use etchosts package from c/common

Use the new logic from c/common to create the hosts file. This will help
to better allign the hosts files between buildah and podman.

Also this fixes several bugs:
- remove host entries when container is stopped and has a netNsCtr
- add entries for containers in a pod
- do not duplicate entries in the hosts file
- use the correct slirp ip when an userns is used

Features:
- configure host.containers.internal entry in containers.conf
- configure base hosts file in containers.conf

Fixes #12003
Fixes #13224

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

3 files changed, 35 insertions, 3 deletions

diff --git a/test/system/030-run.bats b/test/system/030-run.bats
index 526003c2d..31db5f1c4 100644
--- a/test/system/030-run.bats
+++ b/test/system/030-run.bats
@@ -782,7 +782,7 @@ EOF
     mv $hosts_tmp /etc/hosts
     assert "$status" = 0 \
            "podman run without /etc/hosts file should work"
-    assert "$output" =~ "^1\.2\.3\.4 foo.com.*" \
+    assert "$output" =~ "^1\.2\.3\.4[[:blank:]]foo\.com.*" \
            "users can add hosts even without /etc/hosts"
 }
 
diff --git a/test/system/200-pod.bats b/test/system/200-pod.bats
index 56449dcad..ef4bf1a6c 100644
--- a/test/system/200-pod.bats
+++ b/test/system/200-pod.bats
@@ -250,7 +250,7 @@ EOF
     is "$output" ".*invalid config provided: cannot set hostname when joining the pod UTS namespace: invalid configuration" "--hostname should not be allowed in share UTS pod"
 
     run_podman run --rm --pod $pod_id $IMAGE cat /etc/hosts
-    is "$output" ".*$add_host_ip $add_host_n" "--add-host was added"
+    is "$output" ".*$add_host_ip[[:blank:]]$add_host_n" "--add-host was added"
     is "$output" ".*	$hostname"            "--hostname is in /etc/hosts"
     #               ^^^^ this must be a tab, not a space
 
diff --git a/test/system/500-networking.bats b/test/system/500-networking.bats
index 3bfc58a07..f5bb76d9a 100644
--- a/test/system/500-networking.bats
+++ b/test/system/500-networking.bats
@@ -133,14 +133,46 @@ load helpers
     done
 }
 
+@test "podman pod manages /etc/hosts correctly" {
+    local pod_name=pod-$(random_string 10)
+    local infra_name=infra-$(random_string 10)
+    local con1_name=con1-$(random_string 10)
+    local con2_name=con2-$(random_string 10)
+    run_podman pod create --name $pod_name  --infra-name $infra_name
+    pid="$output"
+    run_podman run --pod $pod_name --name $con1_name $IMAGE cat /etc/hosts
+    is "$output" ".*\s$pod_name $infra_name.*" "Pod hostname in /etc/hosts"
+    is "$output" ".*127.0.0.1\s.*$con1_name.*" "Container1 name in /etc/hosts"
+    # get the length of the hosts file
+    old_lines=${#lines[@]}
+
+    # since the first container should be cleaned up now we should only see the
+    # new host entry and the old one should be removed (lines check)
+    run_podman run --pod $pod_name --name $con2_name $IMAGE cat /etc/hosts
+    is "$output" ".*\s$pod_name $infra_name.*" "Pod hostname in /etc/hosts"
+    is "$output" ".*127.0.0.1\s.*$con2_name.*" "Container2 name in /etc/hosts"
+    is "${#lines[@]}" "$old_lines" "Number of hosts lines is equal"
+
+    run_podman pod rm $pod_name
+    is "$output" "$pid" "Only ID in output (no extra errors)"
+}
+
 @test "podman run with slirp4ns assigns correct addresses to /etc/hosts" {
     CIDR="$(random_rfc1918_subnet)"
     IP=$(hostname -I | cut -f 1 -d " ")
     local conname=con-$(random_string 10)
     run_podman run --rm --network slirp4netns:cidr="${CIDR}.0/24" \
                 --name $conname --hostname $conname $IMAGE cat /etc/hosts
-    is "$output"   ".*${IP}	host.containers.internal"   "host.containers.internal should be the cidr+2 address"
+    is "$output"   ".*${IP}	host.containers.internal"   "host.containers.internal should be host address"
     is "$output"   ".*${CIDR}.100	$conname $conname"   "$conname should be the cidr+100 address"
+
+    if is_rootless; then
+    # check the slirp ip also works correct with userns
+        run_podman run --rm --userns keep-id --network slirp4netns:cidr="${CIDR}.0/24" \
+                --name $conname --hostname $conname $IMAGE cat /etc/hosts
+        is "$output"   ".*${IP}	host.containers.internal"   "host.containers.internal should be host address"
+        is "$output"   ".*${CIDR}.100	$conname $conname"   "$conname should be the cidr+100 address"
+    fi
 }
 
 @test "podman run with slirp4ns adds correct dns address to resolv.conf" {