packaging: package for Debian

Add Debian packaging script and instructions.

client/cmd/dexc-desktop/README.md

@@ -0,0 +1,7 @@
+## Debian
+Build with `./debian-package.sh`. The deb archive is located in **./build**.
+
+For development, you'll need to install the WebKit Development Libraries.
+`apt install libgtk-3-dev libwebkit2gtk-4.0-dev`
+For production, they are specified as DEPENDS in the control file and the
+package manager will install them.

client/cmd/dexc-desktop/debian-package.sh

@@ -0,0 +1,122 @@
+#!/usr/bin/env bash
+
+# A good getting-started guide for Debian packaging can be found at
+# https://www.internalpointers.com/post/build-binary-deb-package-practical-guide
+
+set -ex
+
+APP="dexc"
+VER="0.7.0-pre"
+META= # "release"
+REV="0"
+ARCH="amd64"
+
+# DEB_NAME follows the prescribed format for debian packaging.
+DEB_NAME="${APP}_${VER}-${REV}_${ARCH}"
+
+# The build directory will be deleted at the beginning of every build. The
+# directory is .gitignore'd.
+BUILD_DIR="./build"
+
+# A directory for binary source files e.g. image files.
+SRC_DIR="./src"
+
+# The DEB_DIR represents the root directory in our target system. The directory
+# structure created under DEB_DIR will be duplicated on the target system
+# during installation.
+DEB_DIR="${BUILD_DIR}/${DEB_NAME}"
+
+# Magic name for a directory containing a specially formatted control file
+# (is it INI?) and special scripts to run during installation.
+CONTROL_DIR="${DEB_DIR}/DEBIAN"
+
+# posinst/postrm are special filenames under the DEBIAN directory. The scripts
+# will be run after installation/uninstall.
+POSTINST_PATH="${CONTROL_DIR}/postinst"
+POSTRM_PATH="${CONTROL_DIR}/postrm"
+
+# The dexc binary.
+BIN_TARGETDIR="/usr/lib/dexc"
+BIN_BUILDDIR="${DEB_DIR}${BIN_TARGETDIR}"
+BIN_FILENAME="${APP}"
+BIN_BUILDPATH="${BIN_BUILDDIR}/${BIN_FILENAME}"
+
+ICON_FILENAME="dexc.png"
+SRC_TARGETDIR="${BIN_TARGETDIR}/src"
+SRC_BUILDDIR="${DEB_DIR}${SRC_TARGETDIR}"
+LIBICON_BUILDPATH="${SRC_BUILDDIR}/${ICON_FILENAME}"
+
+# The Desktop Entry is a format for "installing" programs on Linux, creating
+# an entry in the main menu.
+# https://specifications.freedesktop.org/desktop-entry-spec/latest/
+DOT_DESKTOP_TARGETDIR="/usr/share/applications"
+DOT_DESKTOP_BUILDDIR="${DEB_DIR}${DOT_DESKTOP_TARGETDIR}"
+DOT_DESKTOP_FILENAME="dexc.desktop"
+DOT_DESKTOP_BUILDPATH="${DOT_DESKTOP_BUILDDIR}/${DOT_DESKTOP_FILENAME}"
+
+# This will be the icon shown for the program in the taskbar. I know that both
+# PNG and SVG will work. If it's a bitmap, should probably be >= 128 x 128 px.
+ICON_TARGETDIR="/usr/share/pixmaps"
+ICON_BUILDDIR="${DEB_DIR}${ICON_TARGETDIR}"
+DESKTOPICON_BUILDPATH="${ICON_BUILDDIR}/${ICON_FILENAME}"
+
+# Prepare the directory structure.
+rm -r "${BUILD_DIR}"
+mkdir -p "${CONTROL_DIR}"
+mkdir -p "${SRC_BUILDDIR}" # subdir of BIN_BUILDDIR
+mkdir -p "${DOT_DESKTOP_BUILDDIR}"
+mkdir -p "${ICON_BUILDDIR}"
+
+# Build dexc
+LDFLAGS="-s -w -X main.Version=${VER}${META:++${META}}"
+GOOS=linux GOARCH=${ARCH} go build -o "${BIN_BUILDPATH}" -ldflags "$LDFLAGS"
+chmod 755 "${BIN_BUILDPATH}"
+
+# Full control file specification -
+# https://www.debian.org/doc/debian-policy/ch-controlfields.html
+cat > "${CONTROL_DIR}/control" <<EOF
+Package: dexc
+Version: ${VER}
+Architecture: ${ARCH}
+Maintainer: Decred developers <briantstafford@gmail.com>
+Depends: libgtk-3-0, libwebkit2gtk-4.0-37
+Description: A multi-wallet backed by Decred DEX
+EOF
+
+# Symlink the binary and update the desktop icons, refresh the "start" menu.
+cat > "${POSTINST_PATH}" <<EOF
+ln -s "${BIN_TARGETDIR}/${BIN_FILENAME}" "/usr/bin/${BIN_FILENAME}"
+update-desktop-database
+EOF
+chmod 775 "${POSTINST_PATH}"
+
+# Remove symlink from postinst.
+cat > "${POSTRM_PATH}" <<EOF
+rm "/usr/bin/${BIN_FILENAME}"
+EOF
+chmod 775 "${POSTRM_PATH}"
+
+# Example file:
+# https://specifications.freedesktop.org/desktop-entry-spec/latest/apa.html
+cat > "${DOT_DESKTOP_BUILDPATH}" <<EOF
+[Desktop Entry]
+Version=${VER}
+Name=Decred DEX Client
+Comment=Multi-wallet backed by Decred DEX
+Exec=${BIN_TARGETDIR}/${BIN_FILENAME}
+Icon=${ICON_TARGETDIR}/${ICON_FILENAME}
+Terminal=false
+Type=Application
+Categories=Office;Development;
+EOF
+chmod 644 "${DOT_DESKTOP_BUILDPATH}"
+
+# Icon
+cp "${SRC_DIR}/${ICON_FILENAME}" "${DESKTOPICON_BUILDPATH}"
+chmod 644 "${DESKTOPICON_BUILDPATH}"
+
+cp "${SRC_DIR}/${ICON_FILENAME}" "${LIBICON_BUILDPATH}"
+chmod 644 "${LIBICON_BUILDPATH}"
+
+# Build the installation archive (.deb file).
+dpkg-deb --build --root-owner-group "${DEB_DIR}"