[CI] Run Docker builds in the right directory.

Make sure we run the Docker builds in the directory containing the
Dockerfile.  Also, prefer lists of arguments rather than strings,
especially when including filenames.

ci_test.py

@@ -16,19 +16,20 @@
 import urllib.request
 import json
 import subprocess
+import shlex
 import sys
 import os
 
 
-def run_command(cmd, log_file=None):
+def run_command(cmd, log_file=None, cwd=None):
     print("Running: {}".format(cmd))
     sys.stdout.flush()
     if log_file:
         file = open(log_file, "w")
-        p = subprocess.Popen(cmd, shell=True, stdout=file, stderr=file)
     else:
-        p = subprocess.Popen(cmd, shell=True)
-
+        file = None
+    p = subprocess.Popen(cmd, shell=True, cwd=cwd, stdout=file, stderr=file)
+
     (output, err) = p.communicate()
     return p.wait()
 
@@ -63,29 +64,44 @@ def main():
     suite_status = True
     dockerfiles = get_dockerfiles()
     for dockerfile in dockerfiles:
-        docker_dir = os.path.dirname(os.path.realpath(__file__))
+        docker_dir,dockerfile_name = os.path.split(os.path.realpath(dockerfile))
+
         print("Testing {}".format(dockerfile))
         sys.stdout.flush()
-        log_file = dockerfile.replace(docker_dir,"").replace("/", "_")
+        log_file = dockerfile_name.replace("/", "_")
         log_file = "{}.log".format(log_file)
-        cmd = "docker build --no-cache=true -f {dockerfile} .".format(dockerfile=dockerfile)
+        cmd = [
+            'docker', 'build', '--no-cache=true',
+            '-f', dockerfile,
+            '.'
+        ]
         if "buildx" in dockerfile:
             # if "buildx" is part of the path, we want to use the new buildx build system and build
             # for both amd64 and arm64.
-            cmd = "docker buildx create --use"
-            run_command(cmd, log_file)
-            cmd = "docker buildx inspect --bootstrap"
-            run_command(cmd, log_file)
-            cmd = "docker buildx build --platform linux/arm64,linux/amd64 --no-cache=true -f {dockerfile} .".format(dockerfile=dockerfile)
-        status = run_command(cmd, log_file)
+            run_command("docker buildx create --use",
+                        log_file=log_file, cwd=docker_dir)
+            run_command("docker buildx inspect --bootstrap",
+                        log_file=log_file, cwd=docker_dir)
+
+            cmd = [
+                'docker', 'buildx', 'build',
+                '--platform', 'linux/arm64,linux/amd64',
+                '--no-cache=true',
+                '-f', dockerfile,
+                '.'
+            ]
+
+        status = run_command(cmd, log_file=log_file, cwd=docker_dir)
         results[dockerfile] = status
         if status != 0:
             suite_status = False
             results[dockerfile] = "FAILED"
         else:
             results[dockerfile] = "PASSED"
 
-        cmd = "mv {log} {results}{log}".format(log=log_file, results=results[dockerfile])
+        cmd = [
+            'mv', log_file, results[dockerfile] + log_file
+        ]
         run_command(cmd)
         print("[{}] - {}".format(results[dockerfile], dockerfile))
         sys.stdout.flush()