diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/guix.texi | 832 |
1 files changed, 832 insertions, 0 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index 47fc199c6c..66316ecd84 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -7658,6 +7658,7 @@ declaration. * Log Rotation:: The rottlog service. * Networking Services:: Network setup, SSH daemon, etc. * X Window:: Graphical display. +* Printing Services:: Local and remote printer support. * Desktop Services:: D-Bus and desktop services. * Database Services:: SQL databases. * Mail Services:: IMAP, POP3, SMTP, and all that. @@ -8702,6 +8703,837 @@ makes the good ol' XlockMore usable. @end deffn +@node Printing Services +@subsubsection Printing Services + +The @code{(gnu services cups)} module provides a Guix service definition +for the CUPS printing service. To add printer support to a GuixSD +system, add a @code{cups-service} to the operating system definition: + +@deffn {Scheme Variable} cups-service-type +The service type for the CUPS print server. Its value should be a valid +CUPS configuration (see below). For example: +@example +(service cups-service-type (cups-configuration)) +@end example +@end deffn + +The CUPS configuration controls the basic things about your CUPS +installation: what interfaces it listens on, what to do if a print job +fails, how much logging to do, and so on. To actually add a printer, +you have to visit the @url{http://localhost:631} URL, or use a tool such +as GNOME's printer configuration services. By default, configuring a +CUPS service will generate a self-signed certificate if needed, for +secure connections to the print server. + +One way you might want to customize CUPS is to enable or disable the web +interface. You can do that directly, like this: + +@example +(service cups-service-type + (cups-configuration + (web-interface? #f))) +@end example + +The available configuration parameters follow. Each parameter +definition is preceded by its type; for example, @samp{string-list foo} +indicates that the @code{foo} parameter should be specified as a list of +strings. There is also a way to specify the configuration as a string, +if you have an old @code{cupsd.conf} file that you want to port over +from some other system; see the end for more details. + +@c The following documentation was initially generated by +@c (generate-documentation) in (gnu services cups). Manually maintained +@c documentation is better, so we shouldn't hesitate to edit below as +@c needed. However if the change you want to make to this documentation +@c can be done in an automated way, it's probably easier to change +@c (generate-documentation) than to make it below and have to deal with +@c the churn as CUPS updates. + + +Available @code{cups-configuration} fields are: + +@deftypevr {@code{cups-configuration} parameter} package cups +The CUPS package. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} package-list extensions +Drivers and other extensions to the CUPS package. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration +Configuration of where to write logs, what directories to use for print +spools, and related privileged configuration parameters. + +Available @code{files-configuration} fields are: + +@deftypevr {@code{files-configuration} parameter} log-location access-log +Defines the access log filename. Specifying a blank filename disables +access log generation. The value @code{stderr} causes log entries to be +sent to the standard error file when the scheduler is running in the +foreground, or to the system log daemon when run in the background. The +value @code{syslog} causes log entries to be sent to the system log +daemon. The server name may be included in filenames using the string +@code{%s}, as in @code{/var/log/cups/%s-access_log}. + +Defaults to @samp{"/var/log/cups/access_log"}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} file-name cache-dir +Where CUPS should cache data. + +Defaults to @samp{"/var/cache/cups"}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} string config-file-perm +Specifies the permissions for all configuration files that the scheduler +writes. + +Note that the permissions for the printers.conf file are currently +masked to only allow access from the scheduler user (typically root). +This is done because printer device URIs sometimes contain sensitive +authentication information that should not be generally known on the +system. There is no way to disable this security feature. + +Defaults to @samp{"0640"}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} log-location error-log +Defines the error log filename. Specifying a blank filename disables +access log generation. The value @code{stderr} causes log entries to be +sent to the standard error file when the scheduler is running in the +foreground, or to the system log daemon when run in the background. The +value @code{syslog} causes log entries to be sent to the system log +daemon. The server name may be included in filenames using the string +@code{%s}, as in @code{/var/log/cups/%s-error_log}. + +Defaults to @samp{"/var/log/cups/error_log"}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} string fatal-errors +Specifies which errors are fatal, causing the scheduler to exit. The +kind strings are: + +@table @code +@item none +No errors are fatal. + +@item all +All of the errors below are fatal. + +@item browse +Browsing initialization errors are fatal, for example failed connections +to the DNS-SD daemon. + +@item config +Configuration file syntax errors are fatal. + +@item listen +Listen or Port errors are fatal, except for IPv6 failures on the +loopback or @code{any} addresses. + +@item log +Log file creation or write errors are fatal. + +@item permissions +Bad startup file permissions are fatal, for example shared TLS +certificate and key files with world-read permissions. +@end table + +Defaults to @samp{"all -browse"}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} boolean file-device? +Specifies whether the file pseudo-device can be used for new printer +queues. The URI @uref{file:///dev/null} is always allowed. + +Defaults to @samp{#f}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} string group +Specifies the group name or ID that will be used when executing external +programs. + +Defaults to @samp{"lp"}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} string log-file-perm +Specifies the permissions for all log files that the scheduler writes. + +Defaults to @samp{"0644"}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} log-location page-log +Defines the page log filename. Specifying a blank filename disables +access log generation. The value @code{stderr} causes log entries to be +sent to the standard error file when the scheduler is running in the +foreground, or to the system log daemon when run in the background. The +value @code{syslog} causes log entries to be sent to the system log +daemon. The server name may be included in filenames using the string +@code{%s}, as in @code{/var/log/cups/%s-page_log}. + +Defaults to @samp{"/var/log/cups/page_log"}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} string remote-root +Specifies the username that is associated with unauthenticated accesses +by clients claiming to be the root user. The default is @code{remroot}. + +Defaults to @samp{"remroot"}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} file-name request-root +Specifies the directory that contains print jobs and other HTTP request +data. + +Defaults to @samp{"/var/spool/cups"}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} sandboxing sandboxing +Specifies the level of security sandboxing that is applied to print +filters, backends, and other child processes of the scheduler; either +@code{relaxed} or @code{strict}. This directive is currently only +used/supported on macOS. + +Defaults to @samp{strict}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} file-name server-keychain +Specifies the location of TLS certificates and private keys. CUPS will +look for public and private keys in this directory: a @code{.crt} files +for PEM-encoded certificates and corresponding @code{.key} files for +PEM-encoded private keys. + +Defaults to @samp{"/etc/cups/ssl"}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} file-name server-root +Specifies the directory containing the server configuration files. + +Defaults to @samp{"/etc/cups"}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} boolean sync-on-close? +Specifies whether the scheduler calls fsync(2) after writing +configuration or state files. + +Defaults to @samp{#f}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group +Specifies the group(s) to use for @code{@@SYSTEM} group authentication. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} file-name temp-dir +Specifies the directory where temporary files are stored. + +Defaults to @samp{"/var/spool/cups/tmp"}. +@end deftypevr + +@deftypevr {@code{files-configuration} parameter} string user +Specifies the user name or ID that is used when running external +programs. + +Defaults to @samp{"lp"}. +@end deftypevr +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level +Specifies the logging level for the AccessLog file. The @code{config} +level logs when printers and classes are added, deleted, or modified and +when configuration files are accessed or updated. The @code{actions} +level logs when print jobs are submitted, held, released, modified, or +canceled, and any of the conditions for @code{config}. The @code{all} +level logs all requests. + +Defaults to @samp{actions}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs? +Specifies whether to purge job history data automatically when it is no +longer required for quotas. + +Defaults to @samp{#f}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols +Specifies which protocols to use for local printer sharing. + +Defaults to @samp{dnssd}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} boolean browse-web-if? +Specifies whether the CUPS web interface is advertised. + +Defaults to @samp{#f}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} boolean browsing? +Specifies whether shared printers are advertised. + +Defaults to @samp{#f}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} string classification +Specifies the security classification of the server. Any valid banner +name can be used, including "classified", "confidential", "secret", +"topsecret", and "unclassified", or the banner can be omitted to disable +secure printing functions. + +Defaults to @samp{""}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} boolean classify-override? +Specifies whether users may override the classification (cover page) of +individual print jobs using the @code{job-sheets} option. + +Defaults to @samp{#f}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type +Specifies the default type of authentication to use. + +Defaults to @samp{Basic}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption +Specifies whether encryption will be used for authenticated requests. + +Defaults to @samp{Required}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} string default-language +Specifies the default language to use for text and web content. + +Defaults to @samp{"en"}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} string default-paper-size +Specifies the default paper size for new print queues. @samp{"Auto"} +uses a locale-specific default, while @samp{"None"} specifies there is +no default paper size. Specific size names are typically +@samp{"Letter"} or @samp{"A4"}. + +Defaults to @samp{"Auto"}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} string default-policy +Specifies the default access policy to use. + +Defaults to @samp{"default"}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} boolean default-shared? +Specifies whether local printers are shared by default. + +Defaults to @samp{#t}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval +Specifies the delay for updating of configuration and state files, in +seconds. A value of 0 causes the update to happen as soon as possible, +typically within a few milliseconds. + +Defaults to @samp{30}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} error-policy error-policy +Specifies what to do when an error occurs. Possible values are +@code{abort-job}, which will discard the failed print job; +@code{retry-job}, which will retry the job at a later time; +@code{retry-this-job}, which retries the failed job immediately; and +@code{stop-printer}, which stops the printer. + +Defaults to @samp{stop-printer}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit +Specifies the maximum cost of filters that are run concurrently, which +can be used to minimize disk, memory, and CPU resource problems. A +limit of 0 disables filter limiting. An average print to a +non-PostScript printer needs a filter limit of about 200. A PostScript +printer needs about half that (100). Setting the limit below these +thresholds will effectively limit the scheduler to printing a single job +at any time. + +Defaults to @samp{0}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice +Specifies the scheduling priority of filters that are run to print a +job. The nice value ranges from 0, the highest priority, to 19, the +lowest priority. + +Defaults to @samp{0}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups +Specifies whether to do reverse lookups on connecting clients. The +@code{double} setting causes @code{cupsd} to verify that the hostname +resolved from the address matches one of the addresses returned for that +hostname. Double lookups also prevent clients with unregistered +addresses from connecting to your server. Only set this option to +@code{#t} or @code{double} if absolutely required. + +Defaults to @samp{#f}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay +Specifies the number of seconds to wait before killing the filters and +backend associated with a canceled or held job. + +Defaults to @samp{30}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval +Specifies the interval between retries of jobs in seconds. This is +typically used for fax queues but can also be used with normal print +queues whose error policy is @code{retry-job} or +@code{retry-current-job}. + +Defaults to @samp{30}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit +Specifies the number of retries that are done for jobs. This is +typically used for fax queues but can also be used with normal print +queues whose error policy is @code{retry-job} or +@code{retry-current-job}. + +Defaults to @samp{5}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} boolean keep-alive? +Specifies whether to support HTTP keep-alive connections. + +Defaults to @samp{#t}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout +Specifies how long an idle client connection remains open, in seconds. + +Defaults to @samp{30}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body +Specifies the maximum size of print files, IPP requests, and HTML form +data. A limit of 0 disables the limit check. + +Defaults to @samp{0}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} multiline-string-list listen +Listens on the specified interfaces for connections. Valid values are +of the form @var{address}:@var{port}, where @var{address} is either an +IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to +indicate all addresses. Values can also be file names of local UNIX +domain sockets. The Listen directive is similar to the Port directive +but allows you to restrict access to specific interfaces or networks. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log +Specifies the number of pending connections that will be allowed. This +normally only affects very busy servers that have reached the MaxClients +limit, but can also be triggered by large numbers of simultaneous +connections. When the limit is reached, the operating system will +refuse additional connections until the scheduler can accept the pending +ones. + +Defaults to @samp{128}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls +Specifies a set of additional access controls. + +Available @code{location-access-controls} fields are: + +@deftypevr {@code{location-access-controls} parameter} file-name path +Specifies the URI path to which the access control applies. +@end deftypevr + +@deftypevr {@code{location-access-controls} parameter} access-control-list access-controls +Access controls for all access to this path, in the same format as the +@code{access-controls} of @code{operation-access-control}. + +Defaults to @samp{()}. +@end deftypevr + +@deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls +Access controls for method-specific access to this path. + +Defaults to @samp{()}. + +Available @code{method-access-controls} fields are: + +@deftypevr {@code{method-access-controls} parameter} boolean reverse? +If @code{#t}, apply access controls to all methods except the listed +methods. Otherwise apply to only the listed methods. + +Defaults to @samp{#f}. +@end deftypevr + +@deftypevr {@code{method-access-controls} parameter} method-list methods +Methods to which this access control applies. + +Defaults to @samp{()}. +@end deftypevr + +@deftypevr {@code{method-access-controls} parameter} access-control-list access-controls +Access control directives, as a list of strings. Each string should be +one directive, such as "Order allow,deny". + +Defaults to @samp{()}. +@end deftypevr +@end deftypevr +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history +Specifies the number of debugging messages that are retained for logging +if an error occurs in a print job. Debug messages are logged regardless +of the LogLevel setting. + +Defaults to @samp{100}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} log-level log-level +Specifies the level of logging for the ErrorLog file. The value +@code{none} stops all logging while @code{debug2} logs everything. + +Defaults to @samp{info}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format +Specifies the format of the date and time in the log files. The value +@code{standard} logs whole seconds while @code{usecs} logs microseconds. + +Defaults to @samp{standard}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients +Specifies the maximum number of simultaneous clients that are allowed by +the scheduler. + +Defaults to @samp{100}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host +Specifies the maximum number of simultaneous clients that are allowed +from a single address. + +Defaults to @samp{100}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies +Specifies the maximum number of copies that a user can print of each +job. + +Defaults to @samp{9999}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time +Specifies the maximum time a job may remain in the @code{indefinite} +hold state before it is canceled. A value of 0 disables cancellation of +held jobs. + +Defaults to @samp{0}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs +Specifies the maximum number of simultaneous jobs that are allowed. Set +to 0 to allow an unlimited number of jobs. + +Defaults to @samp{500}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer +Specifies the maximum number of simultaneous jobs that are allowed per +printer. A value of 0 allows up to MaxJobs jobs per printer. + +Defaults to @samp{0}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user +Specifies the maximum number of simultaneous jobs that are allowed per +user. A value of 0 allows up to MaxJobs jobs per user. + +Defaults to @samp{0}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time +Specifies the maximum time a job may take to print before it is +canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs. + +Defaults to @samp{10800}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size +Specifies the maximum size of the log files before they are rotated, in +bytes. The value 0 disables log rotation. + +Defaults to @samp{1048576}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout +Specifies the maximum amount of time to allow between files in a +multiple file print job, in seconds. + +Defaults to @samp{300}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} string page-log-format +Specifies the format of PageLog lines. Sequences beginning with percent +(@samp{%}) characters are replaced with the corresponding information, +while all other characters are copied literally. The following percent +sequences are recognized: + +@table @samp +@item %% +insert a single percent character + +@item %@{name@} +insert the value of the specified IPP attribute + +@item %C +insert the number of copies for the current page + +@item %P +insert the current page number + +@item %T +insert the current date and time in common log format + +@item %j +insert the job ID + +@item %p +insert the printer name + +@item %u +insert the username +@end table + +A value of the empty string disables page logging. The string @code{%p +%u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@} +%@{job-name@} %@{media@} %@{sides@}} creates a page log with the +standard items. + +Defaults to @samp{""}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables +Passes the specified environment variable(s) to child processes; a list +of strings. + +Defaults to @samp{()}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies +Specifies named access control policies. + +Available @code{policy-configuration} fields are: + +@deftypevr {@code{policy-configuration} parameter} string name +Name of the policy. +@end deftypevr + +@deftypevr {@code{policy-configuration} parameter} string job-private-access +Specifies an access list for a job's private values. @code{@@ACL} maps +to the printer's requesting-user-name-allowed or +requesting-user-name-denied values. @code{@@OWNER} maps to the job's +owner. @code{@@SYSTEM} maps to the groups listed for the +@code{system-group} field of the @code{files-config} configuration, +which is reified into the @code{cups-files.conf(5)} file. Other +possible elements of the access list include specific user names, and +@code{@@@var{group}} to indicate members of a specific group. The +access list may also be simply @code{all} or @code{default}. + +Defaults to @samp{"@@OWNER @@SYSTEM"}. +@end deftypevr + +@deftypevr {@code{policy-configuration} parameter} string job-private-values +Specifies the list of job values to make private, or @code{all}, +@code{default}, or @code{none}. + +Defaults to @samp{"job-name job-originating-host-name +job-originating-user-name phone"}. +@end deftypevr + +@deftypevr {@code{policy-configuration} parameter} string subscription-private-access +Specifies an access list for a subscription's private values. +@code{@@ACL} maps to the printer's requesting-user-name-allowed or +requesting-user-name-denied values. @code{@@OWNER} maps to the job's +owner. @code{@@SYSTEM} maps to the groups listed for the +@code{system-group} field of the @code{files-config} configuration, +which is reified into the @code{cups-files.conf(5)} file. Other +possible elements of the access list include specific user names, and +@code{@@@var{group}} to indicate members of a specific group. The +access list may also be simply @code{all} or @code{default}. + +Defaults to @samp{"@@OWNER @@SYSTEM"}. +@end deftypevr + +@deftypevr {@code{policy-configuration} parameter} string subscription-private-values +Specifies the list of job values to make private, or @code{all}, +@code{default}, or @code{none}. + +Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri +notify-subscriber-user-name notify-user-data"}. +@end deftypevr + +@deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls +Access control by IPP operation. + +Defaults to @samp{()}. +@end deftypevr +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files +Specifies whether job files (documents) are preserved after a job is +printed. If a numeric value is specified, job files are preserved for +the indicated number of seconds after printing. Otherwise a boolean +value applies indefinitely. + +Defaults to @samp{86400}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history +Specifies whether the job history is preserved after a job is printed. +If a numeric value is specified, the job history is preserved for the +indicated number of seconds after printing. If @code{#t}, the job +history is preserved until the MaxJobs limit is reached. + +Defaults to @samp{#t}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout +Specifies the amount of time to wait for job completion before +restarting the scheduler. + +Defaults to @samp{30}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} string rip-cache +Specifies the maximum amount of memory to use when converting documents +into bitmaps for a printer. + +Defaults to @samp{"128m"}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} string server-admin +Specifies the email address of the server administrator. + +Defaults to @samp{"root@@localhost.localdomain"}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias +The ServerAlias directive is used for HTTP Host header validation when +clients connect to the scheduler from external interfaces. Using the +special name @code{*} can expose your system to known browser-based DNS +rebinding attacks, even when accessing sites through a firewall. If the +auto-discovery of alternate names does not work, we recommend listing +each alternate name with a ServerAlias directive instead of using +@code{*}. + +Defaults to @samp{*}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} string server-name +Specifies the fully-qualified host name of the server. + +Defaults to @samp{"localhost"}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens +Specifies what information is included in the Server header of HTTP +responses. @code{None} disables the Server header. @code{ProductOnly} +reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor} +reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}. +@code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is +the output of the @code{uname} command. @code{Full} reports @code{CUPS +2.0.0 (@var{uname}) IPP/2.0}. + +Defaults to @samp{Minimal}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} string set-env +Set the specified environment variable to be passed to child processes. + +Defaults to @samp{"variable value"}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen +Listens on the specified interfaces for encrypted connections. Valid +values are of the form @var{address}:@var{port}, where @var{address} is +either an IPv6 address enclosed in brackets, an IPv4 address, or +@code{*} to indicate all addresses. + +Defaults to @samp{()}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options +Sets encryption options. By default, CUPS only supports encryption +using TLS v1.0 or higher using known secure cipher suites. The +@code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are +required for some older clients that do not implement newer ones. The +@code{AllowSSL3} option enables SSL v3.0, which is required for some +older clients that do not support TLS v1.0. + +Defaults to @samp{()}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} boolean strict-conformance? +Specifies whether the scheduler requires clients to strictly adhere to +the IPP specifications. + +Defaults to @samp{#f}. +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout +Specifies the HTTP request timeout, in seconds. + +Defaults to @samp{300}. + +@end deftypevr + +@deftypevr {@code{cups-configuration} parameter} boolean web-interface? +Specifies whether the web interface is enabled. + +Defaults to @samp{#f}. +@end deftypevr + +At this point you're probably thinking ``oh dear, Guix manual, I like +you but you can stop already with the configuration options''. Indeed. +However, one more point: it could be that you have an existing +@code{cupsd.conf} that you want to use. In that case, you can pass an +@code{opaque-cups-configuration} as the configuration of a +@code{cups-service-type}. + +Available @code{opaque-cups-configuration} fields are: + +@deftypevr {@code{opaque-cups-configuration} parameter} package cups +The CUPS package. +@end deftypevr + +@deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf +The contents of the @code{cupsd.conf}, as a string. +@end deftypevr + +@deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf +The contents of the @code{cups-files.conf} file, as a string. +@end deftypevr + +For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in +strings of the same name, you could instantiate a CUPS service like +this: + +@example +(service cups-service-type + (opaque-cups-configuration + (cupsd.conf cupsd.conf) + (cups-files.conf cups-files.conf))) +@end example + + @node Desktop Services @subsubsection Desktop Services |