Bootstrap skeleton based on snapd.

cmd/mkversion.sh

@@ -0,0 +1,86 @@
+#!/bin/sh
+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/mkversions.log
+#exec >> $logfile 2>&1
+#echo "env: $(set)"
+#echo "mkversion.sh run from: $0"
+#echo "pwd: $(pwd)"
+
+# we have two directories we need to care about:
+# - our toplevel pkg builddir which is where "mkversion.sh" is located
+#   and where "snap-confine" expects its cmd/VERSION file
+# - the GO_GENERATE_BUILDDIR which may be the toplevel pkg dir. but
+#   during "dpkg-buildpackage" it will become a different _build/ dir
+#   that dh-golang creates and that only contains a subset of the
+#   files of the toplevel buildir. 
+PKG_BUILDDIR=$(dirname "$0")/..
+GO_GENERATE_BUILDDIR="$(pwd)"
+
+# run from "go generate" adjust path
+if [ "$GOPACKAGE" = "cmd" ]; then
+    GO_GENERATE_BUILDDIR="$(pwd)/.."
+fi
+
+OUTPUT_ONLY=false
+if [ "$1" = "--output-only" ]; then
+    OUTPUT_ONLY=true
+    shift
+fi
+
+# If the version is passed in as an argument to mkversion.sh, let's use that.
+if [ -n "$1" ]; then
+    v="$1"
+    o=shell
+fi
+
+if [ -z "$v" ]; then
+    # Let's try to derive the version from git..
+    if command -v git >/dev/null; then
+        # not using "--dirty" here until the following bug is fixed:
+        # https://bugs.launchpad.net/snapcraft/+bug/1662388
+        v="$(git describe --always | sed -e 's/-/+git/;y/-/./' )"
+        o=git
+    fi
+fi
+
+if [ -z "$v" ]; then
+    # at this point we maybe in _build/src/github etc where we have no
+    # debian/changelog (dh-golang only exports the sources here)
+    # switch to the real source dir for the changelog parsing
+    v="$(cd "$PKG_BUILDDIR"; dpkg-parsechangelog --show-field Version)";
+    o=debian/changelog
+fi
+
+if [ -z "$v" ]; then
+    exit 1
+fi
+
+if [ "$OUTPUT_ONLY" = true ]; then
+    echo "$v"
+    exit 0
+fi
+
+echo "*** Setting version to '$v' from $o." >&2
+
+cat <<EOF > "$GO_GENERATE_BUILDDIR/cmd/version_generated.go"
+package cmd
+
+// generated by mkversion.sh; do not edit
+
+func init() {
+	Version = "$v"
+}
+EOF
+
+cat <<EOF > "$PKG_BUILDDIR/cmd/VERSION"
+$v
+EOF
+
+#cat <<EOF > "$PKG_BUILDDIR/data/info"
+#VERSION=$v
+#EOF

cmd/pebble/cmd_debug.go

@@ -0,0 +1,26 @@
+// Copyright (c) 2014-2020 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
+
+type cmdDebug struct{}
+
+var shortDebugHelp = "Run debug commands"
+var longDebugHelp = `
+The debug command contains a selection of additional sub-commands.
+
+Debug commands can be removed without notice and may not work on
+non-development systems.
+`

cmd/pebble/cmd_help.go

@@ -0,0 +1,255 @@
+// Copyright (c) 2014-2020 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 (
+	"bytes"
+	"fmt"
+	"io"
+	"regexp"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/jessevdk/go-flags"
+)
+
+var shortHelpHelp = "Show help about a command"
+var longHelpHelp = `
+The help command displays information about commands.
+`
+
+// addHelp adds --help like what go-flags would do for us, but hidden
+func addHelp(parser *flags.Parser) error {
+	var help struct {
+		ShowHelp func() error `short:"h" long:"help"`
+	}
+	help.ShowHelp = func() error {
+		// this function is called via --help (or -h). In that
+		// case, parser.Command.Active should be the command
+		// on which help is being requested (like "pebble foo
+		// --help", active is foo), or nil in the toplevel.
+		if parser.Command.Active == nil {
+			// this means *either* a bare 'pebble --help',
+			// *or* 'pebble --help command'
+			//
+			// If we return nil in the first case go-flags
+			// will throw up an ErrCommandRequired on its
+			// own, but in the second case it'll go on to
+			// run the command, which is very unexpected.
+			//
+			// So we force the ErrCommandRequired here.
+
+			// toplevel --help gets handled via ErrCommandRequired
+			return &flags.Error{Type: flags.ErrCommandRequired}
+		}
+		// not toplevel, so ask for regular help
+		return &flags.Error{Type: flags.ErrHelp}
+	}
+	hlpgrp, err := parser.AddGroup("Help Options", "", &help)
+	if err != nil {
+		return err
+	}
+	hlpgrp.Hidden = true
+	hlp := parser.FindOptionByLongName("help")
+	hlp.Description = "Show this help message"
+	hlp.Hidden = true
+
+	return nil
+}
+
+type cmdHelp struct {
+	All        bool `long:"all"`
+	Manpage    bool `long:"man" hidden:"true"`
+	Positional struct {
+		Subs []string `positional-arg-name:"<command>"`
+	} `positional-args:"yes"`
+	parser *flags.Parser
+}
+
+func init() {
+	addCommand("help", shortHelpHelp, longHelpHelp, func() flags.Commander { return &cmdHelp{} },
+		map[string]string{
+			"all": "Show a short summary of all commands",
+			"man": "Generate the manpage",
+		}, nil)
+}
+
+func (cmd *cmdHelp) setParser(parser *flags.Parser) {
+	cmd.parser = parser
+}
+
+// manfixer is a hackish way to fix drawbacks in the generated manpage:
+// - no way to get it into section 8
+// - duplicated TP lines that break older groff (e.g. 14.04), lp:1814767
+type manfixer struct {
+	bytes.Buffer
+	done bool
+}
+
+func (w *manfixer) Write(buf []byte) (int, error) {
+	if !w.done {
+		w.done = true
+		if bytes.HasPrefix(buf, []byte(".TH pebble 1 ")) {
+			// io.Writer.Write must not modify the buffer, even temporarily
+			n, _ := w.Buffer.Write(buf[:9])
+			w.Buffer.Write([]byte{'8'})
+			m, err := w.Buffer.Write(buf[10:])
+			return n + m + 1, err
+		}
+	}
+	return w.Buffer.Write(buf)
+}
+
+var tpRegexp = regexp.MustCompile(`(?m)(?:^\.TP\n)+`)
+
+func (w *manfixer) flush() {
+	str := tpRegexp.ReplaceAllLiteralString(w.Buffer.String(), ".TP\n")
+	io.Copy(Stdout, strings.NewReader(str))
+}
+
+func (cmd cmdHelp) Execute(args []string) error {
+	if len(args) > 0 {
+		return ErrExtraArgs
+	}
+	if cmd.Manpage {
+		// you shouldn't try to to combine --man with --all nor a
+		// subcommand, but --man is hidden so no real need to check.
+		out := &manfixer{}
+		cmd.parser.WriteManPage(out)
+		out.flush()
+		return nil
+	}
+	if cmd.All {
+		if len(cmd.Positional.Subs) > 0 {
+			return fmt.Errorf("help accepts a command, or '--all', but not both.")
+		}
+		printLongHelp(cmd.parser)
+		return nil
+	}
+
+	var subcmd = cmd.parser.Command
+	for _, subname := range cmd.Positional.Subs {
+		subcmd = subcmd.Find(subname)
+		if subcmd == nil {
+			sug := "pebble help"
+			if x := cmd.parser.Command.Active; x != nil && x.Name != "help" {
+				sug = "pebble help " + x.Name
+			}
+			return fmt.Errorf("unknown command %q, see '%s'.", subname, sug)
+		}
+		// this makes "pebble help foo" work the same as "pebble foo --help"
+		cmd.parser.Command.Active = subcmd
+	}
+	if subcmd != cmd.parser.Command {
+		return &flags.Error{Type: flags.ErrHelp}
+	}
+	return &flags.Error{Type: flags.ErrCommandRequired}
+}
+
+type helpCategory struct {
+	Label       string
+	Description string
+	Commands    []string
+}
+
+// helpCategories helps us by grouping commands
+var helpCategories = []helpCategory{{
+	Label:       "Basics",
+	Description: "basic management",
+	Commands:    []string{"foo", "bar", "baz"},
+}, {
+	Label:       "...more",
+	Description: "slightly more advanced management",
+	Commands:    []string{"more-foo", "more-bar", "more-baz"},
+}}
+
+var (
+	longPebbleDescription = strings.TrimSpace(`
+Pebble lets you control services and perform managemnet actions on
+the system that is running them.
+`)
+	pebbleUsage               = "Usage: pebble <command> [<options>...]"
+	pebbleHelpCategoriesIntro = "Commands can be classified as follows:"
+	pebbleHelpAllFooter       = "For more information about a command, run 'pebble help <command>'."
+	pebbleHelpFooter          = "For a short summary of all commands, run 'pebble help --all'."
+)
+
+func printHelpHeader() {
+	fmt.Fprintln(Stdout, longPebbleDescription)
+	fmt.Fprintln(Stdout)
+	fmt.Fprintln(Stdout, pebbleUsage)
+	fmt.Fprintln(Stdout)
+	fmt.Fprintln(Stdout, pebbleHelpCategoriesIntro)
+	fmt.Fprintln(Stdout)
+}
+
+func printHelpAllFooter() {
+	fmt.Fprintln(Stdout)
+	fmt.Fprintln(Stdout, pebbleHelpAllFooter)
+}
+
+func printHelpFooter() {
+	printHelpAllFooter()
+	fmt.Fprintln(Stdout, pebbleHelpFooter)
+}
+
+// this is called when the Execute returns a flags.Error with ErrCommandRequired
+func printShortHelp() {
+	printHelpHeader()
+	maxLen := 0
+	for _, categ := range helpCategories {
+		if l := utf8.RuneCountInString(categ.Label); l > maxLen {
+			maxLen = l
+		}
+	}
+	for _, categ := range helpCategories {
+		fmt.Fprintf(Stdout, "%*s: %s\n", maxLen+2, categ.Label, strings.Join(categ.Commands, ", "))
+	}
+	printHelpFooter()
+}
+
+// this is "pebble help --all"
+func printLongHelp(parser *flags.Parser) {
+	printHelpHeader()
+	maxLen := 0
+	for _, categ := range helpCategories {
+		for _, command := range categ.Commands {
+			if l := len(command); l > maxLen {
+				maxLen = l
+			}
+		}
+	}
+
+	// flags doesn't have a LookupCommand?
+	commands := parser.Commands()
+	cmdLookup := make(map[string]*flags.Command, len(commands))
+	for _, cmd := range commands {
+		cmdLookup[cmd.Name] = cmd
+	}
+
+	for _, categ := range helpCategories {
+		fmt.Fprintln(Stdout)
+		fmt.Fprintf(Stdout, "  %s (%s):\n", categ.Label, categ.Description)
+		for _, name := range categ.Commands {
+			cmd := cmdLookup[name]
+			if cmd == nil {
+				fmt.Fprintf(Stderr, "??? Cannot find command %q mentioned in help categories, please report!\n", name)
+			} else {
+				fmt.Fprintf(Stdout, "    %*s  %s\n", -maxLen, name, cmd.ShortDescription)
+			}
+		}
+	}
+	printHelpAllFooter()
+}