Create Debian package (#56)

Closes #54 

* Update package metadata

* First steps to building Debian packages

* Rename workflow

* Remove unsupported option from cargo build

* Specify directory where to download binaries

* Move comment

* Split logic over two steps

* More aggressive caching of previously built artifacts

* Use standard GitHub Action caches

* More detailed inspection of cache results

* Creating the package requires Rust ARM-target to be installed

* A bit less troubleshooting

* No need to build the project again, just the Debian package

* Do not strip the binary

This avoids re-installing cross-compilation tools

* Better inspection of intermediary results

* Verbose invocation of cargo deb

* First shot at creating a Debian service

.github/workflows/build-packages.yml

@@ -0,0 +1,87 @@
+name: Build Debian packages for Raspberry Pi
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    # Consider creating a matrix to also include armv7-unknown-linux-musleabihf
+
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v3.5.3
+
+      - name: Set up Cargo cache
+        uses: actions/cache@v3.3.1
+        continue-on-error: false
+        with:
+          path: |
+            ~/.cargo/bin/
+            ~/.cargo/registry/index/
+            ~/.cargo/registry/cache/
+            ~/.cargo/git/db/
+            target/            
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+          restore-keys: ${{ runner.os }}-cargo-
+
+      - name: Install cross-compilation tools
+        uses: taiki-e/setup-cross-toolchain-action@v1.15.0
+        with:
+          target: arm-unknown-linux-musleabihf
+
+      - name: Perform build
+        run: |
+          cargo build --target arm-unknown-linux-musleabihf --release --features ""
+
+  package:
+    runs-on: ubuntu-latest
+    needs: [ build ]
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v3.5.3
+        with:
+          fetch-depth: 0
+
+      - name: Set up Cargo cache
+        uses: actions/cache@v3.3.1
+        continue-on-error: false
+        with:
+          path: |
+            ~/.cargo/bin/
+            ~/.cargo/registry/index/
+            ~/.cargo/registry/cache/
+            ~/.cargo/git/db/
+            target/            
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+          restore-keys: ${{ runner.os }}-cargo-
+
+      - name: Inspect downloaded binaries
+        run: |
+          file target/arm-unknown-linux-musleabihf/release/dsmr-rs
+
+      - name: Prepare packaging
+        run: |
+          sudo apt update -y
+          sudo apt install -y dpkg dpkg-dev liblzma-dev libssl-dev
+          cargo install cargo-deb
+          rustup target add arm-unknown-linux-musleabihf
+
+      - name: Create Debian package
+        run: |
+          cargo deb --target arm-unknown-linux-musleabihf --no-build --no-strip -v
+
+      - name: Inspect generated packages
+        run: |
+          find target/ -name "*.deb" -exec file {} \;
+      
+      - name: Upload Debian packages
+        uses: actions/upload-artifact@v3.1.2
+        if: github.ref == 'refs/heads/main'
+        with:
+          name: binaries
+          path: target/debian/

Cargo.toml

@@ -3,9 +3,19 @@ name = "dsmr-rs"
 version = "0.1.0"
 authors = ["Maarten Mulders <mthmulders@noreply.github.com>"]
 edition = "2018"
+description = "A utility to ship 'smart meter' readings over HTTP"
+license = "MIT License"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
+[package.metadata.deb]
+maintainer = "Maarten Mulders"
+maintainer-scripts = "debian/"
+copyright = "2021 - 2023 Maarten Mulders"
+
+[package.metadata.deb.systemd-units]
+
+
 [dependencies]
 config = "0.13.3"
 log = "0.4.19"

debian/postinst

@@ -0,0 +1,49 @@
+# Inspired by https://github.com/NLnetLabs/krill/blob/main/pkg/debian/postinst
+
+#!/bin/sh
+set -e
+
+PKG_CONF="/etc/dsmr-rs.conf"
+PKG_CONF_PERMS=640
+PKG_USER="dsmr-rs"
+
+create_user() {
+    if id ${PKG_USER} > /dev/null 2>&1; then return; fi
+    adduser --system --no-create-home --group ${PKG_USER}
+}
+
+create_configuration() {
+    if [ ! -f "${PKG_CONF}" ]; then
+        cat <<EOF > ${PKG_CONF}
+# The DSMR-reader API to forward telegrams to
+DATALOGGER_API_HOSTS=https://my.host.name
+
+# The serial port to read telegrams from
+DATALOGGER_SERIAL_PORT=/dev/ttyUSB0
+
+# The API key to authenticate against the DSMR-reader API
+DATALOGGER_API_KEYS=something-secret
+
+# The input method for reading telegrams. Expected to always be 'serial', so effectively ignored.
+DATALOGGER_INPUT_METHOD=serial
+
+# Baudrate for reading telegrams from the serial line.
+DATALOGGER_SERIAL_BAUDRATE=9600
+
+EOF
+        # Ensure that the config file has the correct ownership
+        chown ${PKG_USER}:${PKG_USER} ${PKG_CONF}
+
+        # Ensure that the config file has the correct permissions
+        chmod ${PKG_CONF_PERMS} ${PKG_CONF}
+    fi
+}
+
+case "$1" in
+configure)
+    create_user
+    create_configuration
+    ;;
+esac
+
+#DEBHELPER#

debian/service

@@ -0,0 +1,9 @@
+[Unit]
+Description=dsmr-rs
+
+[Service]
+EnvironmentFile=/etc/dsmr-rs.conf
+ExecStart=/usr/bin/dsmr-rs
+
+[Install]
+WantedBy=multi-user.target