While trying to debug a panic in kubelet, I have been trying unsuccessfully to attach delve to kubelet executable:
me@mycomputer:~$ sudo dlv attach 23796
could not attach to pid 23796: could not open debug infofile and objdump --syms reveal no debug info is included in kubelet:
me@mycomputer:~$ file _output/bin/kubelet
_output/bin/kubelet: ELF 64-bit LSB executable, x86-64, version 1
(SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2,
BuildID[sha1]=c7a1645940f91048eea9086bd0500deb7ec75b38, for
GNU/Linux 3.2.0, stripped
me@mycomputer:~$ objdump --syms _output/bin/kubelet
_output/bin/kubelet: file format elf64-x86-64
SYMBOL TABLE:
no symbolsI have tried different options while building kubelet:
make WHAT=cmd/kubelet GOGCFLAGS=-dwarfor:
make WHAT=cmd/kubelet GOFLAGS=-dwarfbut still no debug info is included in the executable. It seems to me that -w option is included by default in go tool link, which strips the DWARF symbol table to save on final executable size (see here). But I was not able to reverse that.
Any thoughts on how I should build kubelet to include debug info?
As JimB advised, go build does the trick:
me@mycomputer:~/kubernetes/cmd/kubelet$ sudo go build kubelet.go
me@mycomputer:~/kubernetes/cmd/kubelet$ file ./kubelet
kubelet: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically
linked, interpreter /lib64/ld-linux-x86-64.so.2,
BuildID[sha1]=a1377345bfab4ca57b28af60eed92f23c81d7ae8, for GNU/Linux 3.2.0,
not strippedAs can be seen, the debug info is not stripped anymore. Now you can copy the output to _output/bin and debug it using delve.