Update Drone pipeline to fix CentOS 7 repository.

Inject CentOS 7 tarballs into RPM repository to allow Teleport 8 to
continue to work on CentOS 7.

.drone.yml

@@ -1913,6 +1913,7 @@ clone:
   disable: true
 depends_on:
 - build-linux-amd64
+- build-linux-amd64-centos7
 steps:
 - name: Check out code
   image: docker:git
@@ -1950,6 +1951,10 @@ steps:
     /go/artifacts/
   - aws s3 cp s3://$AWS_S3_BUCKET/teleport/$${S3_PATH}teleport-ent-v$${VERSION}-linux-amd64-bin.tar.gz
     /go/artifacts/
+  - aws s3 cp s3://$AWS_S3_BUCKET/teleport/$${S3_PATH}teleport-v$${VERSION}-linux-amd64-centos7-bin.tar.gz
+    /go/artifacts/
+  - aws s3 cp s3://$AWS_S3_BUCKET/teleport/$${S3_PATH}teleport-ent-v$${VERSION}-linux-amd64-centos7-bin.tar.gz
+    /go/artifacts/
   environment:
     AWS_ACCESS_KEY_ID:
       from_secret: AWS_ACCESS_KEY_ID
@@ -1967,7 +1972,9 @@ steps:
   - mkdir -m0700 $GNUPG_DIR
   - echo "$GPG_RPM_SIGNING_ARCHIVE" | base64 -d | tar -xzf - -C $GNUPG_DIR
   - chown -R root:root $GNUPG_DIR
+  # Build mainline and CentOS 7 RPMs.
   - make rpm
+  - make rpm RPM_FLAGS="-c centos7"
   - rm -rf $GNUPG_DIR
   environment:
     ARCH: amd64
@@ -2045,6 +2052,7 @@ clone:
   disable: true
 depends_on:
 - build-linux-amd64-fips
+- build-linux-amd64-centos7-fips
 steps:
 - name: Check out code
   image: docker:git
@@ -2080,6 +2088,8 @@ steps:
     export S3_PATH="tag/"; fi
   - aws s3 cp s3://$AWS_S3_BUCKET/teleport/$${S3_PATH}teleport-ent-v$${VERSION}-linux-amd64-fips-bin.tar.gz
     /go/artifacts/
+  - aws s3 cp s3://$AWS_S3_BUCKET/teleport/$${S3_PATH}teleport-ent-v$${VERSION}-linux-amd64-centos7-fips-bin.tar.gz
+    /go/artifacts/
   environment:
     AWS_ACCESS_KEY_ID:
       from_secret: AWS_ACCESS_KEY_ID
@@ -2097,7 +2107,9 @@ steps:
   - mkdir -m0700 $GNUPG_DIR
   - echo "$GPG_RPM_SIGNING_ARCHIVE" | base64 -d | tar -xzf - -C $GNUPG_DIR
   - chown -R root:root $GNUPG_DIR
+  # Build mainline and CentOS 7 artifacts.
   - make -C e rpm
+  - make -C e rpm RPM_FLAGS="-c centos7"
   - rm -rf $GNUPG_DIR
   environment:
     ARCH: amd64
@@ -4604,7 +4616,7 @@ steps:
           echo "---> Publishing packages to repos for ${DRONE_TAG}"
         fi
 
-  - name: Download RPM repo contents
+  - name: "RPM: Download RPM repository"
     image: amazon/aws-cli
     environment:
       AWS_S3_BUCKET:
@@ -4618,15 +4630,24 @@ steps:
         path: /rpmrepo
     commands:
     - mkdir -p /rpmrepo/teleport/cache
-    # we explicitly want to delete anything present locally which has been deleted
-    # from the upstream S3 bucket
+    # Explicitly delete anything present locally before copying over new assets
+    # to ensure the repository remains in sync.
     - aws s3 sync s3://$AWS_S3_BUCKET/teleport/ /rpmrepo/teleport/ --delete
     - mkdir -p /rpmrepo/teleport/${DRONE_TAG##v}
-    - cp -a /go/artifacts/*.rpm /rpmrepo/teleport/${DRONE_TAG##v}/
+    # This is a hack for Teleport 8. Copy over CentOS 7 RPMs for x86_64 instead
+    # of the mainline RPMs which only run on CentOS 8+.
+    #
+    # In Teleport 9 we will switch the buildbox to CentOS 7 and no longer need
+    # to do this. This should never make it into master or branch/v9.
+    - cp -a /go/artifacts/*centos7.x86_64.rpm /rpmrepo/teleport/${DRONE_TAG##v}/
+    - cp -a /go/artifacts/*centos7-fips.x86_64.rpm /rpmrepo/teleport/${DRONE_TAG##v}/
+    - cp -a /go/artifacts/*arm.rpm /rpmrepo/teleport/${DRONE_TAG##v}/
+    - cp -a /go/artifacts/*arm64.rpm /rpmrepo/teleport/${DRONE_TAG##v}/
+    - cp -a /go/artifacts/*i386.rpm /rpmrepo/teleport/${DRONE_TAG##v}/
 
   # we do this using a CentOS 7 container to make sure that the repo files are
   # compatible with older versions, also there's no createrepo package in alpine main
-  - name: Regenerate RPM repo metadata
+  - name: "RPM: Regenerate RPM repository metadata"
     image: centos:7
     volumes:
       - name: rpmrepo
@@ -4635,7 +4656,7 @@ steps:
     - yum -y install createrepo
     - createrepo --cachedir /rpmrepo/teleport/cache --update /rpmrepo/teleport
 
-  - name: Sync RPM repo changes to S3
+  - name: "RPM: Publish RPM repository to S3"
     image: amazon/aws-cli
     environment:
       AWS_S3_BUCKET:
@@ -4760,6 +4781,6 @@ volumes:
       name: drone-s3-debrepo-pvc
 ---
 kind: signature
-hmac: bed10918e395a842810075ba8125364c264062ef2cb554a20bf5bf6e6d0e6195
+hmac: b3ea3b08231c8687650d3605f624cf5bacfbc8088e8567f43518079383f4adac
 
 ...