Rewrite of the entrypoint in Golang (#71)

- General improvements
    - Parallel download of only needed files at start
    - Prettier console output with all streams merged (openvpn, unbound, shadowsocks etc.)
    - Simplified Docker final image
    - Faster bootup
- DNS over TLS
    - Finer grain blocking at DNS level: malicious, ads and surveillance
    - Choose your DNS over TLS providers
    - Ability to use multiple DNS over TLS providers for DNS split horizon
    - Environment variables for DNS logging
    - DNS block lists needed are downloaded and built automatically at start, in parallel
- PIA
    - A random region is selected if the REGION parameter is left empty (thanks @rorph for your PR)
    - Routing and iptables adjusted so it can work as a Kubernetes pod sidecar (thanks @rorph for your PR)

internal/params/tinyproxy.go

@@ -0,0 +1,94 @@
+package params
+
+import (
+	"strconv"
+
+	libparams "github.com/qdm12/golibs/params"
+	"github.com/qdm12/private-internet-access-docker/internal/models"
+)
+
+// GetTinyProxy obtains if TinyProxy is on from the environment variable
+// TINYPROXY, and using PROXY as a retro-compatibility name
+func (p *paramsReader) GetTinyProxy() (activated bool, err error) {
+	// Retro-compatibility
+	s, err := p.envParams.GetEnv("PROXY")
+	if err != nil {
+		return false, err
+	} else if len(s) != 0 {
+		p.logger.Warn("You are using the old environment variable PROXY, please consider changing it to TINYPROXY")
+		return p.envParams.GetOnOff("PROXY", libparams.Compulsory())
+	}
+	return p.envParams.GetOnOff("TINYPROXY", libparams.Default("off"))
+}
+
+// GetTinyProxyLog obtains the TinyProxy log level from the environment variable
+// TINYPROXY_LOG, and using PROXY_LOG_LEVEL as a retro-compatibility name
+func (p *paramsReader) GetTinyProxyLog() (models.TinyProxyLogLevel, error) {
+	// Retro-compatibility
+	s, err := p.envParams.GetEnv("PROXY_LOG_LEVEL")
+	if err != nil {
+		return models.TinyProxyLogLevel(s), err
+	} else if len(s) != 0 {
+		p.logger.Warn("You are using the old environment variable PROXY_LOG_LEVEL, please consider changing it to TINYPROXY_LOG")
+		s, err = p.envParams.GetValueIfInside("PROXY_LOG_LEVEL", []string{"info", "warning", "error", "critical"}, libparams.Compulsory())
+		return models.TinyProxyLogLevel(s), err
+	}
+	s, err = p.envParams.GetValueIfInside("TINYPROXY_LOG", []string{"info", "warning", "error", "critical"}, libparams.Default("info"))
+	return models.TinyProxyLogLevel(s), err
+}
+
+// GetTinyProxyPort obtains the TinyProxy listening port from the environment variable
+// TINYPROXY_PORT, and using PROXY_PORT as a retro-compatibility name
+func (p *paramsReader) GetTinyProxyPort() (port uint16, err error) {
+	// Retro-compatibility
+	portStr, err := p.envParams.GetEnv("PROXY_PORT")
+	if err != nil {
+		return 0, err
+	} else if len(portStr) != 0 {
+		p.logger.Warn("You are using the old environment variable PROXY_PORT, please consider changing it to TINYPROXY_PORT")
+	} else {
+		portStr, err = p.envParams.GetEnv("TINYPROXY_PORT", libparams.Default("8888"))
+		if err != nil {
+			return 0, err
+		}
+	}
+	if err := p.verifier.VerifyPort(portStr); err != nil {
+		return 0, err
+	}
+	portUint64, err := strconv.ParseUint(portStr, 10, 16)
+	return uint16(portUint64), err
+}
+
+// GetTinyProxyUser obtains the TinyProxy server user from the environment variable
+// TINYPROXY_USER, and using PROXY_USER as a retro-compatibility name
+func (p *paramsReader) GetTinyProxyUser() (user string, err error) {
+	defer p.unsetEnv("PROXY_USER")
+	defer p.unsetEnv("TINYPROXY_USER")
+	// Retro-compatibility
+	user, err = p.envParams.GetEnv("PROXY_USER")
+	if err != nil {
+		return user, err
+	}
+	if len(user) != 0 {
+		p.logger.Warn("You are using the old environment variable PROXY_USER, please consider changing it to TINYPROXY_USER")
+		return user, nil
+	}
+	return p.envParams.GetEnv("TINYPROXY_USER")
+}
+
+// GetTinyProxyPassword obtains the TinyProxy server password from the environment variable
+// TINYPROXY_PASSWORD, and using PROXY_PASSWORD as a retro-compatibility name
+func (p *paramsReader) GetTinyProxyPassword() (password string, err error) {
+	defer p.unsetEnv("PROXY_PASSWORD")
+	defer p.unsetEnv("TINYPROXY_PASSWORD")
+	// Retro-compatibility
+	password, err = p.envParams.GetEnv("PROXY_PASSWORD")
+	if err != nil {
+		return password, err
+	}
+	if len(password) != 0 {
+		p.logger.Warn("You are using the old environment variable PROXY_PASSWORD, please consider changing it to TINYPROXY_PASSWORD")
+		return password, nil
+	}
+	return p.envParams.GetEnv("TINYPROXY_PASSWORD")
+}