Improve `makecontainerpkg`

* Add my GPG key to the pacman keyring (not nice to hard-code it in the
  Dockerfile but good enough for now)
* Install ccache into the base image to support makepkg's ccache option
* Split syncing packages and execution of `makepkg` so syncing can be
  avoided when only building source package
* Don't quote `CRE`, it is unlikely spaces are needed here and using
  chained commands (e.g. `sudo …`) might be useful
* Add documentation

README.md

@@ -51,9 +51,40 @@ Requests regarding binary packages can be tracked on the issue tracker of this
 GitHub project as well, e.g. within the [general discussion
 issue](https://github.com/Martchus/PKGBUILDs/issues/94).
 
-## Docker image
-Checkout the repository
-[docker-mingw-qt5](https://github.com/mdimura/docker-mingw-qt5).
+## Container image, building packages within a container
+The directory `devel/container` contains a script to build a container image
+suitable to run Arch Linux's `makepkg` script so you can build from PKGBUILDs on
+any environment where Docker, Podman or any other suitable container runtime is
+available.
+
+It also contains a script called `makecontainerpkg` which behaves like
+`makechrootpkg` from Arch Linux's devtools but uses the previously mentioned
+container image. Therefore it does *not* require devtools, a chroot setup and
+systemd-nsapwn. Instead, any container runtime should be sufficient (tested with
+Docker).
+
+The usage of `makecontainerpkg` is very similar to `makechrootpkg`. Simply run
+the script in a directory containing a `PKGBUILD` file. If the directory
+contains a file called `pacman.conf` and/or `makepkg.conf` those files are
+configured to be used during the build. The call syntax is the following:
+```
+makecontainerpkg [cre args] --- [makepkg args]
+```
+
+Example where the host pacman cache and ccache directories are mounted into the
+container and a package rebuild is forced via `makepkg`'s flag `-f`:
+```
+makecontainerpkg -v /var/cache/pacman/pkg/ -v /run/media/devel/ccache:/ccache -- -f CCACHE_DIR=/ccache
+```
+
+Set the environment variable `CRE` to the container runtime executable (by
+default `docker`) and set `CRE_IMAGE` to use a different container image.
+
+---
+
+There's also the 3rdparty repository
+[docker-mingw-qt5](https://github.com/mdimura/docker-mingw-qt5) which contains
+an image with many mingw-w64 package pre-installed.
 
 ## Structure
 Each package is in its own subdirectoy:

devel/container/base-devel/Dockerfile

@@ -4,7 +4,11 @@ MAINTAINER Martchus <martchus@gmx.net>
 RUN mkdir -p /startdir /build && \
     useradd -m -d /build -u 1000 -U -s /bin/bash builduser && \
     chown -R builduser:builduser /build && \
-    pacman -Syu --noconfirm --needed base-devel pacman-contrib && \
+    pacman-key --init && \
+    pacman-key --recv-keys B9E36A7275FC61B464B67907E06FE8F53CDC6A4C && \
+    pacman-key --finger    B9E36A7275FC61B464B67907E06FE8F53CDC6A4C && \
+    pacman-key --lsign-key B9E36A7275FC61B464B67907E06FE8F53CDC6A4C && \
+    pacman -Syu --noconfirm --needed base-devel pacman-contrib ccache && \
     pacman -Scc --noconfirm && \
     paccache -r -k0 && \
     rm -rf /usr/share/man/* /tmp/* /var/tmp/*

devel/container/containerbuild

@@ -1,7 +1,5 @@
 #!/bin/bash
 set -e
-source PKGBUILD
-pacman -Syu --noconfirm --needed "${depends[@]}" "${makedepends[@]}" "${checkdepends[@]}"
 export LOGDEST=$PWD SRCPKGDEST=$PWD SRCDEST=$PWD PKGDEST=$PWD BUILDDIR=/build
 export BUILDTOOL=makecontainerbuild BUILDTOOLVER="0.0.1"
 chown builduser:builduser "$PWD"

devel/container/containersync

@@ -0,0 +1,7 @@
+#!/bin/bash
+set -e
+for config_file in {makepkg,pacman}.conf; do
+    [[ -f $config_file ]] && cp --target-directory=/etc "$config_file"
+done
+source PKGBUILD
+pacman -Syu --noconfirm --needed "${depends[@]}" "${makedepends[@]}" "${checkdepends[@]}"

devel/container/imagebuild

@@ -1,4 +1,4 @@
 #!/bin/bash
 set -e
 bindir=$(dirname "$0")
-"${CRE:-docker}" image build --tag "${CRE_IMAGE:-archlinux-base-devel}" "$bindir/base-devel"
+${CRE:-docker} image build --tag "${CRE_IMAGE:-archlinux-base-devel}" "$bindir/base-devel"

devel/container/makecontainerpkg

@@ -1,15 +1,14 @@
 #!/bin/bash
 set -e
 
-# load "containerbuild" script
-bindir=$(dirname "$0")
-script=$(cat "$bindir/containerbuild")
-
 # parse arguments
 cre_args=(--workdir "/startdir" -v "$PWD":/startdir --rm)
-script_args= read_script_args=
+script_args= read_script_args= no_sync=
 for arg in "$@"; do
     if [[ $read_script_args ]]; then
+        if [[ $arg == '--nodeps' ]] || [[ $arg == '-d' ]]; then
+            no_sync=1
+        fi
         script_args+=" '$arg'"
     else
         if [[ $arg == '--' ]]; then
@@ -20,9 +19,16 @@ for arg in "$@"; do
     fi
 done
 
+# load "containerbuild" and "containersync" script
+bindir=$(dirname "$0")
+script=$(cat "$bindir/containerbuild")
+if ! [[ $no_sync ]]; then
+    script_sync=$(cat "$bindir/containersync")
+fi
+
 # allow one to prevent the container from stopping via DEBUG variable
 if [[ $DEBUG ]]; then
     script_args+=' ; sleep infinity'
 fi
 
-"${CRE:-docker}" run "${cre_args[@]}" "${CRE_IMAGE:-archlinux-base-devel}" bash -c "$script $script_args"
+${CRE:-docker} run "${cre_args[@]}" "${CRE_IMAGE:-archlinux-base-devel}" bash -c "$script_sync $script $script_args"