Created
April 13, 2015 22:38
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ZOMG a bash powers HTTP web service that runs via the `socat` web app container like so: socat TCP4-LISTEN:8080 EXEC:/path/to/server/script
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| #!/usr/bin/env bash | |
| # Purpose: Provide HTTP server that displays the current server date to | |
| # validate the artifact structure and play with. | |
| declare -a _http_responses=( | |
| [200]="OK" | |
| [201]="Created" | |
| [202]="Accepted" | |
| [204]="No Content" | |
| [301]="Moved Permanently" | |
| [302]="Found" | |
| [307]="Temporary Redirect" | |
| [400]="Bad Request" | |
| [401]="Unauthorized" | |
| [403]="Forbidden" | |
| [404]="Not Found" | |
| [405]="Method Not Allowed" | |
| [500]="Internal Server Error" | |
| [501]="Not Implemented Error" | |
| [502]="Bad Gateway" | |
| [503]="Temporarily Unavailable" | |
| ) | |
| function _recv() { | |
| echo "< $*" >&2 | |
| } | |
| function _send() { | |
| printf '%s\r\n' "$*" | |
| } | |
| function _send_headers() { | |
| local -r dt="$(date +"%a, %d %b %Y %H:%M:%S %Z")" | |
| local -r hst="$(hostname -s)" | |
| local -a hdrs=( | |
| "Date: ${dt}" | |
| "Expires: ${dt}" | |
| "Content-Type: text/plain" | |
| "Server: hello-bash@${hst}/0.0.1" | |
| ) | |
| for h in "${hdrs[@]}"; do | |
| _send "${h}" | |
| done | |
| } | |
| function _send_body() { | |
| _send "Yo yo yo!" | |
| } | |
| function _send_response() { | |
| _send "${1}" | |
| _send_headers | |
| _send "" | |
| _send_body | |
| } | |
| function _respond_with() { | |
| if [ "$#" -ne 1 ]; then | |
| >&2 "Error: Expected one argument for ${FUNCNAME}, received $#." | |
| >&2 "Usage: ${0} CODE" | |
| return 1 | |
| fi | |
| local -r code="${1}" | |
| _send_response "${code} ${_http_responses[${code}]}" | |
| } | |
| function _parse_request() { | |
| if [ "$#" -ne 1 ]; then | |
| >&2 "Error: Expected one argument for ${FUNCNAME}, received $#." | |
| >&2 "Usage: ${0} REQUEST_LINE" | |
| return 1 | |
| fi | |
| local -r req="${1%%$'r'}" | |
| read -r req_method req_uri req_http_ver <<<"${req}" | |
| # Validate request (only support GET and / URI so far :) | |
| if [ "${req_method}" = "GET" -a "${req_uri}" = "/" -a -n "${req_http_ver}" ]; then | |
| _respond_with 200 | |
| elif [ "${req_uri}" != "/" ]; then | |
| _respond_with 404 | |
| elif [ -z "${req_http_ver}" ]; then | |
| _respond_with 400 | |
| else | |
| _respond_with 500 | |
| fi | |
| } | |
| function _main() { | |
| read -r line || _respond_with 400 | |
| _parse_request "${line}" | |
| } | |
| if [ "${BASH_SOURCE[0]}" != "${0}" ]; then | |
| export -f _respond_with | |
| export -f _parse_request | |
| else | |
| set -eu | |
| _main | |
| fi |
It's the missing HTTP/1.0
See the example here:
https://stuff.mit.edu/afs/sipb/machine/penguin-lust/src/socat-1.7.1.2/EXAMPLES
socat -T 1 -d -d tcp-l:10081,reuseaddr,fork,crlf system:"echo -e \"\\\"HTTP/1.0 200 OK\\\nDocumentType: text/html\\\n\\\n<html>date: \$\(date\)<br>server:\$SOCAT_SOCKADDR:\$SOCAT_SOCKPORT<br>client: \$SOCAT_PEERADDR:\$SOCAT_PEERPORT\\\n<pre>\\\"\"; cat; echo -e \"\\\"\\\n</pre></html>\\\"\""
That example is also using socat to convert LF to CRLF, so, if following that example, you wouldn't need _send(), just plain echo everywhere.
We don't need to use the system: option from that example, exec: is fine, since we are using a script in a file, not shell commands directly on the commandline.
Restored my version that went away when that account was deleted (I'm the "ghost" above)
https://gist.github.com/bkw777/e026f514306065e3d4e2c5b85e911838
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Erm, second thought, this is not a web service after all.
The output all ends up in the content and the headers are not treated as headers by real http clients.
try:
curl -D apache_headers.txt localhost >apache_content.txt
curl -D bash_headers.txt localhost:8080 >bash_content.txt
Perhaps somehow a newline is getting output before the headers, or perhaps it's something else entirely.