[libvirt] [PATCH 16/17] virt-login-shell: add ability to auto-detect shell from container
Currently the shell must be looked up from the config setting in
/etc/libvirt/virt-login-shell.conf. This is inflexible if there
are containers where different users need different shells. Add
add a new 'auto-shell' config parameter which instructs us to
query the containers' /etc/passwd for the shell to be exec'd.
Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com>
---
tools/virt-login-shell.c | 33 +++++++++++++++++++++++++++++++++
tools/virt-login-shell.conf | 14 ++++++++++++++
2 files changed, 47 insertions(+)
diff --git a/tools/virt-login-shell.c b/tools/virt-login-shell.c
index 6e8056d..7680266 100644
--- a/tools/virt-login-shell.c
+++ b/tools/virt-login-shell.c
@@ -100,6 +100,24 @@ static int virLoginShellAllowedUser(virConfPtr conf,
return ret;
}
+static int virLoginShellGetAutoShell(virConfPtr conf, bool *autoshell)
+{
+ virConfValuePtr p;
+
+ p = virConfGetValue(conf, "auto_shell");
+ if (!p) {
+ autoshell = false;
+ } else if (p->type == VIR_CONF_LONG ||
+ p->type == VIR_CONF_ULONG) {
+ *autoshell = (p->l != 0);
+ } else {
+ virReportSystemError(EINVAL, "%s",
+ _("auto-shell must be a boolean value"));
+ return -1;
+ }
+ return 0;
+}
+
static int virLoginShellGetShellArgv(virConfPtr conf,
char ***retshargv,
size_t *retshargvlen)
@@ -221,6 +239,7 @@ main(int argc, char **argv)
char *tmp;
char *term = NULL;
virErrorPtr saved_err = NULL;
+ bool autoshell = false;
struct option opt[] = {
{"help", no_argument, NULL, 'h'},
@@ -300,6 +319,8 @@ main(int argc, char **argv)
if (virLoginShellGetShellArgv(conf, &shargv, &shargvlen) < 0)
goto cleanup;
+ if (virLoginShellGetAutoShell(conf, &autoshell) < 0)
+ goto cleanup;
conn = virConnectOpen("lxc:///");
if (!conn)
@@ -351,6 +372,18 @@ main(int argc, char **argv)
goto cleanup;
}
+ if (autoshell) {
+ tmp = virGetUserShell(uid);
+ if (tmp) {
+ virStringFreeList(shargv);
+ shargvlen = 1;
+ if (VIR_ALLOC_N(shargv[0], shargvlen + 1) < 0)
+ goto cleanup;
+ shargv[0] = tmp;
+ shargv[1] = NULL;
+ }
+ }
+
if (cmdstr) {
if (VIR_REALLOC_N(shargv, shargvlen + 3) < 0)
goto cleanup;
diff --git a/tools/virt-login-shell.conf b/tools/virt-login-shell.conf
index e29d222..4a504b3 100644
--- a/tools/virt-login-shell.conf
+++ b/tools/virt-login-shell.conf
@@ -18,6 +18,20 @@
# Note there is no need to pass a '--login' / '-l' argument since
# virt-login-shell will always request a login shell
+# Normally virt-login-shell will always use the shell identified
+# by the 'shell' configuration setting above. If the container
+# is running a full OS, it might be desirable to allow the choice
+# of shell to be delegated to the owner of the shell, by querying
+# the /etc/passwd file inside the container
+#
+# To allow for that, uncomment the following:
+# auto_shell = 1
+#
+# NB, this should /not/ be used if any container is sharing the
+# host filesystem /etc, as this would cause virt-login-shell to
+# look at the host's /etc/passwd finding itself as the listed
+# shell. Hilarious recursion would then ensue.
+
# allowed_users specifies the user names of all users that are allowed to
# execute virt-login-shell. You can specify the users as a comma
# separated list of usernames or user groups.
--
2.5.5