overlord/ifacestate: setup security backends phased by backends first

tests/regression/lp-1802581/mock-gpio.py

@@ -0,0 +1,54 @@
+#!/usr/bin/python3
+
+import os
+import selectors
+import sys
+
+
+def data_to_gpio(data):
+    return "gpio"+data.decode().strip()
+
+
+def export_ready(fd, mask):
+    data = os.read(fd, 128)
+    # allow quit
+    if data == b'quit\n':
+        return False
+    with open(data_to_gpio(data), "w"):
+        pass
+    return True
+
+
+def unexport_ready(fd, mask):
+    os.remove(data_to_gpio(os.read(fd, 128)))
+    return True
+
+
+def dispatch(sel):
+    for key, mask in sel.select():
+        callback = key.data
+        if not callback(key.fileobj, mask):
+            return False
+    return True
+
+
+if __name__ == "__main__":
+    os.chdir(sys.argv[1])
+
+    # fake gpio export/unexport files
+    os.mkfifo("export")
+    os.mkfifo("unexport")
+
+    # ensure that we create the right 
+    sel = selectors.DefaultSelector()
+    efd = os.open("export", os.O_RDWR | os.O_NONBLOCK)
+    ufd = os.open("unexport", os.O_RDWR | os.O_NONBLOCK)
+    sel.register(efd, selectors.EVENT_READ, export_ready)
+    sel.register(ufd, selectors.EVENT_READ, unexport_ready)
+    while True:
+        if not dispatch(sel):
+            break
+
+    # cleanup
+    os.close(efd)
+    os.close(ufd)

tests/regression/lp-1802581/task.yaml

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+summary: Regression test for  1802581
+
+systems: [ubuntu-core-16-64]
+
+environment:
+    GPIO_MOCK_DIR: /home/test/gpio-mock
+
+prepare: |
+    echo "Mock gpio"
+    mkdir -p "$GPIO_MOCK_DIR"
+    systemd-run --unit mock-gpio -- "$(pwd)/mock-gpio.py" "$GPIO_MOCK_DIR"
+    # shellcheck source=tests/lib/systemd.sh
+    . "$TESTSLIB/systemd.sh"
+    wait_for_service mock-gpio
+    mount --bind "$GPIO_MOCK_DIR" /sys/class/gpio
+
+restore: |
+    systemctl stop mock-gpio || true
+    umount /sys/class/gpio || true
+    rm -rf "$GPIO_MOCK_DIR"
+
+execute: |
+    echo "Install a snap that uses the gpio consumer"
+    #shellcheck source=tests/lib/snaps.sh
+    . "$TESTSLIB"/snaps.sh
+    install_local gpio-consumer
+
+    echo "And connect the gpio pin"
+    snap connect gpio-consumer:gpio :gpio-pin
+    snap interfaces | MATCH ":gpio-pin.*gpio-consumer:gpio"
+
+    # LP-1802581
+    echo "Now disable and enable the snap to ensure lp: #1802581 is fixed"
+    snap disable gpio-consumer
+    snap enable gpio-consumer
+
+    echo "Check that the connection is still here after enable"
+    snap interfaces | MATCH ":gpio-pin.*gpio-consumer:gpio"