From ee48dbd55f544d9ee4a17497b5757be7e854c869 Mon Sep 17 00:00:00 2001 From: Nils Carlson Date: Mon, 6 Jul 2015 00:00:59 +0200 Subject: [PATCH] core: Add machine-id setting Allow for overriding all other machine-ids which may be present on the system using a kernel command line systemd.machine_id or --machine-id= option. This is especially useful for network booted systems where the machine-id needs to be static, or for containers where a specific machine-id is wanted. --- man/kernel-command-line.xml | 1 + man/machine-id.xml | 6 ++++ man/systemd.xml | 17 +++++++++++ src/core/machine-id-setup.c | 23 +++++++++----- src/core/machine-id-setup.h | 2 +- src/core/main.c | 32 ++++++++++++++++++-- src/machine-id-setup/machine-id-setup-main.c | 2 +- 7 files changed, 71 insertions(+), 12 deletions(-) diff --git a/man/kernel-command-line.xml b/man/kernel-command-line.xml index 309220632e..42d5e006bb 100644 --- a/man/kernel-command-line.xml +++ b/man/kernel-command-line.xml @@ -91,6 +91,7 @@ systemd.default_standard_output= systemd.default_standard_error= systemd.setenv= + systemd.machine_id= Parameters understood by the system and service manager to control system behavior. For details, see diff --git a/man/machine-id.xml b/man/machine-id.xml index db72c2a01c..d318ec54ec 100644 --- a/man/machine-id.xml +++ b/man/machine-id.xml @@ -84,6 +84,12 @@ at install time. Use systemd-firstboot1 to initialize it on mounted (but not booted) system images. + + The machine-id may also be set, for example when network + booting, by setting the systemd.machine_id= + kernel command line parameter or passing the option + to systemd. A machine-id may not + be set to all zeros. diff --git a/man/systemd.xml b/man/systemd.xml index 6de18f8294..367972099b 100644 --- a/man/systemd.xml +++ b/man/systemd.xml @@ -255,6 +255,14 @@ . + + + + Override the machine-id set on the hard drive, + userful for network booting or for containers. May not be set + to all zeros. + + @@ -976,6 +984,15 @@ than once to set multiple variables. + + systemd.machine_id= + + Takes a 32 character hex value to be + used for setting the machine-id. Intended mostly for + network booting where the same machine-id is desired + for every boot. + + quiet diff --git a/src/core/machine-id-setup.c b/src/core/machine-id-setup.c index 145ba2a28d..09b0449c80 100644 --- a/src/core/machine-id-setup.c +++ b/src/core/machine-id-setup.c @@ -198,7 +198,7 @@ static int generate_machine_id(char id[34], const char *root) { return 0; } -int machine_id_setup(const char *root) { +int machine_id_setup(const char *root, sd_id128_t machine_id) { const char *etc_machine_id, *run_machine_id; _cleanup_close_ int fd = -1; bool writable = true; @@ -248,15 +248,22 @@ int machine_id_setup(const char *root) { } } - if (read_machine_id(fd, id) >= 0) - return 0; + /* A machine id argument overrides all other machined-ids */ + if (!sd_id128_is_null(machine_id)) { + sd_id128_to_string(machine_id, id); + id[32] = '\n'; + id[33] = 0; + } else { + if (read_machine_id(fd, id) >= 0) + return 0; - /* Hmm, so, the id currently stored is not useful, then let's - * generate one */ + /* Hmm, so, the id currently stored is not useful, then let's + * generate one */ - r = generate_machine_id(id, root); - if (r < 0) - return r; + r = generate_machine_id(id, root); + if (r < 0) + return r; + } if (writable) if (write_machine_id(fd, id) >= 0) diff --git a/src/core/machine-id-setup.h b/src/core/machine-id-setup.h index f7707c3bf9..a2168a8d4a 100644 --- a/src/core/machine-id-setup.h +++ b/src/core/machine-id-setup.h @@ -22,4 +22,4 @@ ***/ int machine_id_commit(const char *root); -int machine_id_setup(const char *root); +int machine_id_setup(const char *root, sd_id128_t machine_id); diff --git a/src/core/main.c b/src/core/main.c index f9de54028e..e415d1c5b8 100644 --- a/src/core/main.c +++ b/src/core/main.c @@ -127,6 +127,7 @@ static bool arg_default_blockio_accounting = false; static bool arg_default_memory_accounting = false; static bool arg_default_tasks_accounting = true; static uint64_t arg_default_tasks_max = UINT64_C(512); +static sd_id128_t arg_machine_id = {}; static void pager_open_if_enabled(void) { @@ -300,6 +301,17 @@ static int parse_crash_chvt(const char *value) { return 0; } +static int set_machine_id(const char *m) { + + if (sd_id128_from_string(m, &arg_machine_id) < 0) + return -EINVAL; + + if (sd_id128_is_null(arg_machine_id)) + return -EINVAL; + + return 0; +} + static int parse_proc_cmdline_item(const char *key, const char *value) { int r; @@ -388,6 +400,12 @@ static int parse_proc_cmdline_item(const char *key, const char *value) { } else log_warning("Environment variable name '%s' is not valid. Ignoring.", value); + } else if (streq(key, "systemd.machine_id") && value) { + + r = set_machine_id(value); + if (r < 0) + log_warning("MachineID '%s' is not valid. Ignoring.", value); + } else if (streq(key, "quiet") && !value) { if (arg_show_status == _SHOW_STATUS_UNSET) @@ -743,7 +761,8 @@ static int parse_argv(int argc, char *argv[]) { ARG_DESERIALIZE, ARG_SWITCHED_ROOT, ARG_DEFAULT_STD_OUTPUT, - ARG_DEFAULT_STD_ERROR + ARG_DEFAULT_STD_ERROR, + ARG_MACHINE_ID }; static const struct option options[] = { @@ -769,6 +788,7 @@ static int parse_argv(int argc, char *argv[]) { { "switched-root", no_argument, NULL, ARG_SWITCHED_ROOT }, { "default-standard-output", required_argument, NULL, ARG_DEFAULT_STD_OUTPUT, }, { "default-standard-error", required_argument, NULL, ARG_DEFAULT_STD_ERROR, }, + { "machine-id", required_argument, NULL, ARG_MACHINE_ID }, {} }; @@ -964,6 +984,14 @@ static int parse_argv(int argc, char *argv[]) { arg_switched_root = true; break; + case ARG_MACHINE_ID: + r = set_machine_id(optarg); + if (r < 0) { + log_error("MachineID '%s' is not valid.", optarg); + return r; + } + break; + case 'h': arg_action = ACTION_HELP; if (arg_no_pager < 0) @@ -1617,7 +1645,7 @@ int main(int argc, char *argv[]) { status_welcome(); hostname_setup(); - machine_id_setup(NULL); + machine_id_setup(NULL, arg_machine_id); loopback_setup(); bump_unix_max_dgram_qlen(); diff --git a/src/machine-id-setup/machine-id-setup-main.c b/src/machine-id-setup/machine-id-setup-main.c index d805bcfdca..9d19307236 100644 --- a/src/machine-id-setup/machine-id-setup-main.c +++ b/src/machine-id-setup/machine-id-setup-main.c @@ -112,7 +112,7 @@ int main(int argc, char *argv[]) { if (arg_commit) r = machine_id_commit(arg_root); else - r = machine_id_setup(arg_root); + r = machine_id_setup(arg_root, SD_ID128_NULL); finish: free(arg_root);