Add snap packaging (#182)

* Add snap packaging

Add a snapcraft.yaml to support building the agent as a snap. Also add
the install and configure hooks to support configuration, as well as a
script to run the agent with the requested configuration.

Signed-off-by: Kyle Fazzari <[email protected]>

* s/system/transport/

Also update default port to 8888 and rename pseudo-serial to
pseudoterminal.

Signed-off-by: Kyle Fazzari <[email protected]>

* Disable daemon upon install

Signed-off-by: Kyle Fazzari <[email protected]>

snap/hooks/configure

@@ -0,0 +1,104 @@
+#!/bin/sh -e
+
+# Confirm that the transport is valid
+transport="$(snapctl get transport)"
+case "$transport" in
+	udp4) ;;
+	udp6) ;;
+	tcp4) ;;
+	tcp6) ;;
+	serial) ;;
+	pseudoterminal) ;;
+	*)
+		echo "'$transport' is not a supported transport" >&2
+		return 1
+		;;
+esac
+
+# Confirm that the middleware is valid
+middleware="$(snapctl get middleware)"
+case "$middleware" in
+	dds) ;;
+	rtps) ;;
+	ced) ;;
+	*)
+		echo "'$middleware' is not a supported middleware" >&2
+		return 1
+		;;
+esac
+
+if [ "$transport" = "serial" ] || [ "$transport" = "pseudoterminal" ]; then
+	# A serial transport if being used, which requires a valid baud rate
+	# as well as a valid device
+	baudrate="$(snapctl get baudrate)"
+	if ! expr "$baudrate" : '^[0-9]\+$' > /dev/null; then
+		echo "'$baudrate' is not a valid baud rate" >&2
+		return 1
+	fi
+
+	device="$(snapctl get device)"
+	if [ -z "$device" ]; then
+		echo "Device must be specified" >&2
+		return 1
+	fi
+else
+	port="$(snapctl get port)"
+	if ! expr "$port" : '^[0-9]\+$' > /dev/null; then
+		echo "'$port' is not a valid port" >&2
+		return 1
+	fi
+fi
+
+# Confirm that discovery is a boolean
+discovery="$(snapctl get discovery)"
+case "$discovery" in
+	true)
+		# Confirm that discovery port is valid
+		port="$(snapctl get discovery-port)"
+		if ! expr "$port" : '^[0-9]\+$' > /dev/null; then
+			echo "'$port' is not a valid discovery port" >&2
+			return 1
+		fi
+		;;
+	false) ;;
+	*)
+		echo "'$discovery' is not a valid boolean for discovery" >&2
+		return 1
+		;;
+esac
+
+# Confirm that the verbosity is valid
+verbosity="$(snapctl get verbosity)"
+if ! expr "$verbosity" : '^[0-6]$' > /dev/null; then
+	echo "'$verbosity' is not a valid verbosity" >&2
+	return 1
+fi
+
+# Confirm that p2p port is valid (assuming it's set)
+p2p_port="$(snapctl get p2p-port)"
+if [ -n "$p2p_port" ]; then
+	port="$(snapctl get p2p-port)"
+	if ! expr "$port" : '^[0-9]\+$' > /dev/null; then
+		echo "'$port' is not a valid p2p port" >&2
+		return 1
+	fi
+fi
+
+# Confirm that daemon is a boolean, and enable the service if true
+daemon="$(snapctl get daemon)"
+case "$daemon" in
+	true)
+		snapctl start --enable "$SNAP_INSTANCE_NAME.daemon"
+
+		# In case it was alraedy started and the configuration changed,
+		# restart the service
+		snapctl restart "$SNAP_INSTANCE_NAME.daemon"
+		;;
+	false)
+		snapctl stop --disable "$SNAP_INSTANCE_NAME.daemon"
+		;;
+	*)
+		echo "'$daemon' is not a valid boolean for daemon" >&2
+		return 1
+		;;
+esac

snap/hooks/install

@@ -0,0 +1,19 @@
+#!/bin/sh -e
+
+# Set default configuration values
+snapctl set transport=udp4
+snapctl set middleware=dds
+snapctl set verbosity=4
+snapctl set discovery=false
+snapctl set discovery-port=7400
+snapctl set p2p-port!  # unset
+
+# Network-specific things
+snapctl set port=8888
+
+# Serial-specific things
+snapctl set baudrate=115200
+snapctl set device!  # unset
+
+# By default the daemon is disabled
+snapctl set daemon=false

snap/local/MicroXRCEAgent-daemon

@@ -0,0 +1,27 @@
+#!/bin/sh -e
+
+set -- --middleware "$(snapctl get middleware)" "$@"
+set -- --verbose "$(snapctl get verbosity)" "$@"
+
+transport="$(snapctl get transport)"
+if [ "$transport" = "serial" ] || [ "$transport" = "pseudoterminal" ]; then
+	set -- --dev "$(snapctl get device)" "$@"
+else
+	set -- --port "$(snapctl get port)" "$@"
+fi
+
+if [ "$(snapctl get discovery)" = "true" ]; then
+	set -- --discovery "$@"
+
+	discovery_port="$(snapctl get discovery-port)"
+	if [ -n "$discovery_port" ]; then
+		set -- --disport "$discovery_port" "$@"
+	fi
+fi
+
+p2p_port="$(snapctl get p2p-port)"
+if [ -n "$p2p_port" ]; then
+	set -- --p2p "$p2p_port" "$@"
+fi
+
+exec "$SNAP/usr/bin/MicroXRCEAgent" "$transport" "$@"

snap/snapcraft.yaml

@@ -0,0 +1,109 @@
+name: micro-xrce-dds-agent
+base: core20
+version: git
+summary: Bridge between Micro XRCE-DDS clients and DDS
+description: |
+  Micro XRCE-DDS Agents receive messages containing Operations from
+  Clients. Agents keep track of the Clients and the Micro XRCE-DDS
+  Entities they create. The Agent uses the Entities to interact with
+  DDS Global Data Space on behalf of the Client.
+
+  The communication between a Micro XRCE-DDS Client and a Micro
+  XRCE-DDS Agent supports three kind transport: UDP, TCP, or SerialPort.
+  While running Micro XRCE-DDS Agent will attend any received
+  request from your Micro XRCE-DDS Clients. Micro XRCE-DDS Agent
+  answers back with the result of a request each time a request is
+  attended.
+
+  The Agent supports being run by the user like this:
+
+      $ micro-xrce-dds-agent --help
+
+  In addition, the Agent supports running as a service that can be
+  enabled with:
+
+      $ snap set micro-xrce-dds-agent daemon=true
+
+  If the service is enabled, by default it uses the `udp4` transport on
+  port 8888. The following parameters can be changed (these are
+  specific to the service, the `micro-xrce-dds-agent` command simply
+  takes command-line arguments, but the capabilities are the same):
+
+  * `transport`. Supported transports are `udp4`, `udp6`, `tcp4`,
+    `tcp6`, `serial`, and `pseudoterminal`. Default is `udp4`. Change
+    with:
+
+        $ snap set micro-xrce-dds-agent transport="new transport"
+
+  * `middleware`. Supported kinds of middleware are `ced`, `rtps`, and
+    `dds`. Default is `dds`. Change with:
+
+        $ snap set micro-xrce-dds-agent middleware="new middleware"
+
+  * `verbosity`. Supported verbosity levels are 0-6, defaulting to 4.
+    Change with:
+
+        $ snap set micro-xrce-dds-agent verbosity="selected verbosity"
+
+  * `discovery`. Enable or disable the discovery server. Defaults to
+    "false". Change with:
+
+        $ snap set micro-xrce-dds-agent discovery="true or false"
+
+  * `discovery-port`. Port on which the discovery server (see above)
+    listens. Defaults to 7400. Change with:
+
+        $ snap set micro-xrce-dds-agent discovery-port="selected port"
+
+  * `p2p-port`. Port to use for the P2P profile. Change with:
+
+        $ snap set micro-xrce-dds-agent p2p-port="selected port"
+
+  * `port`. Port on which the agent listens. Only applicable to one of
+    the UDP or TCP transports (see above). Defaults to 8888. Change with:
+
+        $ snap set micro-xrce-dds-agent port="selected port"
+
+  * `baudrate`. Baud rate to use when accessing serial ports. Only
+    applicable when using the `serial` or `pseudoterminal` transport.
+    Defaults to 115200. Change with:
+
+        $ snap set micro-xrce-dds-agent baudrate="baud rate"
+
+  * `device`. The serial device to use. Only applicable when using the
+    `serial` or `pseudoterminal` transport. Change with:
+
+        $ snap set micro-xrce-dds-agent device="device path"
+
+
+grade: stable
+confinement: strict
+
+architectures:
+  - build-on: amd64
+  - build-on: arm64
+  - build-on: armhf
+  - build-on: ppc64el
+
+parts:
+  agent:
+    plugin: cmake
+    source: .
+    cmake-parameters: [-DCMAKE_INSTALL_PREFIX=/usr]
+    build-packages: [make, gcc, g++]
+
+  runner:
+    plugin: dump
+    source: snap/local/
+    organize:
+      '*': usr/bin/
+
+apps:
+  micro-xrce-dds-agent:
+    command: usr/bin/MicroXRCEAgent
+    plugs: [network, network-bind, serial-port]
+
+  daemon:
+    command: usr/bin/MicroXRCEAgent-daemon
+    daemon: simple
+    plugs: [network, network-bind, serial-port]