feat(snap): Add snap packaging

.gitignore

@@ -26,4 +26,12 @@ LintOutput.json
 device-usb-camera
 run
 
-#VERSION
+VERSION
+
+# snap files
+*.snap
+*.assert
+prime/
+stage/
+parts/
+squashfs-root/

snap/README.md

@@ -0,0 +1,45 @@
+# EdgeX USB Camera Device Service Snap
+[![edgex-device-usb-camera](https://snapcraft.io/edgex-device-usb-camera/badge.svg)](https://snapcraft.io/edgex-device-usb-camera)
+
+This directory contains the snap packaging of the EdgeX USB Camera device service.
+
+The snap is built automatically and published on the Snap Store as [edgex-device-usb-camera].
+
+For usage instructions, please refer to Device Camera section in [Getting Started using Snaps][docs].
+
+## Build from source
+Execute the following command from the top-level directory of this repo:
+```
+snapcraft -v
+```
+
+This will create a snap package file with `.snap` extension. It can be installed locally by setting the `--dangerous` flag:
+```bash
+sudo snap install --dangerous <snap-file>
+```
+
+The [snapcraft overview](https://snapcraft.io/docs/snapcraft-overview) provides additional details.
+
+### Obtain a Secret Store token
+The `edgex-secretstore-token` snap slot makes it possible to automatically receive a token from a locally installed platform snap.
+
+If the snap is built and installed locally, the interface will not auto-connect. You can check the status of the connections by running the `snap connections edgex-device-usb-camera` command.
+
+To manually connect and obtain a token:
+```bash
+sudo snap connect edgexfoundry:edgex-secretstore-token edgex-device-usb-camera:edgex-secretstore-token
+```
+
+Please refer [here][secret-store-token] for further information.
+
+### Connect the camera interface
+The [`camera`](https://snapcraft.io/docs/camera-interface) interface is currently **NOT automatically connected** as it is pending auto-connection permissions from the store.
+
+To connect manually:
+```
+snap connect edgex-device-usb-camera:camera :camera
+```
+
+[edgex-device-usb-camera]: https://snapcraft.io/edgex-device-usb-camera
+[docs]: https://docs.edgexfoundry.org/2.2/getting-started/Ch-GettingStartedSnapUsers/#device-usb-camera
+[secret-store-token]: https://docs.edgexfoundry.org/2.2/getting-started/Ch-GettingStartedSnapUsers/#secret-store-token

snap/hooks/configure

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+exec $SNAP/bin/helper-go configure

snap/hooks/install

@@ -0,0 +1,3 @@
+#!/bin/bash -e
+
+exec $SNAP/bin/helper-go install

snap/local/bin/source-env-file.sh

@@ -0,0 +1,21 @@
+#!/bin/bash -e
+
+# convert cmdline to string array
+ARGV=($@)
+
+# grab binary path
+BINPATH="${ARGV[0]}"
+
+# binary name == service name/key
+SERVICE=$(basename "$BINPATH")
+ENV_FILE="$SNAP_DATA/config/$SERVICE/res/$SERVICE.env"
+TAG="edgex-$SERVICE."$(basename "$0")
+
+if [ -f "$ENV_FILE" ]; then
+    logger --tag=$TAG "sourcing $ENV_FILE"
+    set -o allexport
+    source "$ENV_FILE" set
+    set +o allexport 
+fi
+
+exec "$@"

snap/local/helper-go/Makefile

@@ -0,0 +1,8 @@
+build:
+	go build -ldflags="-s -w" -o helper-go
+
+tidy:
+	go mod tidy -compat=1.17
+
+clean:
+	rm -f helper-go

snap/local/helper-go/configure.go

@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2022 Canonical Ltd
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ *  in compliance with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0'
+ */
+
+package main
+
+import (
+	"strings"
+
+	"github.com/canonical/edgex-snap-hooks/v2/log"
+	"github.com/canonical/edgex-snap-hooks/v2/options"
+	"github.com/canonical/edgex-snap-hooks/v2/snapctl"
+)
+
+func configure() {
+	log.SetComponentName("configure")
+
+	// config options are always enabled for this service
+	err := snapctl.Set("app-options", "true").Run()
+	if err != nil {
+		log.Fatalf("could not enable config options: %v", err)
+	}
+
+	err = options.ProcessAppConfig("device-usb-camera")
+	if err != nil {
+		log.Fatalf("could not process options: %v", err)
+	}
+
+	// If autostart is not explicitly set, default to "no"
+	// as only example service configuration and profiles
+	// are provided by default.
+	autostart, err := snapctl.Get("autostart").Run()
+	if err != nil {
+		log.Fatalf("Reading config 'autostart' failed: %v", err)
+	}
+	if autostart == "" {
+		log.Debug("autostart is NOT set, initializing to 'no'")
+		autostart = "no"
+	}
+	autostart = strings.ToLower(autostart)
+	log.Debugf("autostart=%s", autostart)
+
+	// services are stopped/disabled by default in the install hook
+	switch autostart {
+	case "true", "yes":
+		err = snapctl.Start("rtsp-simple-server", "device-usb-camera").Enable().Run()
+		if err != nil {
+			log.Fatalf("Can't start service: %s", err)
+		}
+	case "false", "no":
+		// no action necessary
+	default:
+		log.Fatalf("Invalid value for 'autostart': %s", autostart)
+	}
+}

snap/local/helper-go/go.mod

@@ -0,0 +1,11 @@
+module github.com/edgexfoundry/device-camera-go/hooks
+
+require github.com/canonical/edgex-snap-hooks/v2 v2.3.0
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/stretchr/testify v1.7.1 // indirect
+	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
+)
+
+go 1.17

snap/local/helper-go/go.sum

@@ -0,0 +1,15 @@
+github.com/canonical/edgex-snap-hooks/v2 v2.3.0 h1:ddXo8b5AsYjTiZ1APyeHWri0//KfU5qhDwPkyK0TUTc=
+github.com/canonical/edgex-snap-hooks/v2 v2.3.0/go.mod h1:rOxrwdYL7hJDhxFH3uV+nVgLPjWOhJWgM5PRD5YG1jI=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b h1:h8qDotaEPuJATrMmW04NCwg7v22aHH28wwpauUhK9Oo=
+gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

snap/local/helper-go/install.go

@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2022 Canonical Ltd
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ *  in compliance with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0'
+ */
+
+package main
+
+import (
+	"os"
+
+	hooks "github.com/canonical/edgex-snap-hooks/v2"
+	"github.com/canonical/edgex-snap-hooks/v2/env"
+	"github.com/canonical/edgex-snap-hooks/v2/log"
+)
+
+// installProfiles copies the profile configuration.toml files from $SNAP to $SNAP_DATA.
+func installConfig() error {
+	resPath := "/config/device-usb-camera/res"
+	err := os.MkdirAll(env.SnapData+resPath, 0755)
+	if err != nil {
+		return err
+	}
+
+	path := resPath + "/configuration.toml"
+	err = hooks.CopyFile(
+		env.Snap+path,
+		env.SnapData+path)
+	if err != nil {
+		return err
+	}
+
+	path = "/config/rtsp-simple-server.yml"
+	err = hooks.CopyFile(
+		env.Snap+path,
+		env.SnapData+path)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func installDevices() error {
+	devicesDir := "/config/device-usb-camera/res/devices"
+
+	err := os.MkdirAll(env.SnapData+devicesDir, 0755)
+	if err != nil {
+		return err
+	}
+
+	err = hooks.CopyFile(
+		hooks.Snap+devicesDir+"/general.usb.camera.toml.example",
+		hooks.SnapData+devicesDir+"/general.usb.camera.toml.example")
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func installDevProfiles() error {
+	profilesDir := "/config/device-usb-camera/res/profiles"
+
+	err := os.MkdirAll(env.SnapData+profilesDir, 0755)
+	if err != nil {
+		return err
+	}
+
+	err = hooks.CopyFile(
+		hooks.Snap+profilesDir+"/general.usb.camera.yaml",
+		hooks.SnapData+profilesDir+"/general.usb.camera.yaml")
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func install() {
+	log.SetComponentName("install")
+
+	err := installConfig()
+	if err != nil {
+		log.Fatalf("error installing config file: %s", err)
+	}
+
+	err = installDevices()
+	if err != nil {
+		log.Fatalf("error installing devices config: %s", err)
+	}
+
+	err = installDevProfiles()
+	if err != nil {
+		log.Fatalf("error installing device profiles config: %s", err)
+	}
+}

snap/local/helper-go/main.go

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2022 Canonical Ltd
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ *  in compliance with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ * SPDX-License-Identifier: Apache-2.0'
+ */
+
+package main
+
+import (
+	"os"
+)
+
+func main() {
+	subCommand := os.Args[1]
+	switch subCommand {
+	case "install":
+		install()
+	case "configure":
+		configure()
+	default:
+		panic("Unknown subcommand: " + subCommand)
+	}
+}