Example scripts

Example scripts that you can use in your lifecycle scripts.

These example scripts may use software that is not be available on every operating system.

Track setup scripts

Wait for bootstrap

Wait for the Instruqt bootstrap process to complete.

set -euxo pipefail

until [ -f /opt/instruqt/bootstrap/host-bootstrap-completed ]; do
    echo "Waiting for instruqt bootstrap to complete"    sleep 1

The bootstrap process may overwrite user files like .bashrc. Wait is encouraged!

Wait for service

Wait for a specific web service in your setup script to finish booting.

while ! curl --fail --output /dev/null https://<hostname>:<port>/<path> 
    sleep 1

Create a file

Create a file using heredoc method.

cat > /file/to/create <<EOF
# Some configuration file
setting_one = true
another_setting = false

You can append to a file by using >> as opposed to >.

Download files

Download files to the local system.

git clone https://githost.com/repo <local_dir>

Start background process

Start a process in the background so your script does not hang.

nohup ./myprogram > foo.out 2> foo.err < /dev/null & disown

Challenge check scripts

File exists

Check if a file exists:

set -euxo pipefail

if [ -f /home/user/file.txt ]; then
    echo "The file at /home/user/file.txt exists"

File doesn't exist

Check if a file doesn't exist (or is not a file):

set -euxo pipefail

if [ ! -f /home/user/file.txt ]; then
    fail-message "No file was found at /home/user/file.txt"

Directory exists

Check if a directory exists:

set -euxo pipefail

if [ -d /root/folder ]; then
    echo "The directory at /root/folder exists"

Directory doesn't exist

Use the following code in your life cycle script to check if a folder doesn't exist (or is not a directory)

set -euxo pipefail

if [ ! -d /root/folder ]; then
    fail-message "The folder at /root/folder doesn't exists"

File contains certain text

Check if a file contains certain text.

set -euxo pipefail

if ! grep "text to find" /path/to/file; then
    fail-message "The file doesn't contain the required text"

Specific command is installed

Check that a specific command is executable with the -x flag.

set -euxo pipefail

if ! [[ -x /usr/local/bin/command ]]; then
  fail-message "Oops, command was not found or is not executable."

Service is running

Check if a service is running.

if pgrep -x SERVICE >/dev/null; then
    echo "The X service is running"

Replace SERVICE with a service name running on that system.

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