alioth/nixpkgs
3
0
Fork 0
forked from mirrors/nixpkgs
Code Releases Activity

{ec2,openstack}-metadata-fetcher: unconditionally fetch metadata

Browse source 
The metadata fetcher scripts run each time an instance starts, and it
is not safe to assume that responses from the instance metadata
service (IMDS) will be as they were on first boot.

Example: an EC2 instance can have its user data changed while
the instance is stopped. When the instance is restarted, we want to
see the new user data applied.
This commit is contained in:
Jack Kelly 2020-11-21 11:44:25 +10:00
parent 8c39655de3
commit 43bfd7e5b1
2 changed files with 18 additions and 30 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

24
nixos/modules/virtualisation/ec2-metadata-fetcher.nix
View file

@ -8,9 +8,14 @@
# Make sure that every package you depend on here is already listed as
# a channel blocker for both the full-sized and small channels.
# Otherwise, we risk breaking user deploys in released channels.
#
# Also note: OpenStack's metadata service for its instances aims to be
# compatible with the EC2 IMDS. Where possible, try to keep the set of
# fetched metadata in sync with ./openstack-metadata-fetcher.nix .
''
metaDir=${targetRoot}etc/ec2-metadata
mkdir -m 0755 -p "$metaDir"
rm -f "$metaDir/*"
get_imds_token() {
# retry-delay of 1 selected to give the system a second to get going,
@ -65,19 +70,8 @@
wget ${wgetExtraOptions} --header "X-aws-ec2-metadata-token: $IMDS_TOKEN" "$@";
}
if ! [ -e "$metaDir/ami-manifest-path" ]; then
wget_imds -O "$metaDir/ami-manifest-path" http://169.254.169.254/1.0/meta-data/ami-manifest-path
fi
if ! [ -e "$metaDir/user-data" ]; then
wget_imds -O "$metaDir/user-data" http://169.254.169.254/1.0/user-data && chmod 600 "$metaDir/user-data"
fi
if ! [ -e "$metaDir/hostname" ]; then
wget_imds -O "$metaDir/hostname" http://169.254.169.254/1.0/meta-data/hostname
fi
if ! [ -e "$metaDir/public-keys-0-openssh-key" ]; then
wget_imds -O "$metaDir/public-keys-0-openssh-key" http://169.254.169.254/1.0/meta-data/public-keys/0/openssh-key
fi
wget_imds -O "$metaDir/ami-manifest-path" http://169.254.169.254/1.0/meta-data/ami-manifest-path
wget_imds -O "$metaDir/user-data" http://169.254.169.254/1.0/user-data && chmod 600 "$metaDir/user-data"
wget_imds -O "$metaDir/hostname" http://169.254.169.254/1.0/meta-data/hostname
wget_imds -O "$metaDir/public-keys-0-openssh-key" http://169.254.169.254/1.0/meta-data/public-keys/0/openssh-key
''

24
nixos/modules/virtualisation/openstack-metadata-fetcher.nix
View file

@ -1,7 +1,12 @@
{ targetRoot, wgetExtraOptions }:
# OpenStack's metadata service aims to be EC2-compatible. Where
# possible, try to keep the set of fetched metadata in sync with
# ./ec2-metadata-fetcher.nix .
''
metaDir=${targetRoot}etc/ec2-metadata
mkdir -m 0755 -p "$metaDir"
rm -f "$metaDir/*"
echo "getting instance metadata..."
@ -9,19 +14,8 @@
wget ${wgetExtraOptions} "$@"
}
if ! [ -e "$metaDir/ami-manifest-path" ]; then
wget_imds -O "$metaDir/ami-manifest-path" http://169.254.169.254/1.0/meta-data/ami-manifest-path
fi
if ! [ -e "$metaDir/user-data" ]; then
wget_imds -O "$metaDir/user-data" http://169.254.169.254/1.0/user-data && chmod 600 "$metaDir/user-data"
fi
if ! [ -e "$metaDir/hostname" ]; then
wget_imds -O "$metaDir/hostname" http://169.254.169.254/1.0/meta-data/hostname
fi
if ! [ -e "$metaDir/public-keys-0-openssh-key" ]; then
wget_imds -O "$metaDir/public-keys-0-openssh-key" http://169.254.169.254/1.0/meta-data/public-keys/0/openssh-key
fi
wget_imds -O "$metaDir/ami-manifest-path" http://169.254.169.254/1.0/meta-data/ami-manifest-path
wget_imds -O "$metaDir/user-data" http://169.254.169.254/1.0/user-data && chmod 600 "$metaDir/user-data"
wget_imds -O "$metaDir/hostname" http://169.254.169.254/1.0/meta-data/hostname
wget_imds -O "$metaDir/public-keys-0-openssh-key" http://169.254.169.254/1.0/meta-data/public-keys/0/openssh-key
''