README_GH_ACTIONS.md
1 # GitHub Actions Workflow Generator
2
3 This directory contains `gen_gh_actions.py`, a script to generate GitHub Actions CI workflows from the same configuration logic used for Travis CI.
4
5 ## Usage
6
7 The script can generate workflows for different platforms:
8
9 ```bash
10 # Generate Linux CI workflow (default)
11 ./scripts/gen_gh_actions.py linux > .github/workflows/linux-ci.yml
12
13 # Generate macOS CI workflow
14 ./scripts/gen_gh_actions.py macos > .github/workflows/macos-ci.yml
15
16 # Generate Windows CI workflow
17 ./scripts/gen_gh_actions.py windows > .github/workflows/windows-ci.yml
18
19 # Generate FreeBSD CI workflow
20 ./scripts/gen_gh_actions.py freebsd > .github/workflows/freebsd-ci.yml
21
22 # Generate combined workflow with all platforms
23 ./scripts/gen_gh_actions.py all > .github/workflows/ci-all.yml
24 ```
25
26 ## Generated Workflows
27
28 ### Linux CI (`linux-ci.yml`)
29 - **test-linux** (AMD64): `ubuntu-latest` (x86_64)
30 - ~96 configurations covering GCC, Clang, various flags
31 - **test-linux-arm64** (ARM64): `ubuntu-24.04-arm` (aarch64)
32 - ~14 configurations including large hugepage tests
33 - **Note:** Free ARM64 runners (Public Preview) - may have longer queue times during peak hours
34
35 **Total:** 110 configurations
36
37 ### macOS CI (`macos-ci.yml`)
38 - **test-macos** (Intel): `macos-15-intel` (x86_64)
39 - ~10 configurations with GCC compiler
40 - **test-macos-arm64** (Apple Silicon): `macos-latest` (arm64)
41 - ~11 configurations including large hugepage tests
42
43 **Total:** 21 configurations
44
45 ### Windows CI (`windows-ci.yml`)
46 - **test-windows** (AMD64): `windows-latest` (x86_64)
47 - 10 configurations covering MinGW-GCC and MSVC compilers
48 - 32-bit and 64-bit builds
49 - Uses MSYS2 for build environment
50
51 **Total:** 10 configurations
52
53 ### FreeBSD CI (`freebsd-ci.yml`)
54 - **test-freebsd** (AMD64): Runs in FreeBSD VM on `ubuntu-latest`
55 - Matrix testing: debug (on/off), prof (on/off), arch (32/64-bit), uncommon configs
56 - 16 total configuration combinations
57 - Uses FreeBSD 15.0 via `vmactions/freebsd-vm@v1`
58 - Uses `gmake` (GNU Make) instead of BSD make
59
60 **Total:** 16 configurations
61
62 ## Architecture Verification
63
64 Each workflow includes a "Show OS version" step that prints:
65
66 **Linux:**
67 ```bash
68 === System Information ===
69 uname -a # Kernel and architecture
70 === Architecture ===
71 uname -m # x86_64, aarch64, etc.
72 arch # Architecture type
73 === CPU Info ===
74 lscpu # Detailed CPU information
75 ```
76
77 **macOS:**
78 ```bash
79 === macOS Version ===
80 sw_vers # macOS version and build
81 === Architecture ===
82 uname -m # x86_64 or arm64
83 arch # i386 or arm64
84 === CPU Info ===
85 sysctl machdep.cpu.brand_string # CPU model
86 ```
87
88 **Windows:**
89 ```cmd
90 === Windows Version ===
91 systeminfo # OS name and version
92 ver # Windows version
93 === Architecture ===
94 PROCESSOR_ARCHITECTURE # AMD64, x86, ARM64
95 ```
96
97 ## GitHub Runner Images
98
99 | Platform | Runner Label | Architecture | OS Version | Strategy |
100 |----------|--------------|--------------|------------|----------|
101 | Linux AMD64 | ubuntu-latest | x86_64 | Ubuntu 22.04+ | Auto-update |
102 | Linux ARM64 | ubuntu-24.04-arm | aarch64 | Ubuntu 24.04 | Free (Public Preview) |
103 | macOS Intel | macos-15-intel | x86_64 | macOS 15 Sequoia | Pinned |
104 | macOS Apple Silicon | macos-15 | arm64 | macOS 15 Sequoia | Pinned |
105 | Windows | windows-latest | x86_64 | Windows Server 2022+ | Auto-update |
106 | FreeBSD | ubuntu-latest (VM) | x86_64 | FreeBSD 15.0 in VM | VM-based |
107
108 ### Runner Strategy Explained
109
110 We use a **hybrid approach** to balance stability and maintenance:
111
112 **Auto-update runners (`-latest`):**
113 - **Linux AMD64**: `ubuntu-latest` - Very stable, rarely breaks, auto-updates to newest Ubuntu LTS
114 - **Windows**: `windows-latest` - Backward compatible, auto-updates to newest Windows Server
115
116 **Pinned runners (specific versions):**
117 - **Linux ARM64**: `ubuntu-24.04-arm` - **Free for public repos** (Public Preview, may have queue delays)
118 - **macOS Intel**: `macos-15-intel` - Last Intel macOS runner (EOL **August 2027**)
119 - **macOS Apple Silicon**: `macos-15` - Pin for control over macOS upgrades
120
121 **Why this approach?**
122 - Reduces maintenance (auto-update where safe)
123 - Prevents surprise breakages (pin where needed)
124 - Balances stability and staying current
125 - Uses free ARM64 runners for public repositories
126
127 ### ARM64 Queue Times
128
129 **If you experience long waits for ARM64 jobs:**
130
131 The `ubuntu-24.04-arm` runner is **free for public repositories** but is in **Public Preview**. GitHub warns: *"you may experience longer queue times during peak usage hours"*.
132
133 To reduce wait times we should upgrade to Team/Enterprise plan - then we could use `ubuntu-24.04-arm64` for faster, paid runners
134
135 ### Important Deprecation Timeline
136
137 | Date | Event | Action Required |
138 |------|-------|------------------|
139 | **August 2027** | macOS Intel runners removed | Must drop Intel macOS testing or use self-hosted |
140 | **TBD** | ARM64 runners leave Public Preview | May see improved queue times |
141
142 **Note:** `macos-15-intel` is the **last Intel-based macOS runner** from GitHub Actions. After August 2027, only Apple Silicon runners will be available.
143
144 ## Platform-Specific Details
145
146 ### Windows Build Process
147 The Windows workflow uses:
148 1. **MSYS2** setup via `msys2/setup-msys2@v2` action
149 2. **MinGW-GCC**: Standard autotools build process in MSYS2 shell
150 3. **MSVC (cl.exe)**: Requires `ilammy/msvc-dev-cmd@v1` for environment setup
151 - Uses `MSYS2_PATH_TYPE: inherit` to inherit Windows PATH
152 - Exports `AR=lib.exe`, `NM=dumpbin.exe`, `RANLIB=:`
153 4. **mingw32-make**: Used instead of `make` (standard in MSYS2)
154
155 ### macOS Build Process
156 - Uses Homebrew to install `autoconf`
157 - Tests on both Intel (x86_64) and Apple Silicon (ARM64)
158 - Standard autotools build process
159 - Excludes certain malloc configurations not supported on macOS
160
161 ### Linux Build Process
162 - Ubuntu Latest for AMD64, Ubuntu 24.04 for ARM64
163 - Installs 32-bit cross-compilation dependencies when needed
164 - Most comprehensive test matrix (110 configurations)
165
166 ## Relationship to Travis CI
167
168 This script mirrors the logic from `gen_travis.py` but generates GitHub Actions workflows instead of `.travis.yml`. The test matrices are designed to provide equivalent coverage to the Travis CI configuration.
169
170 ## Regenerating Workflows
171
172 To regenerate all workflows after modifying `gen_gh_actions.py`:
173
174 ```bash
175 ./scripts/gen_gh_actions.py linux > .github/workflows/linux-ci.yml
176 ./scripts/gen_gh_actions.py macos > .github/workflows/macos-ci.yml
177 ./scripts/gen_gh_actions.py windows > .github/workflows/windows-ci.yml
178 ```
179
180 **Note**: The generated files should not be edited by hand. All changes should be made to `gen_gh_actions.py` and then regenerated.
181
182