internal/ci/ci.go

 1// Package ci parses .gitbay/ci.yml, the per-repo build configuration:
 2//
 3//	jobs:
 4//	  test:
 5//	    steps:
 6//	      - go test ./...
 7//
 8// Each job becomes one build per push; each step is a shell command the
 9// runner executes with `sh -c`, stopping at the first failure.
10package ci
11
12import (
13	"fmt"
14	"regexp"
15	"sort"
16
17	yaml "go.yaml.in/yaml/v3"
18)
19
20// ConfigPath is where the build configuration lives in a repository.
21const ConfigPath = ".gitbay/ci.yml"
22
23const (
24	maxJobs     = 10
25	maxSteps    = 50
26	maxStepSize = 4096
27)
28
29var jobName = regexp.MustCompile(`^[a-z0-9][a-z0-9_-]{0,39}$`)
30
31type Job struct {
32	Name     string
33	Steps    []string
34	Schedule string // cron expression; scheduled jobs run on schedule, not on push
35}
36
37// Parse returns the jobs in name order, or an error describing the first
38// problem so the pusher can fix the file.
39func Parse(raw []byte) ([]Job, error) {
40	var doc struct {
41		Jobs map[string]struct {
42			Steps    []string `yaml:"steps"`
43			Schedule string   `yaml:"schedule"`
44		} `yaml:"jobs"`
45	}
46	if err := yaml.Unmarshal(raw, &doc); err != nil {
47		return nil, fmt.Errorf("parsing %s: %w", ConfigPath, err)
48	}
49	if len(doc.Jobs) == 0 {
50		return nil, fmt.Errorf("%s defines no jobs", ConfigPath)
51	}
52	if len(doc.Jobs) > maxJobs {
53		return nil, fmt.Errorf("%s defines %d jobs; max %d", ConfigPath, len(doc.Jobs), maxJobs)
54	}
55	var jobs []Job
56	for name, j := range doc.Jobs {
57		if !jobName.MatchString(name) {
58			return nil, fmt.Errorf("bad job name %q: lowercase letters, digits, - and _; max 40 chars", name)
59		}
60		if len(j.Steps) == 0 {
61			return nil, fmt.Errorf("job %q has no steps", name)
62		}
63		if len(j.Steps) > maxSteps {
64			return nil, fmt.Errorf("job %q has %d steps; max %d", name, len(j.Steps), maxSteps)
65		}
66		for _, s := range j.Steps {
67			if len(s) > maxStepSize {
68				return nil, fmt.Errorf("job %q has a step over %d bytes", name, maxStepSize)
69			}
70		}
71		if j.Schedule != "" {
72			if _, err := ParseCron(j.Schedule); err != nil {
73				return nil, fmt.Errorf("job %q: %v", name, err)
74			}
75		}
76		jobs = append(jobs, Job{Name: name, Steps: j.Steps, Schedule: j.Schedule})
77	}
78	sort.Slice(jobs, func(i, k int) bool { return jobs[i].Name < jobs[k].Name })
79	return jobs, nil
80}