refactor(build): improve err when file specified by -f does not exist

When the user specifies a Containerfile or Dockfile with the -f flag in podman build, if the file does not exist, the error should be intuitive to the user.

Fixed: containers#22940

Signed-off-by: Kevin Cui <bh@bugs.cc>

cmd/podman/common/build.go

@@ -202,10 +202,7 @@ func ParseBuildOpts(cmd *cobra.Command, args []string, buildOpts *BuildFlagsWrap
 		// No context directory or URL was specified.  Try to use the home of
 		// the first locally-available Containerfile.
 		for i := range containerFiles {
-			if strings.HasPrefix(containerFiles[i], "http://") ||
-				strings.HasPrefix(containerFiles[i], "https://") ||
-				strings.HasPrefix(containerFiles[i], "git://") ||
-				strings.HasPrefix(containerFiles[i], "github.com/") {
+			if isURL(containerFiles[i]) {
 				continue
 			}
 			absFile, err := filepath.Abs(containerFiles[i])
@@ -239,6 +236,36 @@ func ParseBuildOpts(cmd *cobra.Command, args []string, buildOpts *BuildFlagsWrap
 		default:
 			return nil, fmt.Errorf("no Containerfile or Dockerfile specified or found in context directory, %s: %w", contextDir, syscall.ENOENT)
 		}
+	} else {
+		for _, f := range containerFiles {
+			if isURL(f) || f == "/dev/stdin" {
+				continue
+			}
+
+			// If it is a directory, skip it and let buildah handle the situation
+			// Because currently the podman CI runs the test script buildah/test/bud.bats,
+			// which checks if the error is a certain string. If we handle it here,
+			// it will cause the buildah tests to never pass (unless we use the same string).
+			// See: https://github.com/containers/buildah/blob/4c781b59b49d66e07324566555339888113eb7e2/imagebuildah/build.go#L139-L141
+			// 	    https://github.com/containers/buildah/blob/4c781b59b49d66e07324566555339888113eb7e2/tests/bud.bats#L3474-L3479
+			//      https://api.cirrus-ci.com/v1/artifact/task/4705206577922048/html/bud-remote-fedora-40-root-host-sqlite.log.html
+			if utils.IsDir(f) {
+				continue
+			}
+
+			// If the file is not found, try again with context directory prepended (if not prepended yet)
+			// Ref: https://github.com/containers/buildah/blob/4c781b59b49d66e07324566555339888113eb7e2/imagebuildah/build.go#L125-L135
+			if utils.FileExists(f) {
+				continue
+			}
+			if !strings.HasPrefix(f, contextDir) {
+				if utils.FileExists(filepath.Join(contextDir, f)) {
+					continue
+				}
+			}
+
+			return nil, fmt.Errorf("the specified Containerfile or Dockerfile does not exist, %s: %w", f, syscall.ENOENT)
+		}
 	}
 
 	var logFile *os.File
@@ -628,3 +655,10 @@ func parseDockerignore(ignoreFile string) ([]string, error) {
 	}
 	return excludes, nil
 }
+
+func isURL(s string) bool {
+	return strings.HasPrefix(s, "http://") ||
+		strings.HasPrefix(s, "https://") ||
+		strings.HasPrefix(s, "git://") ||
+		strings.HasPrefix(s, "github.com/")
+}

test/e2e/build_test.go

@@ -94,6 +94,28 @@ var _ = Describe("Podman build", func() {
 		Expect(session).Should(ExitCleanly())
 	})
 
+	It("podman build with not found Containerfile or Dockerfile", func() {
+		cwd, err := os.Getwd()
+		Expect(err).ToNot(HaveOccurred())
+
+		targetPath := filepath.Join(podmanTest.TempDir, "notfound")
+		err = os.Mkdir(targetPath, 0755)
+		Expect(err).ToNot(HaveOccurred())
+
+		Expect(os.Chdir(targetPath)).To(Succeed())
+		defer func() {
+			Expect(os.Chdir(cwd)).To(Succeed())
+		}()
+
+		session := podmanTest.Podman([]string{"build", "."})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(ExitWithError(125, "no Containerfile or Dockerfile specified or found in context director"))
+
+		session = podmanTest.Podman([]string{"build", "-f", "foo"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(ExitWithError(125, "the specified Containerfile or Dockerfile does not exist"))
+	})
+
 	It("podman build with logfile", func() {
 		logfile := filepath.Join(podmanTest.TempDir, "logfile")
 		session := podmanTest.Podman([]string{"build", "--pull=never", "--tag", "test", "--logfile", logfile, "build/basicalpine"})