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app-emulation/wa-linux-agent: Use networkctl to propagate hostname#1978

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pothos merged 2 commits intomainfrom
kai/azure-hostname
May 3, 2024
Merged

app-emulation/wa-linux-agent: Use networkctl to propagate hostname#1978
pothos merged 2 commits intomainfrom
kai/azure-hostname

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@pothos pothos commented May 3, 2024

The if-up-down to trigger the DHCP request causes problems. It's better
to directly ask systemd-networkd to issue the request. It seems that
one needs to use "reconfigure" instead of "forcerenew", so I went with
only that instead of somehow trying to see if "forcerenew" has an
effect.

How to use

For this comment #1950 (comment)

Testing done

Used flatcar-update -P … -E … to switch to the built image, and checked that waagent triggers the DHCP renewal:

May 03 14:06:56 newname systemd-hostnamed[2482]: Hostname set to <newname> (static)
May 03 14:06:56 newname systemd-resolved[1538]: System hostname changed to 'newname'.
May 03 14:06:56 newname sudo[2479]: pam_unix(sudo:session): session closed for user root
May 03 14:07:06 newname waagent[2401]: 2024-05-03T14:07:06.006518Z INFO EnvHandler ExtHandler EnvMonitor: Detected hostname change: hello2 -> newname
May 03 14:07:06 newname waagent[2401]: 2024-05-03T14:07:06.007770Z INFO EnvHandler ExtHandler Examine /proc/net/route for primary interface
May 03 14:07:06 newname waagent[2401]: 2024-05-03T14:07:06.007969Z INFO EnvHandler ExtHandler Primary interface is [eth0]
May 03 14:07:06 newname systemd-networkd[1736]: eth0: found matching network '/usr/lib/systemd/network/zz-default.network', based on potentially unpredictable interface name.
May 03 14:07:06 newname systemd-networkd[1736]: eth0: Configuring with /usr/lib/systemd/network/zz-default.network.
May 03 14:07:06 newname systemd-networkd[1736]: eth0: DHCP lease lost
May 03 14:07:06 newname systemd-networkd[1736]: eth0: DHCPv6 lease lost
May 03 14:07:06 newname systemd-networkd[1736]: eth0: DHCPv4 address 10.0.0.4/24, gateway 10.0.0.1 acquired from 168.63.129.16

There is no Link DOWN, Lost carrier anymore for eth0 and enP52305s1.

pothos added 2 commits May 3, 2024 20:37
This reverts commit 9556c7f
because waagent looks for internal hostname changes and wants to
propagate them to the Azure VM properties by issuing a new DHCP request.
The if-up-down to trigger the DHCP request causes problems. It's better
to directly ask systemd-networkd to issue the request. It seems that
one needs to use "reconfigure" instead of "forcerenew", so I went with
only that instead of somehow trying to see if "forcerenew" has an
effect.
@pothos pothos mentioned this pull request May 3, 2024
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love the approach

@pothos pothos merged commit f06ebd3 into main May 3, 2024
@pothos pothos deleted the kai/azure-hostname branch May 3, 2024 14:12
jepio added a commit that referenced this pull request Jun 21, 2024
app-emulation/wa-linux-agent: Use networkctl to propagate hostname

Signed-off-by: Jeremi Piotrowski <jpiotrowski@microsoft.com>
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2 participants