print helpful error when IP address not allowed to access psql (#139)

pkg/tui/views/psql.go

@@ -3,6 +3,9 @@ package views
 import (
 	"context"
 	"fmt"
+	"io"
+	"net"
+	"net/http"
 	"os/exec"
 
 	tea "github.com/charmbracelet/bubbletea"
@@ -76,14 +79,62 @@ func loadDataPSQL(ctx context.Context, in *PSQLInput) (*exec.Cmd, error) {
 		return nil, err
 	}
 
-	connectionInfo, err := postgres.NewRepo(c).GetPostgresConnectionInfo(ctx, in.PostgresID)
+	pgc := postgres.NewRepo(c)
+
+	pg, err := pgc.GetPostgres(ctx, in.PostgresID)
+	if err != nil {
+		return nil, err
+	}
+
+	// only check access if error is nil in case ipify is down
+	userIP, ok := getUserIP()
+	if ok {
+		hasAccess, err := hasAccessToPostgres(pg, userIP)
+		if err != nil {
+			return nil, err
+		}
+
+		if !hasAccess {
+			return nil, fmt.Errorf("IP address (%s) not in allow list for %s", userIP, pg.Name)
+		}
+	}
+
+	connectionInfo, err := pgc.GetPostgresConnectionInfo(ctx, in.PostgresID)
 	if err != nil {
 		return nil, err
 	}
 
 	return exec.Command(string(in.Tool), connectionInfo.ExternalConnectionString), nil
 }
 
+func hasAccessToPostgres(pg *client.PostgresDetail, userIP net.IP) (bool, error) {
+	for _, allowedIPs := range pg.IpAllowList {
+		_, cidr, err := net.ParseCIDR(allowedIPs.CidrBlock)
+		if err != nil {
+			return false, err
+		}
+
+		if cidr.Contains(userIP) {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
+func getUserIP() (net.IP, bool) {
+	userIPRes, err := http.Get("https://api.ipify.org")
+	if err != nil {
+		return nil, false
+	}
+
+	userIPBytes, err := io.ReadAll(userIPRes.Body)
+	if err != nil {
+		return nil, false
+	}
+
+	return net.ParseIP(string(userIPBytes)), true
+}
+
 func (v *PSQLView) Init() tea.Cmd {
 	if v.postgresTable != nil {
 		return v.postgresTable.Init()