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On Sun, Mar 18, 2012 at 2:02 AM, Graham Murray <graham@×××××××××××.uk> wrote: |
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> Canek Peláez Valdés <caneko@×××××.com> writes: |
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> |
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>> * Really simple service unit files: The service unit files are really |
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>> small, really simple, really easy to understand/modify. Compare the 9 |
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>> lines of sshd.service: |
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>> |
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>> $ cat /etc/systemd/system/sshd.service |
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>> [Unit] |
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>> Description=SSH Secure Shell Service |
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>> After=syslog.target |
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>> |
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>> [Service] |
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>> ExecStart=/usr/sbin/sshd -D |
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>> |
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>> [Install] |
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>> WantedBy=multi-user.target |
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>> |
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>> with the 84 of /etc/init.d/sshd (80 without comments). |
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> |
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> But the 80 lines of /etc/init.d/sshd do a lot more than just and stop |
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> the service. |
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|
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Yes, it does. |
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|
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> They ensure that there is an sshd configuration file and |
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> give a meaningful message (including where to find the sample) if it is |
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> not present, and check for the presence of the hostkeys (again which are |
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> needed) and create them if they are not present. Your 9 lines of |
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> sshd.service do none of this. |
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That is completely true. I also think that those checks does not |
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belong into the init script: I think the configuration file presence |
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should be guarantee by the package manager at install time, and so the |
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creation of the hostkeys. |
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|
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Having said that, systemd provides ConditionPathExists, which allows |
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you to set a file as necessary for a service execution. So my 9 lines |
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transform into |
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|
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$ cat /etc/systemd/system/sshd.service |
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[Unit] |
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Description=SSH Secure Shell Service |
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After=syslog.target |
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ConditionPathExists=/etc/ssh/sshd_config |
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|
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[Service] |
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ExecStart=/usr/sbin/sshd -D |
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|
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[Install] |
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WantedBy=multi-user.target |
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|
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If the config file doesn't exists, the service will not start, and you |
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can check the reason why with |
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|
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systemctl status sshd.service |
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|
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And of course you can set another mini sevice unit file to create the |
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hostkeys. But I repeat: I think those tasks belong into the package |
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manager, no the init script. |
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|
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Regards. |
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-- |
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Canek Peláez Valdés |
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Posgrado en Ciencia e Ingeniería de la Computación |
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Universidad Nacional Autónoma de México |
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