Upload ssh key to TeamCity server; works for version 2018.1.1 (build 58406).

upload_ssh_key.sh

#!/bin/bash

#
# Upload an SSH private key to a TeamCity project
# See https://youtrack.jetbrains.com/issue/TW-42311
# License: Public domain. No warranty expressed or implied. Use at own risk.
#
# Environment
#
# Must set environment variable TEAMCITY_SERVER_URL to https://<teamcity-hostname>. That
# URL may not return 3xx redirects
#
# TEAMCITY_USER: if not set, uses `whoami`
# TEAMCITY_PASSWORD: if not set, prompts at stdin
#
# Inputs:
# $1 - TeamCity external project ID
# $2 - Filename of SSH private key
# [$3] - Name of key in TeamCity (optional, default is $2)
#

die() {
    echo $1 1>&2
    exit 1
}

usage() {
    die "Usage: $0 tc-project-id private-key-filename [private-key-name]"
}

check_vars() {
    for var in $*; do
        [ -z "${!var}" ] && die "$var not set or empty"
    done
}


# Set global input variables
set_inputs() {

    EXTERNAL_PROJECT_ID=$1
    PRIVATE_KEY_FILENAME=$2
    PRIVATE_KEY_NAME=${3:-$PRIVATE_KEY_FILENAME}
    TEAMCITY_USER=${TEAMCITY_USER:-$(whoami)}
    [ -z "${TEAMCITY_PASSWORD}" ] && read -p Password: -s TEAMCITY_PASSWORD

    check_vars TEAMCITY_USER TEAMCITY_PASSWORD EXTERNAL_PROJECT_ID PRIVATE_KEY_FILENAME \
               PRIVATE_KEY_NAME TEAMCITY_SERVER_URL

    INTERNAL_PROJECT_ID=$(get_project_id)
    [ -z ${INTERNAL_PROJECT_ID} ] && die "Failed to get internal project id"
}

find_project_id() {
    # Given source of ssh-keys form, find hidden input with project id
    sed -e '/hidden.*projectId.*value="[^"]/!d' -e 's/.*value="\(..*\)".*/\1/'
}

fetch_project_page() {
    # Get project ID from ssh-keys form, so we can POST it back
    local url="${TEAMCITY_SERVER_URL}/admin/editProject.html?projectId=${EXTERNAL_PROJECT_ID}&tab=ssh-manager"
    curl -s --fail -u "${TEAMCITY_USER}:${TEAMCITY_PASSWORD}" $url
    [ $? -ne 0 ] && die "$url: curl exit status $?, see \$ man curl"
}

fetch_project_id() {
    local url="${TEAMCITY_SERVER_URL}/app/rest/projects/${EXTERNAL_PROJECT_ID}/internalId"
    local project_id=$(curl -s -u "${TEAMCITY_USER}:${TEAMCITY_PASSWORD}" $url)
    echo $project_id
}

get_project_id() {
    fetch_project_id
    # If using an earlier version of TeamCity that doesn't support the
    # URL /app/rest/projects/<project-id>/internalId, you can get it from the
    # text of the ssh-keys page; comment out the line above, and uncomment the
    # line below.
#    fetch_project_page | find_project_id
}

check_push_error() {
    local result=$(sed -e '/Dialog\.error/!d' -e 's/.*SshKeysDialog.error("//' -e 's/".*//')
    [ "$result" ] && die "$result"
}

do_push() {
    local url="${TEAMCITY_SERVER_URL}/admin/sshKeys.html"

    curl -s --fail -X POST -u ${TEAMCITY_USER}:${TEAMCITY_PASSWORD} \
         -F "file:fileToUpload=@${PRIVATE_KEY_FILENAME}" \
         -F "fileName=${PRIVATE_KEY_NAME}" \
         -F "projectId=${INTERNAL_PROJECT_ID}" \
         -F "action=createSshKey" \
         $url || die "$url: curl exit status $?, see \$ man curl"
}

push_private_key() {
    do_push | check_push_error
}


#
# Main
#

set_inputs $*
push_private_key