fix(ds-identify): relocate /run on *BSD (canonical#4677)

shuffle code-paths around such that we initialize RUN_PATH, and all the
things that depend on it after figuring out which OS we're on, while
still alowing these global variables to be overwritten from the outside.
On BSD /run is not ephemeral, so here we set RUN_PATH to /var/run.
Ensure everything is initialized for 'print_info', not just for 'main'.

For the tests, we equally ensure that for not-Linux systems the data is
written into `rootd + var/run` instead of `rootd + run`.

Sponsored by: The FreeBSD Foundation

tests/unittests/test_ds_identify.py

@@ -18,16 +18,14 @@
     populate_dir_with_ts,
 )
 
-UNAME_MYSYS = (
-    "Linux 4.4.0-62-generic #83-Ubuntu SMP Wed Jan 18 14:10:15 UTC 2017 x86_64"
-)
+UNAME_MYSYS = "Linux #83-Ubuntu SMP Wed Jan 18 14:10:15 UTC 2017 x86_64"
 UNAME_PPC64EL = (
-    "Linux 4.4.0-83-generic #106-Ubuntu SMP "
-    "Mon Jun 26 17:53:54 UTC 2017 "
+    "Linux #106-Ubuntu SMP mon Jun 26 17:53:54 UTC 2017 "
     "ppc64le ppc64le ppc64le"
 )
 UNAME_FREEBSD = (
-    "FreeBSD 12.1-RELEASE-p10 FreeBSD 12.1-RELEASE-p10 GENERIC  amd64"
+    "FreeBSD FreeBSD 14.0-RELEASE-p3 releng/14.0-n265398-20fae1e1699"
+    "GENERIC-MMCCAM amd64"
 )
 UNAME_OPENBSD = "OpenBSD GENERIC.MP#1397 amd64"
 
@@ -340,7 +338,17 @@ def write_mock(data):
             },
         ]
 
-        written = [d["name"] for d in mocks]
+        uname = "Linux"
+        runpath = "run"
+        written = []
+        for d in mocks:
+            written.append(d["name"])
+            if d["name"] == "uname":
+                uname = d["out"].split(" ")[0]
+        # set runpath so that BSDs use /var/run rather than /run
+        if uname != "Linux":
+            runpath = "var/run"
+
         for data in mocks:
             mocklines.append(write_mock(data))
         for d in default_mocks:
@@ -363,7 +371,7 @@ def write_mock(data):
             err = e.stderr
 
         cfg = None
-        cfg_out = os.path.join(rootd, "run/cloud-init/cloud.cfg")
+        cfg_out = os.path.join(rootd, runpath, "cloud-init/cloud.cfg")
         if os.path.exists(cfg_out):
             contents = util.load_file(cfg_out)
             try:

tools/ds-identify

@@ -68,7 +68,6 @@ DI_DISABLED="disabled"
 DI_DEBUG_LEVEL="${DEBUG_LEVEL:-1}"
 
 PATH_ROOT=${PATH_ROOT:-""}
-PATH_RUN=${PATH_RUN:-"${PATH_ROOT}/run"}
 PATH_SYS_CLASS_DMI_ID=${PATH_SYS_CLASS_DMI_ID:-${PATH_ROOT}/sys/class/dmi/id}
 PATH_SYS_HYPERVISOR=${PATH_SYS_HYPERVISOR:-${PATH_ROOT}/sys/hypervisor}
 PATH_SYS_CLASS_BLOCK=${PATH_SYS_CLASS_BLOCK:-${PATH_ROOT}/sys/class/block}
@@ -82,11 +81,17 @@ PATH_PROC_UPTIME=${PATH_PROC_UPTIME:-${PATH_ROOT}/proc/uptime}
 PATH_ETC_CLOUD="${PATH_ETC_CLOUD:-${PATH_ROOT}/etc/cloud}"
 PATH_ETC_CI_CFG="${PATH_ETC_CI_CFG:-${PATH_ETC_CLOUD}/cloud.cfg}"
 PATH_ETC_CI_CFG_D="${PATH_ETC_CI_CFG_D:-${PATH_ETC_CI_CFG}.d}"
-PATH_RUN_CI="${PATH_RUN_CI:-${PATH_RUN}/cloud-init}"
-PATH_RUN_CI_CFG=${PATH_RUN_CI_CFG:-${PATH_RUN_CI}/cloud.cfg}
-PATH_RUN_DI_RESULT=${PATH_RUN_DI_RESULT:-${PATH_RUN_CI}/.ds-identify.result}
 
-DI_LOG="${DI_LOG:-${PATH_RUN_CI}/ds-identify.log}"
+# Declare global here, so they can be overwritten from the outside.
+# if not overwritten from the outside, we'll populate them with system default
+# paths, once we have determined the system we're running on.
+# This is done in set_run_path(), which must run after read_uname_info().
+PATH_RUN="${PATH_RUN:-}"
+PATH_RUN_CI="${PATH_RUN_CI:-}"
+PATH_RUN_CI_CFG="${PATH_RUN_CI_CFG:-}"
+PATH_RUN_DI_RESULT="${PATH_RUN_DI_RESULT:-}"
+
+DI_LOG="${DI_LOG:-}"
 _DI_LOGGED=""
 
 # set DI_MAIN='noop' in environment to source this file with no main called.
@@ -1579,6 +1584,9 @@ collect_info() {
 }
 
 print_info() {
+    DI_LOG=stderr
+    ensure_sane_path
+    read_uname_info
     collect_info
     _print_info
 }
@@ -1835,12 +1843,25 @@ read_uptime() {
     return
 }
 
+set_run_path() {
+    if [ "$DI_UNAME_KERNEL_NAME" = "Linux" ]; then
+        PATH_RUN=${PATH_RUN:-"${PATH_ROOT}/run"}
+    else
+        PATH_RUN=${PATH_RUN:-"${PATH_ROOT}/var/run"}
+    fi
+
+    PATH_RUN_CI="${PATH_RUN_CI:-${PATH_RUN}/cloud-init}"
+    PATH_RUN_CI_CFG=${PATH_RUN_CI_CFG:-${PATH_RUN_CI}/cloud.cfg}
+    PATH_RUN_DI_RESULT=${PATH_RUN_DI_RESULT:-${PATH_RUN_CI}/.ds-identify.result}
+
+    DI_LOG="${DI_LOG:-${PATH_RUN_CI}/ds-identify.log}"
+}
+
 _main() {
     local dscheck_fn="" ret_dis=1 ret_en=0
 
     read_uptime
     debug 1 "[up ${_RET}s]" "ds-identify $*"
-    read_uname_info
     read_virt
     read_kernel_cmdline
     if is_disabled; then
@@ -1963,6 +1984,9 @@ _main() {
 main() {
     local ret=""
     ensure_sane_path
+    read_uname_info
+    set_run_path
+
     [ -d "$PATH_RUN_CI" ] || mkdir -p "$PATH_RUN_CI"
     if [ "${1:+$1}" != "--force" ] && [ -f "$PATH_RUN_CI_CFG" ] &&
         [ -f "$PATH_RUN_DI_RESULT" ]; then