How and where can I see Docker image deployment structure?

Question

I recently deployed docker image (jre 8) and run the application on mac. It is telling me there are files missing and I couldn't figure out where this file is deployed (it was supposed to be in the root folder) but the application couldn't find it.

I appericiate your help.

EDIT:

I have this code

InputStream pkcs12Cert=new SharedFileInputStream("certFile.pfx"); 

"certFile.pfx" is in root directory and when I run my app in Intelij, it works without any problem but on docker this line code throws file not found exception.

Here is part of the pom file

<properties>
  <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
  <dropwizard.version>1.0.2</dropwizard.version>
  <mainClass>com.MainApp</mainClass>

  <docker.registry.name> </docker.registry.name>
  <docker.repository.name>${docker.registry.name}emp/${project.artifactId}</docker.repository.name>
</properties>

<build>
  <plugins>
    <plugin>
      <groupId>org.jolokia</groupId>
      <artifactId>docker-maven-plugin</artifactId>
      <version>0.13.3</version>
      <configuration>
        <images>
          <image>
            <alias>${project.artifactId}</alias>
            <name>${docker.repository.name}:${project.version}</name>
            <build>
              <from>java:8-jre</from>
              <maintainer>com.emp</maintainer>
              <assembly>
                <descriptor>docker-assembly.xml</descriptor>
              </assembly>
              <ports>
                <port>8080</port>
                <port>8181</port>
              </ports>
              <cmd>
                <!-- Setting local timezone and than start a server-->
                <shell>echo "CA" > /etc/timezone \
                  &amp;&amp; dpkg-reconfigure -f noninteractive tzdata \
                  &amp;&amp; mkdir /tz \
                  &amp;&amp; cp /etc/timezone /tz/ \
                  &amp;&amp; cp /etc/localtime /tz/ \
                  &amp;&amp; java -jar \
                  /maven/${project.build.finalName}.jar server \
                  /maven/emp.yml</shell>
              </cmd>
            </build>
          </image>
        </images>
      </configuration>
    </plugin>
  </plugins>
</build>