Merge pull request #524 from mutagen-io/v018-backports

all: backport Docker transport fix in #523

.github/workflows/ci.yml

@@ -31,7 +31,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
-          go-version: '1.23.2'
+          go-version: '1.23.6'
       - name: "Install sha256sum"
         run: brew install coreutils
       - run: scripts/ci/setup_go.sh
@@ -72,7 +72,7 @@ jobs:
     timeout-minutes: 30
     strategy:
       matrix:
-        goversion: ['1.22.8', '1.23.2']
+        goversion: ['1.22.12', '1.23.6']
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
@@ -93,7 +93,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
-          go-version: '1.23.2'
+          go-version: '1.23.6'
       - run: scripts/ci/setup_go.sh
         shell: bash
       - run: scripts/ci/setup_docker.sh
@@ -127,7 +127,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
-          go-version: '1.23.2'
+          go-version: '1.23.6'
       - uses: docker/setup-qemu-action@v3
       - uses: docker/setup-buildx-action@v3
       - uses: docker/login-action@v3

images/sidecar/linux/Dockerfile

@@ -1,5 +1,5 @@
 # Use an Alpine-based Go builder.
-FROM golang:1.23.2-alpine3.20 AS builder
+FROM golang:1.23.6-alpine3.21 AS builder
 
 # Disable cgo in order to match the behavior of our release binaries (and to
 # avoid the need for gcc on certain architectures).
@@ -21,7 +21,7 @@ RUN ["go", "build", "-o", "mutagen-agent-sspl", "-tags", "mutagenagent,mutagenss
 
 
 # Switch to a vanilla Alpine base for the final image.
-FROM alpine:3.20 AS base
+FROM alpine:3.21 AS base
 
 # Copy the sidecar entry point from the builder.
 COPY --from=builder ["/mutagen/mutagen-sidecar", "/usr/bin/mutagen-sidecar"]

pkg/agent/transport/docker/transport.go

@@ -509,6 +509,20 @@ func (t *dockerTransport) ClassifyError(processState *os.ProcessState, errorOutp
 		return false, false, fmt.Errorf("unable to probe container: %w", err)
 	}
 
+	// Check if the error code indicates that an agent installation attempt is
+	// warranted. In Docker v28.0.0 and later, the exit codes for "invalid
+	// command" and "command not found" are properly delineated (into 126 and
+	// 127, respectively). Prior to that, they were both returned as 126. The
+	// remainder of this comment applies to pre-v28.0.0 Docker versions and is
+	// retained for posterity. It makes suggestions about how we might use these
+	// delineated values to better detect Windows containers, which might be an
+	// optimization worth pursuing at some point, but it would involve probing
+	// the Docker engine version and adjusting behavior accordingly. Also, this
+	// new delineated behavior might not apply on Windows, so we'd need to check
+	// that first.
+	//
+	// For Docker pre-v28.0.0:
+	//
 	// Docker alises cases of both "invalid command" (POSIX shell error 126) and
 	// "command not found" (POSIX shell error 127) to an exit code of 126. It
 	// even aliases the Windows container equivalents of these errors to 126.
@@ -533,7 +547,8 @@ func (t *dockerTransport) ClassifyError(processState *os.ProcessState, errorOutp
 	// Anyway, the exit code we need to look out for with both POSIX and Windows
 	// containers is 126, and since we know the remote platform already, we can
 	// return that information without needing to resort to the error string.
-	if !process.IsPOSIXShellInvalidCommand(processState) {
+	if !(process.IsPOSIXShellInvalidCommand(processState) ||
+		process.IsPOSIXShellCommandNotFound(processState)) {
 		return false, false, errors.New("unknown process exit error")
 	}
 

scripts/ci/docker/linux/Dockerfile

@@ -1,5 +1,5 @@
 # Set the base image.
-FROM alpine:3.20
+FROM alpine:3.21
 
 # Add the HTTP demo server.
 COPY ["httpdemo", "/httpdemo"]