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|
#!/bin/false
#
# This file should be sourced, not run
log() {
if [ "$#" != 2 ] ; then
echo "log_critical=Error in promise module (log must be used with 2 arguments, level and message)"
exit 1
fi
level="$1"
message="$2"
echo "log_$level=$message"
}
reset_state() {
# Set global variables before we begin another request
# Variables parsed directly from request:
request_operation=""
request_log_level=""
request_promise_type=""
request_promiser=""
for var in $(env | cut -d '=' -f 1 | grep '^request_attribute_'); do
unset $var
done
# Variables to put into response:
response_result=""
# Other state:
saw_unknown_key="no"
saw_unknown_attribute="no"
unknown_attribute_names=""
}
handle_input_line() {
# Split the line of input on the first '=' into 2 - key and value
IFS='=' read -r key value <<< "$1"
case "$key" in
operation)
request_operation="$value" ;;
log_level)
request_log_level="$value" ;;
promise_type)
request_promise_type="$value" ;;
promiser)
request_promiser="$value" ;;
attribute_*)
attribute_name=${key#"attribute_"}
if ! expr " $required_attributes $optional_attributes " : ".* $attribute_name " >/dev/null; then
saw_unknown_attribute="yes"
unknown_attribute_names="$unknown_attribute_names, $attribute_name"
fi
eval "request_${key}=\$value" ;;
*)
saw_unknown_key="yes" ;;
esac
}
receive_request() {
# Read lines from input until empty line
# Call handle_input_line for each non-empty line
while IFS='$\n' read -r line; do
if [ "x$line" = "x" ] ; then
break
fi
handle_input_line "$line" # Parses a key=value pair
done
}
write_response() {
echo "operation=$request_operation"
echo "result=$response_result"
echo "result_classes=$response_classes"
echo ""
}
operation_terminate() {
response_result="success"
type do_terminate >/dev/null 2>&1 && do_terminate
write_response
exit 0
}
operation_validate() {
response_result="valid"
if [ "$saw_unknown_attribute" != "no" -a "$all_attributes_are_valid" != "yes" ] ; then
log error "Unknown attribute/s: ${unknown_attribute_names#, }"
response_result="invalid"
fi
if [ ! -z "$required_attributes" ]; then
for attribute_name in $required_attributes; do
# Note: ${!varname} syntax expands to value of variable, which name
# is saved in $varname variable. Example:
# var_1=something
# varname=var_1
# echo "${!varname}" # prints "something"
varname="request_attribute_$attribute_name"
if [ -z "${!varname}" ]; then
log error "Attribute '$attribute_name' is missing or empty"
response_result="invalid"
fi
done
fi
type do_validate >/dev/null 2>&1 && do_validate
write_response
}
operation_evaluate() {
response_result="error" # it's responsibility of do_evaluate to override this
type do_evaluate >/dev/null 2>&1 && do_evaluate
write_response
}
operation_unknown() {
response_result="error"
log error "Promise module received unexpected operation: $request_operation"
write_response
}
perform_operation() {
case "$request_operation" in
validate_promise)
operation_validate ;;
evaluate_promise)
operation_evaluate ;;
terminate)
operation_terminate ;;
*)
operation_unknown ;;
esac
}
handle_request() {
response_classes=""
reset_state # 1. Reset global variables
receive_request # 2. Receive / parse an operation from agent
perform_operation # 3. Perform operation (validate, evaluate, terminate)
}
skip_header() {
# Skip until (and including) the first empty line
while IFS='$\n' read -r line; do
if [ "x$line" = "x" ] ; then
return;
fi
done
}
module_main() {
# Check arguments provided by the caller. Must have two arguments with no spaces.
if [ "$#" != 2 ] || expr "$1$2" : ".* " >/dev/null; then
exit 1
fi
module_name="$1"
module_version="$2"
# Skip the protocol header given by agent:
skip_header
# Write our header to request line based protocol:
echo "$module_name $module_version v1 line_based"
echo ""
type do_initialize >/dev/null 2>&1 && do_initialize
# Loop indefinitely, handling requests:
while true; do
handle_request
done
# Should never get here.
}
|
