feat: Add mecached_exporter role (#256)

Add new role: `memcached_exporter`

Signed-off-by: SuperQ <[email protected]>

roles/memcached_exporter/README.md

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+<p><img src="https://www.circonus.com/wp-content/uploads/2015/03/sol-icon-itOps.png" alt="graph logo" title="graph" align="right" height="60" /></p>
+
+# Ansible Role: memcached_exporter
+
+## Description
+
+Deploy prometheus [memcached_exporter](https://github.com/prometheus/memcached_exporter) using ansible.
+
+## Requirements
+
+- Ansible >= 2.9 (It might work on previous versions, but we cannot guarantee it)
+- gnu-tar on Mac deployer host (`brew install gnu-tar`)
+- Passlib is required when using the basic authentication feature (`pip install passlib[bcrypt]`)
+
+## Role Variables
+
+All variables which can be overridden are stored in [defaults/main.yml](defaults/main.yml) file as well as in [meta/argument_specs.yml](meta/argument_specs.yml).
+Please refer to the [collection docs](https://prometheus-community.github.io/ansible/branch/main/memcached_exporter_role.html) for description and default values of the variables.
+
+## Example
+
+### Demo site
+
+We provide demo site for full monitoring solution based on prometheus and grafana. Repository with code and links to running instances is [available on github](https://github.com/prometheus/demo-site) and site is hosted on [DigitalOcean](https://digitalocean.com).
+
+## Local Testing
+
+The preferred way of locally testing the role is to use Docker and [molecule](https://github.com/ansible-community/molecule) (v3.x). You will have to install Docker on your system. See "Get started" for a Docker package suitable to for your system. Running your tests is as simple as executing `molecule test`.
+
+## Continuous Intergation
+
+Combining molecule and circle CI allows us to test how new PRs will behave when used with multiple ansible versions and multiple operating systems. This also allows use to create test scenarios for different role configurations. As a result we have a quite large test matrix which can take more time than local testing, so please be patient.
+
+## Contributing
+
+See [contributor guideline](CONTRIBUTING.md).
+
+## Troubleshooting
+
+See [troubleshooting](TROUBLESHOOTING.md).
+
+## License
+
+This project is licensed under MIT License. See [LICENSE](/LICENSE) for more details.

roles/memcached_exporter/defaults/main.yml

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+---
+memcached_exporter_version: 0.13.0
+memcached_exporter_binary_local_dir: ""
+memcached_exporter_binary_url: "https://github.com/{{ _memcached_exporter_repo }}/releases/download/v{{ memcached_exporter_version }}/\
+                           memcached_exporter-{{ memcached_exporter_version }}.linux-{{ go_arch }}.tar.gz"
+memcached_exporter_checksums_url: "https://github.com/{{ _memcached_exporter_repo }}/releases/download/v{{ memcached_exporter_version }}/sha256sums.txt"
+memcached_exporter_skip_install: false
+
+memcached_exporter_memcached_pid_file: ""
+
+memcached_exporter_web_listen_address: "0.0.0.0:9150"
+memcached_exporter_web_telemetry_path: "/metrics"
+
+memcached_exporter_tls_server_config: {}
+
+memcached_exporter_http_server_config: {}
+
+memcached_exporter_basic_auth_users: {}
+
+memcached_exporter_log_level: "info"
+memcached_exporter_log_format: "logfmt"
+
+memcached_exporter_binary_install_dir: "/usr/local/bin"
+memcached_exporter_system_group: "memcached-exp"
+memcached_exporter_system_user: "{{ memcached_exporter_system_group }}"

roles/memcached_exporter/handlers/main.yml

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+---
+- name: Restart memcached_exporter
+  listen: "restart memcached_exporter"
+  become: true
+  ansible.builtin.systemd:
+    daemon_reload: true
+    name: memcached_exporter
+    state: restarted
+  when:
+    - not ansible_check_mode

roles/memcached_exporter/meta/argument_specs.yml

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+---
+# yamllint disable rule:line-length
+argument_specs:
+  main:
+    short_description: "Prometheus memcached_exporter"
+    description:
+      - "Deploy prometheus L(memcached exporter,https://github.com/prometheus/memcached_exporter) using ansible"
+    author:
+      - "Prometheus Community"
+    options:
+      memcached_exporter_version:
+        description: "memcached_exporter package version. Also accepts latest as parameter."
+        default: "0.11.0"
+      memcached_exporter_skip_install:
+        description: "memcached_exporter installation tasks gets skipped when set to true."
+        type: bool
+        default: false
+      memcached_exporter_binary_local_dir:
+        description:
+          - "Enables the use of local packages instead of those distributed on github."
+          - "The parameter may be set to a directory where the C(memcached_exporter) binary is stored on the host where ansible is run."
+          - "This overrides the I(memcached_exporter_version) parameter"
+      memcached_exporter_binary_url:
+        description: "URL of the memcached_exporter binaries .tar.gz file"
+        default: "https://github.com/{{ _memcached_exporter_repo }}/releases/download/v{{ memcached_exporter_version }}/memcached_exporter-{{ memcached_exporter_version }}.linux-{{ go_arch }}.tar.gz"
+      memcached_exporter_checksums_url:
+        description: "URL of the memcached_exporter checksums file"
+        default: "https://github.com/{{ _memcached_exporter_repo }}/releases/download/v{{ memcached_exporter_version }}/sha256sums.txt"
+      memcached_exporter_web_listen_address:
+        description: "Address on which memcached exporter will listen"
+        default: "0.0.0.0:9150"
+      memcached_exporter_web_telemetry_path:
+        description: "Path under which to expose metrics"
+        default: "/metrics"
+      memcached_exporter_tls_server_config:
+        description:
+          - "Configuration for TLS authentication."
+          - "Keys and values are the same as in L(memcached_exporter docs,https://github.com/prometheus/exporter-toolkit/blob/master/docs/web-configuration.md)."
+        type: "dict"
+      memcached_exporter_http_server_config:
+        description:
+          - "Config for HTTP/2 support."
+          - "Keys and values are the same as in L(memcached_exporter docs,https://github.com/prometheus/exporter-toolkit/blob/master/docs/web-configuration.md)."
+        type: "dict"
+      memcached_exporter_basic_auth_users:
+        description: "Dictionary of users and password for basic authentication. Passwords are automatically hashed with bcrypt."
+        type: "dict"
+      memcached_exporter_log_level:
+        description: "Only log messages with the given severity or above. One of: [debug, info, warn, error]"
+        default: "info"
+      memcached_exporter_log_format:
+        description: "Output format of log messages. One of: [logfmt, json]"
+        default: "logfmt"
+      memcached_exporter_memcached_pid_file:
+        description:
+          - "The path to the memcached PID file for process monitoring"
+        default: ""
+      memcached_exporter_binary_install_dir:
+        description:
+          - "I(Advanced)"
+          - "Directory to install memcached_exporter binary"
+        default: "/usr/local/bin"
+      memcached_exporter_system_group:
+        description:
+          - "I(Advanced)"
+          - "System group for memcached_exporter"
+        default: "memcached-exp"
+      memcached_exporter_system_user:
+        description:
+          - "I(Advanced)"
+          - "memcached_exporter user"
+        default: "memcached-exp"

roles/memcached_exporter/meta/main.yml

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+---
+galaxy_info:
+  author: "Prometheus Community"
+  description: "Prometheus memcached_exporter"
+  license: "Apache"
+  min_ansible_version: "2.9"
+  platforms:
+    - name: "Ubuntu"
+      versions:
+        - "focal"
+        - "jammy"
+    - name: "Debian"
+      versions:
+        - "bullseye"
+        - "buster"
+    - name: "EL"
+      versions:
+        - "7"
+        - "8"
+        - "9"
+    - name: "Fedora"
+      versions:
+        - "37"
+        - '38'
+  galaxy_tags:
+    - "monitoring"
+    - "prometheus"
+    - "exporter"
+    - "metrics"
+    - "system"

roles/memcached_exporter/molecule/alternative/molecule.yml

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+---
+provisioner:
+  inventory:
+    group_vars:
+      all:
+        memcached_exporter_binary_local_dir: "/tmp/memcached_exporter-linux-amd64"
+        memcached_exporter_web_listen_address: "127.0.0.1:8080"
+
+        memcached_exporter_tls_server_config:
+          cert_file: /etc/memcached_exporter/tls.cert
+          key_file: /etc/memcached_exporter/tls.key
+        memcached_exporter_http_server_config:
+          http2: true
+        memcached_exporter_basic_auth_users:
+          randomuser: examplepassword
+        go_arch: amd64
+        memcached_exporter_version: 0.12.0

roles/memcached_exporter/molecule/alternative/prepare.yml

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+---
+- name: Run local preparation
+  hosts: localhost
+  gather_facts: false
+  tasks:
+    - name: Download memcached_exporter binary to local folder
+      become: false
+      ansible.builtin.get_url:
+        url: "https://github.com/prometheus/memcached_exporter/releases/download/v{{\
+          \ memcached_exporter_version }}/memcached_exporter-{{ memcached_exporter_version }}.linux-{{\
+          \ go_arch }}.tar.gz"
+        dest: "/tmp/memcached_exporter-{{ memcached_exporter_version }}.linux-{{ go_arch }}.tar.gz"
+        mode: 0644
+      register: _download_binary
+      until: _download_binary is succeeded
+      retries: 5
+      delay: 2
+      check_mode: false
+
+    - name: Unpack memcached_exporter binary
+      become: false
+      ansible.builtin.unarchive:
+        src: "/tmp/memcached_exporter-{{ memcached_exporter_version }}.linux-{{ go_arch }}.tar.gz"
+        dest: "/tmp"
+        creates: "/tmp/memcached_exporter-{{ memcached_exporter_version }}.linux-{{ go_arch\
+          \ }}/memcached_exporter"
+      check_mode: false
+
+    - name: Link to memcached_exporter binaries directory
+      become: false
+      ansible.builtin.file:
+        src: "/tmp/memcached_exporter-{{ memcached_exporter_version }}.linux-amd64"
+        dest: "/tmp/memcached_exporter-linux-amd64"
+        state: link
+      check_mode: false
+
+    - name: Install pyOpenSSL for certificate generation
+      ansible.builtin.pip:
+        name: "pyOpenSSL"
+
+    - name: Create private key
+      community.crypto.openssl_privatekey:
+        path: "/tmp/tls.key"
+
+    - name: Create CSR
+      community.crypto.openssl_csr:
+        path: "/tmp/tls.csr"
+        privatekey_path: "/tmp/tls.key"
+
+    - name: Create certificate
+      community.crypto.x509_certificate:
+        path: "/tmp/tls.cert"
+        csr_path: "/tmp/tls.csr"
+        privatekey_path: "/tmp/tls.key"
+        provider: selfsigned
+
+- name: Run target preparation
+  hosts: all
+  any_errors_fatal: true
+  tasks:
+    - name: Create memcached_exporter cert dir
+      ansible.builtin.file:
+        path: "{{ memcached_exporter_tls_server_config.cert_file | dirname }}"
+        state: directory
+        owner: root
+        group: root
+        mode: u+rwX,g+rwX,o=rX
+
+    - name: Copy cert and key
+      ansible.builtin.copy:
+        src: "{{ item.src }}"
+        dest: "{{ item.dest }}"
+        mode: "{{ item.mode | default('0644') }}"
+      loop:
+        - src: "/tmp/tls.cert"
+          dest: "{{ memcached_exporter_tls_server_config.cert_file }}"
+        - src: "/tmp/tls.key"
+          dest: "{{ memcached_exporter_tls_server_config.key_file }}"

roles/memcached_exporter/molecule/alternative/tests/test_alternative.py

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+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import os
+import testinfra.utils.ansible_runner
+
+testinfra_hosts = testinfra.utils.ansible_runner.AnsibleRunner(
+    os.environ['MOLECULE_INVENTORY_FILE']).get_hosts('all')
+
+
+def test_directories(host):
+    dirs = [
+        "/etc/memcached_exporter"
+    ]
+    for dir in dirs:
+        d = host.file(dir)
+        assert d.is_directory
+        assert d.exists
+
+
+def test_service(host):
+    s = host.service("memcached_exporter")
+    try:
+        assert s.is_running
+    except AssertionError:
+        # Capture service logs
+        journal_output = host.run('journalctl -u memcached_exporter --since "1 hour ago"')
+        print("\n==== journalctl -u memcached_exporter Output ====\n")
+        print(journal_output)
+        print("\n============================================\n")
+        raise  # Re-raise the original assertion error
+
+
+def test_protecthome_property(host):
+    s = host.service("memcached_exporter")
+    p = s.systemd_properties
+    assert p.get("ProtectHome") == "yes"
+
+
+def test_socket(host):
+    sockets = [
+        "tcp://127.0.0.1:8080"
+    ]
+    for socket in sockets:
+        s = host.socket(socket)
+        assert s.is_listening

roles/memcached_exporter/molecule/default/molecule.yml

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+---
+provisioner:
+  inventory:
+    group_vars:
+      all:
+        memcached_exporter_web_listen_address: "127.0.0.1:9150"