debian: run as a daemon, ask informed consent (#162)

* Set verbose mode, depend on adduser

* Run as daemon

* Generate manpage

* Implement informed consent

* Set version

* Switch format to native

* Set environment

* Update packaging

* Create test and release pipelines

* Update debian/ooniprobe-cli.service

Co-authored-by: Simone Basso <bassosimone@gmail.com>

* Update debian/ooniprobe-cli.service

Co-authored-by: Simone Basso <bassosimone@gmail.com>

* Update debian/ooniprobe.conf.disabled

Co-authored-by: Simone Basso <bassosimone@gmail.com>

* fix(linux-debian-packages): build also on pull requests

Otherwise there's no way for us to test :^).

* fix(debian/control): ubuntu 20.04 has debhelper 12

See https://packages.ubuntu.com/focal/debhelper

* fix(debian/control): debhelper-compat relations doesn't work the way I thought

* Update debian/ooniprobe-cli.timer

Co-authored-by: Simone Basso <bassosimone@gmail.com>

debian/ooniprobe-cli.postinst

@@ -0,0 +1,23 @@
+#!/bin/sh
+set -e
+
+. /usr/share/debconf/confmodule
+db_version 2.0
+
+if [ "$1" = "configure" ]; then
+    if ! getent passwd ooniprobe >/dev/null; then
+        adduser --quiet --system --group --home /var/lib/ooniprobe ooniprobe
+    fi
+fi
+
+# Extract the answer
+db_get ooniprobe-cli/ask-consent || true
+consent="$RET"
+CF=/etc/ooniprobe/ooniprobe.conf
+
+[ "$consent" = true ]  && [ -f ${CF}.disabled ] && mv ${CF}.disabled ${CF}
+[ "$consent" = false ] && [ -f ${CF} ]          && mv ${CF} ${CF}.disabled
+
+#DEBHELPER#
+
+exit 0