Add support for provisioning and rebuilding via interface

internal/models/instances_system.go

@@ -0,0 +1,50 @@
+package models
+
+// System represents system information.
+// It is embedded into the instances struct by gorm.
+type System struct {
+	// NOTE(twiesing): Any changes here should be reflected in instance_{provision,rebuild}.html and remote/api.ts.
+	PHP                string `gorm:"column:php;not null"`
+	OpCacheDevelopment bool   `gorm:"column:opcache_devel;not null"`
+}
+
+const (
+	imagePrefix = "docker.io/library/php:"
+	imageSuffix = "-apache-bullseye"
+)
+
+// OpCacheMode returns the name of the `opcache-*.ini` configuration being included in the docker image
+func (system System) OpCacheMode() string {
+	if system.OpCacheDevelopment {
+		return "devel"
+	}
+	return "prod"
+}
+
+var (
+	phpVersions   = []string{"8.0", "8.1", "8.2"}
+	phpVersionMap = (func() map[string]struct{} {
+		m := make(map[string]struct{}, len(phpVersions))
+		for _, v := range phpVersions {
+			m[v] = struct{}{}
+		}
+		return m
+	})()
+)
+
+// DefaultPHPVersion is the default php version
+const DefaultPHPVersion = "8.1"
+
+// KnownPHPVersions returns a slice of php versions.
+func KnownPHPVersions() []string {
+	return append([]string(nil), phpVersions...)
+}
+
+// GetDockerBaseImage returns the docker base image used by the given system.
+func (system System) GetDockerBaseImage() string {
+	version := DefaultPHPVersion
+	if _, ok := phpVersionMap[system.PHP]; ok {
+		version = system.PHP
+	}
+	return imagePrefix + version + imageSuffix
+}