Declarative manifest entries

Declarative manifest entries provide an option to add, remove and replace manifest headers of a bundle, without modifying the jar file. This is very helpful for:

• external bundles, which cannot be modified
• using signed jars

In such cases framework must implicitly apply the modified headers to the matched bundles.

Requirements

• Define manifest entries to be replaced in a separate file.
• Define a syntax to add, modify and remove manifest headers.
• Multiple bundles MUST be supported.
• There MUST be a system property to optionally enable this functionality.

Solution

A separate file – manifest_setup.prs is used to describe manifest headers modification in a declarative way. It is located in bin/vms/ folder.

To enable this functionality the system property mbs.manifest.setup.enabled MUST be set to true.

The manifest_setup.prs file consists of multiple sections and comments with the following format:

<bundle_symbolic_name>(#<version>)?:

<manifest_header_1>: <manifest_header_operation_1>

<manifest_header_2>: <manifest_header_operation_2>

...

<manifest_header_n>: <manifest_header_operation_n>

Sections are separated by either an empty line(s) or a comment line(s). Manifest header operations are performed only if the bundle symbolic name and the bundle version are matched.

The following manifest header operations are defined:

• A: B – override manifest header with new content
• A: ! – remove manifest header
• A: B+ – insert content before original value
• A: +B – insert content after original value
• A: A1*A2 – insert content before and after original value

If a header is not available in the original bundle manifest, it will be added automatically by the framework.

An escape character is supported – the ' \ ' symbol.

The following section demonstrates how this functionality is used.

Example

The user may define a manifest_setup.prs file in the bin/vms folder in the following way:

# This is an example manifest setup file. The following lines are examples how manifest header modification/replacement

# mechanism works. Make sure the system property mbs.manifest.setup.enabled is set to true,

# so that this file is taken into account. Character escaping for special symbols is supported.

# Multiple insertions are not supported.

# All sections must start with "<bsn>(#<version>)?:"

# Manifest headers will be modified for the target bundle.

com.prosyst.mbs.osgi.scr#1.0.0:

# adding/replacing of header A with value B

A: B

# removal of header C

C: !

# appending a value E after header D original value

D: +E

# inserting a header F original value between G1 and G2

F: G1*G2

# more examples

U: W*

X: *Y

# insert a "*" value to header

L: *\*

# replace with a "+" value

R: \+

# A section with no version

com.prosyst.mbs.osgi.scr:

X: Y