GKEをいじっていてとあるdockerコンテナからcurlを叩きたかったのでsshログインしてapt installしたところFATAL -> Failed to forkと言われた。

root@container-name-8df5b4f7-chmsm:/# apt install curl -y
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  krb5-locales libcurl3 libgmp10 libgnutls30 libgssapi-krb5-2 libhogweed4 libidn2-0 libk5crypto3 libkeyutils1 libkrb5-3 libkrb5support0 libldap-2.4-2
  libldap-common libnghttp2-14 libp11-kit0 libpsl5 librtmp1 libsasl2-2 libsasl2-modules libsasl2-modules-db libssh2-1 libssl1.0.2 libtasn1-6 libunistring0
  publicsuffix
Suggested packages:
  gnutls-bin krb5-doc krb5-user libsasl2-modules-gssapi-mit | libsasl2-modules-gssapi-heimdal libsasl2-modules-ldap libsasl2-modules-otp
  libsasl2-modules-sql
The following NEW packages will be installed:
  curl krb5-locales libcurl3 libgmp10 libgnutls30 libgssapi-krb5-2 libhogweed4 libidn2-0 libk5crypto3 libkeyutils1 libkrb5-3 libkrb5support0 libldap-2.4-2
  libldap-common libnghttp2-14 libp11-kit0 libpsl5 librtmp1 libsasl2-2 libsasl2-modules libsasl2-modules-db libssh2-1 libssl1.0.2 libtasn1-6 libunistring0
  publicsuffix
0 upgraded, 26 newly installed, 0 to remove and 8 not upgraded.
Need to get 5373 kB of archives.
After this operation, 14.4 MB of additional disk space will be used.
0% [Waiting for headers] [Waiting for headers]FATAL -> Failed to fork.

原因はメモリ不足の模様。

特に要件を決めてなかったのでmemory: 50Miと仮で入れておりとりあえず200Miくらいにあげると無事インストールできた。