..running it a few more times eventually result in success.
+ strace confd -debug -verbose -onetime -node 192.168.61.100:4001 -config-file /app/confd.toml
execve("/usr/local/bin/confd", ["confd", "-debug", "-verbose", "-onetime", "-node", "192.168.61.100:4001", "-config-file", "/app/confd.toml"], [/* 11 vars */]) = 0
arch_prctl(ARCH_SET_FS, 0x9fab10) = 0
sched_getaffinity(0, 128, {3, 0, 0, 0}) = 32
mmap(NULL, 262144, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f539db8b000
mmap(0xc000000000, 65536, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xc000000000
munmap(0xc000000000, 65536) = 0
mmap(0xc210000000, 1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xc210000000
mmap(0xc20fff0000, 65536, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xc20fff0000
mmap(0xc000000000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xc000000000
mmap(NULL, 65536, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f539db7b000
mmap(NULL, 1439992, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f539da1b000
mmap(NULL, 131072, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f539d9fb000
sigaltstack({ss_sp=0xc210002000, ss_flags=0, ss_size=32768}, NULL) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigaction(SIGHUP, NULL, {SIG_DFL, [], 0}, 8) = 0
rt_sigaction(SIGHUP, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGINT, NULL, {SIG_DFL, [], 0}, 8) = 0
rt_sigaction(SIGINT, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGQUIT, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGILL, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGTRAP, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGABRT, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGBUS, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGFPE, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGUSR1, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGSEGV, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGUSR2, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGPIPE, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGALRM, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGTERM, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGSTKFLT, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGCHLD, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGURG, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGXCPU, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGXFSZ, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGVTALRM, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGPROF, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGWINCH, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGIO, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGPWR, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGSYS, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRTMIN, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_2, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_3, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_4, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_5, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_6, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_7, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_8, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_9, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_10, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_11, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_12, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_13, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_14, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_15, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_16, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_17, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_18, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_19, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_20, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_21, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_22, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_23, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_24, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_25, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_26, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_27, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_28, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_29, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_30, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_31, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigaction(SIGRT_32, {0x4255c0, ~[], SA_RESTORER|SA_STACK|SA_RESTART|SA_SIGINFO, 0x425630}, NULL, 8) = 0
rt_sigprocmask(SIG_SETMASK, ~[], [], 8) = 0
clone(child_stack=0x7f539da1afa0, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD) = 25
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
mmap(NULL, 4080, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f539d9fa000
mmap(NULL, 1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f539d8fa000
futex(0x9facf8, FUTEX_WAKE, 1) = 1
rt_sigprocmask(SIG_SETMASK, ~[], [], 8) = 0
clone(child_stack=0x7f539da16fa0, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD) = 26
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
futex(0xa014e8, FUTEX_WAIT, 0, NULL) = 0
rt_sigprocmask(SIG_SETMASK, ~[], [], 8) = 0
clone(child_stack=0x7f539da14fa0, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD) = 28
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
futex(0xa014e8, FUTEX_WAIT, 0, NULL) = 0
open("/proc/sys/net/core/somaxconn", O_RDONLY|O_CLOEXEC) = 3
futex(0xa014e8, FUTEX_WAIT, 0, NULL) = 0
read(3, "128\n", 4096) = 4
read(3, "", 4092) = 0
close(3) = 0
socket(PF_INET, SOCK_STREAM, IPPROTO_TCP) = 3
close(3) = 0
socket(PF_INET6, SOCK_STREAM, IPPROTO_TCP) = 3
setsockopt(3, SOL_IPV6, IPV6_V6ONLY, [0], 4) = 0
bind(3, {sa_family=AF_INET6, sin6_port=htons(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 28) = 0
socket(PF_INET6, SOCK_STREAM, IPPROTO_TCP) = 4
setsockopt(4, SOL_IPV6, IPV6_V6ONLY, [0], 4) = 0
futex(0x9facf8, FUTEX_WAKE, 1) = 1
bind(4, {sa_family=AF_INET6, sin6_port=htons(0), inet_pton(AF_INET6, "::ffff:127.0.0.1", &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 28) = 0
close(4) = 0
close(3) = 0
socket(PF_FILE, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
setsockopt(3, SOL_SOCKET, SO_BROADCAST, [1], 4) = 0
epoll_create1(O_CLOEXEC) = 4
epoll_ctl(4, EPOLL_CTL_ADD, 3, {EPOLLIN|EPOLLOUT|EPOLLET|0x2000, {u32=2646200624, u64=139997105213744}}) = 0
connect(3, {sa_family=AF_FILE, path="/run/systemd/journal/socket"}, 30) = -1 ENOENT (No such file or directory)
epoll_ctl(4, EPOLL_CTL_DEL, 3, {0, {u32=4236712, u64=4236712}}) = 0
close(3) = 0
readlink("/proc/self/exe", "/usr/local/bin/confd", 128) = 20
readlink("/proc/self/exe", "/usr/local/bin/confd", 128) = 20
open("/app/confd.toml", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=154, ...}) = 0
read(3, "[confd]\nconfdir = \"/app\"\ninterv"..., 666) = 154
read(3, "", 512) = 0
close(3) = 0
open("/etc/localtime", O_RDONLY) = 3
read(3, "TZif2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\1\0\0\0\1\0\0\0\0"..., 4096) = 118
read(3, "", 4096) = 0
close(3) = 0
open("/proc/sys/kernel/hostname", O_RDONLY|O_CLOEXEC) = 3
read(3, "c0cd58e62acc\n", 512) = 13
close(3) = 0
open("/proc/sys/kernel/hostname", O_RDONLY|O_CLOEXEC) = 3
read(3, "c0cd58e62acc\n", 512) = 13
close(3) = 0
socket(PF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_IP) = 3
setsockopt(3, SOL_SOCKET, SO_BROADCAST, [1], 4) = 0
epoll_ctl(4, EPOLL_CTL_ADD, 3, {EPOLLIN|EPOLLOUT|EPOLLET|0x2000, {u32=2646200624, u64=139997105213744}}) = 0
connect(3, {sa_family=AF_INET, sin_port=htons(4001), sin_addr=inet_addr("192.168.61.100")}, 16) = -1 EINPROGRESS (Operation now in progress)
futex(0xc21002c8e8, FUTEX_WAKE, 1) = 1
futex(0x9faa58, FUTEX_WAIT, 0, {0, 998960735} <unfinished ... exit status 0>