Subject: [PATCH] guix: scripts: environment: add tls certs to networked containers

From: Richard Sent <[email-masked]>
Date: Tue, 9 Apr 2024 15:05:29 -0400

* guix/scripts/environment.scm: Add --no-tls flag. By default when starting a
container with -N, add nss-certs package and set SSL_CERT_DIR and
SSL_CERT_FILE environment variables. When --no-tls is passed, default to old
behavior.
* doc/guix.texi: Document it.

Change-Id: I3d222522fa9785fbf589f15efd14e6d6d072bfa7
---
Hi Guix!

Given the discussion on IRC and guix-devel [1] recently about making
nss-certs easier to use, this patch modifies guix environment (and
thus guix shell) to automatically add nss-certs to the profile when
sharing the network namespace, as well as setting the
mostly-standardized SSL_CERT_DIR and SSL_CERT_FILE environment
variables.

This behavior can be reverted with the --no-tls flag. Since presumably
the majority of shell users want TLS to work out of the box, adding
TLS by default makes sense to me.

Previous workarounds were verbose [2] and prone to failure [3].

[1] https://lists.gnu.org/archive/html/guix-devel/2024-04/msg00020.html

[2] https://lists.gnu.org/archive/html/guix-patches/2020-05/msg00197.html

[3] See tail of https://logs.guix.gnu.org/guix/2024-04-08.log, [2]
works coincidentally since guix system w/ nss-certs happens to have
identical nss-certs hash as the guix building the shell profile.
Otherwise the system version would not be visible inside the
container.

 doc/guix.texi                |  8 ++++++++
 guix/scripts/environment.scm | 28 +++++++++++++++++++++++++++-
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index 5827e0de14..912ed79ccd 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -6214,6 +6214,10 @@ Invoking guix shell
 Containers created without this flag only have access to the loopback
 device.
 
+@item --no-tls
+For containers that share the network namespace, disable automatically
+adding TLS/SSL certificates.
+
 @item --link-profile
 @itemx -P
 For containers, link the environment profile to @file{~/.guix-profile}
@@ -6711,6 +6715,10 @@ Invoking guix environment
 Containers created without this flag only have access to the loopback
 device.
 
+@item --no-tls
+For containers that share the network namespace, disable automatically
+adding TLS/SSL certificates.
+
 @item --link-profile
 @itemx -P
 For containers, link the environment profile to @file{~/.guix-profile}
diff --git a/guix/scripts/environment.scm b/guix/scripts/environment.scm
index 1d7a6e198d..b38882a4ca 100644
--- a/guix/scripts/environment.scm
+++ b/guix/scripts/environment.scm
@@ -49,6 +49,7 @@ (define-module (guix scripts environment)
   #:autoload   (guix build syscalls) (set-network-interface-up openpty login-tty)
   #:use-module (gnu system file-systems)
   #:autoload   (gnu packages) (specification->package+output)
+  #:autoload   (gnu packages certs) (nss-certs)
   #:autoload   (gnu packages bash) (bash)
   #:autoload   (gnu packages bootstrap) (bootstrap-executable %bootstrap-guile)
   #:autoload   (gnu packages package-management) (guix)
@@ -72,6 +73,9 @@ (define-module (guix scripts environment)
 (define %default-shell
   (or (getenv "SHELL") "/bin/sh"))
 
+(define %default-tls-certs
+  (list nss-certs))
+
 (define* (show-search-paths profile manifest #:key pure?)
   "Display the search paths of MANIFEST applied to PROFILE.  When PURE? is #t,
 do not augment existing environment variables with additional search paths."
@@ -108,6 +112,9 @@ (define (show-environment-options-help)
   -C, --container        run command within an isolated container"))
   (display (G_ "
   -N, --network          allow containers to access the network"))
+  (display (G_ "
+      --no-tls           do not add SSL/TLS certificates or set environment
+                         variables for a networked container"))
   (display (G_ "
   -P, --link-profile     link environment profile to ~/.guix-profile within
                          an isolated container"))
@@ -244,6 +251,9 @@ (define %options
          (option '(#\N "network") #f #f
                  (lambda (opt name arg result)
                    (alist-cons 'network? #t result)))
+         (option '(#\T "no-tls") #f #f
+                 (lambda (opt name arg result)
+                   (alist-cons 'no-tls? #t result)))
          (option '(#\W "nesting") #f #f
                  (lambda (opt name arg result)
                    (alist-cons 'nesting? #t result)))
@@ -359,6 +369,11 @@ (define (options/resolve-packages store opts)
                      (packages->outputs (load* file module) mode)))
                   (('manifest . file)
                    (manifest-entries (load-manifest file)))
+                  (('network? . #t)
+                   (if (assoc-ref opts 'no-tls?)
+                       '()
+                       (manifest-entries
+                        (packages->manifest %default-tls-certs))))
                   (('nesting? . #t)
                    (if (assoc-ref opts 'profile)
                        '()
@@ -725,7 +740,7 @@ (define* (launch-environment/fork command profile manifest
 
 (define* (launch-environment/container #:key command bash user user-mappings
                                        profile manifest link-profile? network?
-                                       map-cwd? emulate-fhs? nesting?
+                                       no-tls? map-cwd? emulate-fhs? nesting?
                                        (setup-hook #f)
                                        (symlinks '()) (white-list '()))
   "Run COMMAND within a container that features the software in PROFILE.
@@ -929,6 +944,11 @@ (define* (launch-environment/container #:key command bash user user-mappings
               ;; Allow local AF_INET communications.
               (set-network-interface-up "lo"))
 
+            (unless no-tls?
+              (setenv "SSL_CERT_DIR" (string-append profile "/etc/ssl/certs"))
+              (setenv "SSL_CERT_FILE" (string-append (getenv "SSL_CERT_DIR")
+                                                     "/ca-certificates.crt")))
+
             ;; For convenience, start in the user's current working
             ;; directory or, if unmapped, the home directory.
             (chdir (if map-cwd?
@@ -1078,6 +1098,7 @@ (define (guix-environment* opts)
          (link-prof?   (assoc-ref opts 'link-profile?))
          (symlinks     (assoc-ref opts 'symlinks))
          (network?     (assoc-ref opts 'network?))
+         (no-tls?      (assoc-ref opts 'no-tls?))
          (no-cwd?      (assoc-ref opts 'no-cwd?))
          (emulate-fhs? (assoc-ref opts 'emulate-fhs?))
          (nesting?     (assoc-ref opts 'nesting?))
@@ -1133,6 +1154,10 @@ (define (guix-environment* opts)
       (when (pair? symlinks)
         (leave (G_ "'--symlink' cannot be used without '--container'~%"))))
 
+    (when (and (not network?)
+               no-tls?)
+      (leave (G_ "'--no-tls' cannot be used without '--networking'~%")))
+
     (with-store/maybe store
       (with-status-verbosity (assoc-ref opts 'verbosity)
         (define manifest-from-opts
@@ -1212,6 +1237,7 @@ (define (guix-environment* opts)
                                                   #:network? network?
                                                   #:map-cwd? (not no-cwd?)
                                                   #:emulate-fhs? emulate-fhs?
+                                                  #:no-tls? no-tls?
                                                   #:nesting? nesting?
                                                   #:symlinks symlinks
                                                   #:setup-hook

base-commit: 35e1d9247e39f3c91512cf3d9ef1467962389e35
-- 
2.41.0