Improved many things.

Got parsing of VCAP right. And some testing.

cmd/check.go

@@ -0,0 +1,78 @@
+/*
+Copyright © 2024 NAME HERE <EMAIL ADDRESS>
+*/
+package cmd
+
+import (
+	"database/sql"
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+	"gov.gsa.fac.backups/internal/logging"
+	vcap "gov.gsa.fac.backups/internal/vcap"
+)
+
+func get_row_count(creds *vcap.RDSCreds, table string) int {
+	var count int
+	// FIXME: Not sure if `disable` is correct for RDS sslmode.
+	connStr := fmt.Sprintf("postgres://%s:%s@%s/%s?sslmode=disable",
+		creds.Username,
+		creds.Password,
+		creds.Host,
+		creds.DB_Name)
+	db, _ := sql.Open("postgres", connStr)
+	defer db.Close()
+	row := db.QueryRow(fmt.Sprintf("SELECT count(*) FROM %s", table))
+	if err := row.Scan(&count); err != nil {
+		logging.Logger.Printf("BACKUPS Could not get count of %s", table)
+	}
+	return count
+}
+
+func check_results(source *vcap.RDSCreds, dest *vcap.RDSCreds, tables []string) {
+	// FIXME: These won't exist in the VCAP_SERVICES version
+	// of the config. We'll have to always... load both?
+	// There needs to be a way to configure this in the remote env.
+	for _, table := range tables {
+		source_row_count := get_row_count(source, table)
+		dest_row_count := get_row_count(dest, table)
+		logging.Logger.Printf("CHECK OK %s source %d dest %d",
+			table, source_row_count, dest_row_count)
+		if source_row_count < dest_row_count {
+			logging.Logger.Printf("CHECK too many rows in '%s' source (%d < %d)",
+				table, source_row_count, dest_row_count)
+			os.Exit(-1)
+		}
+	}
+}
+
+// checkCmd represents the check command
+var checkCmd = &cobra.Command{
+	Use:   "check",
+	Short: "Checks table counts between source and destination",
+	Long: `
+When given a source and destination, this command returns 0 when the 
+number of rows in the source are equal to or higher than the number 
+of rows in the destination.
+
+This is because the clone tool is used against live tables. It is likely
+that the source will increase between the time of the clone and the check.
+
+Expects a space-separated list of table names as arguments.
+`,
+	Args: cobra.MinimumNArgs(1),
+	Run: func(cmd *cobra.Command, args []string) {
+		source_creds, dest_creds := vcap.GetCreds(SourceDB, DestinationDB)
+		check_results(source_creds, dest_creds, args)
+
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(checkCmd)
+	checkCmd.Flags().StringVarP(&SourceDB, "source-db", "", "", "source database (req)")
+	checkCmd.Flags().StringVarP(&DestinationDB, "destination-db", "", "", "destination database (req)")
+	checkCmd.MarkFlagRequired("source-db")
+	checkCmd.MarkFlagRequired("destination-db")
+}

cmd/clone.go

@@ -0,0 +1,99 @@
+/*
+Copyright © 2024 NAME HERE <EMAIL ADDRESS>
+*/
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/bitfield/script"
+	"github.com/spf13/cobra"
+	"gov.gsa.fac.backups/internal/logging"
+	vcap "gov.gsa.fac.backups/internal/vcap"
+
+	_ "github.com/lib/pq"
+)
+
+// https://bitfieldconsulting.com/golang/scripting
+func pg_dump(creds *vcap.RDSCreds) *script.Pipe {
+	// Compose the command as a slice
+	cmd := []string{
+		"pg_dump",
+		"--clean",
+		"--no-password",
+		"--if-exists",
+		"--no-privileges",
+		"--no-owner",
+		"--format plain",
+		"--dbname",
+		fmt.Sprintf("postgres://%s:%s@%s:%s/%s",
+			creds.Username,
+			creds.Password,
+			creds.Host,
+			creds.Port,
+			creds.DB_Name,
+		),
+	}
+	// Combine the slice for printing and execution.
+	combined := strings.Join(cmd[:], " ")
+	// This will log the password...
+	// logging.Logger.Printf("BACKUPS Running `%s`\n", combined)
+	logging.Logger.Printf("BACKUPS pg_dump targeting %s", creds.DB_Name)
+	return script.Exec(combined)
+}
+
+func psql(in_pipe *script.Pipe, creds *vcap.RDSCreds) *script.Pipe {
+	cmd := []string{
+		"psql",
+		"--no-password",
+		"--dbname",
+		fmt.Sprintf("postgres://%s:%s@%s:%s/%s",
+			creds.Username,
+			creds.Password,
+			creds.Host,
+			creds.Port,
+			creds.DB_Name,
+		),
+	}
+	combined := strings.Join(cmd[:], " ")
+	logging.Logger.Printf("BACKUPS psql targeting %s", creds.DB_Name)
+	return in_pipe.Exec(combined)
+}
+
+func clone(source *vcap.RDSCreds, dest *vcap.RDSCreds) {
+	psql_pipe := psql(pg_dump(source), dest)
+	psql_pipe.Wait()
+	if err := psql_pipe.Error(); err != nil {
+		logging.Logger.Println("BACKUPS Pipe failed")
+		os.Exit(-1)
+	}
+}
+
+// snapshotDbToDbCmd represents the snapshotDbToDb command
+var cloneCmd = &cobra.Command{
+	Use:   "clone",
+	Short: "pg_dump | psql, source to destination",
+	Long: `
+An imperfect, point-in-time snapshot.
+	
+This command copies the source database to the destination 
+database by streaming STDOUT of 'pg_dump' piped into the STNDIN 
+of 'psql'. The former reads from the FAC production database, and 
+writes to a snapshot clone DB.
+`,
+	Run: func(cmd *cobra.Command, args []string) {
+		source_creds, dest_creds := vcap.GetCreds(SourceDB, DestinationDB)
+		clone(source_creds, dest_creds)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(cloneCmd)
+	cloneCmd.Flags().StringVarP(&SourceDB, "source-db", "", "", "source database (req)")
+	cloneCmd.Flags().StringVarP(&DestinationDB, "destination-db", "", "", "destination database (req)")
+	cloneCmd.MarkFlagRequired("source-db")
+	cloneCmd.MarkFlagRequired("destination-db")
+
+}

cmd/root.go

@@ -9,15 +9,20 @@ import (
 	"github.com/spf13/cobra"
 )
 
-// rootCmd represents the base command when called without any subcommands
-var rootCmd = &cobra.Command{
-	Use:   "backups",
-	Short: "A tool for backing up, testing, and restoring",
-	Long:  ``,
-	// Uncomment the following line if your bare application
-	// has an action associated with it:
-	// Run: func(cmd *cobra.Command, args []string) { },
-}
+var (
+	SourceDB      string
+	DestinationDB string
+
+	// rootCmd represents the base command when called without any subcommands
+	rootCmd = &cobra.Command{
+		Use:   "backups",
+		Short: "A tool for backing up, testing, and restoring",
+		Long:  ``,
+		// Uncomment the following line if your bare application
+		// has an action associated with it:
+		// Run: func(cmd *cobra.Command, args []string) { },
+	}
+)
 
 // Execute adds all child commands to the root command and sets flags appropriately.
 // This is called by main.main(). It only needs to happen once to the rootCmd.

config.yaml

@@ -1,3 +1,7 @@
+# The keys "fac-db" and "fac-snapshot-db"
+# must match the names of the DBs in use.
+# Locally, these must be the names of the 
+# containers.
 fac-db:
   db_name: postgres
   host: 127.0.0.1