doc: mysql-configuration: Fix typo.

* doc/guix.texi (Database Services): Fix typo of 'mysql-configuration'.

services: Add opensmtpd service.

* gnu/services/mail.scm (<opensmtpd-configuration>): New record type.
(%default-opensmtpd-config-file, %opensmtpd-accounts): New variables.
(opensmtpd-shepherd-service, opensmtpd-activation): New procedures.
(opensmtpd-service-type): New variable.
* doc/guix.texi (Mail Services): Document it.

offload: Rewrite to make direct RPCs to the remote daemon.

* guix/scripts/offload.scm (<build-machine>)[daemon-socket]: New field.
(connect-to-remote-daemon): New procedure.
(%gc-root-file, register-gc-root, remove-gc-roots, offload): Remove.
(transfer-and-offload): Rewrite using 'connect-to-remote-daemon' and
RPCs over SSH.
(store-import-channel, store-export-channel): New procedures.
(send-files, retrieve-files): Rewrite using these.

offload: Use Guile-SSH instead of GNU lsh.

* guix/scripts/offload.scm (<build-machine>)[ssh-options]: Remove.
[host-key, host-key-type]: New fields.
(%lsh-command, %lshg-command, user-lsh-private-key): Remove.
(user-openssh-private-key, private-key-from-file*): New procedures.
(host-key->type+key, open-ssh-session): New procedures.
(remote-pipe): Remove 'mode' parameter.  Rewrite in terms of
'open-ssh-session' etc.  Update users.
(send-files)[missing-files]: Rewrite using the bidirectional channel
port.
Remove call to 'call-with-compressed-output-port'.
(retrieve-files): Remove call to 'call-with-decompressed-port'.
(machine-load): Remove exit status logic.
* doc/guix.texi (Requirements): Mention Guile-SSH.
(Daemon Offload Setup): Document 'host-key' and 'private-key'.  Show the
default value on each @item line.
* m4/guix.m4 (GUIX_CHECK_GUILE_SSH): New macro.
* config-daemon.ac: Use 'GUIX_CHECK_GUILE_SSH'.  Set
'HAVE_DAEMON_OFFLOAD_HOOK' as a function of that.

doc: Fix typos in "Kerberos Services".

* doc/guix.texi (Kerberos Services): Fix typos.

doc: Document encrypted root partitions.

This is a followup to f7f292d359e0eb77617f4ecf6b3164f868ec1784.

* doc/guix.texi (Preparing for Installation): Give commands for
encrypted root installation.
(Proceeding with the Installation): Add item about mapped devices.
(File Systems): Mention that 'dependencies' can list <mapped-device>
objects.
* gnu/system/examples/desktop.tmpl (mapped-devices): New field.
(file-systems): Add 'dependencies' field.

doc: Document 'wpa-supplicant-service-type'.

Reported by Chris Marusich <cmmarusich@gmail.com>.

* doc/guix.texi (Networking Services): Remove 'wpa-supplicant-service'
procedure, which doesn't exist, and document
'wpa-supplicant-service-type'.

Add system start-up files for "guix publish".

* .gitignore: add etc/guix-publish.conf and /etc/guix-publish.service.
* etc/guix-publish.conf.in: New file.
* etc/guix-publish.service.in: New file.
* nix/local.mk (etc/guix-%.service, etc/guix-%.conf): Generalized former
  build-rules for by using patterns.
  (nodist_systemdservice_DATA): Add etc/guix-publish.service, update
  comment.
  (nodist_upstartjob_DATA): Add etc/guix-publish.conf, update comment.
* doc/guix.texi (Invoking guix publish): Add description for enabling
  "guix publish" on host distros using the new files.

doc: Symlink daemon start-up files.

This patch ensures that always the current profile's daemon will be used.

The .service file contains the path to the guix-daemon within the store. Thus
when copying the file, it will point to the very version of guix-daemon used
at the time of copying – even after system upgrade or when this version has
been garbage collected from the store.

* doc/guix.texi (Binary Installation): Change example code for installing
  the systemd and Upstart files to use symbolic links instead of copying
  the files.

gnu: system: Add openfwwf-firmware to %base-firmware.

* gnu/system.scm (%base-firmware): Add openfwwf-firmware.
* doc/guix.texi (Hardware Considerations): Mention b43-open support.
(operating-system Reference)[firmware]: Likewise.

gnu: services: Add git-service.

* gnu/services/version-control.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.
* doc/guix.texi (Misellaneous Services)[Version Control]: New section.

Co-authored-by: 宋文武 <iyzsong@member.fsf.org>

lint: Add 'mirror-url' checker.

* guix/scripts/lint.scm (origin-uris): New procedure.
(check-source): Use it.
(check-mirror-url): New procedure.
(%checkers): Add 'mirror-url' checker.
* tests/lint.scm ("mirror-url")
("mirror-url: one suggestion"): New tests.
* doc/guix.texi (Invoking guix lint): Document it.

services: static-networking: Add netmask.

Reported by Mathieu Lirzin and Andreas Enge.

* gnu/services/networking.scm (<static-networking>)[netmask]: New
field.
(static-networking-service-type): Honor it.
* gnu/services/networking.scm (static-networking-service): Add #:netmask
and honor it.
* doc/guix.texi (Networking Services): Adjust accordingly.

guix download: Add '-o' option.

* guix/scripts/download.scm (download-to-file, download-to-store*): New
procedures.
(%default-options): Add 'download-proc'.
(show-help): Adjust description and document '-o'.
(%options): Add '-o'.
(guix-download): Remove 'store' variable.  Add 'fetch' and define 'path'
to as its result.
* tests/guix-download.sh: Add test.

services: Add wpa-supplicant-service.

* gnu/services/networking.scm (wpa-supplicant-service): New procedure.
(wpa-supplicant-service-type): New variable.
* doc/guix.texi (Networking Services): Document it.

Merge branch 'core-updates'

doc: Added some index entries.

* doc/guix.texi: Added various @cindex tags to assist readers.

doc: Mention elpa.gnu.org package signatures.

* doc/guix.texi (Invoking guix import): Document elpa.gnu.org
signatures.

gnu: Add pam-krb5 service.

* doc/guix.texi (Kerberos Services): New node.
* gnu/services/kerberos.scm: New file.
* gnu/local.mk: Add it.

guix download: Add '--no-check-certificate' option.

* guix/download.scm (download-to-store): Add #:verify-certificate?
parameter and honor it.
* guix/scripts/download.scm (%default-options): Add
'verify-certificate?' key.
(show-help, %options): Add '--no-check-certificate'.
(guix-download): Pass #:verify-certificate to 'download-to-store'.
* doc/guix.texi (Invoking guix download): Document it.