Ansible/Hosts/Dynamic Inventory - Revision history

Admin: /* Example: Vagrant Dynamic Inventory Script */

2018-11-11T01:44:32Z

Example: Vagrant Dynamic Inventory Script

Admin: /* Python script */

2018-11-11T01:22:06Z

Python script

← Older revision		Revision as of 01:22, 11 November 2018
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	The script uses the boto library to interact with the AWS API. The object defines methods for parsing user command line arguments, and implements a number of other methods to do things like ask for a list of nodes, filter nodes by attribute, and store/retrieve information from a cache on disk to prevent everything from going extremely slowly due to slow AWS API responses.		The script uses the boto library to interact with the AWS API. The object defines methods for parsing user command line arguments, and implements a number of other methods to do things like ask for a list of nodes, filter nodes by attribute, and store/retrieve information from a cache on disk to prevent everything from going extremely slowly due to slow AWS API responses.

	Key ~~bits~~:		Key methods defined for the object:

	* read input file: https://github.com/ansible/ansible/blob/devel/contrib/inventory/ec2.py#L304		* read input file: https://github.com/ansible/ansible/blob/devel/contrib/inventory/ec2.py#L304
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	* process API call returns: https://github.com/ansible/ansible/blob/devel/contrib/inventory/ec2.py#L1542		* process API call returns: https://github.com/ansible/ansible/blob/devel/contrib/inventory/ec2.py#L1542

	~~Call~~ order:		The call order of the script, when run, is:

	* object is created https://github.com/ansible/ansible/blob/devel/contrib/inventory/ec2.py#L1709		* object is created https://github.com/ansible/ansible/blob/devel/contrib/inventory/ec2.py#L1709

Admin: /* Example executable dynamic inventory script */

2018-11-11T01:21:31Z

Example executable dynamic inventory script

← Older revision		Revision as of 01:21, 11 November 2018
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	==Example ~~executable dynamic inventory script~~==		==Example: Vagrant Dynamic Inventory Script==

	Let's walk through an example script with Vagrant.		Let's walk through an example script with Vagrant.
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	This example script is written in Python. It takes two input arguments, <code>--host=X</code> and <code>--list</code>, and interacts with Vagrant to return the requested information.		This example script is written in Python. It takes two input arguments, <code>--host=X</code> and <code>--list</code>, and interacts with Vagrant to return the requested information.

	~~===Vagrant===~~		===Getting List of Hosts===

	====Getting List of Hosts====

	Start with how to get a list of hosts for the <code>--list</code> flag.		Start with how to get a list of hosts for the <code>--list</code> flag.
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	</pre>		</pre>

	====Getting Machine Configuration Details====		===Getting Machine Configuration Details===

	Now we need to get host-specific details for the <code>--host=X</code> flag.		Now we need to get host-specific details for the <code>--host=X</code> flag.
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	</pre>		</pre>

	====Parsing user arguments====		===Parsing user arguments===

	A quick argparser tutorial for the flags we're interested in parsing:		A quick argparser tutorial for the flags we're interested in parsing:
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	Now we can call this function and use args.list or args.host to access the values of the flags.		Now we can call this function and use args.list or args.host to access the values of the flags.

	====Putting it all together====		===Putting it all together===

	Here is the final dynamic inventory script:		Here is the final dynamic inventory script:
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	</pre>		</pre>

	====Running the dynamic inventory script====		===Running the dynamic inventory script===

	Once we've written the dynamic inventory script and we're ready to run Ansible using it, we can pass the inventory script using the -i flag:		Once we've written the dynamic inventory script and we're ready to run Ansible using it, we can pass the inventory script using the -i flag:
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	===EC2===		==Example: EC2 Dynamic Inventory Script==

	There is a very thorough EC2 dynamic inventory script in the Ansible Github repository: https://raw.githubusercontent.com/ansible/ansible/devel/contrib/inventory/ec2.py		There is a very thorough EC2 dynamic inventory script in the Ansible Github repository: https://raw.githubusercontent.com/ansible/ansible/devel/contrib/inventory/ec2.py
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	Let's run through an overview of how it works.		Let's run through an overview of how it works.

	====Environment variables====		===Environment variables===

	This dynamic inventory script uses lots of environment variables. The most important are:		This dynamic inventory script uses lots of environment variables. The most important are:
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	Note that each of these can also be specified in the .ini file.		Note that each of these can also be specified in the .ini file.

	====Important====		===Important===

	By default, the ec2.ini file is configured for all Amazon cloud services. You have to turn off the ones you don't want (elasticcache, rds, etc.)		By default, the ec2.ini file is configured for all Amazon cloud services. You have to turn off the ones you don't want (elasticcache, rds, etc.)
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	Ref: https://docs.ansible.com/ansible/latest/user_guide/intro_dynamic_inventory.html#inventory-script-example-aws-ec2		Ref: https://docs.ansible.com/ansible/latest/user_guide/intro_dynamic_inventory.html#inventory-script-example-aws-ec2

	====Python script====		===Python script===

	The script proper defines a Python object that manages all of the information received from the AWS API.		The script proper defines a Python object that manages all of the information received from the AWS API.

Admin: /* Putting it all together */

2018-11-11T01:20:05Z

Putting it all together

← Older revision		Revision as of 01:20, 11 November 2018
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	Here is the final dynamic inventory script:		Here is the final dynamic inventory script:

			(In the ansible repo under contrib/inventory: https://github.com/ansible/ansible/tree/devel/contrib/inventory)

	'''dynamic_vagrant.py''':		'''dynamic_vagrant.py''':

Admin: /* Flags */

2018-11-10T20:10:53Z

Flags

← Older revision		Revision as of 20:10, 10 November 2018
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	=Flags=		=Flags=

			[[Category:Python]]

	[[Category:Ansible]]		[[Category:Ansible]]
	[[Category:Ansible Hosts]]		[[Category:Ansible Hosts]]
	[[Category:Infrastructure]]		[[Category:Infrastructure]]

			[[Category:Dynamic Inventory]]
			[[Category:AWS]]
			[[Category:Vagrant]]

Admin: /* EC2 */

2018-11-10T20:10:18Z

EC2

← Older revision		Revision as of 20:10, 10 November 2018
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	Note that each of these can also be specified in the .ini file.		Note that each of these can also be specified in the .ini file.

			====Important====

			By default, the ec2.ini file is configured for all Amazon cloud services. You have to turn off the ones you don't want (elasticcache, rds, etc.)

			Ref: https://docs.ansible.com/ansible/latest/user_guide/intro_dynamic_inventory.html#inventory-script-example-aws-ec2

	====Python script====		====Python script====

Admin: /* Python script */

2018-11-10T20:05:22Z

Python script

← Older revision		Revision as of 20:05, 10 November 2018
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	The script uses the boto library to interact with the AWS API. The object defines methods for parsing user command line arguments, and implements a number of other methods to do things like ask for a list of nodes, filter nodes by attribute, and store/retrieve information from a cache on disk to prevent everything from going extremely slowly due to slow AWS API responses.		The script uses the boto library to interact with the AWS API. The object defines methods for parsing user command line arguments, and implements a number of other methods to do things like ask for a list of nodes, filter nodes by attribute, and store/retrieve information from a cache on disk to prevent everything from going extremely slowly due to slow AWS API responses.

			Key bits:

			* read input file: https://github.com/ansible/ansible/blob/devel/contrib/inventory/ec2.py#L304
			* parse cli: https://github.com/ansible/ansible/blob/devel/contrib/inventory/ec2.py#L523
			* get instances: https://github.com/ansible/ansible/blob/devel/contrib/inventory/ec2.py#L593
			* get route names for instances from route 53: https://github.com/ansible/ansible/blob/devel/contrib/inventory/ec2.py#L1468
			* get a dictionary with instance information: https://github.com/ansible/ansible/blob/devel/contrib/inventory/ec2.py#L1489
			* process API call returns: https://github.com/ansible/ansible/blob/devel/contrib/inventory/ec2.py#L1542

			Call order:

			* object is created https://github.com/ansible/ansible/blob/devel/contrib/inventory/ec2.py#L1709
			* init method is called: https://github.com/ansible/ansible/blob/devel/contrib/inventory/ec2.py#L245
			* credentials are set up
			* cache is loaded (if present)
			* data is printed (list of nodes)

	=Flags=		=Flags=

Admin: /* EC2 */

2018-11-10T19:58:05Z

EC2

← Older revision		Revision as of 19:58, 10 November 2018
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	Note that each of these can also be specified in the .ini file.		Note that each of these can also be specified in the .ini file.

			====Python script====

			The script proper defines a Python object that manages all of the information received from the AWS API.

			The script uses the boto library to interact with the AWS API. The object defines methods for parsing user command line arguments, and implements a number of other methods to do things like ask for a list of nodes, filter nodes by attribute, and store/retrieve information from a cache on disk to prevent everything from going extremely slowly due to slow AWS API responses.

	=Flags=		=Flags=

Admin: /* Environment variables */

2018-11-10T19:45:39Z

Environment variables

← Older revision		Revision as of 19:45, 10 November 2018
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	This dynamic inventory script uses lots of environment variables. The most important are:		This dynamic inventory script uses lots of environment variables. The most important are:

	* AWS_ACCESS_KEY_ID to set your AWS API access key (for boto)		* <code>AWS_ACCESS_KEY_ID</code> to set your AWS API access key (for boto)
	* AWS_SECRET_ACCESS_KEY to set your AWS API access secret (for boto)		* <code>AWS_SECRET_ACCESS_KEY</code> to set your AWS API access secret (for boto)
	* AWS_PROFILE to specify a boto profile		* <code>AWS_PROFILE</code> to specify a boto profile
	* EC2_INSTANCE_FILTERS to filter the AWS instances returned on various criteria. Extremely detailed API reference for filtering is [https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DescribeInstances.html#query-DescribeInstances-filters here]		* <code>EC2_INSTANCE_FILTERS</code> to filter the AWS instances returned on various criteria. Extremely detailed API reference for filtering is [https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DescribeInstances.html#query-DescribeInstances-filters here]

	Note that each of these can also be specified in the .ini file.		Note that each of these can also be specified in the .ini file.

Admin: /* EC2 */

2018-11-10T19:28:22Z

EC2

← Older revision		Revision as of 19:28, 10 November 2018
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	This script also has an .ini configuration file associated with it: https://raw.githubusercontent.com/ansible/ansible/devel/contrib/inventory/ec2.ini		This script also has an .ini configuration file associated with it: https://raw.githubusercontent.com/ansible/ansible/devel/contrib/inventory/ec2.ini

			Let's run through an overview of how it works.

			====Environment variables====

			This dynamic inventory script uses lots of environment variables. The most important are:

			* AWS_ACCESS_KEY_ID to set your AWS API access key (for boto)
			* AWS_SECRET_ACCESS_KEY to set your AWS API access secret (for boto)
			* AWS_PROFILE to specify a boto profile
			* EC2_INSTANCE_FILTERS to filter the AWS instances returned on various criteria. Extremely detailed API reference for filtering is [https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DescribeInstances.html#query-DescribeInstances-filters here]

			Note that each of these can also be specified in the .ini file.

	=Flags=		=Flags=