Use JSON output for getting product versions

[radeksimko]

Currently we leverage the default (mainly human-readable) output of terraform version and consul version, but both have introduced JSON output which we could leverage and fall back to the default human output if parsing or execution fails.

https://www.terraform.io/docs/cli/commands/version.html#json
https://www.consul.io/commands/version#json-output

hc-install/product/terraform.go

Lines 29 to 49 in 9fcc92b

	GetVersion: func(ctx context.Context, path string) (*version.Version, error) {
	cmd := exec.CommandContext(ctx, path, "version")
	out, err := cmd.Output()
	if err != nil {
	return nil, err
	}
	stdout := strings.TrimSpace(string(out))
	submatches := terraformVersionOutputRe.FindStringSubmatch(stdout)
	if len(submatches) != 2 {
	return nil, fmt.Errorf("unexpected number of version matches %d for %s", len(submatches), stdout)
	}
	v, err := version.NewVersion(submatches[1])
	if err != nil {
	return nil, fmt.Errorf("unable to parse version %q: %w", submatches[1], err)
	}
	return v, err
	},

hc-install/product/consul.go

Lines 31 to 51 in 9fcc92b

	GetVersion: func(ctx context.Context, path string) (*version.Version, error) {
	cmd := exec.CommandContext(ctx, path, "version")
	out, err := cmd.Output()
	if err != nil {
	return nil, err
	}
	stdout := strings.TrimSpace(string(out))
	submatches := consulVersionOutputRe.FindStringSubmatch(stdout)
	if len(submatches) != 2 {
	return nil, fmt.Errorf("unexpected number of version matches %d for %s", len(submatches), stdout)
	}
	v, err := version.NewVersion(submatches[1])
	if err != nil {
	return nil, fmt.Errorf("unable to parse version %q: %w", submatches[1], err)
	}
	return v, err
	},