Step Overview (Sun N1 Service Provisioning System 5.1 Plan and Component Developer's Guide)

Sun N1 Service Provisioning System 5.1 Plan and Component Developer's Guide

Step Overview

Steps are simple instructions that can be part of both plans and components. The provisioning system supports the following kinds of steps:

Steps that can only be called from within a component. Such steps can only be called from install blocks or from uninstall blocks. See Install-Only Steps for Components in Sun N1 Service Provisioning System 5.1 XML Schema Reference Guide and Uninstall-Only Steps for Components in Sun N1 Service Provisioning System 5.1 XML Schema Reference Guide.
Steps that can only be called from a plan. Such steps can only be called from composite plans or from simple plans. See Plan-Only Steps for Composite Plans in Sun N1 Service Provisioning System 5.1 XML Schema Reference Guide and Plan-Only Steps for Simple Plans in Sun N1 Service Provisioning System 5.1 XML Schema Reference Guide.
Steps that can be called from either a plan or from a component. See Chapter 2, Shared Schema Used by Components and Simple Plans, in Sun N1 Service Provisioning System 5.1 XML Schema Reference Guide.

Component References

A number of steps can reference components in the following situations:

Components that have yet to be installed can use the <install> step.

Steps that refer to components that have yet to be installed only need to specify the name of the component and an optional version.
Components that have already been installed can use the following steps:
- <uninstall>
- <call>
- <checkDependency>
- <createDependency>
- <addSnapshot>
Steps that refer to an installed component must specify the installPath attribute because the same component can be installed more than once on the same server.

Example 1–1 Using Component References

Assume that the “Apache” component is installed on a host with the following attribute settings.

Component Instance	installPath	version	installDate
A	`/opt`	1.3	6/1/01 6:00 p.m.
B	`/usr/local`	1.4	6/1/01 5:00 p.m.
C	`/opt`	1.2	6/2/01 5:00 p.m.
D	`/usr/local/bin`	1.4	6/3/01 5:00 p.m.
E	`/export`	1.1	6/4/01 5:00 p.m.

The following shows which installed component is referenced when values for various combinations of the installPath and version attributes are supplied.

installPath	version	versionOp	Result	Explanation
None	None	None	E	The most recently installed component on the target host is used, regardless of the values of version and installPath.
`/opt`	None	None	C	The most recently installed component in the named install path is used regardless of the value of version.
`/usr/bin`	None	None	ERROR	No component is installed in the specified path.
None	1.4	`=`	D	The most recently installed component that has the specified version is chosen, regardless of the value of installPath.
None	1.5	Any	ERROR	No component is installed with the specified version.
`/usr/local`	1.4	`=`, `>=`	B	The component that matches the specified installPath and version attribute values is chosen.
`/usr/local`	1.2	`=`	ERROR	No such version is installed at the specified install path.
`/usr/local`	1.2	`>`, `>=`	B	The values for installPath, version, and versionOp match.
`/opt`	3	Any	ERROR	If two or more components are installed in the same path and they have the same name, the most recently installed component effectively overwrites any other components that have been installed earlier. Components that have been installed at an earlier time cannot be accessed, even if directly specified.