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Transaction Triggers

Transactional scope triggers (tx triggers) are run after the new filesystem transaction has been blitted to disk, and just before the new /usr tree is activated. These triggers run within a specialised container and have read-write access to the new /usr tree, but only have read-only access to the /etc directory.

Transaction triggers must be installed in /usr/share/moss/triggers/tx.d with a .yaml suffix.

Sample trigger​

This simple trigger will run depmod -a 6.6.15 when any files are installed to /usr/lib/modules/6.6.15/. Note that identical commands (after expansion) will be collapsed automatically to a single run.

name: depmod
description: |
    Update kernel module dependencies

# Define all of our handlers
handlers:
    depmod:
        # Run `depmod` with these arguments
        run: /usr/sbin/depmod
        args: ["-a", "$(version)"]

paths:
    # Set up a match
    "/usr/lib/modules/(version:*)/*" :
        # Run these handlers for this match.
        handlers:
            - depmod
        type: directory

To install this trigger in your recipe:

%install_file %(pkgdir)/trigger.yaml %(installroot)/usr/share/moss/triggers/tx.d/gdk_pixbuf.yaml