Create, Modify, and Delete Files
Prerequisites
- Read the tutorial Tutorial for Running Examples
- Ensure you have read and understand the section on how to make an example stand alone
- Ensure you have read the note at the end of that section regarding modification of the body common control to the following:
body common control {
inputs => {
"libraries/cfengine_stdlib.cf",
};
}
Note: This change is not necessary for supporting each of the examples in this tutorial. It will be included only in those examples that require it.
List Files
Note: The following workflow assumes the directory /home/user already exists. If it does not either create the directory or adjust the example to a path of your choosing.
Create a file /var/cfengine/masterfiles/file_test.cf that includes the following text:
bundle agent list_file { vars: "ls" slist => lsdir("/home/user","test_plain.txt","true"); reports: "ls: $(ls)"; }
Run the following command to remove any existing test file at the location we wish to use for testing this example:
rm /home/user/test_plain.txt
Test to ensure there is no file /home/user/test_plain.txt, using the following command (the expected result is that there should be no file listed at the location /home/user/test_plain.txt):
ls /home/user/test_plain.txt
Run the following command to instruct CFEngine to see if the file exists (the expected result is that no report will be generated (because the file does not exist):
/var/cfengine/bin/cf-agent --no-lock --file /var/cfengine/masterfiles/file_test.cf --bundlesequence list_file
Create a file for testing the example, using the following command:
touch /home/user/test_plain.txt
Run the following command to instruct CFEngine to search for the file (the expected result is that a report will be generated, because the file exists):
/var/cfengine/bin/cf-agent --no-lock --file /var/cfengine/masterfiles/file_test.cf --bundlesequence list_file
Double check the file exists, using the following command (the expected result is that there will be a file listed at the location /home/user/test_plain.txt):
ls /home/user/test_plain.txt
Run the following command to remove the file:
rm /home/user/test_plain.txt
Create a File
bundle agent testbundle
{
files:
"/home/user/test_plain.txt"
perms => system,
create => "true";
}
bundle agent list_file
{
vars:
"ls" slist => lsdir("/home/user","test_plain.txt","true");
reports:
"ls: $(ls)";
}
bundle agent list_file_2
{
vars:
"ls" slist => lsdir("/home/user","test_plain.txt","true");
reports:
"ls: $(ls)";
}
body perms system
{
mode => "0640";
}
ls /home/user/test_plain.txt
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,testbundle,list_file_2
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,list_file_2
ls /home/user/test_plain.txt
rm /home/user/test_plain.txt
Delete a File
body common control {
inputs => {
"libraries/cfengine_stdlib.cf",
};
}
bundle agent testbundle
{
files:
"/home/user/test_plain.txt"
perms => system,
create => "true";
}
bundle agent test_delete
{
files:
"/home/user/test_plain.txt"
delete => tidy;
}
bundle agent list_file
{
vars:
"ls" slist => lsdir("/home/user","test_plain.txt","true");
reports:
"ls: $(ls)";
}
bundle agent list_file_2
{
vars:
"ls" slist => lsdir("/home/user","test_plain.txt","true");
reports:
"ls: $(ls)";
}
body perms system
{
mode => "0640";
}
rm /home/user/test_plain.txt
ls /home/user/test_plain.txt
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,testbundle,list_file_2
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,list_file_2
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,test_delete,list_file_2
ls /home/user/test_plain.txt
rm /home/user/test_plain.txt
(last command will throw an error because the file doesn't exist!)
Modify a File
rm /home/user/test_plain.txt
ls /home/user/test_plain.txt
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,testbundle,list_file_2
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,list_file_2
body common control {
inputs => {
"libraries/cfengine_stdlib.cf",
};
}
bundle agent testbundle
{
files:
"/home/user/test_plain.txt"
perms => system,
create => "true";
}
bundle agent test_delete
{
files:
"/home/user/test_plain.txt"
delete => tidy;
}
bundle agent list_file
{
vars:
"ls" slist => lsdir("/home/user","test_plain.txt","true");
reports:
"ls: $(ls)";
}
bundle agent list_file_2
{
vars:
"ls" slist => lsdir("/home/user","test_plain.txt","true");
reports:
"ls: $(ls)";
}
# Finds the file, if exists calls bundle to edit line
bundle agent outer_bundle_1
{
files:
"/home/user/test_plain.txt"
create => "false",
edit_line => inner_bundle_1;
}
# Finds the file, if exists calls bundle to edit line
bundle agent outer_bundle_2
{
files:
"/home/user/test_plain.txt"
create => "false",
edit_line => inner_bundle_2;
}
# Inserts lines
bundle edit_line inner_bundle_1
{
vars:
"msg" string => "Helloz to World!";
insert_lines:
"$(msg)";
}
# Replaces lines
bundle edit_line inner_bundle_2
{
replace_patterns:
"Helloz to World!"
replace_with => hello_world;
}
body replace_with hello_world
{
replace_value => "Hello World";
occurrences => "all";
}
body perms system
{
mode => "0640";
}
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,test_delete,list_file_2
ls /home/user/test_plain.txt
rm /home/user/test_plain.txt
Copy a File and Edit its Text
body common control {
inputs => {
"libraries/cfengine_stdlib.cf",
};
}
bundle agent testbundle
{
files:
"/home/ichien/test_plain.txt"
perms => system,
create => "true";
reports:
"test_plain.txt has been created";
}
bundle agent test_delete
{
files:
"/home/ichien/test_plain.txt"
delete => tidy;
}
bundle agent do_files_exist
{
vars:
"mylist" slist => { "/home/ichien/test_plain.txt", "/home/ichien/test_plain_2.txt" };
classes:
"exists" expression => filesexist("@(mylist)");
reports:
exists::
"test_plain.txt and test_plain_2.txt files exist";
!exists::
"test_plain.txt and test_plain_2.txt files do not exist";
}
bundle agent do_files_exist_2
{
vars:
"mylist" slist => { "/home/ichien/test_plain.txt", "/home/ichien/test_plain_2.txt" };
classes:
"exists" expression => filesexist("@(mylist)");
reports:
exists::
"test_plain.txt and test_plain_2.txt files both exist";
!exists::
"test_plain.txt and test_plain_2.txt files do not exist";
}
bundle agent list_file_1
{
vars:
"ls1" slist => lsdir("/home/ichien","test_plain.txt","true");
"ls2" slist => lsdir("/home/ichien","test_plain_2.txt","true");
"file_content_1" string => readfile( "/home/ichien/test_plain.txt" , "33" );
"file_content_2" string => readfile( "/home/ichien/test_plain_2.txt" , "33" );
reports:
#"ls1: $(ls1)";
#"ls2: $(ls2)";
"Contents of /home/ichien/test_plain.txt = $(file_content_1)";
"Contents of /home/ichien/test_plain_2.txt = $(file_content_2)";
}
bundle agent list_file_2
{
vars:
"ls1" slist => lsdir("/home/ichien","test_plain.txt","true");
"ls2" slist => lsdir("/home/ichien","test_plain_2.txt","true");
"file_content_1" string => readfile( "/home/ichien/test_plain.txt" , "33" );
"file_content_2" string => readfile( "/home/ichien/test_plain_2.txt" , "33" );
reports:
#"ls1: $(ls1)";
#"ls2: $(ls2)";
"Contents of /home/ichien/test_plain.txt = $(file_content_1)";
"Contents of /home/ichien/test_plain_2.txt = $(file_content_2)";
}
bundle agent outer_bundle_1
{
files:
"/home/ichien/test_plain.txt"
create => "false",
edit_line => inner_bundle_1;
}
# Copies file
bundle agent copy_a_file
{
files:
"/home/ichien/test_plain_2.txt"
copy_from => local_cp("/home/ichien/test_plain.txt");
reports:
"test_plain.txt has been copied to test_plain_2.txt";
}
bundle agent outer_bundle_2
{
files:
"/home/ichien/test_plain_2.txt"
create => "false",
edit_line => inner_bundle_2;
}
bundle edit_line inner_bundle_1
{
vars:
"msg" string => "Helloz to World!";
insert_lines:
"$(msg)";
reports:
"inserted $(msg) into test_plain.txt";
}
bundle edit_line inner_bundle_2
{
replace_patterns:
"Helloz to World!"
replace_with => hello_world;
reports:
"Text in test_plain_2.txt has been replaced";
}
body replace_with hello_world
{
replace_value => "Hello World";
occurrences => "all";
}
body perms system
{
mode => "0640";
}
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence test_delete,do_files_exist,testbundle,outer_bundle_1,copy_a_file,do_files_exist_2,list_file_1,outer_bundle_2,list_file_2