nestedlog-email

#!/bin/bash

# Copyright 2021 Stephen Warren <swarren@wwwdotorg.org>
# SPDX-License-Identifier: MIT

set -e

function usage_and_exit {
    cat > /dev/stderr <<EOF
usage_and_exit: $0 command...
-f from      Email from address.
             (Mandatory)
-t to        Email to address.
             (Mandatory)
             (Can be specified multiple times)
-s subject   Email subject.
             (Mandatory)
command...   The command and arguments to execute.
EOF
    exit 1
}

mail_from=
mail_tos=()
mail_subject=

while [ $# -gt 0 ]; do
    case "$1" in
        -f)
            if [ -z "$2" ]; then
                echo "ERROR: -f requires an argument" > /dev/stderr
                usage_and_exit
            fi
            mail_from="$2"
            shift
            ;;
        -t)
            if [ -z "$2" ]; then
                echo "ERROR: -t requires an argument" > /dev/stderr
                usage_and_exit
            fi
            mail_tos+=("$2")
            shift
            ;;
        -s)
            if [ -z "$2" ]; then
                echo "ERROR: -s requires an argument" > /dev/stderr
                usage_and_exit
            fi
            mail_subject="$2"
            shift
            ;;
        -h)
            usage_and_exit
            ;;
        --)
            shift
            break
            ;;
        -*)
            echo "Unknown option: $1" > /dev/stderr
            usage_and_exit
            ;;
        *)
            break
            ;;
    esac
    shift
done

if [ -z "${mail_from}" ]; then
    echo "ERROR: -f not specified" > /dev/stderr
    usage_and_exit
fi

if [ ${#mail_tos} -eq 0 ]; then
    echo "ERROR: -t not specified" > /dev/stderr
    usage_and_exit
fi

if [ -z "${mail_subject}" ]; then
    echo "ERROR: -s not specified" > /dev/stderr
    usage_and_exit
fi

function cleanup {
    set +e
    [ -n "${tmp_dir}" ] && rm -rf "${tmp_dir}"
}
tmp_dir=$(mktemp -d)
trap cleanup exit 

log_html="${tmp_dir}/log.html"
log_text="${tmp_dir}/log.txt"
multipart="${tmp_dir}/mulitpart.txt"

set +e
nestedlog log --emit-html-inline "${log_html}" --emit-text "${log_text}" "$@"
cmd_ret=$?
set -e
if [ ${cmd_ret} -eq 0 ]; then
    mail_subject="(OK) ${mail_subject}"
elif [ ${cmd_ret} -eq 100 ]; then
    mail_subject="(WARNING) ${mail_subject}"
else
    mail_subject="(ERROR) ${mail_subject}"
fi

rm -f "${multipart}"

echo -n "Date: " >> "${multipart}"
date -R >> "${multipart}"

for to in "${mail_tos[@]}"; do
    echo "To: <${to}>" >> "${multipart}"
done

cat >> "${multipart}" <<EOF
From: <${mail_from}>
Subject: ${mail_subject}
Content-type: multipart/alternative; boundary="XXXXX_multipart_XXXXX"

--XXXXX_multipart_XXXXX
Content-type: text/plain; charset=utf-8
Content-transfer-encoding: 8BIT

EOF

cat >> "${multipart}" < "${log_text}"

cat >> "${multipart}" <<EOF

--XXXXX_multipart_XXXXX
Content-type: text/html; charset=utf-8
Content-transfer-encoding: 8BIT

EOF

cat >> "${multipart}" < "${log_html}"

cat >> "${multipart}" <<EOF

--XXXXX_multipart_XXXXX--
EOF

sendmail -bm "${mail_tos[@]}" < "${multipart}"