git Resource
This page is generated from the Chef Infra Client source code.To suggest a change, edit the git.rb file and submit a pull request to the Chef Infra Client repository.
Use the git resource to manage source control resources that exist in a git repository. git version 1.6.5 (or higher) is required to use all of the functionality in the git resource.
Syntax
A git resource block manages source control resources that exist in a git repository:
git "#{Chef::Config[:file_cache_path]}/app_name" do
repository node[:app_name][:git_repository]
revision node[:app_name][:git_revision]
action :sync
end
The full syntax for all of the properties that are available to the git resource is:
git 'name' do
additional_remotes Hash # default value: {}
checkout_branch String
depth Integer
destination String # default value: 'name' unless specified
enable_checkout true, false # default value: true
enable_submodules true, false # default value: false
environment Hash
group String, Integer
remote String # default value: "origin"
repository String
revision String # default value: "HEAD"
ssh_wrapper String
timeout Integer
user String, Integer
action Symbol # defaults to :sync if not specified
end
where:
git
is the resource.name
is the name given to the resource block.action
identifies which steps Chef Infra Client will take to bring the node into the desired state.additional_remotes
,checkout_branch
,depth
,destination
,enable_checkout
,enable_submodules
,environment
,group
,remote
,repository
,revision
,ssh_wrapper
,timeout
, anduser
are the properties available to this resource.
Actions
The git resource has the following actions:
:checkout
- Clone or check out the source. When a checkout is available, this provider does nothing.
:export
- Export the source, excluding or removing any version control artifacts.
:nothing
- This resource block does not act unless notified by another resource to take action. Once notified, this resource block either runs immediately or is queued up to run at the end of a Chef Infra Client run.
:sync
- (default) Update the source to the specified version, or get a new clone or checkout. This action causes a hard reset of the index and working tree, discarding any uncommitted changes.
Properties
The git resource has the following properties:
additional_remotes
- Ruby Type: Hash | Default Value:
{}
A Hash of additional remotes that are added to the git repository configuration.
checkout_branch
- Ruby Type: String
Do a one-time checkout from git or use when a branch in the upstream repository is named
deploy
. To prevent the git resource from attempting to check out master from master, setenable_checkout
tofalse
when using thecheckout_branch
property. Seerevision
.
depth
- Ruby Type: Integer
The number of past revisions to be included in the git shallow clone. Unless specified the default behavior will do a full clone.
destination
- Ruby Type: String | Default Value:
The resource block's name
The location path to which the source is to be cloned, checked out, or exported. Default value: the name of the resource block.
enable_checkout
- Ruby Type: true, false | Default Value:
true
Check out a repo from master. Set to
false
when using thecheckout_branch
attribute to prevent the git resource from attempting to check outmaster
frommaster
.
enable_submodules
- Ruby Type: true, false | Default Value:
false
Perform a sub-module initialization and update.
environment
- Ruby Type: Hash
A Hash of environment variables in the form of
({"ENV_VARIABLE" => "VALUE"})
. (These variables must exist for a command to be run successfully.)Note
The git provider automatically sets the
ENV['HOME']
andENV['GIT_SSH']
environment variables. To override this behavior and provide different values, addENV['HOME']
and/orENV['GIT_SSH']
to theenvironment
Hash.
group
- Ruby Type: String, Integer
The system group that will own the checked-out code.
remote
- Ruby Type: String | Default Value:
origin
The remote repository to use when synchronizing an existing clone.
repository
- Ruby Type: String
The URI of the code repository.
revision
- Ruby Type: String | Default Value:
HEAD
A branch, tag, or commit to be synchronized with git. This can be symbolic, like
HEAD
or it can be a source control management-specific revision identifier. Seecheckout_branch
.The value of the
revision
attribute may change over time. From one branch to another, to a tag, to a specific SHA for a commit, and then back to a branch. Therevision
attribute may even be changed in a way where history gets rewritten.Instead of tracking a specific branch or doing a headless checkout, Chef Infra Client maintains its own branch (via the git resource) that does not exist in the upstream repository. Chef Infra Client is then free to forcibly check out this branch to any commit without destroying the local history of an existing branch.
For example, to explicitly track an upstream repository’s master branch:
revision 'master'
Use the
git rev-parse
andgit ls-remote
commands to verify that Chef Infra Client is synchronizing commits correctly. (Chef Infra Client always runsgit ls-remote
on the upstream repository to verify the commit is made to the correct repository.)
ssh_wrapper
- Ruby Type: String
The path to the wrapper script used when running SSH with git. The
GIT_SSH
environment variable is set to this.
timeout
- Ruby Type: Integer
The amount of time (in seconds) to wait for a command to execute before timing out. When this property is specified using the deploy resource, the value of the
timeout
property is passed from the deploy resource to the git resource.
user
- Ruby Type: String, Integer | Default Value:
`HOME` environment variable of the user running chef-client
The system user that will own the checked-out code.
Common Resource Functionality
Chef resources include common properties, notifications, and resource guards.
Common Properties
The following properties are common to every resource:
compile_time
Ruby Type: true, false | Default Value:
false
Control the phase during which the resource is run on the node. Set to true to run while the resource collection is being built (the
compile phase
). Set to false to run while Chef Infra Client is configuring the node (theconverge phase
).ignore_failure
Ruby Type: true, false, :quiet | Default Value:
false
Continue running a recipe if a resource fails for any reason.
:quiet
will not display the full stack trace and the recipe will continue to run if a resource fails.retries
Ruby Type: Integer | Default Value:
0
The number of attempts to catch exceptions and retry the resource.
retry_delay
Ruby Type: Integer | Default Value:
2
The delay in seconds between retry attempts.
sensitive
Ruby Type: true, false | Default Value:
false
Ensure that sensitive resource data is not logged by Chef Infra Client.
Notifications
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.If the referenced resource does not exist, an error is raised. In contrast,
subscribes
will not fail if the source resource is not found.
A timer specifies the point during a Chef Infra 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 a Chef Infra Client run.
:immediate
,:immediately
Specifies that a notification should be run immediately, for each resource notified.
The syntax for notifies
is:
notifies :action, 'resource[name]', :timer
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 the nginx
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
example nginx
) when a change is detected.
If the other resource does not exist, the subscription will not raise an
error. Contrast this with the stricter semantics of notifies
, which
will raise an error if the other resource does not exist.
A timer specifies the point during a Chef Infra 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 a Chef Infra Client run.
:immediate
,:immediately
Specifies that a notification should be run immediately, for each resource notified.
The syntax for subscribes
is:
subscribes :action, 'resource[name]', :timer
Guards
A guard property can be used to evaluate the state of a node during the execution phase of a Chef Infra Client run. Based on the results of this evaluation, a guard property is then used to tell Chef Infra Client if it should continue executing a resource. A guard property accepts either a string value or a Ruby block value:
- A string is executed as a shell command. If the command returns
0
, the guard is applied. If the command returns any other value, then the guard property is not applied. String guards in a powershell_script run Windows PowerShell commands and may returntrue
in addition to0
. - A block is executed as Ruby code that must return either
true
orfalse
. If the block returnstrue
, the guard property is applied. If the block returnsfalse
, the guard property is not applied.
A guard property is useful for ensuring that a resource is idempotent by allowing that resource to test for the desired state as it is being executed, and then if the desired state is present, for Chef Infra Client to do nothing.
PropertiesThe following properties can be used to define a guard that is evaluated during the execution phase of a Chef Infra Client run:
not_if
Prevent a resource from executing when the condition returns
true
.only_if
Allow a resource to execute only if the condition returns
true
.
Examples
The following examples demonstrate various approaches for using the git resource in recipes:
Use the git mirror
git '/opt/my_sources/couch' do
repository 'git://git.apache.org/couchdb.git'
revision 'master'
action :sync
end
Use different branches
To use different branches, depending on the environment of the node:
branch_name = if node.chef_environment == 'QA'
'staging'
else
'master'
end
git '/home/user/deployment' do
repository 'git@github.com:git_site/deployment.git'
revision branch_name
action :sync
user 'user'
group 'test'
end
Where the branch_name
variable is set to staging or master, depending on the environment of the node. Once this is determined, the branch_name
variable is used to set the revision for the repository. If the git status command is used after running the example above, it will return the branch name as deploy
, as this is the default value. Run Chef Infra Client in debug mode to verify that the correct branches are being checked out:
sudo chef-client -l debug
Install an application from git using bash
The following example shows how Bash can be used to install a plug-in for rbenv named ruby-build, which is located in git version source control. First, the application is synchronized, and then Bash changes its working directory to the location in which ruby-build is located, and then runs a command.
git "/Users/tsmith/.chef/cache/ruby-build" do
repository 'git://github.com/rbenv/ruby-build.git'
revision 'master'
action :sync
end
bash 'install_ruby_build' do
cwd "/Users/tsmith/.chef/cache/ruby-build"
user 'rbenv'
group 'rbenv'
code <<-EOH
./install.sh
EOH
environment 'PREFIX' => '/usr/local'
end
Notify a resource post-checkout
git "/Users/tsmith/.chef/cache/my_app" do
repository node['my_app']['git_repository']
revision node['my_app']['git_revision']
action :sync
notifies :run, 'bash[compile_my_app]', :immediately
end
Pass in environment variables
git '/opt/my_sources/couch' do
repository 'git://git.apache.org/couchdb.git'
revision 'master'
environment 'VAR' => 'whatever'
action :sync
end