111        };
112
113       will print the content of 'files/etc/ntpd.conf.prod' if it exists.
114
115       Note: the appended environment mechanism is always applied, after the
116       'path_map' mechanism, if that is configured.
117
118   file($file_name, %options)
119       This function is the successor of install file. Please use this
120       function to upload files to your server.
121
122        task "prepare", "server1", "server2", sub {
123          file "/file/on/remote/machine",
124            source => "/file/on/local/machine";
125
126          file "/etc/hosts",
127            content => template("templates/etc/hosts.tpl"),
128            owner  => "user",
129            group  => "group",
130            mode   => 700,
131            on_change => sub { say "Something was changed." },
132            on_no_change => sub { say "Nothing has changed." };
133
134          file "/etc/motd",
135            content => `fortune`;
136
137          file "/etc/named.conf",
138            content    => template("templates/etc/named.conf.tpl"),
139            no_overwrite => TRUE;  # this file will not be overwritten if already exists.
140
141          file "/etc/httpd/conf/httpd.conf",
142            source => "/files/etc/httpd/conf/httpd.conf",
143            on_change => sub { service httpd => "restart"; };
144
145          file "/etc/named.d",
146            ensure => "directory",  # this will create a directory
147            owner  => "root",
148            group  => "root";
149
150          file "/etc/motd",
151            ensure => "absent";   # this will remove the file or directory
152
153        };
154
155       The first parameter is either a string or an array reference. In the
156       latter case the function is called for all strings in the array.
157       Therefore, the following constructs are equivalent:
158
159         file '/tmp/test1', ensure => 'directory';
160         file '/tmp/test2', ensure => 'directory';
161
162         file [ qw( /tmp/test1 /tmp/test2 ) ], ensure => 'directory'; # use array ref
163
164         file [ glob('/tmp/test{1,2}') ], ensure => 'directory'; # explicit glob call for array contents
165
166       Use the glob carefully as it can leak local filesystem information
167       (e.g. when using wildcards).
168
169       The source is subject to a path resolution algorithm. This algorithm
170       can be configured using the set function to set the value of the
171       path_map variable to a hash containing path prefixes as its keys.  The
172       associated values are arrays listing the prefix replacements in order
173       of (decreasing) priority.
174
175         set "path_map", {
176           "files/" => [ "files/{environment}/{hostname}/_root_/",
177                         "files/{environment}/_root_/" ]
178         };
179
180       With this configuration, the file "files/etc/ntpd.conf" will be probed
181       for in the following locations:
182
183        - files/{environment}/{hostname}/_root_/etc/ntpd.conf
184        - files/{environment}/_root_/etc/ntpd.conf
185        - files/etc/ntpd.conf
186
187       Furthermore, if a path prefix matches multiple prefix entries in
188       'path_map', e.g. "files/etc/ntpd.conf" matching both "files/" and
189       "files/etc/", the longer matching prefix(es) have precedence over
190       shorter ones. Note that keys without a trailing slash (i.e.
191       "files/etc") will be treated as having a trailing slash when matching
192       the prefix ("files/etc/").
193
194       If no file is found using the above procedure and source is relative,
195       it will search from the location of your Rexfile or the .pm file if you
196       use Perl packages.
197
198       All the possible variables ('{environment}', '{hostname}', ...) are
199       documented in the CMDB YAML documentation.
200
201       Hooks
202
203       This function supports the following hooks:
204
205       before
206           This gets executed before anything is done. All original parameters
207           are passed to it, including the applied defaults ("ensure =>
208           'present'", resolved path for "source").
209
210           The return value of this hook overwrites the original parameters of
211           the function call.
212
213       before_change
214           This gets executed right before the new file is written. All
215           original parameters are passed to it, including the applied
216           defaults ("ensure => 'present'", resolved path for "source").
217
218       after_change
219           This gets executed right after the file is written. All original
220           parameters, including the applied defaults ("ensure => 'present'",
221           resolved path for "source"), and any returned results are passed to
222           it.
223
224       after
225           This gets executed right before the "file()" function returns. All
226           original parameters, including the applied defaults ("ensure =>
227           'present'", resolved path for "source"), and any returned results
228           are passed to it.
229
230   file_write($file_name)
231       This function opens a file for writing (it will truncate the file if it
232       already exists). It returns a Rex::FS::File object on success.
233
234       On failure it will die.
235
236        my $fh;
237        eval {
238          $fh = file_write("/etc/groups");
239        };
240
241        # catch an error
242        if($@) {
243          print "An error occurred. $@.\n";
244        }
245
246        # work with the filehandle
247        $fh->write("...");
248        $fh->close;
249
250   file_append($file_name)
251   file_read($file_name)
252       This function opens a file for reading. It returns a Rex::FS::File
253       object on success.
254
255       On failure it will die.
256
257        my $fh;
258        eval {
259          $fh = read("/etc/groups");
260        };
261
262        # catch an error
263        if($@) {
264          print "An error occurred. $@.\n";
265        }
266
267        # work with the filehandle
268        my $content = $fh->read_all;
269        $fh->close;
270
271   cat($file_name)
272       This function returns the complete content of $file_name as a string.
273
274        print cat "/etc/passwd";
275
276   delete_lines_matching($file, $regexp)
277       Delete lines that match $regexp in $file.
278
279        task "clean-logs", sub {
280           delete_lines_matching "/var/log/auth.log" => "root";
281        };
282
283   delete_lines_according_to($search, $file, @options)
284       This is the successor of the delete_lines_matching() function. This
285       function also allows the usage of on_change and on_no_change hooks.
286
287       It will search for $search in $file and remove the found lines. If
288       on_change hook is present it will execute this if the file was changed.
289
290        task "cleanup", "server1", sub {
291          delete_lines_according_to qr{^foo:}, "/etc/passwd",
292           on_change => sub {
293             say "removed user foo.";
294           };
295        };
296
297   append_if_no_such_line($file, $new_line, @regexp)
298       Append $new_line to $file if none in @regexp is found. If no regexp is
299       supplied, the line is appended unless there is already an identical
300       line in $file.
301
302        task "add-group", sub {
303          append_if_no_such_line "/etc/groups", "mygroup:*:100:myuser1,myuser2", on_change => sub { service sshd => "restart"; };
304        };
305
306       Since 0.42 you can use named parameters as well
307
308        task "add-group", sub {
309          append_if_no_such_line "/etc/groups",
310            line  => "mygroup:*:100:myuser1,myuser2",
311            regexp => qr{^mygroup},
312            on_change => sub {
313                       say "file was changed, do something.";
314                     };
315
316          append_if_no_such_line "/etc/groups",
317            line  => "mygroup:*:100:myuser1,myuser2",
318            regexp => [qr{^mygroup:}, qr{^ourgroup:}]; # this is an OR
319        };
320
321   append_or_amend_line($file, $line, @regexp)
322       Similar to append_if_no_such_line, but if the line in the regexp is
323       found, it will be updated. Otherwise, it will be appended.
324
325        task "update-group", sub {
326          append_or_amend_line "/etc/groups",
327            line  => "mygroup:*:100:myuser3,myuser4",
328            regexp => qr{^mygroup},
329            on_change => sub {
330              say "file was changed, do something.";
331            },
332            on_no_change => sub {
333              say "file was not changed, do something.";
334            };
335        };
336
337   extract($file [, %options])
338       This function extracts a file. The target directory optionally
339       specified with the `to` option will be created automatically.
340
341       Supported formats are .box, .tar, .tar.gz, .tgz, .tar.Z, .tar.bz2,
342       .tbz2, .zip, .gz, .bz2, .war, .jar.
343
344        task prepare => sub {
345          extract "/tmp/myfile.tar.gz",
346           owner => "root",
347           group => "root",
348           to   => "/etc";
349
350          extract "/tmp/foo.tgz",
351           type => "tgz",
352           mode => "g+rwX";
353        };
354
355       Can use the type=> option if the file suffix has been changed. (types
356       are tar, tgz, tbz, zip, gz, bz2)
357
358   sed($search, $replace, $file)
359       Search some string in a file and replace it.
360
361        task sar => sub {
362          # this will work line by line
363          sed qr{search}, "replace", "/var/log/auth.log";
364
365          # to use it in a multiline way
366          sed qr{search}, "replace", "/var/log/auth.log",
367           multiline => TRUE;
368        };
369
370       Like similar file management commands, it also supports "on_change" and
371       "on_no_change" hooks.
372
373
374
375perl v5.34.0                      2021-07-21            Rex::Commands::File(3)
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