Re: Unable to set root password with clear text using preseed/early_command

[Glen Huang <heyhgl@gmail.com>]

Thanks for the tip.

I’m not sure if escaping is the issue. I tried directly specifying the password:

debconf-set passwd/root-password passwd1234
debconf-set passwd/root-password-again passwd1234

Still got prompted.

I tried to debug it with

d-i preseed/early_command string \
    set -x; \
    . /usr/share/debconf/confmodule; \
    db_set passwd/root-password passwd1234; \
    db_set passwd/root-password-again passwd1234; \
    db_input critical passwd/root-password

And the syslog shows RET='value set’ for db_set passwd/root-password, and RET='question will be asked’ for db_input critical passwd/root-password.

It seems the password type is somehow specially handled and could’t be set this way? But very strange that it works when specifying "d-i passwd/root-password password …” in preseed to set it. I’m still unable to locate the code that does the special handling for password type.

> On Feb 16, 2022, at 6:01 AM, Geert Stappers <stappers@stappers.nl> wrote:
> 
> On Tue, Feb 15, 2022 at 08:08:08PM +0800, Glen Huang wrote:
>> Hi,
>> 
>> I want to set the root password to a random string. this is the preseed I use:
>> 
>> d-i preseed/early_command string \
>>    pw="$(tr -dc A-Za-z0-9 </dev/urandom | head -c 24)"; \
>>    debconf-set passwd/root-password "$pw"; \
>>    debconf-set passwd/root-password-again "$pw"
>> 
>> However, the installer still prompts me for the root password.
>> 
>> Setting the crypted password works though:
>> 
>> d-i preseed/early_command string \
>>    debconf-set passwd/root-password-crypted '<crypted-string>'
>> 
>> Directly setting the password also works:
>> 
>> d-i passwd/root-password password r00tme
>> d-i passwd/root-password-again password r00tme
>> 
>> From https://sources.debian.org/src/user-setup/1.88/user-setup-ask/#L36,
>> it seems the installer will ask for the root password if
>> root-password-crypted is empty or !. My guess is that in the direct
>> version, somehow root-password-crypted gets a corresponding value when
>> only root-password and root-password-again are set, but I couldn't
>> find the code responsible for that.
>> 
>> I'd be grateful if anyone could shed some light.
>> 
> 
> Completely UNtested, a.k.a.  sharing a thought:
> 
>  d-i preseed/early_command string \
>      tr -dc A-Za-z0-9 </dev/urandom | head -c 24 > /tmp/pw ; \
>      cat /tmp/pw | debconf-set passwd/root-password - ; \
>      cat /tmp/pw | debconf-set passwd/root-password-again -
> 
> 
> Groeten
> Geert Stappers
> Not knowing how much of the early_command_string gets into log file.
> -- 
> Silence is hard to parse
>