From bc4e49734be5d73f485b30f49f97c00d26a6d156 Mon Sep 17 00:00:00 2001
From: aviau <alexandre@alexandreviau.net>
Date: Fri, 22 Jan 2021 09:19:29 -0500
Subject: [PATCH] images/haveImageID: use docker images, not inspect

Docker inspect will not exit 0 if no version of the image is available
on the machine, leading to the method failing. There is no flag to
adjust this in docker inspect, the only solution would be to parse the
error message but that would be fragile.

Instead, we opt to use `docker images` which has a very similar output
with the exception that it will list all tags available for that image
and that it will not fail on absent images.
---
 internal/images/docker.go | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/internal/images/docker.go b/internal/images/docker.go
index b150f3b2b..667363b1d 100644
--- a/internal/images/docker.go
+++ b/internal/images/docker.go
@@ -17,6 +17,7 @@ limitations under the License.
 package images // import "perkeep.org/internal/images"
 
 import (
+	"bufio"
 	"bytes"
 	"errors"
 	"fmt"
@@ -66,12 +67,26 @@ func haveDocker() bool {
 }
 
 func haveImageID(name, id string) (ok bool, err error) {
-	out, err := exec.Command("docker", "inspect", "-f", "{{.Id}}", name).Output()
+	out, err := exec.Command(
+		"docker",
+		"images",
+		"--quiet",
+		"--no-trunc",
+		"--format",
+		"{{.ID}}",
+		name,
+	).Output()
 	if err != nil {
 		return false, err
 	}
-	have := strings.TrimSpace(string(out))
-	return have == id, nil
+	scanner := bufio.NewScanner(bytes.NewReader(out))
+	for scanner.Scan() {
+		line := strings.TrimSpace((scanner.Text()))
+		if line == id {
+			return true, nil
+		}
+	}
+	return false, nil
 }
 
 // Pull retrieves the docker image with 'docker pull'.