When running from within a k8s pod, use the k8s API to get the cgroup name (#5576)

* When running from within a k8s pod, use the k8s API to get the pod name

* Check the last part of an underscore-delimited or slash-delimited container id

* Add a docker image builder that adds a single image to a user-specified registry, for use in k8s

* When running in k8s, disable cgroups that the pod API does not return

* Use longer name for k8s containers

* Add reference to build-test.sh to packaging/docker/README.md

* Anonymous statistics should not break when /proc/1/sched is not available

1 files changed, 7 insertions, 3 deletions

diff --git a/collectors/cgroups.plugin/sys_fs_cgroup.c b/collectors/cgroups.plugin/sys_fs_cgroup.c
index 41079a43b4..66dfc2d6aa 100644
--- a/collectors/cgroups.plugin/sys_fs_cgroup.c
+++ b/collectors/cgroups.plugin/sys_fs_cgroup.c
@@ -893,7 +893,7 @@ static inline void cgroup_get_chart_name(struct cgroup *cg) {
 
     snprintfz(command, CGROUP_CHARTID_LINE_MAX, "exec %s '%s'", cgroups_rename_script, cg->chart_id);
 
-    debug(D_CGROUP, "executing command \"%s\" for cgroup '%s'", command, cg->id);
+    debug(D_CGROUP, "executing command \"%s\" for cgroup '%s'", command, cg->chart_id);
     FILE *fp = mypopen(command, &cgroup_pid);
     if(fp) {
         // debug(D_CGROUP, "reading from command '%s' for cgroup '%s'", command, cg->id);
@@ -904,12 +904,16 @@ static inline void cgroup_get_chart_name(struct cgroup *cg) {
         // debug(D_CGROUP, "closed command for cgroup '%s'", cg->id);
 
         if(s && *s && *s != '\n') {
-            debug(D_CGROUP, "cgroup '%s' should be renamed to '%s'", cg->id, s);
+            debug(D_CGROUP, "cgroup '%s' should be renamed to '%s'", cg->chart_id, s);
 
             s = trim(s);
             if (s) {
-                if(likely(!name_error))
+                if(likely(name_error==0))
                     cg->pending_renames = 0;
+                else if (unlikely(name_error==3)) {
+                    debug(D_CGROUP, "cgroup '%s' disabled based due to rename command output", cg->chart_id);
+                    cg->enabled = 0;
+                }
 
                 if(likely(cg->pending_renames < 2)) {
                     freez(cg->chart_title);