Shell / Bash

Create a Bash template#

Go to Task Templates and click New Template.
Select Bash as the app type.
Configure it:

Field	Description
Name	A descriptive name for the template
Repository	The repository containing your script
Playbook / Script	Relative path to the script, e.g. `scripts/deploy.sh`
Variable Groups	Variable groups whose values are injected as environment variables

Create, then Run.

Passing variables#

Values from the selected variable groups arrive as environment variables:

#!/bin/bash
set -euo pipefail
 
echo "Deploying to $TARGET_HOST"

Secrets from the Secrets tab of a variable group arrive the same way, but are never written to the task log.

If the template is a build or deploy type, Semaphore also supplies the pipeline variables — SEMAPHORE_TASK_DETAILS_TYPE, SEMAPHORE_TASK_DETAILS_TARGET_VERSION, and the rest. See Pipelines.

Rules of the road#

Make the script executable (chmod +x) or give it a valid shebang (#!/bin/bash).
Scripts run non-interactively. Anything that waits for input hangs the task until it is stopped.
Exit code 0 means success. Any non-zero exit marks the task failed — so set -e is usually what you want, not a nicety.
To act on remote hosts, use Ansible rather than wrapping ssh in a script: you get inventory, credentials and per-host reporting for free.

Where it runs#

The script executes wherever the task executes — on the Semaphore server by default, or on the runner that picks the task up. Whatever the script calls (aws, kubectl, psql) has to be installed there.

Next steps#

Python — when the script outgrows bash
Pipelines — build and deploy variables
Runners — choosing where scripts execute