ansible-taskrunner 2.11.0

Description:

ansibletaskrunner 2.11.0

Table of Contents generated with DocToc

Overview
TL;DR
Use case and example

Given
The Challenge
Investigation
Assessment
Proposed Solution


Technical Details
Creating a task manifest file

Add the hosts block
Add the vars block
Populate the vars block - defaults
Populate the vars block - define global options
Populate the vars block - define subcommands

Populate the vars block - cli options - mapped variables


Populate the vars block - help/message
Populate the vars block - embedded shell functions

More about embedded shell functions

Bash example:
Python example:
Ruby example:




Populate the vars block - dynamic inventory expression
Populate the vars block - inventory file
Add tasks


Usage Examples
Installation

More Examples


Appendix

The Options Separator
Bastion Mode
Special Variables

ansible_playbook_command
pre_execution
post_execution
environment_vars

ANSIBLE_ Variables


cli_provider
ansible_run_flags
tasks_file
command


Mutually Exclusive Options
Cloned subcommands
Simple Templating
Single-Executable Releases
Unit Testing


TODO - Add more tests!
License and Credits




Overview
ansible-taskrunner is a cli app that is essentially an ansible wrapper.
It reads an ansible playbook file as its input, which serves as a task manifest.
If no task manifest is specified, the app will search for 'Taskfile.yaml' in the current working directory.
The inspiration for the tool comes from the gnu make command, which operates in similar fashion, i.e.

A Makefile defines available build steps
The make command consumes the Makefile at runtime and exposes these steps as command-line options

If you are running this tool from Windows, please read the section on Bastion Mode
TL;DR

Ever wanted to add custom switches to the ansible-playbook command? Something like this:
ansible-playbook -i myinventory.txt -d dbhost1 -w webhost1 -t value1 myplaybook.yaml
Well, you can through the use of an ansible-playbook wrapper
That's where tasks comes in:
tasks -s -b bar -f foo1
translates to:
ansible-playbook -i /tmp/ansible-inventory16xdkrjd.tmp.ini \ -e "{'some_foo_variable':'foo1'}" -e "{'some_bar_variable':'bar'}" -e "{'playbook_targets':'local'}" Taskfile.yaml


Jump down to the usage examples to see this in action
Review the installation instructions if you want to test-drive it
Read on if you want to dig deeper into the tool


Use case and example

Given

An enterprise-grade application named contoso-app
Multiple teams:

Development
Engineering
DBA
Operations
QA


Ansible is the primary means of invoking business and operational processes across the numerous environments


The Challenge
You must ensure all teams adopt a standardized approach to running ansible workloads

Investigation
Upon investigating the current approach, you observe the following:

Users tend to create wrapper scripts that call the ansible-playbook command
These scripts don't follow any naming convention, as you've noted:

run.sh
start.sh
playbook.sh


These shell scripts have common attributes:

Dynamically populate ansible-playbook variables via the --extra-vars option
Dynamically creating ansible inventories
Performing pre/post-flight tasks
Providing a command-line interface




Assessment
Advantages to the above approach:

Quick-n-dirty, anyone can get started relatively quickly with writing ansible automation

Disadvantages:

Lack of standards:
Leads to difficulty in collaboration and code refactoring
Decreased re-usability of codebase

This design encourages standalone playbooks
Makes it more difficult to package actions as roles
Duplicate efforts across codebase




Proposed Solution
Employ a pre-execution script that operates at a layer above the ansible-playbook command:

Accomplishes the same as the above, but in more uniform manner
Support for custom command-line parameters/flags
Dynamic inventory expression
Embedded shell functions

Advantages to this approach:

Easier to manage

If you know YAML and Ansible, you can get started relatively quickly with writing ansible automation


Single executable (/usr/local/bin/tasks)

Disadvantages:

Target ansible controller needs to have the tasks command installed

Back To Top

Technical Details
As stated in the overview, this tool functions much like the make command in that
it accepts an input file that essentially extends its cli options.
We create a specially formatted ansible-playbook that serves as a task manifest file (by default, Taskfile.yaml).
This task manifest file:

Extends the tasks command
Is a valid ansible playbook (Taskfile.yaml), and can thus be launched with the ansible-playbook command
Variables available to the pre-execution phase are also available to the ansible execution phase


Creating a task manifest file
In the following sections, we'll be building a sample manifest/playbook.
Start by opening up your favorite text/IDE/editor and creating
a new task manifest file named Taskfile.yaml.

Add the hosts block
Add hosts, gather_facts, etc:

Click to Expand
Taskfile.yaml
### The hosts block
- hosts: myhosts
gather_facts: true
become: true



Add the vars block
Remember, the task runner will ultimately be calling the ansible-playbook command against
this very same file, so it must be a valid ansible playbook.
Let's add the 'vars' block, which allows us to populate some default values:

Click to Expand
Taskfile.yaml
### The hosts block
- hosts: myhosts
gather_facts: true
become: true
### The vars block
vars:



Populate the vars block - defaults
Let's add some default variables to the playbook:

Click to Expand
Taskfile.yaml
### The hosts block
- hosts: myhosts
gather_facts: true
become: true
### The vars block
vars:
var1: value1
var2: value2
var3: value3
var4: |-
This is a multi-line value
of type string
var5:
- listvalue1
- listvalue2
- listvalue3
- listvalue4
var6:
some_key:
some_child_key: dictvalue1
var7: $(echo some_value)
var8: 8000
dbhosts:
- dbhost1
- dbhost2
- dbhost3
webhosts:
- webhost1
- webhost2
- webhost3


As you can see, we've defined a number of variables holding different values.
The rules for evaluation of these are as follows:
Variable | Ansible Evaluation | Shell Function Evaluation
-------------------------------------------- | ----------------------- | -----------------------
str_var: value1 | String | String
bool_var: True | Boolean | String
num_var: 3 | Integer | Integer
multiline_var: | | Multiline String | String (heredoc)
This is a multi-line value | |
of type string | |
list_var: | List Object | String (heredoc)
- item1 | |
- item2 | |
dict_var: | Dictionary Object | JSON String (heredoc)
key1: somevalue1 | |
key2: somevalue2 | |
shell_var: $(grep somestring /some/file.txt) | String | Depends on output

Additionally, arguments supplied from the command-line conform
to the type specified in the options definition, with "string" being the default type.
Back To Top

Populate the vars block - define global options
Global options are available to all subcommands.
These are defined under the vars.globals.options key.
Let's add a simple example:

Click to Expand
Taskfile.yaml
### The hosts block
- hosts: myhosts
gather_facts: true
become: true
### The vars block
vars:
var1: value1
var2: value2
var3: value3
var4: |-
This is a multi-line value
of type string
var5:
- listvalue1
- listvalue2
- listvalue3
- listvalue4
var6:
some_key:
some_child_key: dictvalue1
var7: $(echo some_value)
var8: 8000
dbhosts:
- dbhost1
- dbhost2
- dbhost3
webhosts:
- webhost1
- webhost2
- webhost3
globals:
options:
my_global_option:
help: "This is my global option"
short: -g
long: --global
var: some_global_variable




Populate the vars block - define subcommands
Next, we define the available subcommands and their options.
Let's add a sub-command named run along with its command-line options:

Click to Expand
Taskfile.yaml
### The hosts block
- hosts: myhosts
gather_facts: true
become: true
### The vars block
vars:
var1: value1
var2: value2
var3: value3
var4: |-
This is a multi-line value
of type string
var5:
- listvalue1
- listvalue2
- listvalue3
- listvalue4
var6:
some_key:
some_child_key: dictvalue1
var7: $(echo some_value)
var8: 8000
dbhosts:
- dbhost1
- dbhost2
- dbhost3
webhosts:
- webhost1
- webhost2
- webhost3
### Global Options Block
globals:
options:
my_global_option:
help: "This is my global option"
short: -g
long: --global
var: some_global_variable
### The commands block
commands:
run:
options:
foo:
help: "This is some foo option"
short: -f
long: --foo
type: choice
var: some_foo_variable
required: True
not_required_if:
- some_bar_variable
options:
- foo1
- foo2
bar:
help: "This is some bar option"
short: -b
long: --bar
type: str
var: some_bar_variable
required: False
required_if:
- hello
- some_baz_variable
baz:
help: "This is some baz option"
short: -z
long: --baz
type: str
var: some_baz_variable
required: False
mutually_exclusive_with:
- some_bar_variable
- some_foo_variable
envvar:
help: "The value for this argument can be derived from an Environmental Variable"
short: -E
long: --env-var
type: str
var: env_var
env_var: SOME_ENVIRONMENT_VARIABLE
env_var_show: True
num:
help: "This is a numeric argument"
short: -n
long: --number
var: some_num_variable
type: int
required: False
env_var_show: True
targets:
help: "Playbook targets"
short: -t
long: --targets
type: str
var: playbook_targets
required: True
multiple:
help: |-
This option can be specified multiple times
short: -m
long: --multiple
type: str
var: multiple_arg
allow_multiple: True
some_switch:
help: |-
This is some boolean option, behaves like Click's switches,
holds the value of True if specified
see: https://github.com/pallets/click
short: -s
long: --some-switch
is_flag: true
var: some_switch
required: True
say_hello:
help: "Invoke the 'hello' embedded shell function"
short: -hello
long: --say-hello
type: str
var: hello
is_flag: True
say_goodbye:
help: "Invoke the 'goodbye' embedded shell function"
short: -goodbye
long: --say-goodbye
type: str
var: goodbye
is_flag: True
hidden_option:
help: "This is a hidden option"
short: -O
long: --hidden-option
is_hidden: True
type: str
var: hidden
is_flag: True
verbose:
help: |-
This is a sample paramter that supports counting, as with:
-v, -vv, -vvv, which would evaluate to 1, 2, and 3, respectively
short: -v
allow_counting: True
var: verbosity



As you can see, commands are defined via YAML, and the syntax is mostly self-explanatory.
Currently, the parameters available to any given option are
consistent with click version 8.1.x, see API — Click Documentation (8.1.x)
Important Notes:

An option's var key:

In the case of standard options, this variable holds the value of the arguments passed to the option
In the case of flags/switches, this variable is a Boolean
The variable is available during the entire runtime


In the above example, the -hello and -goodbye options point to special mapped
variables that themselves map to corresponding shell functions defined in the subcommand's
functions directive. We'll discuss this more in section embedded-shell-functions.


Populate the vars block - cli options - mapped variables
As I mentioned before, the above mapped variables can be used during runtime.
That is, they can be referenced in any defined shell functions,
dynamic inventory expression logic, as well as during ansible execution.
Consider the -f|-foo from the example.
Whatever argument you pass to this option becomes the value for the mapped variable some_foo_variable.
Again, this variable is made available to the underlying subprocess call, and thus to ansible.
So when we call the tasks command like so tasks run -f foo1, the value for the some_foo_variable becomes foo.

Populate the vars block - help/message
Next, we add the help/message section:

Click to Expand
Taskfile.yaml
### The hosts block
- hosts: myhosts
gather_facts: true
become: true
### The vars block
vars:
var1: value1
var2: value2
var3: value3
var4: |-
This is a multi-line value
of type string
var5:
- listvalue1
- listvalue2
- listvalue3
- listvalue4
var6:
some_key:
some_child_key: dictvalue1
var7: $(echo some_value)
var8: 8000
dbhosts:
- dbhost1
- dbhost2
- dbhost3
webhosts:
- webhost1
- webhost2
- webhost3
### Global Options Block
globals:
options:
my_global_option:
help: "This is my global option"
short: -g
long: --global
var: some_global_variable
### The commands block
commands:
run:
options:
foo:
help: "This is some foo option"
short: -f
long: --foo
type: choice
var: some_foo_variable
required: True
not_required_if:
- some_bar_variable
options:
- foo1
- foo2
bar:
help: "This is some bar option"
short: -b
long: --bar
type: str
var: some_bar_variable
required: False
required_if:
- hello
- some_baz_variable
baz:
help: "This is some baz option"
short: -z
long: --baz
type: str
var: some_baz_variable
required: False
mutually_exclusive_with:
- some_bar_variable
- some_foo_variable
envvar:
help: "The value for this argument can be derived from an Environmental Variable"
short: -E
long: --env-var
type: str
var: env_var
env_var: SOME_ENVIRONMENT_VARIABLE
env_var_show: True
num:
help: "This is a numeric argument"
short: -n
long: --number
var: some_num_variable
type: int
required: False
env_var_show: True
targets:
help: "Playbook targets"
short: -t
long: --targets
type: str
var: playbook_targets
required: True
multiple:
help: |-
This option can be specified multiple times
short: -m
long: --multiple
type: str
var: multiple_arg
allow_multiple: True
some_switch:
help: |-
This is some boolean option, behaves like Click's switches,
holds the value of True if specified
see: https://github.com/pallets/click
short: -s
long: --some-switch
is_flag: true
var: some_switch
required: True
say_hello:
help: "Invoke the 'hello' embedded shell function"
short: -hello
long: --say-hello
type: str
var: hello
is_flag: True
say_goodbye:
help: "Invoke the 'goodbye' embedded shell function"
short: -goodbye
long: --say-goodbye
type: str
var: goodbye
is_flag: True
hidden_option:
help: "This is a hidden option"
short: -O
long: --hidden-option
is_hidden: True
type: str
var: hidden
is_flag: True
verbose:
help: |-
This is a sample paramter that supports counting, as with:
-v, -vv, -vvv, which would evaluate to 1, 2, and 3, respectively
short: -v
allow_counting: True
var: verbosity
help:
message: |
Invoke the 'run' command
epilog: |
This line will be displayed at the end of the help text message
examples:
- example1: |
tasks $command
- example2: |
Usage example 2


Running tasks run --help should return the list of parameters along with the help message you defined.

Populate the vars block - embedded shell functions

Add embedded shell functions:
Taskfile.yaml
### The hosts block
- hosts: myhosts
gather_facts: true
become: true
### The vars block
vars:
var1: value1
var2: value2
var3: value3
var4: |-
This is a multi-line value
of type string
var5:
- listvalue1
- listvalue2
- listvalue3
- listvalue4
var6:
some_key:
some_child_key: dictvalue1
var7: $(echo some_value)
var8: 8000
dbhosts:
- dbhost1
- dbhost2
- dbhost3
webhosts:
- webhost1
- webhost2
- webhost3
### Global Options Block
globals:
options:
my_global_option:
help: "This is my global option"
short: -g
long: --global
var: some_global_variable
### The commands block
commands:
run:
options:
foo:
help: "This is some foo option"
short: -f
long: --foo
type: choice
var: some_foo_variable
required: True
not_required_if:
- some_bar_variable
options:
- foo1
- foo2
bar:
help: "This is some bar option"
short: -b
long: --bar
type: str
var: some_bar_variable
required: False
required_if:
- hello
- some_baz_variable
baz:
help: "This is some baz option"
short: -z
long: --baz
type: str
var: some_baz_variable
required: False
mutually_exclusive_with:
- some_bar_variable
- some_foo_variable
envvar:
help: "The value for this argument can be derived from an Environmental Variable"
short: -E
long: --env-var
type: str
var: env_var
env_var: SOME_ENVIRONMENT_VARIABLE
env_var_show: True
num:
help: "This is a numeric argument"
short: -n
long: --number
var: some_num_variable
type: int
required: False
env_var_show: True
targets:
help: "Playbook targets"
short: -t
long: --targets
type: str
var: playbook_targets
required: True
multiple:
help: |-
This option can be specified multiple times
short: -m
long: --multiple
type: str
var: multiple_arg
allow_multiple: True
some_switch:
help: |-
This is some boolean option, behaves like Click's switches,
holds the value of True if specified
see: https://github.com/pallets/click
short: -s
long: --some-switch
is_flag: true
var: some_switch
required: True
say_hello:
help: "Invoke the 'hello' embedded shell function"
short: -hello
long: --say-hello
type: str
var: hello
is_flag: True
say_goodbye:
help: "Invoke the 'goodbye' embedded shell function"
short: -goodbye
long: --say-goodbye
type: str
var: goodbye
is_flag: True
hidden_option:
help: "This is a hidden option"
short: -O
long: --hidden-option
is_hidden: True
type: str
var: hidden
is_flag: True
verbose:
help: |-
This is a sample paramter that supports counting, as with:
-v, -vv, -vvv, which would evaluate to 1, 2, and 3, respectively
short: -v
allow_counting: True
var: verbosity
### The help message
help:
message: |
Invoke the 'run' command
epilog: |
This line will be displayed at the end of the help text message
examples:
- example1: |
tasks $command
- example2: |
Usage example 2
### Embedded shell functions
functions:
hello:
shell: bash
help: Say hello
source: |-
echo Hello! The value for var1 is $var1
goodbye:
shell: bash
help: Say goodbye
source: |-
echo The value for var1 is $var1. Goodbye!



Again, notice the two switches -hello and -goodbye, with mapped variables hello and goodbye, respectively.
These mapped variables correspond to keys in the functions block with matching names.
As such, specifying either or both -hello and -goodbye in your tasks run invocation
will short-circuit normal operation and execute the corresponding functions
in the order in which you call them.
Try it yourself by running:

tasks run -t local -s -b bar -m one -m two -vvv -O -hello -goodbye
tasks run -t local -s -b bar -m one -m two -vvv -O -goodbye -hello

There is also a special flag ---invoke-function that is globally available to all subcommands.
Invocation is as follows: tasks <subcommand> ---invoke-function <function_name>.
In our example, we would run: tasks run -t local -s -b bar -m one -m two -vvv -O ---invoke-function hello
For more usage examples, see the appendix.

More about embedded shell functions
Let's briefly side-step into embedded shell functions.
The syntax for nesting these under the functions key is as follows:
name_of_function:
shell: bash, ruby, or python
help: Help Text to Display
hidden: false/true
source: |-
{{ code }}

Back To Top

Bash example:
hello:
shell: bash
help: Hello World in Bash
hidden: false
source: |-
echo 'Hello World!'


Python example:
hello:
shell: python
help: Hello World in Python
hidden: false
source: |-
print('Hello World!')


Ruby example:
hello:
shell: ruby
help: Hello World in Ruby
hidden: false
source: |-
puts 'Hello World!'

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Populate the vars block - dynamic inventory expression
A useful feature of this tool is the ability to define your ansible
inventory as a dynamic expression in the Taskfile itself.
To do so, we populate the with the inventory_expression key.
When the inventory is defined in this manner, the logic is as follows:

The inventory expression is evaluated
An ephemeral inventory file is created with the
contents of this file being the output, or result, of that expression
The fully qualified path to the ephemeral inventory file is specified as the
argument to the ansible-playbook inventory parameter -i

Let's define our inventory expression:

Click to Expand
Taskfile.yaml
### The hosts block
- hosts: myhosts
gather_facts: true
become: true
### The vars block
vars:
var1: value1
var2: value2
var3: value3
var4: |-
This is a multi-line value
of type string
var5:
- listvalue1
- listvalue2
- listvalue3
- listvalue4
var6:
some_key:
some_child_key: dictvalue1
var7: $(echo some_value)
var8: 8000
dbhosts:
- dbhost1
- dbhost2
- dbhost3
webhosts:
- webhost1
- webhost2
- webhost3
### Global Options Block
globals:
options:
my_global_option:
help: "This is my global option"
short: -g
long: --global
var: some_global_variable
### The commands block
commands:
run:
options:
foo:
help: "This is some foo option"
short: -f
long: --foo
type: choice
var: some_foo_variable
required: True
not_required_if:
- some_bar_variable
options:
- foo1
- foo2
bar:
help: "This is some bar option"
short: -b
long: --bar
type: str
var: some_bar_variable
required: False
required_if:
- hello
- some_baz_variable
baz:
help: "This is some baz option"
short: -z
long: --baz
type: str
var: some_baz_variable
required: False
mutually_exclusive_with:
- some_bar_variable
- some_foo_variable
envvar:
help: "The value for this argument can be derived from an Environmental Variable"
short: -E
long: --env-var
type: str
var: env_var
env_var: SOME_ENVIRONMENT_VARIABLE
env_var_show: True
num:
help: "This is a numeric argument"
short: -n
long: --number
var: some_num_variable
type: int
required: False
env_var_show: True
targets:
help: "Playbook targets"
short: -t
long: --targets
type: str
var: playbook_targets
required: True
multiple:
help: |-
This option can be specified multiple times
short: -m
long: --multiple
type: str
var: multiple_arg
allow_multiple: True
some_switch:
help: |-
This is some boolean option, behaves like Click's switches,
holds the value of True if specified
see: https://github.com/pallets/click
short: -s
long: --some-switch
is_flag: true
var: some_switch
required: True
say_hello:
help: "Invoke the 'hello' embedded shell function"
short: -hello
long: --say-hello
type: str
var: hello
is_flag: True
say_goodbye:
help: "Invoke the 'goodbye' embedded shell function"
short: -goodbye
long: --say-goodbye
type: str
var: goodbye
is_flag: True
hidden_option:
help: "This is a hidden option"
short: -O
long: --hidden-option
is_hidden: True
type: str
var: hidden
is_flag: True
verbose:
help: |-
This is a sample paramter that supports counting, as with:
-v, -vv, -vvv, which would evaluate to 1, 2, and 3, respectively
short: -v
allow_counting: True
var: verbosity
### The help message
help:
message: |
Invoke the 'run' command
epilog: |
This line will be displayed at the end of the help text message
examples:
- example1: |
tasks $command
- example2: |
Usage example 2
### Embedded shell functions
functions:
hello:
shell: bash
help: Say hello
source: |-
echo Hello! The value for var1 is $var1
goodbye:
shell: bash
help: Say goodbye
source: |-
echo The value for var1 is $var1. Goodbye!
### The inventory expression
inventory_expression: |
[local]
localhost ansible_connection=local
[web_hosts]
$(echo -e "${webhosts}" | tr ',' '\n')
[db_hosts]
$(echo -e "${dbhosts}" | tr ',' '\n')
[myhosts:children]
web_hosts
db_hosts


As you can see, the inventory expression is dynamic, as
it gets evaluated based on the output of inline shell commands.
Let's focus on the variable $webhosts.
As per the logic described above, the variable $webhosts is a heredoc with a value of:
webhosts='
webhost1
webhost2
webhost3
'

As such, the web_hosts group in the inventory expression ...
[web_hosts]
$(echo -e "${webhosts}" | tr ',' '\n')

... will evaluate to:
[web_hosts]
webhost1
webhost2
webhost3

Also, notice how the inline shell command transforms commas into newline characters by way of the transform (tr) command.
This makes it so that if we were to have defined the webhosts variable
in the Tasksfile as webhosts: webhost1,webhost2,webhost3, it would have had the same outcome
as defining it as a list object in the vars block.

Populate the vars block - inventory file
We can specify an inventory file instead of an inventory expression with the inventory_file key.

Click to Expand
Taskfile.yaml
### The hosts block
- hosts: myhosts
gather_facts: true
become: true
### The vars block
vars:
var1: value1
var2: value2
var3: value3
var4: |-
This is a multi-line value
of type string
var5:
- listvalue1
- listvalue2
- listvalue3
- listvalue4
var6:
some_key:
some_child_key: dictvalue1
var7: $(echo some_value)
var8: 8000
dbhosts:
- dbhost1
- dbhost2
- dbhost3
webhosts:
- webhost1
- webhost2
- webhost3
### Global Options Block
globals:
options:
my_global_option:
help: "This is my global option"
short: -g
long: --global
var: some_global_variable
### The commands block
commands:
run:
options:
foo:
help: "This is some foo option"
short: -f
long: --foo
type: choice
var: some_foo_variable
required: True
not_required_if:
- some_bar_variable
options:
- foo1
- foo2
bar:
help: "This is some bar option"
short: -b
long: --bar
type: str
var: some_bar_variable
required: False
required_if:
- hello
- some_baz_variable
baz:
help: "This is some baz option"
short: -z
long: --baz
type: str
var: some_baz_variable
required: False
mutually_exclusive_with:
- some_bar_variable
- some_foo_variable
envvar:
help: "The value for this argument can be derived from an Environmental Variable"
short: -E
long: --env-var
type: str
var: env_var
env_var: SOME_ENVIRONMENT_VARIABLE
env_var_show: True
num:
help: "This is a numeric argument"
short: -n
long: --number
var: some_num_variable
type: int
required: False
env_var_show: True
targets:
help: "Playbook targets"
short: -t
long: --targets
type: str
var: playbook_targets
required: True
multiple:
help: |-
This option can be specified multiple times
short: -m
long: --multiple
type: str
var: multiple_arg
allow_multiple: True
some_switch:
help: |-
This is some boolean option, behaves like Click's switches,
holds the value of True if specified
see: https://github.com/pallets/click
short: -s
long: --some-switch
is_flag: true
var: some_switch
required: True
say_hello:
help: "Invoke the 'hello' embedded shell function"
short: -hello
long: --say-hello
type: str
var: hello
is_flag: True
say_goodbye:
help: "Invoke the 'goodbye' embedded shell function"
short: -goodbye
long: --say-goodbye
type: str
var: goodbye
is_flag: True
hidden_option:
help: "This is a hidden option"
short: -O
long: --hidden-option
is_hidden: True
type: str
var: hidden
is_flag: True
verbose:
help: |-
This is a sample paramter that supports counting, as with:
-v, -vv, -vvv, which would evaluate to 1, 2, and 3, respectively
short: -v
allow_counting: True
var: verbosity
### The help message
help:
message: |
Invoke the 'run' command
epilog: |
This line will be displayed at the end of the help text message
examples:
- example1: |
tasks $command
- example2: |
Usage example 2
### Embedded shell functions
functions:
hello:
shell: bash
help: Say hello
source: |-
echo Hello! The value for var1 is $var1
goodbye:
shell: bash
help: Say goodbye
source: |-
echo The value for var1 is $var1. Goodbye!
### Inventory file
inventory_file: '/some/path/some/inventory.yaml'


Notes of Importance:

The value you provide to the inventory_file key supports templating

That is, any of the variables available runtime variables can be used, for example:

inventory_file: '/some/path/some/inventory_$foo_variable.yaml'
inventory_file: '/some/path/some/inventory_$var1.yaml'




You should not be specifying both an inventory_file and an inventory_expression, as you get unexpected results.

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Add tasks
Finally, let's add some proper ansible tasks!

Click to Expand
Taskfile.yaml
### The hosts block
- hosts: myhosts
gather_facts: true
become: true
### The vars block
vars:
var1: value1
var2: value2
var3: value3
var4: |-
This is a multi-line value
of type string
var5:
- listvalue1
- listvalue2
- listvalue3
- listvalue4
var6:
some_key:
some_child_key: dictvalue1
var7: $(echo some_value)
var8: 8000
dbhosts:
- dbhost1
- dbhost2
- dbhost3
webhosts:
- webhost1
- webhost2
- webhost3
### Global Options Block
globals:
options:
my_global_option:
help: "This is my global option"
short: -g
long: --global
var: some_global_variable
### The commands block
commands:
run:
options:
foo:
help: "This is some foo option"
short: -f
long: --foo
type: choice
var: some_foo_variable
required: True
not_required_if:
- some_bar_variable
options:
- foo1
- foo2
bar:
help: "This is some bar option"
short: -b
long: --bar
type: str
var: some_bar_variable
required: False
required_if:
- hello
- some_baz_variable
baz:
help: "This is some baz option"
short: -z
long: --baz
type: str
var: some_baz_variable
required: False
mutually_exclusive_with:
- some_bar_variable
- some_foo_variable
envvar:
help: "The value for this argument can be derived from an Environmental Variable"
short: -E
long: --env-var
type: str
var: env_var
env_var: SOME_ENVIRONMENT_VARIABLE
env_var_show: True
num:
help: "This is a numeric argument"
short: -n
long: --number
var: some_num_variable
type: int
required: False
env_var_show: True
targets:
help: "Playbook targets"
short: -t
long: --targets
type: str
var: playbook_targets
required: True
multiple:
help: |-
This option can be specified multiple times
short: -m
long: --multiple
type: str
var: multiple_arg
allow_multiple: True
some_switch:
help: |-
This is some boolean option, behaves like Click's switches,
holds the value of True if specified
see: https://github.com/pallets/click
short: -s
long: --some-switch
is_flag: true
var: some_switch
required: True
say_hello:
help: "Invoke the 'hello' embedded shell function"
short: -hello
long: --say-hello
type: str
var: hello
is_flag: True
say_goodbye:
help: "Invoke the 'goodbye' embedded shell function"
short: -goodbye
long: --say-goodbye
type: str
var: goodbye
is_flag: True
hidden_option:
help: "This is a hidden option"
short: -O
long: --hidden-option
is_hidden: True
type: str
var: hidden
is_flag: True
verbose:
help: |-
This is a sample paramter that supports counting, as with:
-v, -vv, -vvv, which would evaluate to 1, 2, and 3, respectively
short: -v
allow_counting: True
var: verbosity
### The help message
help:
message: |
Invoke the 'run' command
epilog: |
This line will be displayed at the end of the help text message
examples:
- example1: |
tasks $command
- example2: |
Usage example 2
### Embedded shell functions
functions:
hello:
shell: bash
help: Say hello
source: |-
echo Hello! The value for var1 is $var1
goodbye:
shell: bash
help: Say goodbye
source: |-
echo The value for var1 is $var1. Goodbye!
### The inventory expression
inventory_expression: |
[local]
localhost ansible_connection=local
[web_hosts]
$(echo -e "${webhosts}" | tr ',' '\n')
[db_hosts]
$(echo -e "${dbhosts}" | tr ',' '\n')
[myhosts:children]
web_hosts
db_hosts
tasks:
- name: Show Variables
debug:
msg: |-
{{ hostvars[inventory_hostname] | to_nice_json }}



The task above will display all available host variables.

Usage Examples
Quick usage examples:

Display help for main command
tasks --help
Display help for the run subcommand
tasks run --help
Initialize your workspace
tasks init
Run the Taskfile.yaml playbook, passing in additional options to the underlying subprocess
tasks run -t local -s -b bar -m one -m two
Don't do anything, just echo the underlying shell command
tasks run -t local -s -b bar -m one -m two -O ---echo
Result should be similar to:
ansible-playbook -i /var/folders/5f/4g4xnnv958q52108qxd2rj_r0000gn/T/ansible-inventorytlmz2hpz.tmp.ini \ -e "{'var1':'${var1}'}" ... Taskfile.yaml
Run the embedded function hello
tasks run -t local -s -b bar -m one -m two -hello
Run the embedded functions hello and goodbye
run -t local -s -b bar -m one -m two -hello -goodbye

Back To Top

Installation
Ansible-taskrunner consists of the tasks command.
It can be installed in a few ways:

pip install ansible-taskrunner
pip install git+https://github.com/berttejeda/ansible-taskrunner.git
Obtaining a release (these lag behind the pip distributions)

Note: You'll need to pre-install a python distribution for the Windows MSI release.
Not yet sure if I am doing something wrong or if that's by design.
I lean toward the former :|

More Examples
Review the examples directory for more hands-on usage samples.

Appendix

The Options Separator
When you pass the --- options separator to any subcommand, anything
after the separator is passed directly to the ansible subprocess.

Bastion Mode
If you're launching the tasks command from a Windows host, this tool will automatically execute in Bastion Mode
Under Bastion Mode, the tasks command will:

Execute the ansible-playbook subprocess via a bastion host, i.e. a remote machine that should have ansible installed
This is done via ssh using the paramiko module

Running in Bastion Mode requires a configuration file containing the ssh connection settings.
To initialize this configuration file, you can simply run tasks init.
For full usage options, enter in tasks init --help.
Once you've initialized the configuration file, you should see sftp-config.json in your workspace.
This configuration file is fashioned after the sftp
plugin for Sublime Text and is thus compatible.

Special Variables

ansible_playbook_command
If you define the playbook variable ansible_playbook_command, this will override the underlying ansible-playbook command invocation.
As an example, suppose I define this variable in the above Taskfile.yaml, as follows:
- hosts: myhosts
gather_facts: true
become: true
vars:
ansible_playbook_command: 'python ${HOME}/ansible_2.7.8/ansible-playbook'
var1: value1
var2: value2
var3: value3
# ...

Upon invoking the tasks command with the ---echo flag:

The temporary inventory would be revealed as:

inventory_is_ephemeral=True
if [[ "$inventory_is_ephemeral" == "True" ]];then
echo -e """${inventory_expression}"""| while read line;do
eval "echo -e ${line}" >> "/var/folders/some/path/ansible-inventoryo4fw4ttc.tmp.ini";
done
fi;

*The above inventory file path will differ, of course

And the underlying shell command would be revealed as:

python ${HOME}/ansible_2.7.8/ansible-playbook \
-i /var/folders/some/path/ansible-inventoryo4fw4ttc.tmp.ini \
-e "{'var1':'${var1}'}" \
-e "{'var2':'${var2}'}" \
-e "{'var3':'${var3}'}" \
... Taskfile.yaml

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pre_execution
Anything defined under the pre_execution variable will be evaluated
before all other statements in the underlying shell expression.
As an example, suppose I define the pre_execution variable in the above Taskfile.yaml, as follows:
- hosts: myhosts
gather_facts: true
become: true
vars:
pre_execution: |-
export pxe_var=some_value
touch /tmp/.run.lock

Upon invoking the tasks command with the ---echo flag:

The underlying shell expression would be revealed as:

...
export pxe_var=some_value
touch /tmp/.run.lock
...

The commands above are always placed before
all variables declarations in the underlying shell expresison.

post_execution
This is similar to pre_execution, except that anything defined under the post_execution variable will be evaluated
after all other statements in the underlying shell expression.

environment_vars
By defining the playbook dictionary variable environment_vars,
the following occurs:

For each dictionary key: value pair:

A corresponding export statement is defined in the underlying shell expression



As an example, suppose I define this variable in the above Taskfile.yaml, as follows:
- hosts: myhosts
gather_facts: true
become: true
vars:
ansible_playbook_command: 'python ${HOME}/ansible_2.7.8/ansible-playbook'
var1: value1
var2: value2
var3: value3
some_path: /some/path
environment_vars:
MY_ENV_VAR1: "${some_path}/${var1}"
MY_ENV_VAR2: "${some_path}/${var2}"
# ...

Upon invoking the tasks command with the ---echo flag:

The underlying shell expression would be revealed as:

var1="value1"
var2="value2"
export MY_ENV_VAR1="${some_path}/${var1}"
export MY_ENV_VAR2="${some_path}/${var2}"

These export statements are always placed after
all variables declarations in the underlying shell expresison.
ANSIBLE_ Variables
Any variables matching ANSIBLE_.* will automatically be expressed as export statements.
As an example, suppose I define such variables in the above Taskfile.yaml, as follows:
- hosts: myhosts
gather_facts: true
become: true
vars:
var1: value1
var2: value2
ANSIBLE_VAULT_PASSWORD_FILE: /some/path/some/password_file
ANSIBLE_CALLBACK_PLUGINS: /some/other/path/some/plugins
# ...

Upon invoking the tasks command with the ---echo flag:

The underlying shell expression would be revealed as:

var1="value1"
var2="value2"
export ANSIBLE_VAULT_PASSWORD_FILE="/some/path/some/password_file"
export ANSIBLE_CALLBACK_PLUGINS="/some/other/path/some/plugins"


cli_provider
You can override the underlying command-line provider in two ways:

Via the tasks config file (see examples)
By defining the variable cli_provider in the specified Taskfile

As an example, suppose I define this variable in the above Taskfile.yaml, as follows:
- hosts: myhosts
gather_facts: true
become: true
vars:
cli_provider: bash
# ...

Upon invoking the tasks command, you will note that the app no longer operates in an ansible-playbook mode, but rather as yaml-abstracted bash-script.
There are three cli-providers built in to the tasks command:

ansible
bash
vagrant


ansible_run_flags
Apart from utilizing the --- options separator, you can specify additional options to pass to the underlying ansible-playbook subprocess by setting an appropriate value for __ansible_run_flags__
via Environmental variable or Taskfile, as with:
__ansible_run_flags__: --diff
or
export __ansible_run_flags__='--diff'

tasks_file
The __tasks_file__ variable points to the current Taskfile.
It is available to the underlying subprocess shell.
command
The __command__ variable points to the name of the invoked subcommand.
It is available to the underlying subprocess shell.
Back To Top

Mutually Exclusive Options
This tool supports the following advanced options:

Mutually Exclusive, see Mutually exclusive option groups in python Click - Stack Overflow.
Mutually Inclusive
Conditionally required

Suppose you want a set of options such that:

You want to accept one option but only if another, related option has not been specified

You can accomplish this by defining your option with the following parameters:
- required: False
- mutually_exclusive_with:
- some_bar_variable
- some_foo_variable

In the above configuration, calling this option along with options
-f|-foo and -b|-bar will trigger an illegal usage error, since you've
marked the option as mutually exclusive with either of these two options.
Feel free to review the Taskfile.yaml, as you'll find an example of:

mutually exclusive
mutually inclusive
conditionally required


Cloned subcommands
There might exist edge cases in which you need two different
subcommands to be defined with identical commandline options.
This could be useful for, say, subcommands like install or uninstall,
where the only differentiating factor between the two would be the
name of the subcommand being invoked.
To enable this, simply declare your subcommand with a pipe | delimiter, as with:
commands:
install|uninstall:
options:
foo:
help: "Install/Uninstall an app"
short: -n
long: --app-name
type: choice
var: app_name
required: True


Simple Templating
As of version 1.1.5, simple templating is available to the following objects:

Help messages
Examples
Options
Options values

What this means is that we expose a limited set of internal variables to the above.
As an example:
help:
message: |
Invoke the 'run' command
epilog: |
This line will be displayed at the end of the help text message
examples:
- example1: |
tasks -f $tf_path --foo foo --bar bar
- example2: |
tasks -f $tf_path --foo foo --baz baz

In the above strings, $tf_path will expand to the internal variable tf_path,
which holds the relative path to the current tasks file.
Below is a list of available variables for your convenience:
Variable | Description
------------- | -------------
__command__ | The name of the current subcommand
cli_args | The current command-line invocation
cli_args_short | The current command-line invocation, minus the executable
sys_platform | The OS Platform as detected by Python
tf_path | The relative path to the specified Taskfile

Additionally, all currently set environmental variables are available for templating.
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Single-Executable Releases
This script also ships as a zipapp executable (similar to a windows .exe).
Head over to the releases page for release downloads.
You can also build your own single-executable zipapp, as follows:

Make sure you have the make-zipapp executable in your path
Invoking build tasks


Build zipapp: python ansible_taskrunner/cli.py -f Makefile.yaml run ---make zipapp

Read More on zipapps: zipapp — Manage executable Python zip archives — Python 3.7.4rc2 documentation

Unit Testing
To run all tests, simply call the test script, as with:
python tests/test_ansible_taskrunner.py
TODO - Add more tests!
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License and Credits
This project adopts the the MIT distribution License.
Releases come bundled with the following opensource python packages:

click, licensed under BSD-3-Clause
pyYaml, licensed under MIT

Lastly, this package was created with Cookiecutter and the audreyr/cookiecutter-pypackage project template.

Cookiecutter: https://github.com/audreyr/cookiecutter
audreyr/cookiecutter-pypackage: https://github.com/audreyr/cookiecutter-pypackage