pleroma_ctl: add an update command

Closes #988 and #1004

rel/files/bin/pleroma_ctl

@@ -1,13 +1,102 @@
 #!/bin/sh
 # XXX: This should be removed when elixir's releases get custom command support
+
+detect_flavour() {
+	arch="$(arch)"
+	if [ "$arch" = "x86_64" ]; then
+		arch="amd64"
+	elif [ "$arch" = "armv7l" ]; then
+		arch="arm"
+	elif [ "$arch" = "aarch64" ]; then
+		arch="arm64"
+	else
+		echo "Unsupported arch: $arch" >&2
+		exit 1
+	fi
+
+	if getconf GNU_LIBC_VERSION >/dev/null; then
+		libc_postfix=""
+	elif [ "$(ldd 2>&1 | head -c 9)" = "musl libc" ]; then
+		libc_postfix="-musl"
+	elif [ "$(find /lib/libc.musl* | wc -l)" ]; then
+		libc_postfix="-musl"
+	else
+		echo "Unsupported libc" >&2
+		exit 1
+	fi
+
+	echo "$arch$libc_postfix"
+}
+
+detect_branch() {
+	version="$(cut -d' ' -f2 <"$RELEASE_ROOT"/releases/start_erl.data)"
+	branch="$(echo "$version" | cut -d'-' -f 4)"
+	if [ "$branch" = "develop" ]; then
+		echo "develop"
+	elif [ "$branch" = "" ]; then
+		echo "master"
+	else
+		echo "Releases are built only for master and develop branches" >&2
+		exit 1
+	fi
+}
+update() {
+	set -e
+	RELEASE_ROOT=$(dirname "$SCRIPTPATH")
+	uri="${PLEROMA_CTL_URI:-https://git.pleroma.social}"
+	project_id="${PLEROMA_CTL_PROJECT_ID:-2}"
+	project_branch="$(detect_branch)"
+	flavour="${PLEROMA_CTL_ARCH:-$(detect_flavour)}"
+	echo "Detected flavour: $flavour"
+	tmp="${PLEROMA_CTL_TMP_DIR:-/tmp}"
+	artifact="$tmp/pleroma.zip"
+	full_uri="${uri}/api/v4/projects/${project_id}/jobs/artifacts/${project_branch}/download?job=${flavour}"
+	echo "Downloading the artifact from ${full_uri} to ${artifact}"
+	curl "$full_uri" -o "${artifact}"
+	echo "Unpacking ${artifact} to ${tmp}"
+	unzip -q "$artifact" -d "$tmp"
+	echo "Copying files over to $RELEASE_ROOT"
+	if [ "$1" != "--no-rm" ]; then
+		rm -r "${RELEASE_ROOT:-?}"/*
+	fi
+	cp -rf "$tmp/release"/* "$RELEASE_ROOT"
+	echo "Removing temporary files"
+	rm -r "$tmp/release"
+	rm "$artifact"
+	echo "Done! Please refer to the changelog/release notes for changes and update instructions"
+	set +e
+}
+
 if [ -z "$1" ] || [ "$1" = "help" ]; then
+	# TODO: Just list the commands on `pleroma_ctl help` and output help for the individual command on `pleroma_ctl help $COMMAND`
 	echo "Usage: $(basename "$0") COMMAND [ARGS]
 
     The known commands are:
 
-        create                     Create database schema (needs to be executed only once)
-        migrate                    Execute database migrations (needs to be done after updates)
-        rollback [VERSION]         Rollback database migrations (needs to be done before downgrading)
+        create
+	  Create database schema (needs to be executed only once)
+
+        migrate
+	  Execute database migrations (needs to be done after updates)
+
+        rollback [VERSION]
+	  Rollback database migrations (needs to be done before downgrading)
+
+	update [OPTIONS]
+	  Update the instance using the latest CI artifact for the current branch.
+
+	  The only supported option is --no-rm, when set the script won't delete the whole directory, but
+	  just force copy over files from the new release. This wastes more space, but may be useful if
+	  some files are stored inside of the release directories (although you really shouldn't store them
+	  there), or if you want to be able to quickly revert a broken update.
+
+	  The script will try to detect your architecture and ABI automatically, but if it is wrong, you can
+	  overwrite it by setting PLEROMA_CTL_ARCH to the desired architecture.
+
+	  By default the artifact will be downloaded from https://git.pleroma.social for pleroma/pleroma (project id: 2)
+	  to /tmp/, you can overwrite these settings by setting PLEROMA_CTL_URI, PLEROMA_CTL_PROJECT_ID and PLEROMA_CTL_TMP_DIR
+	  respectievly.
+
 
     and any mix tasks under Pleroma namespace, for example \`mix pleroma.user COMMAND\` is
     equivalent to \`$(basename "$0") user COMMAND\`
@@ -18,7 +107,10 @@ if [ -z "$1" ] || [ "$1" = "help" ]; then
 else
 	SCRIPT=$(readlink -f "$0")
 	SCRIPTPATH=$(dirname "$SCRIPT")
-	if [ "$1" = "migrate" ] || [ "$1" = "rollback" ] || [ "$1" = "create" ] || [ -n "$PLEROMA_CTL_RPC_DISABLED" ]; then
+
+	if [ "$1" = "update" ]; then
+		update "$2"
+	elif [ "$1" = "migrate" ] || [ "$1" = "rollback" ] || [ "$1" = "create" ] || [ -n "$PLEROMA_CTL_RPC_DISABLED" ]; then
 		"$SCRIPTPATH"/pleroma eval 'Pleroma.ReleaseTasks.run("'"$*"'")'
 	else
 		"$SCRIPTPATH"/pleroma rpc 'Pleroma.ReleaseTasks.run("'"$*"'")'