feat: add dokku_resource_limit and dokku_resource_reserve modules (#104)

The `dokku_resource_limit` and `dokku_resource_reserve` modules allow limiting and reserving
resources (cpu, ram, ...) for individual apps.

Co-authored-by: Leopold Talirz <leopold.talirz@gmail.com>

README.md

@@ -603,6 +603,100 @@ Manage the registry configuration for a given dokku application
     state: absent
 ```
 
+### dokku_resource_limit
+
+Manage resource limits for a given dokku application
+
+#### Parameters
+
+|Parameter|Choices/Defaults|Comments|
+|---------|----------------|--------|
+|app<br /><sup>*required*</sup>||The name of the app|
+|clear_before|*Choices:* <ul><li>True</li><li>**False** (default)</li></ul>|Clear all resource limits before applying|
+|process_type||The process type selector|
+|resources||The Resource type and quantity (required when state=present)|
+|state|*Choices:* <ul><li>**present** (default)</li><li>absent</li></ul>|The state of the resource limits|
+
+#### Example
+
+```yaml
+- name: Limit CPU and memory of a dokku app
+  dokku_resource_limit:
+    app: hello-world
+    resources:
+      cpu: 100
+      memory: 100
+
+- name: name: Limit resources per process type of a dokku app
+  dokku_resource_limit:
+    app: hello-world
+    process_type: web
+    resources:
+      cpu: 100
+      memory: 100
+
+- name: Clear limits before applying new limits
+  dokku_resource_limit:
+    app: hello-world
+    state: present
+    clear_before: True
+    resources:
+      cpu: 100
+      memory: 100
+
+- name: Remove all resource limits
+  dokku_resource_limit:
+    app: hello-world
+    state: absent
+```
+
+### dokku_resource_reserve
+
+Manage resource reservations for a given dokku application
+
+#### Parameters
+
+|Parameter|Choices/Defaults|Comments|
+|---------|----------------|--------|
+|app<br /><sup>*required*</sup>||The name of the app|
+|clear_before|*Choices:* <ul><li>True</li><li>**False** (default)</li></ul>|Clear all reserves before apply|
+|process_type||The process type selector|
+|resources||The Resource type and quantity (required when state=present)|
+|state|*Choices:* <ul><li>**present** (default)</li><li>absent</li></ul>|The state of the resource reservations|
+
+#### Example
+
+```yaml
+- name: Reserve CPU and memory for a dokku app
+  dokku_resource_reserve:
+    app: hello-world
+    resources:
+      cpu: 100
+      memory: 100
+
+- name: Create a reservation per process type of a dokku app
+  dokku_resource_reserve:
+    app: hello-world
+    process_type: web
+    resources:
+      cpu: 100
+      memory: 100
+
+- name: Clear all reservations before applying
+  dokku_resource_reserve:
+    app: hello-world
+    state: present
+    clear_before: True
+    resources:
+      cpu: 100
+      memory: 100
+
+- name: Remove all resource reservations
+  dokku_resource_reserve:
+    app: hello-world
+    state: absent
+```
+
 ### dokku_service_create
 
 Creates a given service

library/dokku_resource_limit.py

@@ -0,0 +1,253 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+# from ansible.module_utils.basic import *
+from ansible.module_utils.basic import AnsibleModule
+import subprocess
+import re
+
+DOCUMENTATION = """
+---
+module: dokku_resource_limit
+short_description: Manage resource limits for a given dokku application
+options:
+  app:
+    description:
+      - The name of the app
+    required: True
+    default: null
+    aliases: []
+  resources:
+    description:
+      - The Resource type and quantity (required when state=present)
+    required: False
+    default: null
+    aliases: []
+  process_type:
+    description:
+      - The process type selector
+    required: False
+    default: null
+    alias: []
+  clear_before:
+    description:
+      - Clear all resource limits before applying
+    required: False
+    default: "False"
+    choices: [ "True", "False" ]
+    aliases: []
+  state:
+    description:
+      - The state of the resource limits
+    required: False
+    default: present
+    choices: [ "present", "absent" ]
+    aliases: []
+author: Alexandre Pavanello e Silva
+requirements: [ ]
+
+"""
+
+EXAMPLES = """
+- name: Limit CPU and memory of a dokku app
+  dokku_resource_limit:
+    app: hello-world
+    resources:
+      cpu: 100
+      memory: 100
+
+- name: name: Limit resources per process type of a dokku app
+  dokku_resource_limit:
+    app: hello-world
+    process_type: web
+    resources:
+      cpu: 100
+      memory: 100
+
+- name: Clear limits before applying new limits
+  dokku_resource_limit:
+    app: hello-world
+    state: present
+    clear_before: True
+    resources:
+      cpu: 100
+      memory: 100
+
+- name: Remove all resource limits
+  dokku_resource_limit:
+    app: hello-world
+    state: absent
+"""
+
+
+def force_list(var):
+    if isinstance(var, list):
+        return var
+    return list(var)
+
+
+def subprocess_check_output(command, split="\n"):
+    error = None
+    output = []
+    try:
+        output = subprocess.check_output(command, shell=True)
+        if isinstance(output, bytes):
+            output = output.decode("utf-8")
+        output = str(output).rstrip("\n")
+        if split is None:
+            return output, error
+
+        output = output.split(split)
+        output = force_list(filter(None, output))
+        output = [o.strip() for o in output]
+    except subprocess.CalledProcessError as e:
+        error = str(e)
+    return output, error
+
+
+def dokku_resource_clear(data):
+    error = None
+    process_type = ""
+    if data["process_type"]:
+        process_type = "--process-type {0}".format(data["process_type"])
+    command = "dokku resource:limit-clear {0} {1}".format(process_type, data["app"])
+    try:
+        subprocess.check_call(command, shell=True)
+    except subprocess.CalledProcessError as e:
+        error = str(e)
+    return error
+
+
+def dokku_resource_limit_report(data):
+
+    process_type = ""
+    if data["process_type"]:
+        process_type = "--process-type {0}".format(data["process_type"])
+    command = "dokku --quiet resource:limit {0} {1}".format(process_type, data["app"])
+
+    output, error = subprocess_check_output(command)
+    if error is not None:
+        return output, error
+    output = [re.sub(r"\s+", "", line) for line in output]
+
+    report = {}
+
+    for line in output:
+        if ":" not in line:
+            continue
+        key, value = line.split(":", 1)
+        report[key] = value
+
+    return report, error
+
+
+def dokku_resource_limit_present(data):
+    is_error = True
+    has_changed = False
+    meta = {"present": False}
+
+    if "resources" not in data:
+        meta["error"] = "missing required arguments: resources"
+        return (is_error, has_changed, meta)
+
+    report, error = dokku_resource_limit_report(data)
+    meta["debug"] = report.keys()
+    if error:
+        meta["error"] = error
+        return (is_error, has_changed, meta)
+
+    for k, v in data["resources"].items():
+        if k not in report.keys():
+            is_error = True
+            has_changed = False
+            meta["error"] = "Unknown resource {0}, choose one of: {1}".format(
+                k, list(report.keys())
+            )
+            return (is_error, has_changed, meta)
+        if report[k] != str(v):
+            has_changed = True
+
+    if data["clear_before"] is True:
+
+        error = dokku_resource_clear(data)
+        if error:
+            meta["error"] = error
+            is_error = True
+            has_changed = False
+            return (is_error, has_changed, meta)
+        has_changed = True
+
+    if not has_changed:
+        meta["present"] = True
+        is_error = False
+        return (is_error, has_changed, meta)
+
+    values = []
+    for key, value in data["resources"].items():
+        values.append("--{0} {1}".format(key, value))
+
+    process_type = ""
+    if data["process_type"]:
+        process_type = "--process-type {0}".format(data["process_type"])
+
+    command = "dokku resource:limit {0} {1} {2}".format(
+        " ".join(values), process_type, data["app"]
+    )
+    try:
+        subprocess.check_call(command, shell=True)
+        is_error = False
+        has_changed = True
+        meta["present"] = True
+    except subprocess.CalledProcessError as e:
+        meta["error"] = str(e)
+    return (is_error, has_changed, meta)
+
+
+def dokku_resource_limit_absent(data):
+    is_error = True
+    has_changed = False
+    meta = {"present": True}
+
+    error = dokku_resource_clear(data)
+    if error:
+        meta["error"] = error
+        is_error = True
+        has_changed = False
+        return (is_error, has_changed, meta)
+
+    is_error = False
+    has_changed = True
+    meta = {"present": False}
+
+    return (is_error, has_changed, meta)
+
+
+def main():
+    fields = {
+        "app": {"required": True, "type": "str"},
+        "process_type": {"required": False, "type": "str"},
+        "resources": {"required": False, "type": "dict"},
+        "clear_before": {"required": False, "type": "bool"},
+        "state": {
+            "required": False,
+            "default": "present",
+            "choices": ["present", "absent"],
+            "type": "str",
+        },
+    }
+    choice_map = {
+        "present": dokku_resource_limit_present,
+        "absent": dokku_resource_limit_absent,
+    }
+
+    module = AnsibleModule(argument_spec=fields, supports_check_mode=False)
+    is_error, has_changed, result = choice_map.get(module.params["state"])(
+        module.params
+    )
+
+    if is_error:
+        module.fail_json(msg=result["error"], meta=result)
+    module.exit_json(changed=has_changed, meta=result)
+
+
+if __name__ == "__main__":
+    main()