An ambient capability only reaches the effective set when euid is
non-zero, so a service that pairs `capabilities = { "^cap_..." }` with a
root user gets none of the restriction it asks for, and keeps the full
root set instead. Finit read the list, applied it, and said nothing. A
build without libcap dropped the list on the floor just as quietly.
Both now warn, naming the service:
nginx: ambient capabilities ('^') have no effect as root, use a
non-root user, or '%' and '!' entries
The ambient entries are read back from the parsed IAB value rather than
matched in the text, so inheritable ('%') and bounding ('!') entries stay
silent -- those work fine as root.
The warning repeats when the .conf files are re-read on runlevel change,
as parse warnings here already do.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
The block conversion changed the bodies of the reference sections but
left every "**Syntax:**" header spelling the line-based format, so each
page opened by teaching the format it then stopped using. Six files
were missed entirely: runparts, files, capabilities, requirements,
runlevels, and switchroot.
runparts had no block spelling written down anywhere, though the parser
has read `runparts`, `runparts-progress`, and `runparts-sysv` all along.
tty gains a table per variant. Its three syntax lines carried nine
positional fields between them, which no longer describes anything the
parser accepts.
Fixes#148
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Implement Linux capability support for services, allowing them to run
with minimal required privileges instead of running as root. This uses
the modern IAB (Inheritable, Ambient, Bounding) API from libcap.
Joachim Wiberg