api/uniter: ReadSettings to use params.Settings

worker/apiuniter/debug/server.go

Index: worker/apiuniter/debug/server.go
=== added file 'worker/apiuniter/debug/server.go'
--- worker/apiuniter/debug/server.go	1970-01-01 00:00:00 +0000
+++ worker/apiuniter/debug/server.go	2013-09-10 12:21:02 +0000
@@ -0,0 +1,116 @@
+// Copyright 2013 Canonical Ltd.
+// Licensed under the AGPLv3, see LICENCE file for details.
+
+package debug
+
+import (
+	"bytes"
+	"errors"
+	"io/ioutil"
+	"os"
+	"os/exec"
+
+	"launchpad.net/goyaml"
+
+	"launchpad.net/juju-core/utils/set"
+)
+
+// ServerSession represents a "juju debug-hooks" session.
+type ServerSession struct {
+	*HooksContext
+	hooks set.Strings
+}
+
+// MatchHook returns true if the specified hook name matches
+// the hook specified by the debug-hooks client.
+func (s *ServerSession) MatchHook(hookName string) bool {
+	return s.hooks.IsEmpty() || s.hooks.Contains(hookName)
+}
+
+// RunHook "runs" the hook with the specified name via debug-hooks.
+func (s *ServerSession) RunHook(hookName, charmDir string, env []string) error {
+	env = append(env, "JUJU_HOOK_NAME="+hookName)
+	cmd := exec.Command("/bin/bash", "-s")
+	cmd.Env = env
+	cmd.Dir = charmDir
+	cmd.Stdin = bytes.NewBufferString(debugHooksServerScript)
+	if err := cmd.Start(); err != nil {
+		return err
+	}
+	go func(proc *os.Process) {
+		// Wait for the SSH client to exit (i.e. release the flock),
+		// then kill the server hook process in case the client
+		// exited uncleanly.
+		path := s.ClientExitFileLock()
+		exec.Command("flock", path, "-c", "true").Run()
+		proc.Kill()
+	}(cmd.Process)
+	return cmd.Wait()
+}
+
+// FindSession attempts to find a debug hooks session for the unit specified
+// in the context, and returns a new ServerSession structure for it.
+func (c *HooksContext) FindSession() (*ServerSession, error) {
+	cmd := exec.Command("tmux", "has-session", "-t", c.tmuxSessionName())
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		if len(out) != 0 {
+			return nil, errors.New(string(out))
+		} else {
+			return nil, err
+		}
+	}
+	// Parse the debug-hooks file for an optional hook name.
+	data, err := ioutil.ReadFile(c.ClientFileLock())
+	if err != nil {
+		return nil, err
+	}
+	var args hookArgs
+	err = goyaml.Unmarshal(data, &args)
+	if err != nil {
+		return nil, err
+	}
+	hooks := set.NewStrings(args.Hooks...)
+	session := &ServerSession{c, hooks}
+	return session, nil
+}
+
+const debugHooksServerScript = `set -e
+export JUJU_DEBUG=$(mktemp -d)
+exec > $JUJU_DEBUG/debug.log >&1
+
+# Set a useful prompt.
+export PS1="$JUJU_UNIT_NAME:$JUJU_HOOK_NAME % "
+
+# Save environment variables and export them for sourcing.
+FILTER='^\(LS_COLORS\|LESSOPEN\|LESSCLOSE\|PWD\)='
+export | grep -v $FILTER > $JUJU_DEBUG/env.sh
+
+# Create an internal script which will load the hook environment.
+cat > $JUJU_DEBUG/hook.sh <<END
+#!/bin/bash
+. $JUJU_DEBUG/env.sh
+echo \$\$ > $JUJU_DEBUG/hook.pid
+exec /bin/bash --noprofile --norc
+END
+chmod +x $JUJU_DEBUG/hook.sh
+
+tmux new-window -t $JUJU_UNIT_NAME -n $JUJU_HOOK_NAME "$JUJU_DEBUG/hook.sh"
+
+# If we exit for whatever reason, kill the hook shell.
+exit_handler() {
+    if [ -f $JUJU_DEBUG/hook.pid ]; then
+        kill -9 $(cat $JUJU_DEBUG/hook.pid) || true
+    fi
+}
+trap exit_handler EXIT
+
+# Wait for the hook shell to start, and then wait for it to exit.
+while [ ! -f $JUJU_DEBUG/hook.pid ]; do
+    sleep 1
+done
+HOOK_PID=$(cat $JUJU_DEBUG/hook.pid)
+while kill -0 "$HOOK_PID" 2> /dev/null; do
+    sleep 1
+done
+`