gnu/services/docker.scm

   1 ;;; GNU Guix --- Functional package management for GNU
   2 ;;; Copyright © 2018 Danny Milosavljevic <dannym@scratchpost.org>
   3 ;;;
   4 ;;; This file is part of GNU Guix.
   5 ;;;
   6 ;;; GNU Guix is free software; you can redistribute it and/or modify it
   7 ;;; under the terms of the GNU General Public License as published by
   8 ;;; the Free Software Foundation; either version 3 of the License, or (at
   9 ;;; your option) any later version.
  10 ;;;
  11 ;;; GNU Guix is distributed in the hope that it will be useful, but
  12 ;;; WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ;;; GNU General Public License for more details.
  15 ;;;
  16 ;;; You should have received a copy of the GNU General Public License
  17 ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 (define-module (gnu services docker)
  20   #:use-module (gnu services)
  21   #:use-module (gnu services configuration)
  22   #:use-module (gnu services base)
  23   #:use-module (gnu services dbus)
  24   #:use-module (gnu services shepherd)
  25   #:use-module (gnu system shadow)
  26   #:use-module (gnu packages docker)
  27   #:use-module (gnu packages linux)               ;singularity
  28   #:use-module (guix records)
  29   #:use-module (guix gexp)
  30   #:use-module (guix packages)
  31
  32   #:export (docker-configuration
  33             docker-service-type
  34             singularity-service-type))
  35
  36 ;;; We're not using serialize-configuration, but we must define this because
  37 ;;; the define-configuration macro validates it exists.
  38 (define (serialize-boolean field-name val)
  39   "")
  40
  41 (define-configuration docker-configuration
  42   (docker
  43    (package docker)
  44    "Docker daemon package.")
  45   (containerd
  46    (package containerd)
  47    "containerd package.")
  48   (proxy
  49    (package docker-libnetwork-cmd-proxy)
  50    "The proxy package to support inter-container and outside-container
  51 loop-back communications.")
  52   (enable-proxy?
  53    (boolean #t)
  54    "Enable or disable the user-land proxy (enabled by default)."))
  55
  56 (define %docker-accounts
  57   (list (user-group (name "docker") (system? #t))))
  58
  59 (define (%containerd-activation config)
  60   (let ((state-dir "/var/lib/containerd"))
  61     #~(begin
  62         (use-modules (guix build utils))
  63         (mkdir-p #$state-dir))))
  64
  65 (define (%docker-activation config)
  66   (%containerd-activation config)
  67   (let ((state-dir "/var/lib/docker"))
  68     #~(begin
  69         (use-modules (guix build utils))
  70         (mkdir-p #$state-dir))))
  71
  72 (define (containerd-shepherd-service config)
  73   (let* ((package (docker-configuration-containerd config)))
  74     (shepherd-service
  75            (documentation "containerd daemon.")
  76            (provision '(containerd))
  77            (start #~(make-forkexec-constructor
  78                      (list (string-append #$package "/bin/containerd"))
  79                      #:log-file "/var/log/containerd.log"))
  80            (stop #~(make-kill-destructor)))))
  81
  82 (define (docker-shepherd-service config)
  83   (let* ((docker (docker-configuration-docker config))
  84          (enable-proxy? (docker-configuration-enable-proxy? config))
  85          (proxy (docker-configuration-proxy config)))
  86     (shepherd-service
  87            (documentation "Docker daemon.")
  88            (provision '(dockerd))
  89            (requirement '(containerd
  90                           dbus-system
  91                           elogind
  92                           file-system-/sys/fs/cgroup/blkio
  93                           file-system-/sys/fs/cgroup/cpu
  94                           file-system-/sys/fs/cgroup/cpuset
  95                           file-system-/sys/fs/cgroup/devices
  96                           file-system-/sys/fs/cgroup/memory
  97                           ; TODO: file-system-/sys/fs/cgroup/pids
  98                           networking
  99                           udev))
 100            (start #~(make-forkexec-constructor
 101                      (list (string-append #$docker "/bin/dockerd")
 102                            "-p" "/var/run/docker.pid"
 103                            (if #$enable-proxy? "--userland-proxy" "")
 104                            "--userland-proxy-path" (string-append #$proxy
 105                                                                   "/bin/proxy"))
 106                      #:pid-file "/var/run/docker.pid"
 107                      #:log-file "/var/log/docker.log"))
 108            (stop #~(make-kill-destructor)))))
 109
 110 (define docker-service-type
 111   (service-type (name 'docker)
 112                 (description "Provide capability to run Docker application
 113 bundles in Docker containers.")
 114                 (extensions
 115                  (list
 116                   (service-extension activation-service-type
 117                                      %docker-activation)
 118                   (service-extension shepherd-root-service-type
 119                                      (lambda (config)
 120                                        (list (containerd-shepherd-service config)
 121                                              (docker-shepherd-service config))))
 122                   (service-extension account-service-type
 123                                      (const %docker-accounts))))
 124                 (default-value (docker-configuration))))
 125
 126 \f
 127 ;;;
 128 ;;; Singularity.
 129 ;;;
 130
 131 (define %singularity-activation
 132   (with-imported-modules '((guix build utils))
 133     #~(begin
 134         (use-modules (guix build utils))
 135
 136         (define %mount-directory
 137           "/var/singularity/mnt/")
 138
 139         ;; Create the directories that Singularity 2.6 expects to find.  Make
 140         ;; them #o755 like the 'install-data-hook' rule in 'Makefile.am' of
 141         ;; Singularity 2.6.1.
 142         (for-each (lambda (directory)
 143                     (let ((directory (string-append %mount-directory
 144                                                     directory)))
 145                       (mkdir-p directory)
 146                       (chmod directory #o755)))
 147                   '("container" "final" "overlay" "session"))
 148         (chmod %mount-directory #o755))))
 149
 150 (define (singularity-setuid-programs singularity)
 151   "Return the setuid-root programs that SINGULARITY needs."
 152   (define helpers
 153     ;; The helpers, under a meaningful name.
 154     (computed-file "singularity-setuid-helpers"
 155                    #~(begin
 156                        (mkdir #$output)
 157                        (for-each (lambda (program)
 158                                    (symlink (string-append #$singularity
 159                                                            "/libexec/singularity"
 160                                                            "/bin/"
 161                                                            program "-suid")
 162                                             (string-append #$output
 163                                                            "/singularity-"
 164                                                            program
 165                                                            "-helper")))
 166                                  '("action" "mount" "start")))))
 167
 168   (list (file-append helpers "/singularity-action-helper")
 169         (file-append helpers "/singularity-mount-helper")
 170         (file-append helpers "/singularity-start-helper")))
 171
 172 (define singularity-service-type
 173   (service-type (name 'singularity)
 174                 (description
 175                  "Install the Singularity application bundle tool.")
 176                 (extensions
 177                  (list (service-extension setuid-program-service-type
 178                                           singularity-setuid-programs)
 179                        (service-extension activation-service-type
 180                                           (const %singularity-activation))))
 181                 (default-value singularity)))