From b33454ae0b488e79faafef75a06090be6b2ac6a2 Mon Sep 17 00:00:00 2001 From: Arun Isaac Date: Fri, 10 May 2019 16:56:16 +0530 Subject: linux-container: Support container network sharing. * gnu/system/linux-container.scm (container-essential-services): If network is to be shared with the host, remove network configuration files from etc service. (containerized-operating-system): If network is to be shared with the host, remove nscd service and map host's /var/run/nscd if it exists. (container-script): If network is to be shared with the host, do not create network namespace. * guix/scripts/system.scm (system-derivation-for-action): Add #:container-shared-network? argument. (perform-action): Add #:container-shared-network? argument. (show-help): Add "-N, --network" help information. (%options): Add network option. (process-action): Call perform-action with #container-shared-network? argument. * doc/guix.texi (Invoking guix system): Document the "-N, --network" option. Co-authored-by: Christopher Baines --- gnu/system/linux-container.scm | 63 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 52 insertions(+), 11 deletions(-) (limited to 'gnu/system/linux-container.scm') diff --git a/gnu/system/linux-container.scm b/gnu/system/linux-container.scm index ded5f279fe..ce786e39b2 100644 --- a/gnu/system/linux-container.scm +++ b/gnu/system/linux-container.scm @@ -1,6 +1,7 @@ ;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2015 David Thompson ;;; Copyright © 2016, 2017, 2019 Ludovic Courtès +;;; Copyright © 2019 Arun Isaac ;;; ;;; This file is part of GNU Guix. ;;; @@ -35,7 +36,7 @@ containerized-operating-system container-script)) -(define (container-essential-services os) +(define* (container-essential-services os #:key shared-network?) "Return a list of essential services corresponding to OS, a non-containerized OS. This procedure essentially strips essential services from OS that are needed on the bare metal and not in a container." @@ -51,9 +52,20 @@ from OS that are needed on the bare metal and not in a container." (let ((locale (operating-system-locale-directory os))) (with-monad %store-monad (return `(("locale" ,locale)))))) - base)) + ;; If network is to be shared with the host, remove network + ;; configuration files from etc-service. + (if shared-network? + (modify-services base + (etc-service-type + files => (remove + (match-lambda + ((filename _) + (member filename + (map basename %network-configuration-files)))) + files))) + base))) -(define (containerized-operating-system os mappings) +(define* (containerized-operating-system os mappings #:key shared-network?) "Return an operating system based on OS for use in a Linux container environment. MAPPINGS is a list of to realize in the containerized OS." @@ -76,27 +88,53 @@ containerized OS." (define useless-services ;; Services that make no sense in a container. Those that attempt to ;; access /dev/tty[0-9] in particular cannot work in a container. - (list console-font-service-type - mingetty-service-type - agetty-service-type)) + (append (list console-font-service-type + mingetty-service-type + agetty-service-type) + ;; Remove nscd service if network is shared with the host. + (if shared-network? + (list nscd-service-type) + (list)))) + + (define shared-network-file-mappings + ;; Files to map if network is to be shared with the host + (append %network-file-mappings + (let ((nscd-run-directory "/var/run/nscd")) + (if (file-exists? nscd-run-directory) + (list (file-system-mapping + (source nscd-run-directory) + (target nscd-run-directory))) + (list))))) + + ;; (write shared-network-file-mappings) + ;; (newline) (operating-system (inherit os) (swap-devices '()) ; disable swap - (essential-services (container-essential-services os)) + (essential-services (container-essential-services + os #:shared-network? shared-network?)) (services (remove (lambda (service) (memq (service-kind service) useless-services)) (operating-system-user-services os))) - (file-systems (append (map mapping->fs (cons %store-mapping mappings)) + (file-systems (append (map mapping->fs + (cons %store-mapping + (append mappings + (if shared-network? + shared-network-file-mappings + (list))))) %container-file-systems user-file-systems)))) -(define* (container-script os #:key (mappings '())) +(define* (container-script os #:key (mappings '()) shared-network?) "Return a derivation of a script that runs OS as a Linux container. MAPPINGS is a list of objects that specify the files/directories that will be shared with the host system." - (let* ((os (containerized-operating-system os mappings)) + (let* ((os (containerized-operating-system + os + mappings + #:shared-network? shared-network?)) (file-systems (filter file-system-needed-for-boot? (operating-system-file-systems os))) (specs (map file-system->spec file-systems))) @@ -121,6 +159,9 @@ that will be shared with the host system." ;; users and groups, which is sufficient for most cases. ;; ;; See: http://www.freedesktop.org/software/systemd/man/systemd-nspawn.html#--private-users= - #:host-uids 65536)))) + #:host-uids 65536 + #:namespaces (if #$shared-network? + (delq 'net %namespaces) + %namespaces))))) (gexp->script "run-container" script))) -- cgit v1.2.3