diskimage-builder/diskimage_builder/elements/dhcp-all-interfaces/README.rst
Derek Higgins 97399e9bb1 Set the dhclient timeout to match DIB_DHCP_TIMEOUT
On initial boot when networking is brought up by cloud-init this
is the timeout that dhclient adheres to. Centos configures
"timeout 300" (for an EC2 bug) in their cloud image, which results
in a 5 minutes delay to boot in cases where no dhcp available (e.g. IPv6
SLAAC). To reduce this boot delay and to provide consistency with
places where we have set other dhcp timeouts set this to DIB_DHCP_TIMEOUT.

Change-Id: I119a002070501c3dfe7c6730b07ee25f422b85b0
Related-Bug: #1758324
2018-04-05 14:29:22 +01:00

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===================
dhcp-all-interfaces
===================
Autodetect network interfaces during boot and configure them for DHCP
The rationale for this is that we are likely to require multiple
network interfaces for use cases such as baremetal and there is no way
to know ahead of time which one is which, so we will simply run a
DHCP client on all interfaces with real MAC addresses (except lo) that
are visible on the first boot.
On non-Gentoo based distributions the script
/usr/local/sbin/dhcp-all-interfaces.sh will be called early in each
boot and will scan available network interfaces and ensure they are
configured properly before networking services are started.
On Gentoo based distributions we will install the dhcpcd package and
ensure the service starts at boot. This service automatically sets
up all interfaces found via dhcp and/or dhcpv6 (or SLAAC).
Environment Variables
---------------------
DIB_DHCP_TIMEOUT
:Required: No
:Default: 30
:Description: Amount of time in seconds that the systemd service(or dhclient)
will wait to get an address. Should be increased in networks such as
Infiniband.
:Example: DIB_DHCP_TIMEOUT=300