[justincormack]

Static binaries used to be common, the normal way of doing stuff. People tend to think that package management killed them, but it was actually glibc which cannot make proper static binaries as it insists on dynamic functionality for some functions, such as name resolution. Now we have Musl libc there may well be a revival in static binaries from C applications, and the C-derived ecosystem.

[SixSigma]

As a demonstration I traced date(1) on CentOS. Here are the file accesses, if you are running diskless, each of these needs a round trip to the file server. (except the final 3, of course)

access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)

open("/etc/ld.so.cache", O_RDONLY) = 3

fstat(3, {st_mode=S_IFREG|0644, st_size=54185, ...}) = 0

close(3) = 0

open("/lib64/librt.so.1", O_RDONLY) = 3

read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0@!\0\0\0\0\0\0"..., 832) = 832

fstat(3, {st_mode=S_IFREG|0755, st_size=43880, ...}) = 0

close(3) = 0

open("/lib64/libc.so.6", O_RDONLY) = 3

read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0p\356\1\0\0\0\0\0"..., 832) = 832

fstat(3, {st_mode=S_IFREG|0755, st_size=1921176, ...}) = 0

close(3) = 0

open("/lib64/libpthread.so.0", O_RDONLY) = 3

read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\340]\0\0\0\0\0\0"..., 832) = 832

fstat(3, {st_mode=S_IFREG|0755, st_size=142640, ...}) = 0

close(3) = 0

open("/usr/lib/locale/locale-archive", O_RDONLY) = 3

fstat(3, {st_mode=S_IFREG|0644, st_size=99158576, ...}) = 0

close(3) = 0

open("/etc/localtime", O_RDONLY) = 3

fstat(3, {st_mode=S_IFREG|0644, st_size=3661, ...}) = 0

fstat(3, {st_mode=S_IFREG|0644, st_size=3661, ...}) = 0

read(3, "TZif2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\7\0\0\0\7\0\0\0\0"..., 4096) = 3661

lseek(3, -2338, SEEK_CUR) = 1323

read(3, "TZif2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\10\0\0\0\10\0\0\0\0"..., 4096) = 2338

close(3) = 0

fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 0), ...}) = 0

write(1, "Tue Feb 24 08:57:58 GMT 2015\n", 29) = 29

close(1) = 0

[justincormack]

Ok, here is strace of date(1), which is dynamically linked, on Alpine Linux which uses Musl libc not glibc.

execve("/bin/date", ["date"], [/* 16 vars */]) = 0

mprotect(0x7777dcd5a000, 4096, PROT_READ) = 0

mprotect(0xdc2d89a3000, 4096, PROT_READ) = 0

arch_prctl(ARCH_SET_FS, 0xdc2d89a4268) = 0

set_tid_address(0xdc2d89a4298) = 2439

clock_gettime(CLOCK_REALTIME, {1424769563, 611556639}) = 0

open("/etc/localtime", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = 3

fstat(3, {st_mode=S_IFREG|0644, st_size=118, ...}) = 0

mmap(NULL, 118, PROT_READ, MAP_SHARED, 3, 0) = 0x7777dcd57000

close(3) = 0

ioctl(1, SNDCTL_TMR_TIMEBASE or SNDRV_TIMER_IOCTL_NEXT_DEVICE or TCGETS, {B38400 opost isig icanon echo ...}) = 0

writev(1, [{"Tue Feb 24 09:19:23 UTC 2015", 28}, {"\n", 1}], 2Tue Feb 24 09:19:23 UTC 2015 ) = 29

close(1) = 0

close(2) = 0

exit_group(0) = ?

+++ exited with 0 +++

[SixSigma]

That is worlds apart.

[SixSigma]

OpenBSD's ktrace is similar

31144 date CALL readlink(0x3c001c16,0xcfbe7048,0x3f)

31144 date NAMI "/etc/malloc.conf"

31144 date RET readlink -1 errno 2 No such file or directory

31144 date CALL open(0x3c001967,0<O_RDONLY>)

31144 date NAMI "/etc/localtime"

31144 date RET open 3

31144 date CALL open(0xcfbde9d4,0<O_RDONLY>)

31144 date NAMI "/usr/share/zoneinfo/posixrules

31144 date RET open 3

[justincormack]

Yes, in many ways Musl is a BSD style libc for Linux (even down to the license). Add pkgsrc and it is pretty BSD-like.