feat: replace the template engine with an in-house parser (#233)

* feat: replace the template engine with an in-house parser

* style: change "could not" to "failed to"

* refactor: remove unused api.SortTTL

* refactor: remove unused config.ParseProxied

* refactor: use the in-house parser in config.ReadDomains

* fix: domainexp.tokenize should not return nil for empty strings

* test(config): improve coverage

* test(domainexp): improve coverage

* test: improve coverage

* docs(README): document the new template engine

.golangci.yaml

@@ -8,6 +8,15 @@ linters-settings:
     suggest-new: true
   exhaustive:
     default-signifies-exhaustive: true
+  govet:
+    settings:
+      printf:
+        funcs:
+          - (github.com/favonia/cloudflare-ddns/internal/pp).Infof
+          - (github.com/favonia/cloudflare-ddns/internal/pp).Noticef
+          - (github.com/favonia/cloudflare-ddns/internal/pp).Warningf
+          - (github.com/favonia/cloudflare-ddns/internal/pp).Errorf
+          - (github.com/favonia/cloudflare-ddns/internal/pp).printf
 
 issues:
   exclude-rules:

README.markdown

@@ -23,7 +23,7 @@ A small and fast DDNS updater for Cloudflare.
 
 ### ⚡ Efficiency
 
-* 🤏 The Docker images are small (less than 4 MB after compression).
+* 🤏 The Docker images are small (less than 3 MB after compression).
 * 🔁 The Go runtime will re-use existing HTTP connections.
 * 🗃️ Cloudflare API responses are cached to reduce the API usage.
 
@@ -34,7 +34,7 @@ Simply list all the domain names and you are done!
 * 🌍 Internationalized domain names (_e.g._, `🐱.example.org`) are fully supported. _(The updater smooths out [some rough edges of the Cloudflare API](https://github.com/cloudflare/cloudflare-go/pull/690#issuecomment-911884832).)_
 * 🃏 Wildcard domain names (_e.g._, `*.example.org`) are also supported.
 * 🔍 This updater automatically finds the DNS zones for you, and it can handle multiple DNS zones.
-* 🕹️ You can toggle IPv4 (`A` records), IPv6 (`AAAA` records) and Cloudflare proxying and change TTL on a per-domain basis.
+* 🕹️ You can toggle IPv4 (`A` records), IPv6 (`AAAA` records) and Cloudflare proxying on a per-domain basis.
 
 ### 🕵️ Privacy
 
@@ -292,9 +292,9 @@ In most cases, `CF_ACCOUNT_ID` is not needed.
 
 | Name | Valid Values | Meaning | Required? | Default Value |
 | ---- | ------------ | ------- | --------- | ------------- |
-| `DOMAINS` | Comma-separated fully qualified domain names or wildcard domain names | The domains the updater should manage for both `A` and `AAAA` records | (See below) | N/A
-| `IP4_DOMAINS` | Comma-separated fully qualified domain names or wildcard domain names | The domains the updater should manage for `A` records | (See below) | N/A
-| `IP6_DOMAINS` | Comma-separated fully qualified domain names or wildcard domain names | The domains the updater should manage for `AAAA` records | (See below) | N/A
+| `DOMAINS` | Comma-separated fully qualified domain names or wildcard domain names | The domains the updater should manage for both `A` and `AAAA` records | (See below) | `""` (empty list)
+| `IP4_DOMAINS` | Comma-separated fully qualified domain names or wildcard domain names | The domains the updater should manage for `A` records | (See below) | `""` (empty list)
+| `IP6_DOMAINS` | Comma-separated fully qualified domain names or wildcard domain names | The domains the updater should manage for `AAAA` records | (See below) | `""` (empty list)
 | `IP4_PROVIDER` | `cloudflare.doh`, `cloudflare.trace`, `ipify`, `local`, and `none` | How to detect IPv4 addresses. (See below) | No | `cloudflare.trace`
 | `IP6_PROVIDER` | `cloudflare.doh`, `cloudflare.trace`, `ipify`, `local`, and `none` | How to detect IPv6 addresses. (See below) | No | `cloudflare.trace`
 
@@ -344,27 +344,32 @@ In most cases, `CF_ACCOUNT_ID` is not needed.
 
 | Name | Valid Values | Meaning | Required? | Default Value |
 | ---- | ------------ | ------- | --------- | ------------- |
-| `PROXIED` | Boolean values, such as `true`, `false`, `0` and `1`. See [strconv.ParseBool](https://pkg.go.dev/strconv#ParseBool) | Whether new DNS records should be proxied by Cloudflare | No | `false`
+| `PROXIED` | Boolean values, such as `true`, `false`, `0` and `1`. See [strconv.ParseBool](https://pkg.go.dev/strconv#ParseBool). See below for experimental support of per-domain proxy settings. | Whether new DNS records should be proxied by Cloudflare | No | `false`
 | `TTL` | Time-to-live (TTL) values in seconds | The TTL values used to create new DNS records | No | `1` (This means “automatic” to Cloudflare)
 
 > <details>
-> <summary>🧪 Experimental support of templates (subject to changes):</summary>
+> <summary>🧪 Experimental per-domain proxy settings (subject to changes):</summary>
 >
-> Both `PROXIED` and `TTL` can be [Jet Templates](https://github.com/CloudyKit/jet/blob/master/docs/syntax.md) for per-domain settings. For example, `PROXIED={{!hasSuffix("example.org")}}` means all domains should be proxied except domains like `www.example.org` and `example.org`. The Go templates are executed with the following two custom functions:
-> - `inDomains(patterns ...string) bool`
+> The `PROXIED` can be a boolean expression. Here are some examples:
+> - `PROXIED=is(example.org)`: enable proxy only for the domain `example.org`
+> - `PROXIED=is(example1.org) || sub(example2.org)`: enable proxy only for the domain `example1.org` and the subdomains of `example2.org`
+> - `PROXIED=!is(example.org)`: enable proxy _except for_ the domain `example.org`
+> - `PROXIED=is(example1.org) || is(example2.org) || is(example3.org)`: enable proxy only for the domains `example1.org`, `example2.org`, and `example3.org`
 >
->   Returns `true` if and only if the target domain matches one of `patterns`. All domains are normalized before comparison. For example, internationalized domain names are converted to Punycode before comparing them.
-> - `hasSuffix(patterns ...string) bool`
+> More formally, a boolean expression has one of the following forms:
+> - A boolean value accepted by [strconv.ParseBool](https://pkg.go.dev/strconv#ParseBool), such as `t` as `true`.
+> - `is(d)` which matches the domain `d`. Note that `is(*.a)` only matches the wildcard domain `*.a`; use `sub(a)` to all subdomains of `a` (including `*.a`).
+> - `sub(d)` which matches subdomains of `d` (not including `d` itself).
+> - `! e` where `e` is a boolean expression, representing logical negation.
+> - `e1 || e2` where `e1` and `e2` are boolean expressions, representing logical or.
+> - `e1 && e2` where `e1` and `e2` are boolean expressions, representing logical and.
 >
->   Returns `true` if and only if the target domain has one of `patterns` as itself or its parent (or ancestor). Note that labels in domains must fully match; for example, the suffix `b.org` will not match `www.bb.org` because `bb.org` and `b.org` are incomparable, while the suffix `bb.org` will match `www.bb.org`.
+> One can use parentheses to group expressions, such as `!(is(a) && (is(b) || is(c)))`.
+> For convenience, the engine also accepts these short forms:
+> - `is(d1, d2, ..., dn) = is(d1) || is(d2) || ... || is(dn)`
+> - `sub(d1, d2, ..., dn) = sub(d1) || sub(d2) || ... || sub(dn)`
 >
-> Some examples:
-> - `TTL={{if hasSuffix("b.c")}} 60 {{else if inDomains("d.e.f","a.bb.c")}} 90 {{else}} 120 {{end}}`
->
->   For the domain `b.c` and its descendants, the TTL is 60, and for the domains `d.e.f` and `a.bb.c`, the TTL is 90, and then for all other domains, the TTL is 120.
-> - `PROXIED={{hasSuffix("b.c") && ! inDomains("a.b.c"))}}`
->
->   Proxy the domain `b.c` and its descendants except for the domain `a.b.c`.
+> Using these short forms, `is(example1.org) || is(example2.org) || is(example3.org)` can be abbreviated as `is(example1.org,example2.org,example3.org)`.
 > </details>
 
 </details>

go.mod

@@ -3,7 +3,6 @@ module github.com/favonia/cloudflare-ddns
 go 1.19
 
 require (
-	github.com/CloudyKit/jet/v6 v6.1.0
 	github.com/cloudflare/cloudflare-go v0.52.0
 	github.com/golang/mock v1.6.0
 	github.com/patrickmn/go-cache v2.1.0+incompatible
@@ -14,7 +13,6 @@ require (
 )
 
 require (
-	github.com/CloudyKit/fastprinter v0.0.0-20200109182630-33d98a066a53 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/google/go-querystring v1.1.0 // indirect
 	github.com/hashicorp/go-cleanhttp v0.5.2 // indirect

go.sum

@@ -1,7 +1,3 @@
-github.com/CloudyKit/fastprinter v0.0.0-20200109182630-33d98a066a53 h1:sR+/8Yb4slttB4vD+b9btVEnWgL3Q00OBTzVT8B9C0c=
-github.com/CloudyKit/fastprinter v0.0.0-20200109182630-33d98a066a53/go.mod h1:+3IMCy2vIlbG1XG/0ggNQv0SvxCAIpPM5b1nCz56Xno=
-github.com/CloudyKit/jet/v6 v6.1.0 h1:hvO96X345XagdH1fAoBjpBYG4a1ghhL/QzalkduPuXk=
-github.com/CloudyKit/jet/v6 v6.1.0/go.mod h1:d3ypHeIRNo2+XyqnGA8s+aphtcVpjP5hPwP/Lzo7Ro4=
 github.com/cloudflare/cloudflare-go v0.52.0 h1:9pa170sl8HBR2c/7I5konGwgDYzlQ4dy3evdG/my9xU=
 github.com/cloudflare/cloudflare-go v0.52.0/go.mod h1:JSdZSD4FjF220O9REnYf0IGx7gUdbWwRgCAv4TusaJc=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=

internal/api/cloudflare.go

@@ -181,7 +181,7 @@ func (h *CloudflareHandle) ListRecords(ctx context.Context, ppfmt pp.PP,
 	for i := range rs {
 		rmap[rs[i].ID], err = netip.ParseAddr(rs[i].Content)
 		if err != nil {
-			ppfmt.Warningf(pp.EmojiImpossible, "Could not parse the IP address in records of %q: %v", domain.Describe(), err)
+			ppfmt.Warningf(pp.EmojiImpossible, "Failed to parse the IP address in records of %q: %v", domain.Describe(), err)
 			return nil, false
 		}
 	}

internal/api/cloudflare_test.go

@@ -633,7 +633,7 @@ func TestListRecordsInvalidIPAddress(t *testing.T) {
 	mockPP := mocks.NewMockPP(mockCtrl)
 	mockPP.EXPECT().Warningf(
 		pp.EmojiImpossible,
-		"Could not parse the IP address in records of %q: %v",
+		"Failed to parse the IP address in records of %q: %v",
 		"sub.test.org",
 		gomock.Any(),
 	)

internal/api/ttl.go

@@ -1,13 +1,10 @@
 package api
 
-import (
-	"sort"
-	"strconv"
-)
+import "strconv"
 
 type TTL int
 
-const TTLAuto = 1
+const TTLAuto TTL = 1
 
 func (t TTL) Int() int {
 	return int(t)
@@ -23,7 +20,3 @@ func (t TTL) Describe() string {
 	}
 	return strconv.Itoa(t.Int())
 }
-
-func SortTTLs(s []TTL) {
-	sort.Slice(s, func(i, j int) bool { return int(s[i]) < int(s[j]) })
-}

internal/config/config.go

@@ -2,13 +2,13 @@ package config
 
 import (
 	"fmt"
-	"strconv"
 	"strings"
 	"time"
 
 	"github.com/favonia/cloudflare-ddns/internal/api"
 	"github.com/favonia/cloudflare-ddns/internal/cron"
 	"github.com/favonia/cloudflare-ddns/internal/domain"
+	"github.com/favonia/cloudflare-ddns/internal/domainexp"
 	"github.com/favonia/cloudflare-ddns/internal/file"
 	"github.com/favonia/cloudflare-ddns/internal/ipnet"
 	"github.com/favonia/cloudflare-ddns/internal/monitor"
@@ -24,8 +24,7 @@ type Config struct {
 	UpdateOnStart    bool
 	DeleteOnStop     bool
 	CacheExpiration  time.Duration
-	TTLTemplate      string
-	TTL              map[domain.Domain]api.TTL
+	TTL              api.TTL
 	ProxiedTemplate  string
 	Proxied          map[domain.Domain]bool
 	DetectionTimeout time.Duration
@@ -49,8 +48,7 @@ func Default() *Config {
 		UpdateOnStart:    true,
 		DeleteOnStop:     false,
 		CacheExpiration:  time.Hour * 6, //nolint:gomnd
-		TTLTemplate:      "1",
-		TTL:              map[domain.Domain]api.TTL{},
+		TTL:              api.TTLAuto,
 		ProxiedTemplate:  "false",
 		Proxied:          map[domain.Domain]bool{},
 		UpdateTimeout:    time.Second * 30, //nolint:gomnd
@@ -168,42 +166,6 @@ func ReadProviderMap(ppfmt pp.PP, field *map[ipnet.Type]provider.Provider) bool
 	return true
 }
 
-func ParseProxied(ppfmt pp.PP, dom domain.Domain, val string) (bool, bool) {
-	val = strings.TrimSpace(val)
-	res, err := strconv.ParseBool(val)
-	if err != nil {
-		ppfmt.Errorf(pp.EmojiUserError, "Proxy setting of %s (%q) is not a boolean value: %v", dom.Describe(), val, err)
-		return false, false
-	}
-
-	return res, true
-}
-
-// ParseTTL turns a template into a valid TTL value.
-//
-// According to [API documentation], the valid range is 1 (auto) and [60, 86400].
-// According to [DNS documentation], the valid range is "Auto" and [30, 86400].
-// We thus accept the union of both ranges---1 (auto) and [30, 86400].
-//
-// [API documentation] https://api.cloudflare.com/#dns-records-for-a-zone-create-dns-record
-// [DNS documentation] https://developers.cloudflare.com/dns/manage-dns-records/reference/ttl
-func ParseTTL(ppfmt pp.PP, dom domain.Domain, val string) (api.TTL, bool) {
-	val = strings.TrimSpace(val)
-	res, err := strconv.Atoi(val)
-	switch {
-	case err != nil:
-		ppfmt.Errorf(pp.EmojiUserError, "TTL of %s (%q) is not a number: %v", dom.Describe(), val, err)
-		return 0, false
-
-	case res != 1 && (res < 30 || res > 86400):
-		ppfmt.Errorf(pp.EmojiUserError, "TTL of %s (%d) should be 1 (auto) or between 30 and 86400", dom.Describe(), res)
-		return 0, false
-
-	default:
-		return api.TTL(res), true
-	}
-}
-
 func describeDomains(domains []domain.Domain) string {
 	if len(domains) == 0 {
 		return "(none)"
@@ -265,20 +227,12 @@ func (c *Config) Print(ppfmt pp.PP) {
 	item("Delete on stop?", "%t", c.DeleteOnStop)
 	item("Cache expiration:", "%v", c.CacheExpiration)
 
-	if len(c.TTL) > 0 {
-		section("TTL of new records:")
-		vals, inverseMap := getInverseMap(c.TTL)
-		api.SortTTLs(vals)
-		for _, val := range vals {
-			item(fmt.Sprintf("TTL is %s:", val.Describe()), describeDomains(inverseMap[val]))
-		}
-	}
-
+	section("New DNS records:")
+	item("TTL:", "%s", c.TTL.Describe())
 	if len(c.Proxied) > 0 {
-		section("Proxy for new records:")
 		_, inverseMap := getInverseMap(c.Proxied)
-		item("Proxied:", "%s", describeDomains(inverseMap[true]))
-		item("Unproxied (DNS only):", "%s", describeDomains(inverseMap[false]))
+		item("Proxied domains:", "%s", describeDomains(inverseMap[true]))
+		item("Unproxied domains:", "%s", describeDomains(inverseMap[false]))
 	}
 
 	section("Timeouts:")
@@ -306,7 +260,7 @@ func (c *Config) ReadEnv(ppfmt pp.PP) bool {
 		!ReadBool(ppfmt, "UPDATE_ON_START", &c.UpdateOnStart) ||
 		!ReadBool(ppfmt, "DELETE_ON_STOP", &c.DeleteOnStop) ||
 		!ReadNonnegDuration(ppfmt, "CACHE_EXPIRATION", &c.CacheExpiration) ||
-		!ReadString(ppfmt, "TTL", &c.TTLTemplate) ||
+		!ReadTTL(ppfmt, "TTL", &c.TTL) ||
 		!ReadString(ppfmt, "PROXIED", &c.ProxiedTemplate) ||
 		!ReadNonnegDuration(ppfmt, "DETECTION_TIMEOUT", &c.DetectionTimeout) ||
 		!ReadNonnegDuration(ppfmt, "UPDATE_TIMEOUT", &c.UpdateTimeout) ||
@@ -317,32 +271,13 @@ func (c *Config) ReadEnv(ppfmt pp.PP) bool {
 	return true
 }
 
-func assignMap[V any](ppfmt pp.PP,
-	m map[domain.Domain]V,
-	e func(domain.Domain) (string, bool),
-	p func(pp.PP, domain.Domain, string) (V, bool),
-	dom domain.Domain,
-) bool {
-	str, ok := e(dom)
-	if !ok {
-		return false
-	}
-	val, ok := p(ppfmt, dom, str)
-	if !ok {
-		return false
-	}
-	m[dom] = val
-	return true
-}
-
 // NormalizeDomains normalizes the fields Provider, TTL and Proxied.
 // When errors are reported, the original configuration remain unchanged.
 //
 //nolint:funlen
 func (c *Config) NormalizeDomains(ppfmt pp.PP) bool {
 	// New maps
 	providerMap := map[ipnet.Type]provider.Provider{}
-	ttlMap := map[domain.Domain]api.TTL{}
 	proxiedMap := map[domain.Domain]bool{}
 	activeDomainSet := map[domain.Domain]bool{}
 
@@ -398,25 +333,16 @@ func (c *Config) NormalizeDomains(ppfmt pp.PP) bool {
 		}
 	}
 
-	// fill in ttlMap and proxyMap
-	ttlExec, ok := domain.ParseTemplate(ppfmt, c.TTLTemplate)
+	// fill in proxyMap
+	proxiedPred, ok := domainexp.ParseExpression(ppfmt, c.ProxiedTemplate)
 	if !ok {
 		return false
 	}
-	proxiedExec, ok := domain.ParseTemplate(ppfmt, c.ProxiedTemplate)
-	if !ok {
-		return false
-	}
-
 	for dom := range activeDomainSet {
-		if !assignMap(ppfmt, ttlMap, ttlExec, ParseTTL, dom) ||
-			!assignMap(ppfmt, proxiedMap, proxiedExec, ParseProxied, dom) {
-			return false
-		}
+		proxiedMap[dom] = proxiedPred(dom)
 	}
 
 	c.Provider = providerMap
-	c.TTL = ttlMap
 	c.Proxied = proxiedMap
 
 	return true