[lxc-devel] [PATCH 1/1] systemd: specify container_ttys in environment
Stéphane Graber
stgraber at ubuntu.com
Wed Jan 28 08:12:30 UTC 2015
On Tue, Jan 27, 2015 at 11:06:22PM +0000, Serge Hallyn wrote:
> Quoting Stéphane Graber (stgraber at ubuntu.com):
> > On Tue, Jan 27, 2015 at 08:48:25PM +0000, Serge Hallyn wrote:
> > > The lxc.tty configuration item specifies a number of ttys to create.
> > > Historically, for each of those, we create a /dev/pts/N entry and
> > > symlink it to /dev/ttyN for older inits to use. For systemd, we should
> > > instead specify each tty name in a $container_ttys environment variable
> > > passed to init.
> > >
> > > See http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface/ and
> > > https://github.com/lxc/lxc/issues/419.
> > >
> > > Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>
> > > ---
> > > src/lxc/conf.c | 43 ++++++++++++++++++++++++++++++++++++++++---
> > > src/lxc/conf.h | 1 +
> > > src/lxc/start.c | 8 +++++---
> > > 3 files changed, 46 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/src/lxc/conf.c b/src/lxc/conf.c
> > > index c7db06f..da4a928 100644
> > > --- a/src/lxc/conf.c
> > > +++ b/src/lxc/conf.c
> > > @@ -943,9 +943,34 @@ static int setup_dev_symlinks(const struct lxc_rootfs *rootfs)
> > > return 0;
> > > }
> > >
> > > -static int setup_tty(const struct lxc_rootfs *rootfs,
> > > - const struct lxc_tty_info *tty_info, char *ttydir)
> > > +/*
> > > + * Build a space-separate list of ptys to pass to systemd.
> > > + */
> > > +static bool append_ptyname(char **pp, char *name)
> > > {
> > > + char *p;
> > > +
> > > + if (!*pp) {
> > > + *pp = malloc(strlen(name) + strlen("container_ttys=") + 1);
> > > + if (!*pp)
> > > + return false;
> > > + sprintf(*pp, "container_ttys=%s", name);
> > > + return true;
> > > + }
> > > + p = realloc(*pp, strlen(*pp) + strlen(name) + 2);
> > > + if (!p)
> > > + return false;
> > > + *pp = p;
> > > + strcat(p, " ");
> > > + strcat(p, name);
> > > + return true;
> > > +}
> > > +
> > > +static int setup_tty(struct lxc_conf *conf)
> > > +{
> > > + const struct lxc_rootfs *rootfs = &conf->rootfs;
> > > + const struct lxc_tty_info *tty_info = &conf->tty_info;
> > > + char *ttydir = conf->ttydir;
> > > char path[MAXPATHLEN], lxcpath[MAXPATHLEN];
> > > int i, ret;
> > >
> > > @@ -999,6 +1024,8 @@ static int setup_tty(const struct lxc_rootfs *rootfs,
> > > SYSERROR("failed to create symlink for tty %d", i+1);
> > > return -1;
> > > }
> > > + /* Now save the relative path in @path for append_ptyname */
> > > + sprintf(path, "%s/tty%d", ttydir, i + 1);
> > > } else {
> > > /* If we populated /dev, then we need to create /dev/ttyN */
> > > if (access(path, F_OK)) {
> > > @@ -1015,6 +1042,12 @@ static int setup_tty(const struct lxc_rootfs *rootfs,
> > > pty_info->name, path);
> > > continue;
> > > }
> > > + /* Now save the relative path in @path for append_ptyname */
> > > + sprintf(path, "tty%d", i + 1);
> > > + }
> > > + if (!append_ptyname(&conf->pty_names, path)) {
> > > + ERROR("Error setting up container_ttys string");
> > > + return -1;
> > > }
> > > }
> > >
> > > @@ -3794,11 +3827,14 @@ int lxc_setup(struct lxc_handler *handler)
> > > ERROR("failed to setup kmsg for '%s'", name);
> > > }
> > >
> > > - if (!lxc_conf->is_execute && setup_tty(&lxc_conf->rootfs, &lxc_conf->tty_info, lxc_conf->ttydir)) {
> > > + if (!lxc_conf->is_execute && setup_tty(lxc_conf)) {
> > > ERROR("failed to setup the ttys for '%s'", name);
> > > return -1;
> > > }
> > >
> > > + if (lxc_conf->pty_names && setenv("container_ttys", lxc_conf->pty_names, 1))
> > > + SYSERROR("failed to set environment variable for container ptys");
> > > +
> > > if (!lxc_conf->is_execute && setup_dev_symlinks(&lxc_conf->rootfs)) {
> > > ERROR("failed to setup /dev symlinks for '%s'", name);
> > > return -1;
> > > @@ -4172,6 +4208,7 @@ void lxc_conf_free(struct lxc_conf *conf)
> > > free(conf->rcfile);
> > > free(conf->init_cmd);
> > > free(conf->unexpanded_config);
> > > + free(conf->pty_names);
> > > lxc_clear_config_network(conf);
> > > free(conf->lsm_aa_profile);
> > > free(conf->lsm_se_context);
> > > diff --git a/src/lxc/conf.h b/src/lxc/conf.h
> > > index 09065a1..8ec3e8e 100644
> > > --- a/src/lxc/conf.h
> > > +++ b/src/lxc/conf.h
> > > @@ -304,6 +304,7 @@ struct lxc_conf {
> > > struct lxc_list caps;
> > > struct lxc_list keepcaps;
> > > struct lxc_tty_info tty_info;
> > > + char *pty_names; // comma-separated list of lxc.tty pty names
> > > struct lxc_console console;
> > > struct lxc_rootfs rootfs;
> > > char *ttydir;
> > > diff --git a/src/lxc/start.c b/src/lxc/start.c
> > > index 161e4c0..b2c9424 100644
> > > --- a/src/lxc/start.c
> > > +++ b/src/lxc/start.c
> > > @@ -745,9 +745,11 @@ static int do_start(void *data)
> > > }
> > > }
> > >
> > > - if (putenv("container=lxc")) {
> > > - SYSERROR("failed to set environment variable 'container=lxc'");
> > > - goto out_warn_father;
> >
> > Why is that being removed?
>
> Oh I was just testing you. yeah...
>
> The "real" patch follows. yeah.
>
> Subject: [PATCH 1/1] systemd: specify container_ttys in environment
>
> The lxc.tty configuration item specifies a number of ttys to create.
> Historically, for each of those, we create a /dev/pts/N entry and
> symlink it to /dev/ttyN for older inits to use. For systemd, we should
> instead specify each tty name in a $container_ttys environment variable
> passed to init.
>
> See http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface/ and
> https://github.com/lxc/lxc/issues/419.
>
> Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>
Acked-by: Stéphane Graber <stgraber at ubuntu.com>
> ---
> src/lxc/conf.c | 43 ++++++++++++++++++++++++++++++++++++++++---
> src/lxc/conf.h | 1 +
> src/lxc/start.c | 7 +++++++
> 3 files changed, 48 insertions(+), 3 deletions(-)
>
> diff --git a/src/lxc/conf.c b/src/lxc/conf.c
> index c7db06f..da4a928 100644
> --- a/src/lxc/conf.c
> +++ b/src/lxc/conf.c
> @@ -943,9 +943,34 @@ static int setup_dev_symlinks(const struct lxc_rootfs *rootfs)
> return 0;
> }
>
> -static int setup_tty(const struct lxc_rootfs *rootfs,
> - const struct lxc_tty_info *tty_info, char *ttydir)
> +/*
> + * Build a space-separate list of ptys to pass to systemd.
> + */
> +static bool append_ptyname(char **pp, char *name)
> {
> + char *p;
> +
> + if (!*pp) {
> + *pp = malloc(strlen(name) + strlen("container_ttys=") + 1);
> + if (!*pp)
> + return false;
> + sprintf(*pp, "container_ttys=%s", name);
> + return true;
> + }
> + p = realloc(*pp, strlen(*pp) + strlen(name) + 2);
> + if (!p)
> + return false;
> + *pp = p;
> + strcat(p, " ");
> + strcat(p, name);
> + return true;
> +}
> +
> +static int setup_tty(struct lxc_conf *conf)
> +{
> + const struct lxc_rootfs *rootfs = &conf->rootfs;
> + const struct lxc_tty_info *tty_info = &conf->tty_info;
> + char *ttydir = conf->ttydir;
> char path[MAXPATHLEN], lxcpath[MAXPATHLEN];
> int i, ret;
>
> @@ -999,6 +1024,8 @@ static int setup_tty(const struct lxc_rootfs *rootfs,
> SYSERROR("failed to create symlink for tty %d", i+1);
> return -1;
> }
> + /* Now save the relative path in @path for append_ptyname */
> + sprintf(path, "%s/tty%d", ttydir, i + 1);
> } else {
> /* If we populated /dev, then we need to create /dev/ttyN */
> if (access(path, F_OK)) {
> @@ -1015,6 +1042,12 @@ static int setup_tty(const struct lxc_rootfs *rootfs,
> pty_info->name, path);
> continue;
> }
> + /* Now save the relative path in @path for append_ptyname */
> + sprintf(path, "tty%d", i + 1);
> + }
> + if (!append_ptyname(&conf->pty_names, path)) {
> + ERROR("Error setting up container_ttys string");
> + return -1;
> }
> }
>
> @@ -3794,11 +3827,14 @@ int lxc_setup(struct lxc_handler *handler)
> ERROR("failed to setup kmsg for '%s'", name);
> }
>
> - if (!lxc_conf->is_execute && setup_tty(&lxc_conf->rootfs, &lxc_conf->tty_info, lxc_conf->ttydir)) {
> + if (!lxc_conf->is_execute && setup_tty(lxc_conf)) {
> ERROR("failed to setup the ttys for '%s'", name);
> return -1;
> }
>
> + if (lxc_conf->pty_names && setenv("container_ttys", lxc_conf->pty_names, 1))
> + SYSERROR("failed to set environment variable for container ptys");
> +
> if (!lxc_conf->is_execute && setup_dev_symlinks(&lxc_conf->rootfs)) {
> ERROR("failed to setup /dev symlinks for '%s'", name);
> return -1;
> @@ -4172,6 +4208,7 @@ void lxc_conf_free(struct lxc_conf *conf)
> free(conf->rcfile);
> free(conf->init_cmd);
> free(conf->unexpanded_config);
> + free(conf->pty_names);
> lxc_clear_config_network(conf);
> free(conf->lsm_aa_profile);
> free(conf->lsm_se_context);
> diff --git a/src/lxc/conf.h b/src/lxc/conf.h
> index 09065a1..8ec3e8e 100644
> --- a/src/lxc/conf.h
> +++ b/src/lxc/conf.h
> @@ -304,6 +304,7 @@ struct lxc_conf {
> struct lxc_list caps;
> struct lxc_list keepcaps;
> struct lxc_tty_info tty_info;
> + char *pty_names; // comma-separated list of lxc.tty pty names
> struct lxc_console console;
> struct lxc_rootfs rootfs;
> char *ttydir;
> diff --git a/src/lxc/start.c b/src/lxc/start.c
> index 161e4c0..1949886 100644
> --- a/src/lxc/start.c
> +++ b/src/lxc/start.c
> @@ -750,6 +750,13 @@ static int do_start(void *data)
> goto out_warn_father;
> }
>
> + if (handler->conf->pty_names) {
> + if (putenv(handler->conf->pty_names)) {
> + SYSERROR("failed to set environment variable for container ptys");
> + goto out_warn_father;
> + }
> + }
> +
> close(handler->sigfd);
>
> /* after this call, we are in error because this
> --
> 2.1.0
>
> _______________________________________________
> lxc-devel mailing list
> lxc-devel at lists.linuxcontainers.org
> http://lists.linuxcontainers.org/listinfo/lxc-devel
--
Stéphane Graber
Ubuntu developer
http://www.ubuntu.com
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