cron_d resource¶
Use the cron_d resource to manage cron job files in the /etc/cron.d directory.
Warning
Chef also ships the cron resource for managing the monolithic /etc/crontab
file on platforms that lack cron.d support. See the cron resource for information on using that resource.
New in Chef Client 14.4.
Syntax¶
A cron_d resource block manages cron.d files. For example, to get a weekly cookbook report from the Chef Supermarket:
cron_d 'cookbooks_report' do
action :create
minute '0'
hour '0'
weekday '1'
user 'getchef'
mailto 'sysadmin@example.com'
home '/srv/supermarket/shared/system'
command %W{
cd /srv/supermarket/current &&
env RUBYLIB="/srv/supermarket/current/lib"
RAILS_ASSET_ID=`git rev-parse HEAD` RAILS_ENV="#{rails_env}"
bundle exec rake cookbooks_report
}.join(' ')
end
The full syntax for all of the properties that are available to the cron_d resource is:
cron_d 'name' do
command String
comment String
cookbook String
cron_name String # default value: 'name' unless specified
day Integer, String # default value: *
environment Hash
home String
hour Integer, String # default value: *
mailto String
minute Integer, String # default value: *
mode String, Integer # default value: 0600
month Integer, String # default value: *
path String
predefined_value String
random_delay Integer
shell String
user String # default value: root
weekday Integer, String # default value: *
action Symbol # defaults to :create if not specified
end
where:
cron_d
is the resource.name
is the name given to the resource block.action
identifies which steps the chef-client will take to bring the node into the desired state.command
,comment
,cookbook
,cron_name
,day
,environment
,home
,hour
,mailto
,minute
,mode
,month
,path
,predefined_value
,random_delay
,shell
,user
, andweekday
are the properties available to this resource.
Actions¶
The cron_d resource has the following actions:
:create
- Default. “Add a cron definition file to /etc/cron.d, but do not update an existing file.
:delete
- Remove a cron definition file from /etc/cron.d if it exists.
:create_if_missing
- Add a cron definition file to /etc/cron.d, but do not update an existing file.
:nothing
- Define this resource block to do nothing until notified by another resource to take action. When this resource is notified, this resource block is either run immediately or it is queued up to be run at the end of the Chef Client run.
Properties¶
The cron_d resource has the following properties:
command
Ruby Type: String |
REQUIRED
The command to be run, or the path to a file that contains the command to be run.
Some examples:
command if [ -x /usr/share/mdadm/checkarray ] && [ $(date +\%d) -le 7 ]; then /usr/share/mdadm/checkarray --cron --all --idle --quiet; fi
and:
command %w{ cd /srv/opscode-community-site/current && env RUBYLIB="/srv/opscode-community-site/current/lib" RAILS_ASSET_ID=`git rev-parse HEAD` RAILS_ENV="#{rails_env}" bundle exec rake cookbooks_report }.join(' ')
and:
command "/srv/app/scripts/daily_report"
comment
Ruby Type: String
A comment to place in the cron.d file.
cookbook
- Ruby Type: String
cron_name
Ruby Type: String | Default Value:
'name'
Set the name of the cron job. If this isn’t specified we’ll use the resource name.
day
Ruby Type: Integer, String | Default Value:
*
The day of month at which the cron entry should run (1 - 31).
environment
Ruby Type: Hash
A Hash containing additional arbitrary environment variables under which the cron job will be run in the form of
({"ENV_VARIABLE" => "VALUE"})
. (These variables must exist for a command to be run successfully.)home
Ruby Type: String
Set the
HOME
environment variable in the cron.d file.”hour
Ruby Type: Integer, String | Default Value:
*
The hour at which the cron entry is to run (0 - 23).
ignore_failure
Ruby Type: true, false | Default Value:
false
Continue running a recipe if a resource fails for any reason.
mailto
Ruby Type: String
Set the
MAILTO
environment variable in the cron.d file.minute
Ruby Type: Integer, String | Default Value:
*
The minute at which the cron entry should run (0 - 59).
mode
- Ruby Type: String, Integer | Default Value:
0600
month
Ruby Type: Integer, String | Default Value:
*
The month in the year on which a cron entry is to run (1 - 12).
notifies
Ruby Type: Symbol, ‘Chef::Resource[String]’
A resource may notify another resource to take action when its state changes. Specify a
'resource[name]'
, the:action
that resource should take, and then the:timer
for that action. A resource may notify more than one resource; use anotifies
statement for each resource to be notified.A timer specifies the point during the Chef Client run at which a notification is run. The following timers are available:
:before
- Specifies that the action on a notified resource should be run before processing the resource block in which the notification is located.
:delayed
- Default. Specifies that a notification should be queued up, and then executed at the end of the Chef Client run.
:immediate
,:immediately
- Specifies that a notification should be run immediately, per resource notified.
The syntax for
notifies
is:notifies :action, 'resource[name]', :timer
path
Ruby Type: String
Set the
PATH
environment variable in the cron.d file.predefined_value
Ruby Type: String
Schedule your cron job with one of the special predefined value instead of ** * pattern. This correspond to “@reboot”, “@yearly”, “@annually”, “@monthly”, “@weekly”, “@daily”, “@midnight” or “@hourly”.
random_delay
Ruby Type: Integer
Set the
RANDOM_DELAY
environment variable in the cron.d file.retries
Ruby Type: Integer | Default Value:
0
The number of times to catch exceptions and retry the resource.
retry_delay
Ruby Type: Integer | Default Value:
2
The retry delay (in seconds).
shell
Ruby Type: String
Set the
SHELL
environment variable in the cron.d file.subscribes
Ruby Type: Symbol, ‘Chef::Resource[String]’
A resource may listen to another resource, and then take action if the state of the resource being listened to changes. Specify a
'resource[name]'
, the:action
to be taken, and then the:timer
for that action.Note that
subscribes
does not apply the specified action to the resource that it listens to - for example:file '/etc/nginx/ssl/example.crt' do mode '0600' owner 'root' end service 'nginx' do subscribes :reload, 'file[/etc/nginx/ssl/example.crt]', :immediately end
In this case the
subscribes
property reloads thenginx
service whenever its certificate file, located under/etc/nginx/ssl/example.crt
, is updated.subscribes
does not make any changes to the certificate file itself, it merely listens for a change to the file, and executes the:reload
action for its resource (in this examplenginx
) when a change is detected.A timer specifies the point during the Chef Client run at which a notification is run. The following timers are available:
:before
- Specifies that the action on a notified resource should be run before processing the resource block in which the notification is located.
:delayed
- Default. Specifies that a notification should be queued up, and then executed at the end of the Chef Client run.
:immediate
,:immediately
- Specifies that a notification should be run immediately, per resource notified.
The syntax for
subscribes
is:subscribes :action, 'resource[name]', :timer
user
Ruby Type: String | Default Value:
root
The name of the user that runs the command.
weekday
Ruby Type: Integer, String | Default Value:
*
The day of the week on which this entry is to run (
0-7
,mon-sun
, or*
), where Sunday is both 0 and 7.
Examples¶
The following examples demonstrate various approaches for using resources in recipes
Run a program at a specified interval
cron_d 'noop' do
hour '5'
minute '0'
command '/bin/true'
end
Run an entry if a folder exists
cron_d 'ganglia_tomcat_thread_max' do
command "/usr/bin/gmetric
-n 'tomcat threads max'
-t uint32
-v '/usr/local/bin/tomcat-stat
--thread-max'"
only_if { ::File.exist?('/home/jboss') }
end
Run every Saturday, 8:00 AM
The following example shows a schedule that will run every hour at 8:00 each Saturday morning, and will then send an email to “admin@example.com” after each run.
cron_d 'name_of_cron_entry' do
minute '0'
hour '8'
weekday '6'
mailto 'admin@example.com'
action :create
end
Run only in November
The following example shows a schedule that will run at 8:00 PM, every weekday (Monday through Friday), but only in November:
cron_d 'name_of_cron_entry' do
minute '0'
hour '20'
day '*'
month '11'
weekday '1-5'
action :create
end