Addresses #5811
This cleans up an error in the logic which removes localhost resolvers
from the host resolv.conf at container creation start time. Specifically
when the determination is made if any nameservers are left after
removing localhost resolvers, it was using a string match on the word
"nameserver", which could have been anywhere (including commented out)
leading to incorrect situations where no nameservers were left but the
default ones were not added.
This also adds some complexity to the regular expressions for finding
nameservers in general, as well as matching on localhost resolvers due
to the recent addition of IPv6 support. Because of IPv6 support now
available in the Docker daemon, the resolvconf code is now aware of
IPv6 enable/disable state and uses that for both filter/cleaning of
nameservers as well as adding default Google DNS (IPv4 only vs. IPv4
and IPv6 if IPv6 enabled). For all these changes, tests have been
added/strengthened to test these additional capabilities.
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
Upstream-commit: 93d51e5e971e001d80e9ffa863439f2d72215b5a
Component: engine
Only modifies non-running containers resolv.conf bind mount, and only if
the container has an unmodified resolv.conf compared to its contents at
container start time (so we don't overwrite manual/automated changes
within the container runtime). For containers which are running when
the host resolv.conf changes, the update will only be applied to the
container version of resolv.conf when the container is "bounced" down
and back up (e.g. stop/start or restart)
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
Upstream-commit: 63a7ccdd2372d87f56f7a86da07c72ea51332c2a
Component: engine
Addresses #8057
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com>
Upstream-commit: 4119c9d7d955757092adc3410da8d75f972bd3c1
Component: engine
In that case /etc/resolv.conf will be generated with no search
option. Usage: --dns-search=.
Docker-DCO-1.1-Signed-off-by: Fabio Falci <fabiofalci@gmail.com> (github: fabiofalci)
Upstream-commit: 804b00cd7d1f084a872211e5043d255c454c8e51
Component: engine
