Up

It’s time to provision your first LinchPin resources.

1   [/tmp/simple]$ linchpin up
2    [WARNING]: Unable to parse /tmp/dummy/simple/localhost as an inventory source

3    [WARNING]: No inventory was parsed, only implicit localhost is available

4   Action 'up' on Target 'simple' is complete

5   ID: 10
6   Action: up

7   Target                  Run ID  uHash   Exit Code
    -------------------------------------------------
8   simple                       2  3a4038          0

In just a few seconds, the command will finish. Because the simple target provides only the dummy_node resource, no actual instances are provisioned. However, a representation can be found at /tmp/dummy.hosts

$ cat /tmp/dummy.hosts
web-3a4038-0.example.net
web-3a4038-1.example.net

More importantly, there are several other things to note. First off, The linchpin command has two basic actions, up and destroy. Each should be pretty self-explanatory.

Summary

Upon completion of every action, there is a summary that is provided. This summary provides details which can be used to repeat the process, or for further reporting with linchpin journal. Let’s cover the process in detail.

uHash

The Unique-ish Hash, or uHash⁸provides a way for each instance to be unique within a set of resources.The uHash is used throughout LinchPin with reporting, idempotency, inventories, etc. The uHash is configurable, but currently is a sha256 hash of some unique data, trimmed to 6 characters.

Run ID

The Run ID:sup:8can be used for idempotency. The Run ID is used for a specific target.

ID

Similar to the Run ID explained above, the ID⁵, or Transaction ID, is provided for idempotency. If desired, the entire transaction can be repeated using this value. Unlike the Run ID, however, the Transaction ID can be used to repeat the entire transaction (multiple targets).

$ linchpin up --tx-id 10

.. snip ..

ID: 11
Action: up

Target                      Run ID  uHash   Exit Code
-------------------------------------------------
simple                           3  3a4038          0

The thing to notice here is that the uHash is the same here as in the original up action above. This provides idempotency when provisioning.

Exit Code

A common desire is to check the exit code⁷. This is provided as an indicator of the action’s success or failure. Commonly, post actions are performed upon resources (eg. configure the system, adding logins, setting up security, etc.)

Destroy

To destroy the previously provisioned resources, use linchpin destroy.

$ linchpin destroy
 [WARNING]: Unable to parse /tmp/dummy/simple/localhost as an inventory source

 [WARNING]: No inventory was parsed, only implicit localhost is available

Action 'destroy' on Target 'simple' is complete

ID: 12
Action: destroy

Target                      Run ID  uHash   Exit Code
-------------------------------------------------
simple                           5  3a4038          0

As with linchpin up, destroy provides a summary of the action taken. In this case, however, the resources have been terminated and cleaned up. With the dummy_node role, the resources are remove from the file.

$ cat /tmp/dummy.hosts
$ wc -l /tmp/dummy.hosts
0 /tmp/dummy.hosts

This concludes the introduction of the LinchPin getting started tutorial. For more information, see Providers.