Frequently Asked Questions


Operating system compatibility

Tip: Operating system compatibility

These Ansible roles and training materials were last tested on Centos 7 and Ubuntu 18.04, but will probably work on other RHEL and Debian variants.

The roles that are used in these training are currently used by usegalaxy.*, and other, servers in maintaining their infrastructure. (US, EU, both are running CentOS 7)

If you have an issue running these trainings on your OS flavour, please report the issue in the training material and we can see if it is possible to solve.

Running Ansible on your remote machine

Tip: Running Ansible on your remote machine

It is possible to have ansible installed on the remote machine and run it there, not just from your local machine connecting to the remote machine.

Your hosts file will need to use localhost, and whenever you run playbooks with ansible-playbook -i hosts playbook.yml, you will need to add -c local to your command.

Be certain that the playbook that you’re writing on the remote machine is stored somewhere safe, like your user home directory, or backed up on your local machine. The cloud can be unreliable and things can disappear at any time.


How to read a Diff

Tip: How to read a Diff

If you haven’t worked with diffs before, this can be something quite new or different.

If we have two files, let’s say a grocery list, in two files. We’ll call them ‘a’ and ‘b’.

code-in Old

$ cat old

code-out New

$ cat new

We can see that they have some different entries. We’ve removed 🍒 because they’re awful, and replaced them with an 🍍

Diff lets us compare these files

$ diff old new
< 🍒
> 🍍

Here we see that ‘pears’ is only in a, and ‘ananas’ is only in b. But otherwise the files are identical.

There are a couple different formats to diffs, one is the ‘unified diff’

$ diff -U2 old new
--- old 2022-02-16 14:06:19.697132568 +0100
+++ new 2022-02-16 14:06:36.340962616 +0100
@@ -3,4 +3,4 @@

This is basically what you see in the training materials which gives you a lot of context about the changes:

  • --- old is the ‘old’ file in our view
  • +++ new is the ‘new’ file
  • @@ these lines tell us where the change occurs and how many lines are added or removed.
  • Lines starting with a - are removed from our ‘new’ file
  • Lines with a + have been added.

So when you go to apply these diffs to your files in the training:

  1. Ignore the header
  2. Remove lines starting with - from your file
  3. Add lines starting with + to your file

The other lines (🍊/🍋 and 🥑) above just provide “context”, they help you know where a change belongs in a file, but should not be edited when you’re making the above change. Given the above diff, you would find a line with a 🍒, and replace it with a 🍍

Added & Removed Lines

Removals are very easy to spot, we just have removed lines

--- old	2022-02-16 14:06:19.697132568 +0100
+++ new 2022-02-16 14:10:14.370722802 +0100
@@ -4,3 +4,2 @@

And additions likewise are very easy, just add a new line, between the other lines in your file.

--- old	2022-02-16 14:06:19.697132568 +0100
+++ new 2022-02-16 14:11:11.422135393 +0100
@@ -1,3 +1,4 @@

Completely new files

Completely new files look a bit different, there the “old” file is /dev/null, the empty file in a Linux machine.

$ diff -U2 /dev/null old
--- /dev/null 2022-02-15 11:47:16.100000270 +0100
+++ old 2022-02-16 14:06:19.697132568 +0100
@@ -0,0 +1,6 @@

And removed files are similar, except with the the new file being /dev/null

--- old	2022-02-16 14:06:19.697132568 +0100
+++ /dev/null 2022-02-15 11:47:16.100000270 +0100
@@ -1,6 +0,0 @@

Galaxy admin interface

Install tools via the Admin UI

Tip: Install tools via the Admin UI

  1. Open Galaxy in your browser and type `` in the tool search box on the left. If “” is among the search results, you can skip the following steps.
  2. Access the Admin menu from the top bar (you need to be logged-in with an email specified in the admin_users setting)
  3. Click “Install and Uninstall”, which can be found on the left, under “Tool Management”
  4. Enter `` in the search interface
  5. Click on the first hit, having devteam as owner
  6. Click the “Install” button for the latest revision
  7. Enter “” as the target section and click “OK”.


Got lost along the way?

Got lost along the way?

If you missed any steps, you can compare against the reference files, or see what changed since the previous tutorial.

Still have questions?
Gitter Chat Support
Galaxy Help Forum