snap: tweak commands

This adds a new (hidden) `snap blame` command reserved for future
use.

cmd/snap/cmd_blame.go

@@ -0,0 +1,53 @@
+// -*- Mode: Go; indent-tabs-mode: t -*-
+
+/*
+ * Copyright (C) 2018 Canonical Ltd
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+package main
+
+import (
+	"fmt"
+	"math/rand"
+
+	"github.com/jessevdk/go-flags"
+)
+
+type cmdBlame struct{}
+
+var authors []string
+
+func init() {
+	cmd := addCommand("blame",
+		"",
+		"",
+		func() flags.Commander {
+			return &cmdBlame{}
+		}, nil, nil)
+	cmd.hidden = true
+}
+
+func (x *cmdBlame) Execute(args []string) error {
+	if len(args) > 0 {
+		return ErrExtraArgs
+	}
+	if len(authors) == 0 {
+		return nil
+	}
+
+	fmt.Fprintf(Stdout, "It's all %s's fault.\n", authors[rand.Intn(len(authors))])
+	return nil
+}

cmd/snap/cmd_blame_generated.go

@@ -0,0 +1,7 @@
+package main
+
+// generated by mkauthors.sh; do not edit
+
+func init() {
+	authors = []string{"Mark Shuttleworth", "Gustavo Niemeyer",  "Sergio Schvezov", "Simon Fels", "Kyle Fazzari", "Sergio Cazzolato", "Leo Arias", "Gustavo Niemeyer", "Federico Gimenez", "Maciej Borzecki", "Jamie Strandboge", "Pawel Stolowski", "John R. Lenton", "Samuele Pedroni", "Zygmunt Krynicki", "Michael Vogt",}
+}

mkauthors.sh

@@ -0,0 +1,59 @@
+#!/bin/bash
+set -e
+
+# debugging if anything fails is tricky as dh-golang eats up all output
+# uncomment the lines below to get a useful trace if you have to touch
+# this again (my advice is: DON'T)
+#set -x
+#logfile=/tmp/mkauthors.log
+#exec >> $logfile 2>&1
+#echo "env: $(set)"
+#echo "mkauthors.sh run from: $0"
+#echo "pwd: $(pwd)"
+
+# we have two directories we need to care about:
+# - our toplevel pkg builddir which is where "mkauthors.sh" is located
+#   and where "snap-confine" expects its cmd/VERSION file
+# - the GO_GENERATE_BUILDDIR which may be the toplevel pkg dir. but
+#   during "dpkg-buildpackage" it will become a different _build/ dir
+#   that dh-golang creates and that only contains a subset of the
+#   files of the toplevel buildir.
+PKG_BUILDDIR=$(dirname "$0")
+GO_GENERATE_BUILDDIR="$(pwd)"
+
+# run from "go generate" adjust path
+if [ "$GOPACKAGE" = "cmd" ]; then
+    GO_GENERATE_BUILDDIR="$(pwd)/.."
+fi
+
+# Let's try to derive authors from git
+if ! command -v git >/dev/null; then
+    exit
+fi
+
+# see if we are in a git branch, if not, do nothing
+if [ ! -d .git ]; then
+    exit
+fi
+
+# "John Lenton" and "John R. Lenton" are the same guy
+raw_authors="$(git shortlog -s|sort -n|grep -v "John Lenton"|tail -n14|cut -f2)"
+authors=""
+while read -r author; do
+    if [ "$author" = "sergio-j-cazzolato" ]; then
+        author="Sergio Cazzolato"
+    fi
+    authors="$authors \"$author\","
+done <<< "$raw_authors"
+
+
+cat <<EOF > "$GO_GENERATE_BUILDDIR/cmd/snap/cmd_blame_generated.go"
+package main
+
+// generated by mkauthors.sh; do not edit
+
+func init() {
+	authors = []string{"Mark Shuttleworth", "Gustavo Niemeyer", $authors}
+}
+EOF
+