From 03039f171f9327cae57d63ecff78e2fd1e483d35 Mon Sep 17 00:00:00 2001
From: Balint Reczey <balint.reczey@canonical.com>
Date: Thu, 14 Mar 2019 19:16:25 +0100
Subject: [PATCH] virt: detect WSL environment as a container

LP: #1816753
---
 debian/patches/series                         |   1 +
 ...SL-environment-as-a-container-id-wsl.patch | 116 ++++++++++++++++++
 2 files changed, 117 insertions(+)
 create mode 100644 debian/patches/virt-detect-WSL-environment-as-a-container-id-wsl.patch

diff --git a/debian/patches/series b/debian/patches/series
index 6faea44ae1..efe8ecebaf 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -99,3 +99,4 @@ journal-do-not-remove-multiple-spaces-after-identifi.patch
 stop-mount-error-propagation.patch
 fix-race-daemon-reload-8803.patch
 Support-system-image-read-only-etc.patch
+virt-detect-WSL-environment-as-a-container-id-wsl.patch
diff --git a/debian/patches/virt-detect-WSL-environment-as-a-container-id-wsl.patch b/debian/patches/virt-detect-WSL-environment-as-a-container-id-wsl.patch
new file mode 100644
index 0000000000..8604224606
--- /dev/null
+++ b/debian/patches/virt-detect-WSL-environment-as-a-container-id-wsl.patch
@@ -0,0 +1,116 @@
+From: Balint Reczey <balint.reczey@canonical.com>
+Date: Wed, 6 Mar 2019 18:46:04 +0100
+Subject: virt: detect WSL environment as a container (id: wsl)
+
+---
+ man/systemd-detect-virt.xml | 13 ++++++++++++-
+ man/systemd.unit.xml        |  3 ++-
+ src/basic/virt.c            | 12 ++++++++++++
+ src/basic/virt.h            |  1 +
+ 4 files changed, 27 insertions(+), 2 deletions(-)
+
+diff --git a/man/systemd-detect-virt.xml b/man/systemd-detect-virt.xml
+index 4426827..c92ea8d 100644
+--- a/man/systemd-detect-virt.xml
++++ b/man/systemd-detect-virt.xml
+@@ -149,7 +149,7 @@
+           </row>
+ 
+           <row>
+-            <entry valign="top" morerows="5">Container</entry>
++            <entry valign="top" morerows="6">Container</entry>
+             <entry><varname>openvz</varname></entry>
+             <entry>OpenVZ/Virtuozzo</entry>
+           </row>
+@@ -178,6 +178,11 @@
+             <entry><varname>rkt</varname></entry>
+             <entry>rkt app container runtime</entry>
+           </row>
++
++          <row>
++            <entry><varname>wsl</varname></entry>
++            <entry><ulink url="https://docs.microsoft.com/en-us/windows/wsl/about">Windows Subsystem for Linux</ulink></entry>
++          </row>
+         </tbody>
+       </tgroup>
+     </table>
+@@ -187,6 +192,12 @@
+     machine and container virtualization are used in
+     conjunction, only the latter will be identified (unless
+     <option>--vm</option> is passed).</para>
++    <para> Windows Subsystem for Linux is not a Linux container,
++    but an environment for running Linux userspace applications on
++    top of the Windows kernel using a Linux-compatible interface.
++    WSL is categorized as a container for practical purposes.
++    Multiple WSL environments share the same kernel and services
++    should generally behave like when being run in a container.</para>
+   </refsect1>
+ 
+   <refsect1>
+diff --git a/man/systemd.unit.xml b/man/systemd.unit.xml
+index 90ca378..c79c91e 100644
+--- a/man/systemd.unit.xml
++++ b/man/systemd.unit.xml
+@@ -1021,7 +1021,8 @@
+         <varname>lxc-libvirt</varname>,
+         <varname>systemd-nspawn</varname>,
+         <varname>docker</varname>,
+-        <varname>rkt</varname> to test
++        <varname>rkt</varname>,
++        <varname>wsl</varname> to test
+         against a specific implementation, or
+         <varname>private-users</varname> to check whether we are running in a user namespace. See
+         <citerefentry><refentrytitle>systemd-detect-virt</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+diff --git a/src/basic/virt.c b/src/basic/virt.c
+index 1bc26ec..7bd9850 100644
+--- a/src/basic/virt.c
++++ b/src/basic/virt.c
+@@ -440,10 +440,12 @@ int detect_container(void) {
+                 { "systemd-nspawn", VIRTUALIZATION_SYSTEMD_NSPAWN },
+                 { "docker",         VIRTUALIZATION_DOCKER         },
+                 { "rkt",            VIRTUALIZATION_RKT            },
++                { "wsl",            VIRTUALIZATION_WSL            },
+         };
+ 
+         static thread_local int cached_found = _VIRTUALIZATION_INVALID;
+         _cleanup_free_ char *m = NULL;
++        _cleanup_free_ char *o = NULL;
+         const char *e = NULL;
+         unsigned j;
+         int r;
+@@ -458,6 +460,15 @@ int detect_container(void) {
+                 goto finish;
+         }
+ 
++        /* "Official" way of detecting WSL https://github.com/Microsoft/WSL/issues/423#issuecomment-221627364 */
++        r = read_one_line_file("/proc/sys/kernel/osrelease", &o);
++        if (r >= 0) {
++                if (strstr(o, "Microsoft") || strstr(o, "WSL")) {
++                        r = VIRTUALIZATION_WSL;
++                        goto finish;
++                }
++        }
++
+         if (getpid_cached() == 1) {
+                 /* If we are PID 1 we can just check our own environment variable, and that's authoritative. */
+ 
+@@ -639,6 +650,7 @@ static const char *const virtualization_table[_VIRTUALIZATION_MAX] = {
+         [VIRTUALIZATION_OPENVZ] = "openvz",
+         [VIRTUALIZATION_DOCKER] = "docker",
+         [VIRTUALIZATION_RKT] = "rkt",
++        [VIRTUALIZATION_WSL] = "wsl",
+         [VIRTUALIZATION_CONTAINER_OTHER] = "container-other",
+ };
+ 
+diff --git a/src/basic/virt.h b/src/basic/virt.h
+index d9badd8..d4e1007 100644
+--- a/src/basic/virt.h
++++ b/src/basic/virt.h
+@@ -49,6 +49,7 @@ enum {
+         VIRTUALIZATION_OPENVZ,
+         VIRTUALIZATION_DOCKER,
+         VIRTUALIZATION_RKT,
++        VIRTUALIZATION_WSL,
+         VIRTUALIZATION_CONTAINER_OTHER,
+         VIRTUALIZATION_CONTAINER_LAST = VIRTUALIZATION_CONTAINER_OTHER,
+ 
-- 
2.17.1