Deeper understanding

This documentation explains the internal structure of 66 on the system and the roles of the different directories and file components.

Never manually changes any directories or files within the 66 ecosystem,as this is the best way to break it.

/var/lib/66

This directory is specified at compile time by using the --with-system-dir= option to ./configure.

This directory stores trees and services configuration files. You should see this following structure

/var/lib/66
└── system
    ├── .resolve
    │   ├── service
    │   │    ├── services -> /var/lib/66/system/service/svc/<service>
    │   │    └── services -> /var/lib/66/system/service/svc/<service>
    │   ├── Master
    │   ├── <tree> resolve file
    │   └── <tree> resolve file
    └── service
        └── svc
            ├── <service>
            │   ├── .resolve
            │   │   └── <service> resolve file
            │   ├── state
            │   │   └── status file
            │   ├── file
            │   └── file     
            ├── <services>
            │   ├── .resolve
            │   │   └── <service> resolve file
            │   ├── state
            │   │   └── status file
            │   ├── file
            │   └── file    
            └── <service>
                ├── .resolve
                │   └── <service> resolve file
                ├── state
                │   └── status file
                ├── file
                └── file

The exact same structure is also available for regular users at the ${HOME}/.66 directory.

The /var/lib/66/system/.resolve directory contains resolve files for trees. Each tree have its own resolve file, while the Master resolve file contains information about all trees available on the system.

The /var/lib/66/system/.resolve/service directory consists of symlinks that point to resolve files for each service. These symlinks enable 66 to quickly access the resolve files for individual services, facilitating the construction of the complete graph of services interdependences.

The /var/lib/66/system/service/svc directory includes service directories, each housing the results of the parse process, as well as internal directories and files essential for 66.

/var/lib/66/system/.resolve/

The content of the resolve file for a tree, such as global, can be viewed using the 66 resolve command in the following manner

66 tree resolve global

This displays information in a self-explanatory manner

name        : global
depends     : None
requiredby  : session
allow       : 0
groups      : admin
contents    : consolekit consolekit-log dbus dbus-log networkmanager networkmanager-log
ndepends    : 0
nrequiredby : 1
nallow      : 1
ngroups     : 1
ncontents   : 6

This information is utilized by 66 to fulfill the user-requested commands. It contains precisely what is necessary and nothing more.

For instance, in a command like 66 tree admin -o depends=security global, the security tree name is appended to the depends field, incrementing the ndepends count by one.

Essentially, trees are just resolve files - keeping it simple, straightforward, and easy.

Master resolve file

The Master resolve file holds significant importance as it contains information about all trees. You can access its contents using the 66 tree resolve Master command, which presents information in a self-explanatory format

name        : Master
allow       : root
enabled     : global session
current     : global
contents    : global session boot
nallow      : 1
nenabled    : 2
ncontents   : 3

The Master resolve file isn't accessible for direct user use. Attempting to execute commands like 66 tree enable Master will result in an error.

This file serves 66 in rapidly accessing an overview of trees on the system. When a user triggers a 66 tree disable session command, it updates the enabled and nenabled fields to reflect the current state of the tree.

/var/lib/66/system/service/svc/\<service>

Every service possesses its individual directory. At its core, this directory houses the outcome of the parse process, heavily reliant on the corresponding frontend file. Yet, all service directories invariably include the .resolve and state subdirectories.

/var/lib/66/system/service/svc/\<service>/.resolve

This directory stores the resolve file for each service, mirroring how /var/lib/66/system/.resolve/ houses the resolve file for a tree. Running 66 resolve \<service\> showcases the content of this file, presenting information similar to the following

name             : openntpd
description      : ntpd daemon
version          : 0.2.1
type             : 0
notify           : 0
maxdeath         : 5
earlier          : 0
hiercopy         : None
intree           : None
ownerstr         : 0
owner            : 0
treename         : global
user             : root
inns             : None
enabled          : 1
home             : /var/lib/66/
frontend         : /etc/66/service/openntpd
servicedir       : /var/lib/66/system/service/svc/openntpd
depends          : sshd openntpd-log
requiredby       : None
optsdeps         : None
contents         : None
ndepends         : 2
nrequiredby      : 0
noptsdeps        : 0
ncontents        : 0
run              : #!/usr/bin/execlineb -P
fdmove 1 0
s6-fdholder-retrieve /run/66/scandir/0/fdholder/s "pipe:66-w-openntpd-log"
fdswap 0 1
./run.user

run_user         : #!/usr/bin/execlineb -P
fdmove -c 2 1
execl-envfile -v4 /etc/66/conf/openntpd/version

    execl-toc -d /var/empty/openntpd
    execl-toc -d ${socket_dir}
    execl-cmdline -s { ntpd ${cmd_args} }


run_build        : auto
run_shebang      : None
run_runas        : None
finish           : #!/usr/bin/execlineb -S0
fdmove 1 0
s6-fdholder-retrieve /run/66/scandir/0/fdholder/s "pipe:66-w-openntpd-log"
fdswap 0 1
./finish.user $@

finish_user      : #!/usr/bin/execlineb -P
fdmove -c 2 1
execl-envfile -v4 /etc/66/conf/openntpd/version
 s6-rmrf ${socket_dir}/${socket_name}

finish_build     : auto
finish_shebang   : None
finish_runas     : None
timeoutkill      : 0
timeoutfinish    : 0
timeoutup        : 0
timeoutdown      : 0
down             : 0
downsignal       : 0
livedir          : /run/66/
status           : /var/lib/66/system/.resolve/service/openntpd/state/status
servicedir       : /run/66/state/0/openntpd
scandir          : /run/66/scandir/0/openntpd
statedir         : /run/66/state/0/openntpd/state
eventdir         : /run/66/state/0/openntpd/event
notifdir         : /run/66/state/0/openntpd/notif
supervisedir     : /run/66/state/0/openntpd/supervise
fdholderdir      : /run/66/scandir/0/fdholder
oneshotddir      : /run/66/scandir/0/oneshotd
logname          : openntpd-log
logdestination   : /var/log/66/openntpd
logbackup        : 3
logmaxsize       : 1000000
logtimestamp     : 3
logwant          : 1
logrun           : #!/usr/bin/execlineb -P
s6-fdholder-retrieve /run/66/scandir/0/fdholder/s "pipe:66-r-openntpd-log"
./run.user

logrun_user      : #!/usr/bin/execlineb -P
fdmove -c 2 1
s6-setuidgid s6log
s6-log -d3 n3 s1000000 /var/log/66/openntpd

logrun_build     : None
logrun_shebang   : None
logrun_runas     : s6log
logtimeoutkill   : 0
logtimeoutfinish : 0
env              :
cmd_args=!-d

# conf_file=!/etc/ntpd.conf

socket_dir=!/run/openntpd


socket_name=!openntpd.sock


envdir           : /etc/66/conf/openntpd
env_overwrite    : 0
configure        : None
directories      : None
files            : None
infiles          : None
ndirectories     : 0
nfiles           : 0
ninfiles         : 0

The 66 status <service> command provides a subset of these information. Too much detail might be overwhelming, so it simplifies the output for ease of use.

Some precision is needed here:

• The intree field corresponds to the InTree field in the frontend file, while treename indicates the current associated tree of the service. Changing the tree with 66 -t <tree> enable <service> modifies treename, leaving intree unchanged.

• The inns field indicates whether the service is a part of a module.

• The run and finish field contains the content of the /var/lib/66/system/svc/service/svc/<service>/run and /var/lib/66/system/svc/service/svc/<service>/finish file respectively.

• Meanwhile, run_user, and finish_user fields are derived from the Start and Stop sections in the frontend file. Specifically, run_user corresponds to Execute in the Start section, and the others function similarly but for the Stop section.

• Other fields like ownerstr, home, frontend, servicedir, livedir, status, servicedir, scandir, statedir, eventdir, notifdir, supervisedir, fdholderdir, oneshotddir, logname, logwant and env_overwrite are used internally for 66's operations.

/var/lib/66/system/service/svc/\<service>/status

This directory houses a binary file named status, which 66 uses to track the service's current operational status. Running 66 state <service> displays output similar to the following

toinit          : 0
toreload        : 0
torestart       : 0
tounsupervise   : 0
toparse         : 0
isparsed        : 1
issupervised    : 1
isup            : 1

For instance, when executing 66 free <service>, the tounsupervise field switches to 1 at the process start and back to 0 at the end. Additionally, isup and issupervised also become 0.

/etc/66

This directory is specified at compile time by using the --with-skeleton= option to ./configure.

It holds various configuration files utilized by 66.

User may want to manage some subdirectories with the exception of the /etc/66/conf below.

/etc/66/conf

This directory is specified at compile time by using the --with-sysadmin-service-conf= option to ./configure.

This directory stores the configuration file of a service, which is the outcome of the Environment section parsed from the frontend file.

The 66 configure <service> command handles this directory. It's advised for users, including system administrators, to avoid direct interaction with these directories and utilize the configure command instead.

Its subdirectories contain versioned files per service and are self-explanatory.

This directory is specified at compile time by using the --with-sysadmin-environment=DIR option to ./configure.

This directory serves as a location for system administrators to provide default environment variables used by a scandir at runtime and propagated to services handled by the scandir.

See the Environment explanation for further information about the behavior, the syntax and the limitations.

/etc/66/seed

This directory is specified at compile time by using the --with-sysadmin-seed= option to ./configure.

This directory is managed by the user and stores seed files, used, for example, by the tree command. If a seed file exists both in this directory and at /usr/share/66/service, the one in this directory takes precedence.

It's crucial for system administrators to avoid altering this directory or its subdirectories, ensuring users can manage it without losing their changes.

/etc/66/service

This directory is specified at compile time by using the --with-sysadmin-service= option to ./configure.

This directory is designated for users to store frontend files. If a frontend file for a service exists both in this directory and at /usr/share/66/service, the file in this directory takes precedence.

It's crucial for system administrators to avoid altering this directory or its subdirectories, ensuring users can manage it without losing their changes.

/usr/share/66/service

This directory is specified at compile time by using the --with-system-service= option to ./configure.

This directory is reserved for system administrators to install frontend file, often through package manager. Any modifications made by users may be overwritten during system updates.

/usr/share/66/script

This directory is specified at compile time by using the --with-system-script= option to ./configure.

This directory serves as a location for system administrators to install additional scripts required by frontend files or those related to the module service type. It's a secure area for administrators to manage scripts effectively.

/usr/share/66/seed

This directory is specified at compile time by using the --with-system-seed= option to ./configure.

this directory is intended for system administrators to install seed files. User modifications in this directory may be lost during system updates.

/run/66

This directory is specified at compile time by using the --livedir= option to ./configure. It also can be specified on-the-fly with the 66 -l option.

This should be within a writable and executable filesystem, likely a RAM filesystem, mounted with exec and rw mount flag.

This directory and its subdirectories are managed by 66. Users, including system administrators, should avoid directly interacting with these directories.

It create at 66 scandir create invocation if it doesn't yet.

/run/66/log

This directory houses log files, usually one per service. It's commonly used for services initiated before a rewritable /var/log directory becomes available.

/run/66/log/0

This directory stores logs generated by scandir-log service, which is internally created by 66. During the boot, the rc.init skeleton file performs actions and captures output using scandir-log. It might also contain uncaught-log entries from services lacking their own logger, making it valuable for debugging purposes.

/run/66/scandir

This directory is managed through the scandir comand. Users, including system administrators, should avoid directly interacting with these directories.

/run/66/scandir/UID

Given 66 can run with root or regular account privileges, this directory contains subdirectories. Each account possesses its own scandir specified by its number. For example, /run/66/scandir/0 is owned by root, while /run/66/scandir/1000 typically belongs to the first regular account created on the system.

This directory consists of service symlinks that point to its corresponding /run/66/state/UID/<service> directory.

note: The 66 scandir create -B invocation create the directory /run/66/scandir/UID/container containing a named file halt. See boot for further information.

/run/66/state

This directory is managed internally by 66 and contains directories and files needed for the run time of services. Users, including system administrators, should avoid directly interacting with these directories.

/run/66/state/UID

As 66 can be executed with root or regular account privilegies, this directory contains subdirectories. Each account has its own state specified by its number. For intance, /run/66/state/0 is owned by root, whereas /run/66/state/1000 is typically owned by the first regular account created on the system.

For instance, the /run/66/state/0/<service> contains a verbatim copy of the /var/lib/66/system/service/svc/<service> for each root service.

Invocating the 66 free <service> remove the corresponding /run/66/state/0/<service> directory.

At start command executed will created the corresponding /run/66/state/0/<service> if it doesn't exist yet.

/var/log/66

This directory is specified at compile time by using the --with-system-log= option to ./configure.

This directory is automatically managed by 66. Users, including system administrators, should avoid directly interacting with these directories.

Each service, if a logger is associated, has its own subdirectory likely /var/log/66/66/<service>.

User can control the rotation of the log file with:

• the Backup field at the Logger section of the frontend file.

• invocating 66 reload -P <service> or 66 signal -aP <service> command.

Resolve files

Resolve files are essentially CDB databases. They are independent of extra libraries, running daemons, or third-party programs. These files are lightweight and efficient to read and write. However, the downside is the inability to upgrade a field without rewriting the entire database whenever modifications are made to any fields.

The size of the database varies based on its contents and typically ranges between 4-7 kilobytes.