[tor-bugs] #21903 [Core Tor/Chutney]: Disable DNS in chutney by default, and add an option to enable it

[Tor Bug Tracker & Wiki]

#21903: Disable DNS in chutney by default, and add an option to enable it
------------------------------+------------------------
 Reporter:  teor              |          Owner:  teor
     Type:  defect            |         Status:  closed
 Priority:  Medium            |      Milestone:
Component:  Core Tor/Chutney  |        Version:
 Severity:  Normal            |     Resolution:  fixed
 Keywords:                    |  Actual Points:
Parent ID:  #19573            |         Points:  0.5
 Reviewer:                    |        Sponsor:
------------------------------+------------------------
Changes (by teor):

 * status:  needs_revision => closed
 * resolution:   => fixed


Comment:

 Implemented and merged to master as c889534.

 Replying to [comment:7 teor]:
 > Here's a design for this:
 > * If the default ServerDNSResolvConfFile is missing, or is a symlink
 with a missing target (thanks, Apple!), chutney applies a workaround
 `ServerDNSResolvConfFile /dev/null`
 > * An environmental variable can be used to set `ServerDNSResolvConfFile`
 >   * This can be used to implement --offline: CHUTNEY_DNS_CONF=/dev/null
 >   * This can be used to implement --dns-conf=X: CHUTNEY_DNS_CONF=X
 > * An environmental variable can be used to not set
 `ServerDNSResolvConfFile`
 >   * This can be used to implement --dns-conf-default:
 CHUTNEY_DNS_CONF=""

 This is implemented.

 > To fix the crash on SETCONF in #21900, the user needs to supply a DNS
 conf with at least one nameserver.

 This is documented, and a local resolv.conf is provided by chutney.

 > To provide a conf that simultaneously:
 > * works offline: CHUTNEY_DNS_CONF=/path/to/empty/or/working/conf
 > * and doesn't crash on SETCONF:
 CHUTNEY_DNS_CONF=/path/to/conf/with/a/dns/server
 >
 > The user must supply a local DNS server that gives the right answers to
 tor (#19573).
 > Or we can fix #21900, and just say /dev/null.
 > (We should document this in the chutney README.)

 This is documented, but providing the right DNS answers is out of scope
 for chutney.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/21903#comment:10>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online