... | ... | @@ -15,12 +15,20 @@ Idea: seamless stacking of multiple module hierarchies, use cases: |
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* modules on another filesystem or location than the default (@PSI: `/opt/psi`)
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* ...
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Overlays can be stacked. The first overlay - the overlay at the bottom of the stack - is called "base overlay".
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==== Limitations
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=== Overlay stacks
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Overlays can be stacked. The first overlay - the overlay at the bottom of the stack - is called "base overlay". Multiple loaded overlays are organised as stack. Loading an overlay pushes it on top of the stack. It is only possible to unload the overlay on top of the stack.
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The 'overlay' at the bottom of the stack is called the base overlay and cannot be unloaded.
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=== Limitations
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The relative directory structure of a hierarchy group must be identical to the base overlay. It is also not possible to define a new hierarchical group.
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Overlays must be loaded before the first module.
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Unloading an overlay is only possible if no modules are loaded.
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Note: an overlay can add new non-hierarchical groups.
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=== Overlay configuration
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... | ... | @@ -68,13 +76,7 @@ The specification of `root_dir` is mandatory. |
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`type`:: Specifies the type of the overlay. The default is `normal`. See below for the type specifications.
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==== Overlay stacks
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It is possible to use/load multiple overlays at the same time. Multiple used/loaded overlays are organised as stack. Using/loading an overlay pushes it on top of the stack. It is only possible to unuse/unload the overlay on top of the stack.
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The 'overlay' at the bottom of the stack is called the base overlay and cannot be unloaded.
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==== Overlay types
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=== Overlay types
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`normal`:: In an overlay of this types the modules in the overlay are added to the already available modules provided by the overlays on the stack. If modules with identical name/version exist in multiple overlays, the module from the overlay which is higher on the stack is used. In other words modules with identical name/version are replaced by overlays loaded later.
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... | ... | @@ -106,4 +108,5 @@ Example: If you load the private overlay from the examples above as replacing, t |
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Note: the Git module from the base overlay is not available any more.
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=== |
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\ No newline at end of file |
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=== Variant files
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TBW |
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\ No newline at end of file |