I hate when I try to write generalized code up front. That is, I try to write a code base that is sufficiently generic that it works for all possible use cases. Some argue for this sort of development. I don’t like it. But I do fall into this every now and then.
Tiburon suffered from some of this. I want one system to “bind them all, and in the PXE process, boot them.” So I threw everything (including the kitchen sink) into it.
It sorta broke on me on Thursday.
I was working on a set of changes to boot Centos 6.2 via Tiburon. I wanted to add some features. I kept running into design … er … features.
So I took a scythe and cleaned out the dead code. I (massively) simplified the current code base. I knew I had to do this, I tried pushing too much functionality into Tiburon, functionality that I’ve since superceded with the boot time autoconfig scripts.
So I pulled that crap out. I rethought a few things, including how I passed some arguments.
Way back when I started learning Perl, I passed arguments to subs (methods) like this:
&function($arg1, $arg2, ..., $argN);
sub function {
my $arg1 = shift;
my $arg2 = shift;
.
.
.
my $argN = shift;
# do stuff
}
Ugly, ain’t it. Hard to maintain too. Basically, if you need more than 2 to 3 arguments, create a hash (collection for python-philic) that maps a named key into a value. Then pass a reference to the hash. Brain dead easy, never have to worry about argument order again.
For reasons I don’t grasp, Tiburon had a few calls like this in its core.
So I fixed em.
Then I had put controller logic in the view logic.
NOOOOOOOOOOOOOOOOOOOOOOOOoo!
The view logic is drop dead simple. So I fixed it.
Now, it just works, same as before, but *far* easier to maintain and write tools to interact with. Setting the default boot mechanism is real easy. Adding new boot mechanisms is real easy. Still have some oddities in how we spec an NFS boot server (have to tie it to an IP address, and I’d like to keep those entries more generic). Possibly some templates and other bits.
But, as they say, the proof is in the pudding. Behold Centos 6.2 from Tiburon:
[root@manager ~]# ssh 10.100.240.146
Last login: Fri Mar 9 15:46:07 2012 from internal-install.storagecluster
[root@manager-1 ~]# ssh 192.168.1.149
Last login: Sat Mar 10 15:47:37 2012 from 192.168.1.250
[root@Centos6 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
tmpfs 7.9G 0 7.9G 0% /dev/shm
none 7.9G 0 7.9G 0% /tmp
[root@Centos6 ~]# uname -r
2.6.32-220.7.1.el6.x86_64
[root@Centos6 ~]# lsscsi
[root@Centos6 ~]#
[root@Centos6 ~]# fdisk -l
[root@Centos6 ~]#
[root@Centos6 ~]# cat /proc/scsi/scsi
Attached devices:
[root@Centos6 ~]#
[root@Centos6 ~]# lsmod
Module Size Used by
ipmi_devintf 8049 0
ipmi_si 42401 0
ipmi_msghandler 35992 2 ipmi_devintf,ipmi_si
cpufreq_ondemand 10448 8
acpi_cpufreq 7955 0
freq_table 4881 2 cpufreq_ondemand,acpi_cpufreq
mperf 1557 1 acpi_cpufreq
microcode 112594 0
serio_raw 4818 0
i2c_i801 11231 0
iTCO_wdt 13662 0
iTCO_vendor_support 3088 1 iTCO_wdt
lm87 25713 0
hwmon_vid 3132 1 lm87
ahci 40455 0
e1000e 219500 0
sfc 189702 0
i2c_algo_bit 5762 1 sfc
i2c_core 31276 4 i2c_i801,lm87,sfc,i2c_algo_bit
dm_mirror 14101 0
dm_region_hash 12170 1 dm_mirror
dm_log 10122 2 dm_mirror,dm_region_hash
dm_mod 81596 2 dm_mirror,dm_log
nfs 398778 1
lockd 74270 1 nfs
fscache 46859 1 nfs
nfs_acl 2647 1 nfs
auth_rpcgss 44895 1 nfs
sunrpc 244046 9 nfs,lockd,nfs_acl,auth_rpcgss
be2iscsi 67608 0
bnx2i 45110 0
cnic 53443 1 bnx2i
uio 10974 1 cnic
ipv6 322029 25 cnic
cxgb4i 28169 0
cxgb4 98717 1 cxgb4i
cxgb3i 24938 0
libcxgbi 52541 2 cxgb4i,cxgb3i
cxgb3 153146 1 cxgb3i
mdio 4732 2 sfc,cxgb3
libiscsi_tcp 16598 3 cxgb4i,cxgb3i,libcxgbi
qla4xxx 170419 0
iscsi_boot_sysfs 9650 2 be2iscsi,qla4xxx
libiscsi 47521 7 be2iscsi,bnx2i,cxgb4i,cxgb3i,libcxgbi,libiscsi_tcp,qla4xxx
scsi_transport_iscsi 48010 5 be2iscsi,bnx2i,libcxgbi,qla4xxx,libiscsi
[root@Centos6 ~]# ifinfo
device: address/netmask MTU Tx (MB) Rx (MB)
eth0: addr not set/mask not set 1500 0.001 8.813
eth1: addr not set/mask not set 1500 0.000 0.000
eth2: 192.168.1.149/255.255.255.0 1500 12.182 142.812
[root@Centos6 ~]# cat /etc/mtab
proc /proc proc rw 0 0
sysfs /sys sysfs rw 0 0
tmpfs /dev/shm tmpfs rw 0 0
none /tmp tmpfs rw 0 0
none /proc/sys/fs/binfmt_misc binfmt_misc rw 0 0
[root@Centos6 ~]# dmesg | grep nfs
Command line: ip=dhcp root=nfs:192.168.1.250:/data/nfs/Centos6.2_x64 rw debug verbose rdshell rd_NO_DM rd_NO_MD rd.ip=auto selinux=0
Kernel command line: ip=dhcp root=nfs:192.168.1.250:/data/nfs/Centos6.2_x64 rw debug verbose rdshell rd_NO_DM rd_NO_MD rd.ip=auto selinux=0
FS-Cache: Netfs 'nfs' registered for caching
dracut: Mounted root filesystem 192.168.1.250:/data/nfs/Centos6.2_x64
[root@Centos6 ~]# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 42
model name : Intel(R) Xeon(R) CPU E31240 @ 3.30GHz
stepping : 7
cpu MHz : 1600.000
cache size : 8192 KB
physical id : 0
siblings : 8
core id : 0
cpu cores : 4
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 sse4_2 x2apic popcnt xsave avx lahf_lm ida arat epb xsaveopt pln pts dts tpr_shadow vnmi flexpriority ept vpid
bogomips : 6585.29
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:
...
[root@Centos6 ~]# top
top - 18:24:49 up 1 day, 1:39, 1 user, load average: 0.08, 0.02, 0.01
Tasks: 181 total, 1 running, 180 sleeping, 0 stopped, 0 zombie
Cpu0 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu1 : 0.0%us, 0.1%sy, 0.0%ni, 99.9%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu2 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu3 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu4 : 0.0%us, 0.1%sy, 0.0%ni, 99.9%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu5 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu6 : 0.0%us, 0.1%sy, 0.0%ni, 99.9%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu7 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 16445012k total, 307444k used, 16137568k free, 0k buffers
Swap: 0k total, 0k used, 0k free, 72800k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
323 root 20 0 0 0 0 S 0.7 0.0 1:32.32 sfc0000:02:00.0
2380 root 20 0 15080 1388 1012 R 0.7 0.0 0:00.01 top
1 root 20 0 19400 1560 1252 S 0.0 0.0 0:00.92 init
2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kthreadd
3 root RT 0 0 0 0 S 0.0 0.0 0:00.00 migration/0
4 root 20 0 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/0
5 root RT 0 0 0 0 S 0.0 0.0 0:00.00 migration/0
6 root RT 0 0 0 0 S 0.0 0.0 0:00.00 watchdog/0
7 root RT 0 0 0 0 S 0.0 0.0 0:00.00 migration/1
8 root RT 0 0 0 0 S 0.0 0.0 0:00.00 migration/1 