Add pocketbase external plugin.

Author: tinkernels

content/explugins/pocketbase.md

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+title = "pocketbase"
+description = "*pocketbase* - PocketBase backend for CoreDNS"
+weight = 10
+tags = [  "plugin" , "pocketbase" ]
+categories = [ "plugin", "external" ]
+date = "2025-04-11T03:31:26+00:00"
+repo = "https://github.com/tinkernels/coredns-pocketbase"
+home = "https://github.com/tinkernels/coredns-pocketbase/blob/master/README.md"
++++
+
+# pocketbase
+
+PocketBase backend for CoreDNS
+
+## Name
+
+pocketbase - PocketBase backend for CoreDNS
+
+## Description
+
+This plugin uses PocketBase as a backend to store DNS records. These will then can served by CoreDNS. The backend uses a
+simple single table data structure that can add and remove records from the DNS server.
+
+## Syntax
+
+```
+pocketbase {
+    [listen LISTEN]
+    [data_dir DATA_DIR]
+    [su_email SU_EMAIL]
+    [su_password SU_PASSWORD]
+    [default_ttl DEFAULT_TTL]
+    [cache_capacity CACHE_CAPACITY]
+}
+```
+
+- `listen` pocketbase listening http address, default to `[::]:8090`,
+- `data_dir` directory to store pocketbase data, default to `pb_data`,
+- `su_email` superuser login email, can be overwritten by environment variable `COREDNS_PB_SUPERUSER_EMAIL`, default to `[email protected]`,
+- `su_password` superuser password, can be overwritten by environment variable `COREDNS_PB_SUPERUSER_PWD`, default to `[email protected]`,
+- `default_ttl` default ttl to use, default to `30`,
+- `cache_capacity` zone data cache capacity, `0` to disable cache, default to `0`.
+
+## Features
+
+### Supported Record Types
+
+- A
+- AAAA
+- CNAME
+- SOA
+- TXT
+- NS
+- MX
+- CAA
+- SRV
+
+*P.S.wildcard records supported*
+
+### Cache
+
+Use `github.com/dgraph-io/ristretto` as in-memory cache handler, handle cache refreshing with PocketBase event subscription mechanism.
+
+## Concept
+
+### PocketBase
+
+[PocketBase](https://github.com/pocketbase/pocketbase) use sqlite3 as storage, and comes with a web console.
+
+This plugin with init a super user and dns model in PocketBase, the admin console with look like
+
+![PocketBase admin console](assets/image/pocketbase-admin.png)
+
+#### Model in PocketBase
+
+```go
+type Record struct {
+	Zone       string `db:"zone" json:"zone"`               // The DNS zone this record belongs to
+	Name       string `db:"name" json:"name"`               // The name of the record (without the zone)
+	RecordType string `db:"record_type" json:"record_type"` // The type of DNS record (A, AAAA, TXT, etc.)
+	Ttl        uint32 `db:"ttl" json:"ttl"`                 // Time to live for the record in seconds
+	Content    string `db:"content" json:"content"`         // The content of the record in JSON format
+}
+```
+
+### DNS records
+
+DNS records content stored as JSON.
+
+```go
+// ARecord represents an A (IPv4) DNS record
+type ARecord struct {
+	Ip net.IP `json:"ip"` // IPv4 address
+}
+```
+```go
+// AAAARecord represents an AAAA (IPv6) DNS record
+type AAAARecord struct {
+	Ip net.IP `json:"ip"` // IPv6 address
+}
+```
+```go
+// TXTRecord represents a TXT DNS record
+type TXTRecord struct {
+	Text string `json:"text"` // Text content of the record
+}
+```
+```go
+// CNAMERecord represents a CNAME DNS record
+type CNAMERecord struct {
+	Host string `json:"host"` // Target hostname
+	Zone string `json:"zone"` // Zone of the record
+}
+```
+```go
+// NSRecord represents an NS (Name Server) DNS record
+type NSRecord struct {
+	Host string `json:"host"` // Name server hostname
+}
+```
+```go
+// MXRecord represents an MX (Mail Exchange) DNS record
+type MXRecord struct {
+	Host       string `json:"host"`       // Mail server hostname
+	Preference uint16 `json:"preference"` // Priority of the mail server
+}
+```
+```go
+// SRVRecord represents an SRV (Service) DNS record
+type SRVRecord struct {
+	Priority uint16 `json:"priority"` // Priority of the service
+	Weight   uint16 `json:"weight"`   // Weight for load balancing
+	Port     uint16 `json:"port"`     // Port number of the service
+	Target   string `json:"target"`   // Target hostname
+}
+```
+```go
+// SOARecord represents an SOA (Start of Authority) DNS record
+type SOARecord struct {
+	Ns      string `json:"ns"`      // Primary name server
+	MBox    string `json:"mbox"`    // Email address of the administrator
+	Refresh uint32 `json:"refresh"` // Refresh interval in seconds
+	Retry   uint32 `json:"retry"`   // Retry interval in seconds
+	Expire  uint32 `json:"expire"`  // Expiration time in seconds
+	MinTtl  uint32 `json:"minttl"`  // Minimum TTL in seconds
+}
+```
+```go
+// CAARecord represents a CAA (Certification Authority Authorization) DNS record
+type CAARecord struct {
+	Flag  uint8  `json:"flag"`  // Critical flag
+	Tag   string `json:"tag"`   // Property identifier
+	Value string `json:"value"` // Property value
+}
+```
+
+## Setup (as an external plugin)
+
+Add this as an external plugin in `plugin.cfg` file from CoreDNS repo
+
+```
+pocketbase:github.com/tinkernels/coredns-pocketbase
+```
+
+*P.S.place pocketbase above cache plugin is recommended.*
+
+Then run
+
+```shell script
+$ go generate
+$ go build
+```
+
+Add any required modules to CoreDNS code as prompted.
+
+## Credits
+
+Inspired by
+
+- [https://github.com/wenerme/coredns-pdsql](https://github.com/wenerme/coredns-pdsql)
+- [https://github.com/arvancloud/redis](https://github.com/arvancloud/redis)
+- [https://github.com/cloud66-oss/coredns_mysql](https://github.com/cloud66-oss/coredns_mysql)