Merge pull request #7631 from cgwalters/systemctl-offline

systemctl,verbs: Introduce SYSTEMCTL_OFFLINE environment variable

src/basic/verbs.c

@@ -23,12 +23,54 @@
 #include <stdbool.h>
 #include <stddef.h>
 
+#include "env-util.h"
 #include "log.h"
 #include "macro.h"
 #include "string-util.h"
 #include "verbs.h"
 #include "virt.h"
 
+/* Wraps running_in_chroot() which is used in various places,
+ * but also adds an environment variable check so external processes
+ * can reliably force this on.
+ */
+bool running_in_chroot_or_offline(void) {
+        int r;
+
+        /* Added to support use cases like rpm-ostree, where from %post
+         * scripts we only want to execute "preset", but not "start"/"restart"
+         * for example.
+         *
+         * See ENVIRONMENT.md for docs.
+         */
+        r = getenv_bool("SYSTEMD_OFFLINE");
+        if (r < 0)
+                log_debug_errno(r, "Parsing SYSTEMD_OFFLINE: %m");
+        else if (r == 0)
+                return false;
+        else
+                return true;
+
+        /* We've had this condition check for a long time which basically
+         * checks for legacy chroot case like Fedora's
+         * "mock", which is used for package builds.  We don't want
+         * to try to start systemd services there, since without --new-chroot
+         * we don't even have systemd running, and even if we did, adding
+         * a concept of background daemons to builds would be an enormous change,
+         * requiring considering things like how the journal output is handled, etc.
+         * And there's really not a use case today for a build talking to a service.
+         *
+         * Note this call itself also looks for a different variable SYSTEMD_IGNORE_CHROOT=1.
+         */
+        r = running_in_chroot();
+        if (r < 0)
+                log_debug_errno(r, "running_in_chroot(): %m");
+        else if (r > 0)
+                return true;
+
+        return false;
+}
+
 int dispatch_verb(int argc, char *argv[], const Verb verbs[], void *userdata) {
         const Verb *verb;
         const char *name;
@@ -84,12 +126,15 @@ int dispatch_verb(int argc, char *argv[], const Verb verbs[], void *userdata) {
                 return -EINVAL;
         }
 
-        if ((verb->flags & VERB_NOCHROOT) && running_in_chroot() > 0) {
-                log_info("Running in chroot, ignoring request.");
+        if ((verb->flags & VERB_ONLINE_ONLY) && running_in_chroot_or_offline()) {
+                if (name)
+                        log_info("Running in chroot, ignoring request: %s", name);
+                else
+                        log_info("Running in chroot, ignoring request.");
                 return 0;
         }
 
-        if (verb->flags & VERB_MUSTBEROOT) {
+        if (verb->flags & VERB_MUST_BE_ROOT) {
                 r = must_be_root();
                 if (r < 0)
                         return r;

src/basic/verbs.h

@@ -23,9 +23,9 @@
 #define VERB_ANY ((unsigned) -1)
 
 typedef enum VerbFlags {
-        VERB_DEFAULT    = 1 << 0,
-        VERB_NOCHROOT   = 1 << 1,
-        VERB_MUSTBEROOT = 1 << 2,
+        VERB_DEFAULT      = 1 << 0,
+        VERB_ONLINE_ONLY  = 1 << 1,
+        VERB_MUST_BE_ROOT = 1 << 2,
 } VerbFlags;
 
 typedef struct {
@@ -35,4 +35,6 @@ typedef struct {
         int (* const dispatch)(int argc, char *argv[], void *userdata);
 } Verb;
 
+bool running_in_chroot_or_offline(void);
+
 int dispatch_verb(int argc, char *argv[], const Verb verbs[], void *userdata);