Parallelize Docker builds

Log output to docker/logs.

docker/.gitignore

@@ -0,0 +1,3 @@
+logs/*.log
+packages/
+unstable/*/bootstrap.ps1

docker/launch.sh

@@ -21,31 +21,39 @@ if [[ -z $DISTROS ]]; then
 fi
 
 for build in $BUILDS; do
-    # cd so $distro is only the distro name
-    pushd "$build"
+    # each distro can be done in parallel; but stable must be done before unstable
     for distro in $DISTROS; do
-        image="powershell/powershell:$build-$distro"
-        if [[ "$TEST" -eq 1 ]]; then
-            echo "Testing $image"
-            command="cd PowerShell; Import-Module ./build.psm1; Install-Dotnet -NoSudo; Start-PSPester -powershell powershell -Pester ./src/Modules/Shared/Pester"
-            # clone repo for stable images because it's not already done
-            if [[ "$build" = stable ]]; then
-                command="git clone --recursive https://github.com/$FORK/PowerShell -b $BRANCH; $command"
+        logfile="$build-$distro.log"
+        if [[ "$TEST" -eq 1 ]]; then logfile="test-$logfile"; fi
+        mkdir -p logs
+        logfile="logs/$logfile"
+        echo "Logging to docker/$logfile"
+        (
+            image="powershell/powershell:$build-$distro"
+            cd "$build"
+            if [[ "$TEST" -eq 1 ]]; then
+                echo "LOG: testing $image"
+                command="cd PowerShell; Import-Module ./build.psm1; Install-Dotnet -NoSudo; Start-PSPester -powershell powershell -Pester ./src/Modules/Shared/Pester"
+                # clone repo for stable images because it's not already done
+                if [[ "$build" = stable ]]; then
+                    command="git clone --recursive https://github.com/$FORK/PowerShell -b $BRANCH; $command"
+                fi
+                # run Pester tests inside container
+                # RUNARGS can be set in the environment
+                docker run $RUNARGS "$image" -c "$command"
+            else
+                echo "LOG: building $image"
+                # copy the common script because it lives outside the docker build context
+                if [[ "$build" = unstable ]]; then
+                    cp bootstrap.ps1 "$distro"
+                    buildargs="--build-arg fork=$FORK --build-arg branch=$BRANCH"
+                fi
+                # build and tag the image so they can be derived from
+                # BUILDARGS can be set in the environment
+                docker build $buildargs $BUILDARGS -t "$image" "$distro"
             fi
-            # run Pester tests inside container
-            # RUNARGS can be set in the environment
-            docker run -it $RUNARGS "$image" -c "$command"
-        else
-            echo "Building $image"
-            # copy the common script because it lives outside the docker build context
-            if [[ "$build" = unstable ]]; then
-                cp bootstrap.ps1 "$distro"
-                buildargs="--build-arg fork=$FORK --build-arg branch=$BRANCH"
-            fi
-            # build and tag the image so they can be derived from
-            # BUILDARGS can be set in the environment
-            docker build $buildargs $BUILDARGS -t "$image" "$distro"
-        fi
+        ) &>> "$logfile" &
     done
-    popd
+    echo "Waiting for $build containers to finish; tail the logs for more information."
+    wait
 done

docker/unstable/.gitignore

@@ -1 +0,0 @@
-*/bootstrap.ps1