chg: start server at a unique address
See the previous patch for motivation. Previously, the server is started at
a globally shared address. This patch appends pid to the address so it
becomes unique.
Note: with Linux pid namespace, the address may be non-unique, but it does
not affect correctness of chg - chg client will receive an redirection and
that's it.
chgserver: truncate base address at "." for hash address
Previously, the hash address is just appending "-$HASH" to base address.
This patch makes it truncate the basename address at "." before appending
"-$HASH".
This makes it possible to spawn new servers in a racy situation and the
client could be sure the server it connects is the new server just spawned.
This is a step towards removing the lock.
One of the functionalities of the lock is to make sure the connect will
connect to a server it just created:
1. start server --address foo
2. connect to foo # wish "foo" is the server just started
With this change, the client could do:
1. start server --address foo.tmp$PID
2. connect to foo.tmp$PID # is the server just started
(note: if it is not, it does not affect correctness - linux pid
namespace is not a concern here)
3. rename foo.tmp$PID to foo
Another functionality of the lock is to avoid starting multiple servers with
a same confighash in parallel. But that also prevents starting multiple
servers with different confighashes in parallel.
ui: do not translate empty configsource() to 'none' (API)
It should be processed when displaying data, so we can get "source": "" in
JSON output.
convert: remove unused-but-set variable introduced in
db9e883566e8
Spotted by pyflakes.