build: rewrite appimage build config

resolves streamlink#798

- build inside ghcr.io/streamlink/appimage-buildenv-{x86_64,i686}
  containers and copy missing libraries from the centos7 base image,
  except those being a dependency of gtk3 or being part of the appimage
  exclusion list
- remove custom appimagekit grunt task
- remove custom squashfs-tools build script
- refactor appimage build task configs and clean up related configs
- rewrite build script and split into two

.github/workflows/main.yml

@@ -138,7 +138,6 @@ jobs:
           yarn install --pure-lockfile --no-progress --non-interactive
           sudo apt install pigz nsis appstream{,-util}
           ./.github/workflows/install-wine.sh
-          ./.github/workflows/build-squashfs-tools.sh
       - name: Build
         run: yarn run grunt clean:tmp_prod webpack:prod
       - name: Compile & package

Gruntfile.js

@@ -28,7 +28,6 @@ module.exports = function( grunt ) {
 				tmp_test: r( "build", "tmp", "test" ),
 				tmp_coverage: r( "build", "tmp", "coverage" ),
 				tmp_installer: r( "build", "tmp", "installer" ),
-				tmp_appimage: r( "build", "tmp", "appimage" ),
 				dist: r( "dist" )
 			}
 		},

build/resources/appimage/build-docker.sh

@@ -0,0 +1,93 @@
+#!/usr/bin/env bash
+set -e
+
+APPDIR="${1}"
+INSTALLDIR="${2}"
+VERSION="${3}"
+ARCH="${4}"
+LIBDIR="${APPDIR}/${INSTALLDIR}/lib"
+
+declare -A excludepackages=(
+  [gtk3]=true
+)
+
+
+# ----
+
+
+SELF=$(basename "$(readlink -f "${0}")")
+log() {
+  echo "[${SELF}] $@"
+}
+err() {
+  log >&2 "$@"
+  exit 1
+}
+
+[[ $# == 4 ]] || err "Invalid arguments"
+[[ -f /.dockerenv ]] || err "This script is supposed to be run from build.sh inside a docker container"
+
+for pkg in $(repoquery --queryformat="%{name}" --requires --recursive --resolve "${!excludepackages[@]}" | sort -u); do
+  excludepackages["${pkg}"]=true
+done
+
+declare -A excludelibraries
+for lib in $(sed -e '/#.*/d; /^[[:space:]]*|[[:space:]]*$/d; /^$/d' /usr/local/share/appimage/excludelist); do
+  excludelibraries["${lib}"]=true
+done
+
+
+find_dependencies() {
+  log "Finding missing dependencies for: $@"
+  declare -A libs
+  for file in "$@"; do
+    [[ -f "${file}" && -x "${file}" ]] || err "File does not exist or is not executable: ${file}"
+    for lib in $(LD_LIBRARY_PATH=$(dirname "${file}") ldd "${file}" | awk '/ => not found/ {print $1}'); do
+      # don't check a lib more than once
+      [[ -n "${excludelibraries["${lib}"]}" ]] && continue
+      excludelibraries["${lib}"]=true
+      # find the lib's package
+      local package=$(repoquery --queryformat="%{name}" --file "${lib}" | head -n1)
+      [[ -z "${package}" ]] && err "Missing package for: ${lib}"
+      [[ -n "${excludepackages["${package}"]}" ]] && continue
+      libs["${lib}"]="${package}"
+    done
+  done
+
+  [[ ${#libs[@]} == 0 ]] && return
+
+  log "Installing packages: ${libs[@]}"
+  yum install -y --setopt=tsflags= "${libs[@]}"
+  log "Copying libraries"
+  for lib in "${!libs[@]}"; do
+    for path in $(repoquery --list --archlist "${ARCH}" "${libs["${lib}"]}"); do
+      if [[ "$(basename -- "${path}")" == "${lib}" ]]; then
+        ( set -x; install -m755 -t "${LIBDIR}" "${path}" )
+      fi
+      if echo "${path}" | grep -Ei '^/usr/share/(doc|licenses)/.*(copying|licen[cs]e|readme|terms).*'; then
+        ( set -x; install -Dm644 -t "${APPDIR}${path}" "${path}" )
+      fi
+    done
+  done
+
+  find_dependencies $(echo "${!libs[@]}" | tr ' ' '\n' | while read -r lib; do echo "${LIBDIR}/${lib}"; done)
+}
+
+build_appimage() {
+  log "Building appimage"
+  [ "${SOURCE_DATE_EPOCH}" ] && mtime="@${SOURCE_DATE_EPOCH}" || mtime=now
+  find "${APPDIR}" -exec touch --no-dereference "--date=${mtime}" '{}' '+'
+  VERSION="${VERSION}" ARCH="${ARCH}" /usr/local/bin/appimagetool \
+    --verbose \
+    --comp gzip \
+    --no-appstream \
+    "${APPDIR}" \
+    output
+}
+
+build() {
+  find_dependencies $(find "${APPDIR}/${INSTALLDIR}" -type f -exec sh -c 'readelf -h {} >/dev/null 2>&1' \; -print)
+  build_appimage
+}
+
+build

build/resources/appimage/build.sh

@@ -0,0 +1,172 @@
+#!/usr/bin/env bash
+set -e
+
+# this build script is meant to be run by the dist:appimage_linux{32,64} grunt tasks
+# don't run it directly unless you know what you're doing
+
+NAME="${1}"
+VERSION="${2}"
+ARCH="${3}"
+DOCKER_IMAGE="${4}"
+DOCKER_DIGEST="${5}"
+INPUT="${6}"
+OUTPUT="${7}"
+
+declare -A DEPS=(
+  [docker]=docker
+  [appstreamcli]=appstreamcli
+  [appstream-util]=appstreamutil
+)
+
+
+# ----
+
+
+SELF=$(basename "$(readlink -f "${0}")")
+DOCKER_SCRIPT="$(dirname "$(readlink -f "${0}")")/build-docker.sh"
+
+log() {
+  echo "[${SELF}] $@"
+}
+err() {
+  log >&2 "$@"
+  exit 1
+}
+
+[[ $# == 7 ]] || err "Invalid arguments"
+
+for dep in "${!DEPS[@]}"; do
+  command -v "${dep}" 2>&1 >/dev/null || err "Missing dependency: ${DEPS["${dep}"]}"
+done
+
+
+# ----
+
+
+tempdir=$(mktemp -d) && trap "rm -rf ${tempdir}" EXIT || exit 255
+cd "${tempdir}"
+
+appdir="${NAME}.AppDir"
+installdir="opt/${NAME}"
+
+
+# ----
+
+
+get_docker_image() {
+  log "Getting docker image"
+  docker image ls --digests "${DOCKER_IMAGE}" | grep "${DOCKER_DIGEST}" 2>&1 >/dev/null \
+    || docker image pull "${DOCKER_IMAGE}@${DOCKER_DIGEST}"
+}
+
+
+prepare_appimage() {
+  log "Installing AppDir files"
+
+  # create AppImage AppDir
+  mkdir -p "${appdir}/${installdir}"
+
+  # copy app contents
+  cp -a "${INPUT}/." "${appdir}/${installdir}/"
+
+  # copy licenses
+  install -Dm644 \
+    -t "${appdir}/usr/share/licenses/${NAME}/" \
+    "${appdir}/${installdir}/LICENSE.txt" \
+    "${appdir}/${installdir}/credits.html"
+
+  # copy appstream metainfo
+  install -Dm644 \
+    -t "${appdir}/usr/share/metainfo/" \
+    "${appdir}/${installdir}/${NAME}.appdata.xml"
+
+  # copy icons
+  for res in 16 32 48 64 128 256; do
+    install -Dm644 \
+      "${appdir}/${installdir}/icons/icon-${res}.png" \
+      "${appdir}/usr/share/icons/hicolor/${res}x${res}/apps/${NAME}.png"
+  done
+
+  # symlink root AppImage icons
+  for link in "${appdir}/.DirIcon" "${appdir}/${NAME}.png"; do
+    ln -sr "${appdir}/usr/share/icons/hicolor/256x256/apps/${NAME}.png" "${link}"
+  done
+
+  # create desktop file
+  mkdir -p "${appdir}/usr/share/applications/"
+  cat > "${appdir}/usr/share/applications/${NAME}.desktop" <<EOF
+[Desktop Entry]
+Type=Application
+Name=Streamlink Twitch GUI
+GenericName=Twitch.tv browser for Streamlink
+Comment=Browse Twitch.tv and watch streams in your videoplayer of choice
+Keywords=streamlink;twitch;
+Categories=AudioVideo;Network;
+Exec=${NAME}
+Icon=${NAME}
+EOF
+
+  # symlink root AppImage desktop file
+  ln -sr "${appdir}/usr/share/applications/${NAME}.desktop" "${appdir}/${NAME}.desktop"
+
+  # symlink executable
+  mkdir -p "${appdir}/usr/bin"
+  ln -sr "${appdir}/${installdir}/${NAME}" "${appdir}/usr/bin/${NAME}"
+
+  # AppRun
+  cat > "${appdir}/AppRun" <<EOF
+#!/usr/bin/env bash
+HERE=\$(dirname "\$(readlink -f "\${0}")")
+export LD_LIBRARY_PATH="\${HERE}/${installdir}/lib\${LD_LIBRARY_PATH:+":\${LD_LIBRARY_PATH}"}"
+"\${HERE}/usr/bin/${NAME}" "\${@}"
+EOF
+  chmod +x "${appdir}/AppRun"
+
+  # remove unneeded stuff
+  rm -rf \
+    "${appdir}/${installdir}/"{add,remove}-menuitem.sh \
+    "${appdir}/${installdir}/"{LICENSE.txt,credits.html} \
+    "${appdir}/${installdir}/${NAME}.appdata.xml" \
+    "${appdir}/${installdir}/icons/"
+}
+
+
+verify_appstream() {
+  log "Verifying appstream data"
+  appstreamcli validate-tree "${appdir}/usr/share/metainfo/${NAME}.appdata.xml"
+  appstream-util validate-relax "${appdir}/usr/share/metainfo/${NAME}.appdata.xml"
+}
+
+
+build_appimage() {
+  log "Building appimage inside container"
+  local target=/build
+  install -m755 -t "${tempdir}" "${DOCKER_SCRIPT}"
+  docker run \
+    --interactive \
+    --rm \
+    --env SOURCE_DATE_EPOCH \
+    --mount "type=bind,source=${tempdir},target=${target}" \
+    --workdir "${target}" \
+    "${DOCKER_IMAGE}@${DOCKER_DIGEST}" \
+    /usr/bin/bash <<EOF
+set -e
+trap "chown -R $(id -u):$(id -g) '${target}'" EXIT
+"./$(basename -- "${DOCKER_SCRIPT}")" \
+  "${appdir}" \
+  "${installdir}" \
+  "${VERSION}" \
+  "${ARCH}"
+EOF
+  install -Dm755 "${tempdir}/output" "${OUTPUT}"
+}
+
+
+build() {
+  prepare_appimage
+  verify_appstream
+  get_docker_image
+  build_appimage
+}
+
+build