feat: manage Seriatim source prerequisites

tasks/dependencies.yml

@@ -0,0 +1,66 @@
+---
+- name: Install Git build dependency
+  ansible.builtin.apt:
+    name: git
+    state: present
+    update_cache: true
+    cache_valid_time: 3600
+  when: seriatim_manage_build_dependencies
+
+- name: Install Go build dependency
+  community.general.snap:
+    name: go
+    state: present
+    classic: true
+    channel: "{{ seriatim_go_snap_channel }}"
+  when: seriatim_manage_build_dependencies
+
+- name: Resolve Git executable
+  ansible.builtin.command:
+    argv:
+      - /usr/bin/which
+      - git
+  register: seriatim_git_path_result
+  changed_when: false
+  failed_when: seriatim_git_path_result.rc != 0
+
+- name: Verify configured Go executable exists
+  ansible.builtin.stat:
+    path: "{{ seriatim_go_binary }}"
+    follow: true
+  register: seriatim_go_binary_stat
+
+- name: Require configured Go executable
+  ansible.builtin.assert:
+    that:
+      - seriatim_go_binary_stat.stat.exists
+      - seriatim_go_binary_stat.stat.isreg
+      - seriatim_go_binary_stat.stat.executable
+    fail_msg: "Configured Go executable is unavailable: {{ seriatim_go_binary }}"
+
+- name: Read Go compiler version
+  ansible.builtin.command:
+    argv:
+      - "{{ seriatim_go_binary }}"
+      - version
+  register: seriatim_go_version_result
+  changed_when: false
+
+- name: Extract Go compiler version components
+  ansible.builtin.set_fact:
+    seriatim_go_version_parts: >-
+      {{ seriatim_go_version_result.stdout
+         | regex_findall('go([0-9]+)\.([0-9]+)')
+         | first
+         | default([]) }}
+
+- name: Require supported Go compiler version
+  ansible.builtin.assert:
+    that:
+      - seriatim_go_version_result.stdout is regex('^go version go[0-9]+\.[0-9]+(?:\.[0-9]+)? ')
+      - seriatim_go_version_parts | length == 2
+      - (seriatim_go_version_parts[0] | int > 1) or
+        (seriatim_go_version_parts[0] | int == 1 and seriatim_go_version_parts[1] | int >= 25)
+    fail_msg: >-
+      Seriatim requires Go 1.25 or newer; detected
+      {{ seriatim_go_version_result.stdout | default('no usable version output') }}.