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- #!/bin/bash
-
- # kill-wpull-connections is a workaround for wpull's bug of HTTPS connections getting stuck, slowing down or entirely stopping progress (https://github.com/ArchiveTeam/wpull/issues/407).
- # It works by attaching to the process and shutting down the TCP connections directly using the `shutdown` syscall. Although written for use with wpull, it can actually be used for any process.
- #
- # Usage:
- # - To kill all TCP connections except those to 127.0.0.1 of a process: `kill-wpull-connections -p $PID`
- # - As a convenience option for ArchiveBot pipeline maintainers, to kill the connections of a running ArchiveBot job: `kill-wpull-connections -j $JOBID`
- # - If you get an error of `gdb.error: 'shutdown' has unknown return type; cast the call to its declared return type` then add the `-c` option *before* `-p` or `-j`, e.g. `kill-wpull-connections -c -p $PID`.
- # - If you're running wpull inside a Docker container without ptrace capabilities, you need to run kill-wpull-connections outside of the container (where you do have ptrace cap) but inside the container's network namespace.
- # One way to do this is: `nsenter --net=$(docker inspect $CONTAINERID | jq -r .[].NetworkSettings.SandboxKey) kill-wpull-connections -p $PID`
-
- function usage_exit {
- # usage E -- print usage; exit with status code E
- echo 'Usage: kill-wpull-connections (-h | [-c] (-p PID | -j JOBID))'
- echo
- echo ' -h: Display this message and exit'
- echo ' -c: Cast return value of shutdown(2) to int explicitly (only necessary on broken machines)'
- echo ' -p PID: Kill connections of wpull process PID'
- echo ' -j JOBID: Kill connections of the wpull process for ArchiveBot job JOBID'
- exit $1
- }
-
- if [[ $# -eq 0 || $# -gt 3 ]]; then usage_exit 1; fi
- if [[ $# -eq 1 && "$1" == '-h' ]]; then usage_exit 0; fi
- if [[ $# -ne 2 && $# -ne 3 ]]; then usage_exit 1; fi
-
- cast=
- if [[ "$1" == '-c' ]]; then cast='(int)'; shift; fi
-
- if [[ "$1" != -[pj] ]]; then usage_exit 1; fi
- if [[ $# -ne 2 ]]; then usage_exit 1; fi
-
- if [[ "$1" == '-p' ]]
- then
- wpullPid=$2
- if [[ "${wpullPid}" == *[^0-9]* ]]
- then
- echo "Error: '${wpullPid}' is not a valid PID"
- exit 1
- fi
- elif [[ "$1" == '-j' ]]
- then
- pids=($(pgrep --full "wpull.*/$2/"))
- if [[ ${#pids[@]} -ne 1 ]]
- then
- echo "Error: not exactly one process found for '$2'"
- exit 1
- fi
- wpullPid=${pids[0]}
- fi
-
- if ! command -v lsof >/dev/null 2>&1
- then
- echo "Error: could not find lsof"
- exit 1
- fi
-
- if ! command -v gdb >/dev/null 2>&1
- then
- echo "Error: could not find gdb"
- exit 1
- fi
-
- if ! ps -p ${wpullPid} >/dev/null 2>&1
- then
- echo "Error: no process with PID ${wpullPid}"
- exit 1
- fi
-
- if [[ -e /proc/sys/kernel/yama/ptrace_scope && "$(< /proc/sys/kernel/yama/ptrace_scope)" != "0" && $EUID -ne 0 ]]
- then
- echo "Warning: /proc/sys/kernel/yama/ptrace_scope is not zero. You likely need to run this script as root."
- fi
-
- gdb -batch -batch-silent \
- -ex "attach ${wpullPid}" \
- -ex 'python import subprocess' \
- -ex 'python def call(s): return subprocess.call(s, shell = True) == 0' \
- -ex 'python call("echo '\''FDs before forced shutdown:'\''") and call("lsof -an -p '${wpullPid}' -i TCP | grep -v 127\.0\.0\.1") and ([gdb.execute("p '${cast}'shutdown(" + fd + ", 2)") for fd in subprocess.check_output("lsof -an -p '${wpullPid}' -i TCP -F pfn | awk '\''NR%2==0{fd=substr($0,2)}NR%2==1&&NR>1&&!/127\.0\.0\.1/{print fd}'\''", shell = True).decode("ascii").strip().split("\n")] or True) and call("echo '\''FDs after forced shutdown:'\''") and call("lsof -an -p '${wpullPid}' -i TCP | grep -v 127\.0\.0\.1")' \
- -ex detach \
- -ex quit
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