chore: add container workflow

Author: sureshg

.github/workflows/build.yml

@@ -38,6 +38,7 @@ jobs:
     outputs:
       version: ${{ steps.gradle-build.outputs.version }}
       artifact_name: ${{ steps.gradle-build.outputs.uberjar_name }}
+      artifact_path: ${{ steps.gradle-build.outputs.uberjar_path }}
 
     runs-on: ${{ matrix.os }}
     strategy:
@@ -151,4 +152,38 @@ jobs:
             ${{ github.workspace }}/release-artifacts/**
           fail_on_unmatched_files: true
         env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+  container-build:
+    name: Run Java app on OpenJDK
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: true
+      matrix:
+        jdk: [ "17" ]
+
+    container:
+      # openjdk:17-jdk-alpine
+      image: openjdk:${{ matrix.jdk }}-slim-buster
+
+    steps:
+      - name: Check out the source code
+        uses: actions/checkout@v2
+
+      - name: Run Java App on OpenJDK ${{ matrix.jdk }} container image
+        if: always()
+        run: |
+          java --show-version src/main/java/JavaApp.java
+        env:
+          RUNNER_CONTEXT: ${{ toJson(runner) }}
+
+      - name: Github Action Contexts
+        run: |
+          echo "$JOB_CONTEXT"
+          echo "$STEPS_CONTEXT"
+          echo "$RUNNER_CONTEXT"
+        env:
+          JOB_CONTEXT: ${{ toJson(job) }}
+          STEPS_CONTEXT: ${{ toJson(steps) }}
+          RUNNER_CONTEXT: ${{ toJson(runner) }}

src/main/java/JavaApp.java

@@ -0,0 +1,84 @@
+import static java.lang.System.out;
+
+import java.io.File;
+import java.net.InetAddress;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.security.KeyStore;
+import java.time.ZoneId;
+import java.util.Arrays;
+import java.util.HexFormat;
+import java.util.Locale;
+import javax.net.ssl.TrustManagerFactory;
+import javax.net.ssl.X509TrustManager;
+
+public class JavaApp {
+
+  public static void main(String[] args) throws Exception {
+
+    final var lineSep =  System.lineSeparator();
+
+    out.printf("%n✧✧✧✧✧ Processes ✧✧✧✧✧%n");
+    var ps = ProcessHandle.allProcesses()
+        .sorted(ProcessHandle::compareTo)
+        .toList();
+    ps.forEach(p -> {
+      var pInfo = p.pid() + " : " + p.info();
+      out.println(pInfo);
+    });
+
+    out.printf("%n✧✧✧✧✧ Trust stores ✧✧✧✧✧%n");
+    var tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
+    tmf.init((KeyStore) null);
+    var issuers = Arrays.stream(tmf.getTrustManagers()).flatMap(tm -> {
+      var x509Tm = (X509TrustManager) tm;
+      return Arrays.stream(x509Tm.getAcceptedIssuers());
+    }).toList();
+    issuers.forEach(cert -> out.println(cert.getIssuerX500Principal()));
+
+    out.printf("%n✧✧✧✧✧ Dns Resolution ✧✧✧✧✧%n");
+    var dns = Arrays.stream(InetAddress.getAllByName("google.com")).toList();
+    dns.forEach(out::println);
+
+    out.printf("%n✧✧✧✧✧ TimeZones ✧✧✧✧✧%n");
+    var tz = ZoneId.getAvailableZoneIds();
+    tz.forEach(out::println);
+
+    out.printf("%n✧✧✧✧✧ Charsets ✧✧✧✧✧%n");
+    var cs = Charset.availableCharsets();
+    cs.forEach((name, charSet) -> out.println(name + " : " + charSet));
+
+    out.printf("%n✧✧✧✧✧ System Locales ✧✧✧✧✧%n");
+    var locales = Locale.getAvailableLocales();
+    for (Locale locale : locales) {
+      out.println(locale);
+    }
+
+    out.printf("%n✧✧✧✧✧ Env Variables ✧✧✧✧✧%n");
+    var env =  System.getenv();
+    env.forEach((k, v) -> out.println(k + " : " + v));
+
+    out.printf("%n✧✧✧✧✧ System Properties ✧✧✧✧✧%n");
+    var props = System.getProperties();
+    props.forEach((k, v) -> out.println(k + " : " + v));
+
+    var lineSepHex = HexFormat.of().formatHex(lineSep.getBytes(StandardCharsets.UTF_8));
+    out.printf("%n✧✧✧✧✧ LineSeparator = %s%n", lineSepHex);
+    out.printf("%n✧✧✧✧✧ File PathSeparator = %s%n", File.pathSeparator);
+
+    var stats = """
+        +------------------------+
+        | Processes      : %5d |
+        | Dns Addresses  : %5d |
+        | Trust Stores   : %5d |
+        | TimeZones      : %5d |
+        | CharSets       : %5d |
+        | Locales        : %5d |
+        | Env Vars       : %5d |
+        | Sys Props      : %5d |
+        +------------------------+
+        """.formatted(ps.size(), dns.size(), issuers.size(), tz.size(), cs.size(),locales.length, env.size(),props.size());
+
+    out.println(stats);
+  }
+}